Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

193 Cards in this Set

  • Front
  • Back
epidural specific uses? why?
Hip and knee surgery. Less blood loss, lower DVT incidence.

Vascular reconstruction of the lower limbs. Improved distal blood flow.

Amputation. Patients given epidural anaesthesia 48-72 hours prior to lower limb amputation may have a lower incidence of phantom limb pain following surgery.

Obstetrics. Epidural analgesia is indicated in obstetric patients in difficult or high-risk labor. Cesarean section performed under central neuraxial block is associated with a lower maternal mortality owing to anesthetic factors than under general anesthetic.

Low concentration local anesthetics, opioids, or combinations of both are effective in the control of postoperative pain in patients undergoing abdominal and thoracic procedures. Epidural analgesia has been shown to minimize the effects of surgery on cardiopulmonary reserve, i.e. diaphragmatic splinting and the inability to cough adequately, in patients with compromised respiratory function, such as those with chronic obstructive airway disease, morbid obesity and in the elderly. Epidural analgesia allows earlier mobilization.

Thoracic trauma with rib or sternum fractures. Adequate analgesia in patients with thoracic trauma improves respiratory function by allowing the patient to breathe adequately, cough and cooperate with chest physiotherapy.
C sections _____ the level of anesthetic
epidural/spinal absolute contraindications
Patient refusal
Coagulopathy. Insertion of an epidural needle or catheter into the epidural space may cause traumatic bleeding into the epidural space. Clotting abnormalities may lead to the development of a large hematoma leading to spinal cord compression.
Therapeutic anticoagulation. As above
Skin infection at injection site. Insertion of the epidural needle through an area of skin infection may introduce pathogenic bacteria into the epidural space, leading to serious complications such as meningitis or epidural abscess.
Raised intracranial pressure. Accidental dural puncture in a patient with raised ICP may lead to brainstem herniation (coning).
Hypovolemia. The sympathetic blockade produced by epidurals, in combination with uncorrected hypovolemia, may cause profound circulatory collapse.
epidural/spinal relative
Uncooperative patients may be impossible to position correctly, and be unable to remain still enough to safely insert an epidural.
Pre-existing neurological disorders, such as multiple sclerosis, may be a contraindication, because any new neurological symptoms may be ascribed to the epidural.
Fixed cardiac output states. Probably relative rather than absolute. This includes aortic stenosis, hypertrophic obstructive cardiomyopathy (HOCM), mitral stenosis and complete heart block. Patients with these cardiovascular abnormalities are unable to increase their cardiac output in response to the peripheral vasodilatation caused by epidural blockade, and may develop profound circulatory collapse which is very difficult to treat.
Anatomical abnormalities of vertebral column may make the placement of an epidural technically impossible.
Prophylactic low dose heparin
Skin-subQ-Supraspinoius-interspinous ligament (thick and hard)-ligamentum falvum (last before POP) POP=epidural space-then subarachnoid then pia….
The epidural space is that part of the ___________ not occupied by the dura mater and its contents.
vertebral canal
The epidural space is a potential space that lies between the _____ and the _______ lining the inside of the vertebral canal.
The epidural space extends from the ________ to the ________.
foramen magnum
sacral hiatus
Epidural space anatomy:

The anterior and posterior nerve roots in their dural covering pass across this potential space to unite in the ________ to form ________.
intervertebral foramen

segmental nerves.
The anterior border of the epidural space consists of the __________ covering the vertebral bodies, and the intervertebral discs.
posterior longitudinal ligament
Laterally, the epidural space is bordered by the ________ and the _________.`
periosteum of the vertebral pedicles

intervertebral foraminae.
Posteriorly, the bordering stuctures of the epidural space are the _________ and their connecting ligaments, the periosteum of the root of the spines, and the interlaminar spaces filled by the __________.
periosteum of the anterior surface of the laminae and articular processes

ligamentum flavum.
The epidural space contains venous plexuses and fatty tissue which is continuous with the fat in the ________.
paravertebral space.
line between illiac crests?

spinal level?

L4, can be 1 above or below

above L4, the spcae gets smaller
A formal pre-anesthetic assessment should be carried out, and this should be no less rigorous than one carried out prior to general anesthesia. Special attention should be given to the patient's _______ status, with the emphasis on _______.

valvular lesions or other conditions that might impair the ability to increase cardiac output in response to the vasodilatation that inevitably follows sympathetic blockade
An epidural must be performed in a work area that is equipped for ___________. Facilities for monitoring ________ and ________ must be available.
airway management and resuscitation

blood pressure
heart rate
Intravenous access, preferably with a large bore cannula (e.g. 18G), is mandatory before the block is sited.

The epidural needle is typically ______G, ____ long with surface markings at 1cm intervals, and has a _____ bevel with a _____ degree curve at the tip. The most commonly used version of this needle is the _____ needle, and the tip is referred to as the _______ tip.
The original winged needle was called the ______ needle.
Normal syringes should not be used because their __________ may make identification of the epidural space more difficult.
greater resistance
A _______ is attached via luer-lok to a connector, which, when tightened, grips the proximal end of the catheter, and serves to prevent the inadvertent injection of particulate matter into the epidural space, and also acts as a bacterial filter.
The epidural space is entered by the tip of the needle after it passes through the _________.
ligamentum flavum
The epidural space is very narrow and is sometimes called a ___________, as the dura and the ligamentum flavum are usually closely adjacent
potential space
The epidural space has to be identified as the bevel of the needle exits the _______, as the dura will be penetrated shortly after if the needle is advanced any further
ligamentum flavum
the negative atmospheric pressure in the epidural space is equivalent to the _______ pressure
When decubitus, the patient should be encouraged to adopt a ________ position, as this tends to open the spaces between the spinous processes and facilitates the identification of the _________ spaces.
curled up

Using local anesthetic raise a subcutaneous wheal at the midpoint between ________. Infiltrate deeper in the midline and _________ to anesthetize the posterior structures
two adjacent vertebrae

Insert epidural needle into the skin, and advance through the ________ ligament, with the needle pointing in a slightly ________ direction. Then advance the needle into the _________ ligament, which is encountered at a depth of _____ cm. until distinct sensation of increased resistance is felt as the needle passes into the _______




ligamentum flavum

(most people pass the needle through the interspinous ligament and into the ligamentum flavum before attaching the LOR syringe)
If loss of resistance to saline is to be used fill the syringe with ______ ml of ______
2-3 ml

The left hand grips the _______, while the dorsum of the left hand ________
wing of the needle between thumb and forefinger

rests against the back.
Once the needle enters the __________, there is usually a distinctive sensation of increased resistance, as this is a dense ligament with a leathery consistency
ligamentum flavum
The catheter has markings showing the distance from its _____ , and should be advanced to _______ cm at the hub of the needle, to ensure that a sufficient length of catheter has entered the epidural space

The markings on the needle will show the depth of the needle from the ______ to the ______

epidural space
if the needle entered the epidural space at a depth of 5cm, the catheter should be withdrawn so that the ____cm mark is at the skin, thus leaving approximately __cm of the catheter inside the epidural space, which is an appropriate length.

The technique when using loss of resistance to air is slightly different. With ___ml of air in the syringe, attach it to the hub of the needle once it has entered the _______ ligament
Grip both wings of the needle between the thumb and forefinger of both hands. The plunger is gently pressed, and if there is resistance ("bounce"), the needle is very carefully advanced, with the dorsum of both hands resting against the back to provide stability. After ____mm, the plunger is again gently pressed, and this procedure is repeated as the needle is carefully advanced through the tissues. The distinctive increase in resistance when the needle enters the ________ is felt, and the process is continued in ___mm increments. There is usually a distinctive "click" when the needle enters the epidural space, and provided great care is taken, and the needle only advanced in ___mm increments, the needle should stop before it reaches the dura.

ligamentum flavum


Paramedian Approach

Insert the needle, not in the midline in the space between the spinous processes, but ____cm lateral to the spinous process of the more ____ vertebra.

Advance the needle perpendicular to the skin until the _____ or ____ is encountered, and then redirect it approx ____ and ______ in an attempt to "walk the needle" off the lamina, at which point the needle should be in close proximity to the _______. The needle is then advanced further using a loss of resistance technique


30° cephalad
15° medially
ligamentum flavum

paramedian approach be good for older folks that have lots of calcification
Due to the downward angulation of the spinous processes of the thoracic vertebrae, particularly in the ________ region, the needle has to be directed much more _______ to proceed through the ligamentous tissue and into the epidural space. The ligaments in this area are also less dense and a false loss of resistance is not uncommon. Because of the oblique arrangement of the spinous processes, the needle has to travel a _____ distance before reaching the ligamentum flavum, and there is _____ space between the spinous processes.




It is therefore much more common to encounter bony resistance during the placement of thoracic epidurals. For this reason, many practitioners prefer to use a paramedian approach in this region.
if you encounter bony resistnace everywhere, what do you do?
try flexing more or changing position. If still unsuccessful, try paramedian approach (if using midline approach).
if you are unable to thread the catheter, what do you do?
try rotating the needle slightly so that the bevel changes direction. Most commercial epidural packs contain a catheter stabiliser, which attaches to the hub of the needle and may make feeding the catheter easier. If still unsuccessful, the needle is unlikely to be in the epidural space. Do not pull back the catheter through the needle as the tip may be cut off.

Unable to thread- try rotating the catheter

The catheters should thread easily
if you continue getting fluid through the needle, what do you do?
if using saline, wait a few seconds to see if it stops flowing. If not, dural puncture is likely. Reposition epidural at a different level. If fluid stops flowing, continue as before, but give small doses of local anesthetic incrementally and observe carefully for signs of subarachnoid block
if there is pain on insertion of the catheter, what do you do?
a brief sensation of "electric shock" on insertion of the catheter is not unusual, but if it persists, the needle or catheter may be up against a nerve root and should be withdrawn and repositioned.
if there in the catheter, what do you do?
This indicates that the catheter has entered an epidural vein. Withdraw catheter by 1-2cm provided this will leave at least 2-3cm in the space and flush through with saline. Aspirate again to see if blood is still flowing through catheter. If blood has stopped, the catheter may be used, but with great care, making sure at all times that 1) catheter is aspirated prior to any subsequent doses of local anesthetic 2) all doses are given in small increments 3) the patient is carefully monitored for any early signs of local anesthetic toxicity.
Factors Affecting Epidural Anesthesia
Site of injection
After lumbar injection, analgesia spreads both caudally and, to a greater extent, cranially, with a delay at the L5 and S1 segments, due to the large size of these nerve roots.
After thoracic injection, analgesia spreads evenly from the site of injection. The upper thoracic and lower cervical roots are resistant to blockade due to their larger size. The epidural space in the thoracic region is usually smaller and a lower volume of local anesthetic is needed.

generally, ____ml of local anesthetic is needed per _____ to be blocked

The dose is a function of the ______ and the ______, and the response is not necessarily the same if the same dose is used but in a different volume and concentration
volume injected
concentration of the solution
A higher volume of a low concentration of local anesthetic will result in a ____ number of segments blocked but with _____ dense sensory block and _____ motor block.
It is important to remember that sympathetic nerve fibers have the ______ diameter and are most ______ blocked
the degree of sympathetic block is related to the _________
number of segments blocked
With an epidural catheter, incremental dosing is possible and this is important in preventing excessively ____ sympathetic block with hypotension.
The need for repeat or "top-up" doses of local anesthetic is dependent on the _______- of the drug
duration of action
Repeat doses should be given before the block regresses to the extent that the patient experiences pain. When it’s time for a redose, approximately ______ of the original dose should be injected to maintain the block.
one half
There is an age related ______ in the volume of local anesthetic needed to achieve a given level of block, presumably due to a decrease in the size and compliance of the epidural space
The patient's height appears to correlate to some extent with the volume of local anesthetic needed, so that an adult of 5ft should receive a volume of local anesthetic at the lower end of the range (i.e. ____ml per segment blocked), while volumes up to ____ml per segment may be required for taller patients. The safest approach is to inject incremental doses and monitor the effect carefully

There is little correlation between the weight of a patient and the volume of local anesthetic needed, although in morbidly obese patients the epidural space may be _______ due to the effect on intra-abdominal pressure, and a ________ volume of local anesthetic is needed.

taller folks may need more and heavier folks may need less
in the sitting position the _______ and _____ are preferentially blocked
lower lumbar
sacral roots
in the lateral decubitus position, the nerve roots on the _______ side are more densely anesthetised.
Commercially available solutions of local anesthetics have a pH between ____________, for chemical stability and bacteriostasis
3.5 and 5.5
Most local anesthetics are _____ bases and exist in their ________ form at thier formulation ph's
ionized (hydrophilic)
Since nerve blockade is dependent on penetration of the ________, and the non-ionized (lipophilic) form crosses membranes more easily, it follows that _____- the pH of the solution will increase the proportion of drug in the non-ionized form and thus enhance nerve membrane penetration and speed up the onset of blockade
lipid nerve cell membranes
The addition of _____ (0.5ml per 10ml of local anesthetic solution) has become popular in achieving more rapid onset of blockade with, for example, emergency Cesarean Section.
8.4% sodium bicarbonate

only locals and epidurals
The segmental nerves in the thoracic and lumbar region contain ____&_____&_____ nerve fibers
somatic sensory, motor and autonomic (sympathetic)
Sensory and autonomic fibers have a ________ diameter and are more _________ blocked than larger, more rapidly-conducting motor fibers.
The relationship between sensory and autonomic outflow is complex, but sympathetic block usually extends _____ levels higher than sensory block.
Epidural blockade, with its attendant sympathetic blockade, exacerbates hypotension by causing ________
peripheral vasodilatation

Hypotension should be corrected promptly with fluid replacement in the first instance
________ compression by the gravid uterus in the supine position leads to ________ due to compression of the inferior vena cava, which results in diminished venous return and a drop in cardiac output

Epidural blockade, with its attendant sympathetic blockade, exacerbates the hypotension by causing peripheral vasodilatation

Hypotension should be corrected promptly with fluid replacement in the first instance

Compression of the aorta also reduces uterine blood flow, and it is clear that the combination of aortocaval compression and epidural blockade can have a profound effect on uterine and therefore placental blood flow
The_______ position should be avoided in pregnant women undergoing epidural analgesia and anesthesia, and the patient should be in a ________ position at all times.

lateral (preferably left) or tilted
Alpha-adrenergic drugs, such as phenylephrine, have traditionally been avoided as they cause constriction of uterine vessels and may worsen uterine hypoperfusion. ______ is the drug of choice, as it is primarily a b-agonist and increases blood pressure by increasing cardiac output. However, should profound hypotension occur, a pure vasoconstrictor may be more effective in raising the blood pressure and therefore the uterine perfusion pressure.
opioids have a ________ effect by acting directly on opioid receptors in the spinal cord.
The amount of opioid should be ______ where there is an increased risk of respiratory depression, i.e. the elderly, the very frail or in patients with significant chronic obstructive airway disease
Caution should be exercised when morphine is administered _________, as it is associated with delayed respiratory depression. This is thought to be as a result of its low lipid solubility, which means that instead of binding to opioid receptors in the spinal cord, some of the drug remains in solution in the CSF, and the circulation of CSF transports the remaining drug to the brainstem where it acts on the respiratory centre. This may occur many hours (up to 24 hours) after morphine has been administered epidurally.
________ produce more profound analgesia and helps the block set up quicker
__________ is the most common side effect of successful therapeutic blockade for procedures above the umbilicus. It is especially common in pregnancy, both in labor and when used for Cesarean Section, and should be corrected promptly using fluid and vasopressors
The presenting symptom of hypotension is often ______, which may occur before a change in blood pressure has even been detected.
Inadvertent ________ due to an excessively large dose of local anesthetic in the epidural space may present with hypotension, nausea, sensory loss or paresthesia of high thoracic or even cervical nerve roots (arms), or difficulty breathing due to blockade of nerve supply to the intercostal muscles.

Difficulty in talking (small tidal volumes due to phrenic block) and drowsiness are signs that the block is becoming excessively high and should be managed as an emergency
high epidural block
Even a moderate dose of local anesthetic, when injected directly into a _______, can cause toxicity
blood vessel
It is vital to _______ from the epidural catheter prior to injecting local anesthetic
Symptoms of toxicity usually follow a sequence of ......
light-headedness, tinnitus, circumoral tingling or numbness and a feeling of anxiety or "impending doom", followed by confusion, tremor, convulsions, coma and cardio-respiratory arrest

Treatment should be supportive, with the use of sedative/anticonvulsants (diazepam) where necessary, and cardiopulmonary resuscitation if required
the LA naropin aka ________ does not have affinity for the heart.

5mg/kg lido max dose plain 7 mg/kg with epi
Bupiv 2/3 (ropiv is equipotent)
The use of a _______ should prevent most cases of total spinal, but cases have been described where the epidural initially appeared to be correctly sited, but subsequent top-up doses caused the symptoms of total spinal. This has been ascribed to migration of the epidural catheter into the subarachnoid space, although the precise mechanism is uncertain.
test dose
Management of total spinal
Airway - secure airway and administer 100% oxygen
Breathing - ventilate by facemask and intubate.
Circulation - treat with i/v fluids and vasopressor e.g. ephedrine 5-10mg
Continue to ventilate until the block wears off (2 - 4 hours)
As the block recedes the patient will begin recovering consciousness followed by breathing and then movement of the arms and finally legs. Consider some sedation (diazepam 5 - 10mg i/v) when the patient begins to recover consciousness but is still intubated and requiring ventilation.
Accidental Dural Puncture (PDPH)

Usually easily recognized by the immediate loss of ______ through the epidural needle
PDPH occurs in ____% of epidural blocks, although it is more common in inexperienced hands
PDPH is typically _______, exacerbated by movement or sitting upright, associated with photophobia, nausea and vomiting, and relieved when _______
lying flat.
______, especially _______ patients, are more susceptible than the elderly
Young patients

Basic measures, such as simple analgesics, caffeine, bed rest, fluid rehydration and reassurance are indicated in the first instance, and are often sufficient to treat the headache
Procedure for epidural blood patch

Clinical diagnosis of post dural puncture headache.
Sufficiently severe so as to be incapacitating.
Unrelieved by 2-3 days of conservative management
Where the headache is severe, or unresponsive to conservative measures, an __________ may be used to treat the headache. This procedure is effective in treating approximately 90% of post dural puncture headaches.
epidural blood patch

Caffiene/blood patch/flat

Patch is 95% effectice, 2nd is 98% effective
Procedure for epidural blood patch\

Unexplained neurological symptoms
Active neurological disease
Localized sepsis in lumbar area
Generalized sepsis
Procedure for epidural blood patch

Obtain informed consent following full explanation of technique, potential hazards and anticipated success rate
Move patient to fully equipped work area
Two operators required, both taking full sterile precautions (gloves, gown, mask)
Position patient in lateral position or sitting
Operator 1: sterilize skin over back, drape and perform epidural puncture at the same level as previous puncture or one level below
Operator 2: simultaneously sterilize skin over antecubital fossa, drape and perform venepuncture withdrawing 20ml of blood.
Blood is handed to operator 1 who injects blood via epidural needle until either the patient complains of a tightness in the buttocks or lower back, or until 20ml is injected.

Pain on injection
Epidural hematoma
The epidural space is filled with a rich network of venous plexuses, and puncture of these veins, with bleeding into the confined epidural space, may lead to the rapid development of a hematoma which may lead to compression of the spinal cord, and can have disastrous consequences for the patient including paraplegia. For this reason, coagulopathy or therapeutic anticoagulation with heparin or oral anticoagulants has long been an absolute contraindication to epidural blockade.

the most common pathogens are _____ and _______.
rare, but potentially serious

The most common pathogens are Staphylococcus aureus and streptococci. Meningitis has been described, as has epidural abscess. In addition to the symptoms of spinal cord compression described above, the patient may exhibit signs of infection such as pyrexia and a raised white cell count. Once again, a high index of suspicion is needed, and surgical decompression of an abscess should be performed without delay.
Failure of Block Can occur as a result of many factors, the most important being the______
experience of the operator
failure of block

Segmental sparing occurs occasionally for reasons that are unclear, but are assumed to be the result of anatomic variation of the epidural space, so that local anesthetic fails to spread evenly throughout the space
The result is that some nerve roots are inadequately soaked with local anesthetic, leaving the dermatomes of these nerve roots poorly anesthetized. Unilateral blockade occurs occasionally, and this is thought to be the result of failure of the local anesthetic solution to spread to one half of the epidural space. Positioning the patient on his side with the unblocked side down is sometimes successful in allowing spread of the local anesthetic to the dependent side, giving bilateral anesthesia.
Spinal anesthesia is induced by injecting small amounts of local anesthetic into the _______ . The injection is usually made in the _____ spine below the level at which the spinal cord ends, which is at ______.
cerebro-spinal fluid (CSF)

Spinal anesthesia is easy to perform and has the potential to provide excellent operating conditions for surgery below _________
the umbilicus
Advantages of Spinal Anesthesia 10]
Cost. Anesthetic drugs and gases are costly and the latter often difficult to transport. The costs associated with spinal anesthesia are minimal.
Patient satisfaction. If a spinal anesthetic and the ensuing surgery are performed skillfully, the majority of patients are very happy with the technique and appreciate the rapid recovery and absence of side effects.
Respiratory disease. Spinal anesthesia produces few adverse effects on the respiratory system as long as unduly high blocks are avoided.
Patent airway. As control of the airway is not compromised, there is a reduced risk of airway obstruction or the aspiration of gastric contents. This advantage may be lost if too much sedation is given.
Diabetic patients. There is little risk of unrecognized hypoglycemia in an awake patient. Diabetic patients can usually return to their normal food and insulin regime soon after surgery as they experience less sedation, nausea and vomiting.
Muscle relaxation. Spinal anesthesia provides excellent muscle relaxation for lower abdominal and lower limb surgery.
Bleeding. Blood loss during operation is less than when the same operation is done under general anesthesia. This is because of a fall in blood pressure and heart rate and improved venous drainage with a resultant decrease in oozing.
Splanchnic blood flow. Because it increases blood flow to the gut, spinal anesthesia may reduce the incidence of anastomotic dehiscence.
Visceral tone. The bowel is contracted during spinal anesthesia and sphincters are relaxed although peristalsis continues. Normal gut function rapidly returns following surgery.
Coagulation. Post-operative deep vein thromboses and pulmonary emboli are less common following spinal anesthesia.
Disadvantages of Spinal Anesthesia
Sometimes it can be difficult to find the dural space and occasionally, it may be impossible to obtain CSF and the technique has to be abandoned. Rarely, despite an apparently faultless technique, anesthesia is not obtained.
Hypotension may occur with higher blocks and the anesthetist must know how to manage this situation with the necessary resuscitation drugs and equipment immediately to hand. As with general anesthesia, continuous, close monitoring of the patient is mandatory.
Some patients are not psychologically suited to be awake, even if sedated, during an operation. They should be identified during the preoperative assessment. Likewise, some surgeons find it very stressful to operate on conscious patients.
_________ may occur with higher spinal blocks and the anesthetist must know how to manage this situation with the necessary resuscitation drugs and equipment immediately to hand.
Indications for Spinal Anesthesia
Spinal anesthesia is best reserved for operations below the umbilicus e.g. hernia repairs, gynacological and urological operations and any operation on the perineum or genitalia. All operations on the leg are possible, but an amputation, though painless, may be an unpleasant experience for an awake patient. In this situation it may be appropriate to combine the spinal with a light general anesthetic.
Spinal anesthesia is particularly suitable for older patients and those with systemic disease such as chronic respiratory disease, hepatic, renal and endocrine disorders such as diabetes. Many patients with mild cardiac disease benefit from the vasodilation that accompanies spinal anesthesia except those with stenotic valvular disease or uncontrolled hypertension (see later). It is suitable for managing patients with trauma if they have been adequately resuscitated and are not hypovolemic. In obstetrics, it is ideal for manual removal of a retained placenta (again, provided there is no hypovolemia). There are definite advantages for both mother and baby in using spinal anesthesia for caesarean section. However, special considerations apply to managing spinal anesthesia in pregnant patients (see later) and it is best to become experienced in its use in the non-pregnant patient before using it for obstetrics.
Many patients with mild cardiac disease benefit from the ___________ that accompanies spinal anesthesia except those with stenotic valvular disease or uncontrolled hypertension
spinal anesthesia is suitable for managing patients with trauma if they have been ________ and are not _______
adequately resuscitated

In obstetrics, spinal anesthesia is ideal for _______. (again, provided there is no hypovolemia).
manual removal of a retained placenta
Even if a long-acting local anesthetic is used, a spinal is not suitable for surgery lasting longer than approximately _____hours.
If an operation unexpectedly lasts longer than 2 hours with a spinal anesthetic, it may be necessary to convert to a _______ anesthetic or supplement the anesthetic with ______ or with a _______ if that drug is available
intravenous ketamine
propofol infusion
with a spinal anesthetic, there is a theoretical risk of introducing infection into the __________ space and causing _______
________ is shortest acting, then lidocaine, then marcaine, _________ (ponticaine) is longest
PDPH incidence is _______ for spinal versus epidural
the same
(twice for students)
Most of the contra-indications to spinal anesthesia apply equally to other forms of regional anesthesia. These include:
Inadequate resuscitation drugs and equipment. No regional anesthetic technique should be attempted if drugs and equipment for resuscitation are not immediately to hand.
Clotting disorders. If bleeding occurs into the epidural space because the spinal needle has punctured an epidural vein, a hematoma could form and compress the spinal cord. Patients with a low platelet count or receiving anticoagulant drugs such as heparin or warfarin are at risk. Remember that patients with liver disease may have abnormal clotting profiles whilst low platelet counts as well as abnormal clotting can occur in pre-eclampsia.
Hypovolemia from whatever cause e.g. bleeding, dehydration due to vomiting, diarrhea or bowel obstruction. Patients must be adequately rehydrated or resuscitated before spinal anesthesia or they will become very hypotensive.
Patient refusal. Patients may be understandably apprehensive and initially state a preference for general anesthesia, but if the advantages of spinal anesthesia are explained they may then agree to the procedure and be pleasantly surprised at the outcome. If, despite adequate explanation, the patient still refuses spinal anesthesia, their wishes should be respected. Likewise, mentally handicapped patients and those with psychiatric problems need careful pre-operative assessment.
Children. Although spinal anesthesia has been successfully performed on children, this is a highly specialized technique best left to experienced pediatric anesthetists.
Sepsis on the back near the site of lumbar puncture lest infection be introduced into the epidural or intrathecal space.
Septicemia. If a patient is septicemic, they are at increased risk of developing a spinal abscess. Epidural abscesses can, however, appear spontaneously in patients who have not had spinal/epidural injections especially if they are immuno-deficient: e.g., patients with AIDS, tuberculosis, and diabetes.
Anatomical deformities of the patient's back. This is a relative contraindication, as it will probably only serve to make the dural puncture more difficult.
Neurological disease. The advantages and disadvantages of spinal anesthesia in the presence of neurological disease need careful assessment. Any worsening of the disease post-operatively may be blamed erroneously on the spinal anesthetic. Raised intracranial pressure, however, is an absolute contra-indication as a dural puncture may precipitate coning of the brain stem.
the onset of a _______ or unforeseen surgical complications may make it imperative that the airway is secured
total spinal block

All the equipment necessary for intubation should, therefore, always be available before spinal anesthesia is commenced. It is always an extremely difficult to decide on whether to embark on a spinal anesthetic when a patient is known to be difficult to intubate.
In the event of an inadequate spinal anesthetic it is much better to _______ and safeguard the airway, then to over-sedate a patient with benzodiazepines or narcotics.
electively administer a light general anesthetic
3 nerve classes
motor, sensory and autonomic

Stimulation of the motor nerves causes muscles to contract and when they are blocked, muscle paralysis results. Sensory nerves transmit sensations such as touch and pain to the spinal cord and from there to the brain, whilst autonomic nerves control the caliber of blood vessels, heart rate, gut contraction and other functions not under conscious control.
Generally, _______ and ______ fibers are blocked before motor fibers.
autonomic and sensory
________ and _________ may occur when the autonomic fibers are blocked and the patient may be aware of pressure or movement and yet feel no pain when surgery starts
a drop in blood pressure
The patient should be well __________ before the local anesthetic is injected and should have an intravenous infusion in place so that further fluids or vasoconstrictors can be given if hypotension occurs.
The spinal cord usually ends at the level of _____ in adults and _____ in children. Dural puncture above these levels is associated with a slight risk of damaging the spinal cord and is best avoided
The __________ ligament which is a thin flat band of ligament running between the spinous processes.
The _________ ligament that joins the tips of the spinous processes together.
The ________ is quite thick, up to about 1cm in the middle and is mostly composed of elastic tissue. It runs vertically from lamina to lamina. When the needle is within the ligaments it will feel gripped and a distinct "give" can often be felt as it passes through the ligament and into the epidural space
ligamentum flavum
The epidural space contains ____ and _____.
fat and blood vessels
This contains the spinal cord and nerve roots surrounded by CSF.
subarachnoid space
_______ solutions tend to spread down (due to gravity) from the level of the injection
It is easier to predict the spread of spinal anesthesia when using a _______baric agent
Isobaric preparations may be made hyperbaric by the addition of _______
___________ is the best agent to use if it is available
0.5% hyperbaric (heavy) bupivacaine
_________ lasts longer than most other spinal anaesthetics: usually 2-3 hours.
5% hyperbaric (heavy) lidocaine, lasts ____ minutes
If 0.2ml of adrenaline 1:1000 is added to the lidocaine, it will usefully _______ its duration of action
Recently concerns have been raised about the safety of 5% lidocaine (it is said to be potentially _________) despite it having been used uneventfully for over forty years. Lidocaine from multi-dose vials should not be used for intrathecal injection as it contains potentially harmful __________.
Tetracaine (Pontocaine).
Tetracaine (Pontocaine). A 1% solution can be prepared with dextrose, saline or water for injection.
Mepivacaine (Carbocaine)
. A 4% hyperbaric (heavy) solution is similar to lidocaine.
It is generally thought that of the commonly used anesthetic agents, ________ has a more rapid onset than bupivacaine, though some authors question this
Meperidine has a very ______ onset but can also wear off rapidly
It should also be remembered, especially when _______ agents have been used, that patient movement, for example putting the patient "head-down" can cause the block to extend even some 20-30 minutes after it has been performed.
A _________ block (below the umbilicus) has no effect on the respiratory system and is, therefore, ideal for patients with respiratory disease unless they cough a lot.
low spinal
A high spinal block can produce _________, but this does not usually create any problems, unless the patient has a very limited respiratory reserve and is, for example, unable to lie flat.
intercostal muscle paralysis
Uncontrolled hypertension or severe valvular disease. Although moderate hypertension is not a contra-indication to spinal anaesthesia, it should be remembered that there is an almost inevitable fall in blood pressure when spinal anaesthesia is induced. This can be particularly precipitous in patients with ____________
severe uncontrolled hypertension
Patients with ________ require a stable blood pressure (sustained after-load) to maintain their coronary perfusion. If they have a sudden fall in blood pressure, they may develop intractable cardiac arrest.
aortic stenosis
Spinal anaesthesia may be advantageous for patients with ________ disease
sickle cell

Follow the same rules as for general anaesthesia: ensure that the patient is well oxygenated, well hydrated and not allowed to become hypotensive. Consider warming the intravenous fluids and do not allow the patient to become cold. Avoid the use of tourniquets.
Premedication is often unnecessary, but if a patient is apprehensive, a benzodiazepine such as ______ may be given orally 1 hour before the operation. Other sedative or narcotic agents may also be used. Anticholinergics such as atropine or scopolamine (hyoscine) are not routinely required.
5-10mg of diazepam
All patients having spinal anaesthesia must have a ______ inserted and be given ______ immediately before the spinal
large intravenous cannulaintravenous fluids
___________ helps prevent hypotension following the vasodilation which is produced with a spinal
Intravenous Pre-loading
A young, fit man having a hernia repair may only need 500mls. Older patients are not able to compensate as efficiently as the young for spinal-induced vasodilation and hypotension and may need 1000mls for a similar procedure. If a high block is planned, at least a 1000mls should be given to all patients. Caesarean section patients need at least 1500mls. Crystalloids such as 0.9% Normal Saline or Hartmans are most commonly used. Dextrose 5% should be avoided as it is not effective for maintaining the blood volume.
Lumbar puncture is most easily performed when there is_______ of the lumbar spine
maximum flexion
The ______ position is preferable in the obese whereas the _______ is better for uncooperative or sedated patients
Consider the consequences of sudden _______ or a _______ for a sitting patient
vaso-vagal attack
Factors Affecting the Spread of the Local Anaesthetic Solution
the baricity of the local anaesthetic solution
the position of the patient
the concentration and volume injected
the level of injection
the speed of injection
The specific gravity of the local anaesthetic solution
The quantity of local anaesthetic
The speed of injection has a slight effect on the eventual extent of the block.
Concentrations of 7.5% dextrose make the local anaesthetic ______ relative to CSF and also ______ the rate at which it diffuses and mixes with the CSF.
hyperbaric (heavy)
Injecting _______ solutions and then _______ probably produces the most controllable blocks.
altering the patient's position
If a patient is kept sitting for several minutes after the injection of a small volume of a hyperbaric solution of local anaesthetic, a classical _______ affecting only ______ will result.
"saddle block"
the sacral nerve roots
Males tend to have wider shoulders than hips and so are in a slight _____ position when lying on their sides, whilst for females with their wider hips, the opposite is true
"head up"
Regardless of the position of the patient at the time of injection and whatever the initial extent of the block obtained, the level of the block may change if the patient's position is altered within twenty minutes of the injection of a ______ agent.
Large volumes of concentrated solutions will produce ______ blockade over a ______ area
As spinal anaesthetics are generally only injected in the lumbar region, the extent of the block is influenced more by the _______ and _______ and ________ than the actual interspace at which the injection occurs
concentration injected
the position of the patient
The speed of injection has a slight effect on the eventual extent of the block. ______ injections result in a more predictable spread while ______ injections produce eddy currents within the CSF and a somewhat less predictable outcome.
increased abdominal pressure from whatever cause (pregnancy, ascites etc.) can lead to engorgement of the epidural veins, compression of the dura and hence a reduction in the volume of the CSF. A given quantity of local anaesthetic injected into the CSF might then be expected to produce a more ________ block.
Preparation for Lumbar Puncture
Assemble the necessary equipment on a sterile surface. It will include:
A spinal needle. The ideal would be 24-25 gauge with a pencil point tip to minimise the risk of the patient developing a post-spinal headache.
An introducer, if using a fine gauge needle as they are thin and flexible, and therefore difficult to direct accurately. A standard 19 gauge (white) disposable needle is suitable for use as an introducer.
A 5ml syringe for the spinal anaesthetic solution.
A 2ml syringe for local anaesthetic to be used for skin infiltration.
A selection of needles for drawing up the local anaesthetic solutions and for infiltrating the skin.
A gallipot with a suitable antiseptic for cleaning the skin, e.g. chlorhexidine, iodine, or methyl alcohol.
Sterile gauze swabs for skin cleansing.
A sticking plaster to cover the puncture site.
The local anaesthetic to be injected intrathecally should be in a single use ampoule. Never use local anaesthetic from a multi-dose vial for intrathecal injection. Spare equipment and drugs should be readily available if needed.
spinal needle.
The ideal would be _____ gauge with a _______ tip to minimise the risk of the patient developing a post-spinal headache.
pencil point
for a spinal, a standard ______ gauge (white) disposable needle is suitable for use as an introducer.
A ____ml syringe for the spinal anaesthetic solution.

A ___ml syringe for local anaesthetic to be used for skin infiltration.

2ml-skin infilatration
pencil tip spinal needle types?
Pencil tip-strotte/whitaker

non pincil-quinke
Performing the Spinal Injection

It is assumed that the patient has had the procedure fully explained, has reliable intravenous access, is in a comfortable position and that resuscitation equipment is immediately available.
Scrub and glove up carefully.
Check the equipment on the sterile trolley.
Draw up the local anaesthetic to be injected intrathecally into the 5ml syringe, from the ampoule opened by your assistant. Read the label. Draw up the exact amount you intend to use, ensuring that your needle does not touch the outside of the ampoule (which is unsterile).
Draw up the local anaesthetic to be used for skin infiltration into the 2ml syringe. Read the label.
Clean the patient's back with the swabs and antiseptic ensuring that your gloves do not touch unsterile skin. Swab radially outwards from the proposed injection site. Discard the swab and repeat several times making sure that a sufficiently large area is cleaned. Allow the solution to dry on the skin.
Locate a suitable interspinous space. You may have to press fairly hard to feel the spinous processes in an obese patient.
Inject a small volume of local anaesthetic under the skin with a disposable 25-gauge needle at the proposed puncture site.
Insert the introducer if using a 24-25 gauge needle. It should be advanced into the ligamentum flavum but care should be exercised in thin patients that an inadvertent dural puncture does not occur.
Insert the spinal needle (through the introducer, if applicable). Ensure that the stylet is in place so that the tip of the needle does not become blocked by particles of tissue or clot. It is imperative that the needle is inserted and stays in the midline and that the bevel is directed laterally. It is angled slightly cephalad (towards the head) and slowly advanced. An increased resistance will be felt as the needle enters the ligamentum flavum, followed by a loss of resistance as the epidural space is entered. Another loss of resistance may be felt as the dura is pierced and CSF should flow from the needle when the stylet is removed. If bone is touched, the needle should be withdrawn a centimetre or so and then re-advanced in a slightly more cephalad direction again ensuring that it stays in the midline. If a 25 gauge spinal needle is being used, be prepared to wait 20-30 seconds for CSF to appear after the stylet has been withdrawn. If no CSF appears, replace the stylet and advance the needle a little further and try again.
When CSF appears, take care not to alter the position of the spinal needle as the syringe of local anaesthetic is being attached. The needle is best immobilised by resting the back of the non-dominant hand firmly against the patient and by using the thumb and index finger to hold the hub of the needle. Be sure to attach the syringe firmly to the hub of the needle; hyperbaric solutions are viscous and resistance to injection will be high, especially through fine gauge needles. It is, therefore, easy to spill some of the local anaesthetic unless care is taken. Aspirate gently to check the needle tip is still intrathecal and then slowly inject the local anaesthetic. When the injection is complete, withdraw the spinal needle, introducer and syringe as one and apply a sticking plaster to the puncture site.
The spinal needle feels as if it is in the right position but no CSF appears......

what do you do......
Wait at least 30 seconds, then try rotating the needle 90 degrees and wait again. If there is still no CSF, attach an empty 2ml syringe and inject 0.5-1ml of air to ensure the needle is not blocked then use the syringe to aspirate whilst slowly withdrawing the spinal needle. Stop as soon as CSF appears in the syringe.
Blood flows from the spinal needle. .....

what do you do......
Wait a short time. If the blood becomes pinkish and finally clear, all is well. If blood only continues to drip, then it is likely that the needle tip is in an epidural vein and it should be advanced a little further to pierce the dura.
The patient complains of sharp, stabbing leg pain...

what do you do......
The needle has hit a nerve root because it has deviated laterally. Withdraw the needle and redirect it more medially away from the affected side.
Wherever the needle is directed, it seems to strike bone. ...

what do you do......
Make sure the patient is still properly positioned with as much lumbar flexion as possible and that the needle is still in the mid-line. If you are not sure whether you are in the midline, ask the patient on which side they feel the needle. Alternatively, if the patient is elderly and cannot bend very much or has heavily calcified interspinous ligaments, it might be better to attempt a paramedian approach to the dura. This is performed by inserting the spinal needle about 0.5-1cm lateral to the mid line at the level of the upper border of a spinous process, then directing it both cephalad and medially. If bone is contacted it is likely to be the vertebral lamina. It should then be possible to "walk" the needle off the bone and into the epidural space, then through it to pierce the dura. When using this technique inject some local anaesthetic into the muscle before inserting the spinal needle.
The patient complains of pain during needle insertion

what do you do......
This suggests that the spinal needle is passing through the muscle on either side of the ligaments. Redirect your needle away from the side of the pain to get back into the midline or inject some local anaesthetic
The patient complains of pain during injection of the spinal solution

what do you do......
Stop injecting and change the position of the needle.
If the patient is unable to lift his legs from the bed, the block is at least up to the ______ region
It is better to test for a ________ using a swab soaked in either ether or alcohol. Do this by first touching the patient with the damp swab on the chest or arm (where sensation is normal), so that they appreciate that the swab feels cold. Then work up from the legs and lower abdomen until the patient again appreciates that the swab feels cold.
loss of temperature sensation

Surgeons and patients should be reminded that when a block is successful, a patient may still be aware of touch but will not feel pain.
No apparent block at all.

what do you do?
If after 10 minutes the patient still has full power in the legs and normal sensation, then the block has failed probably because the injection was not intrathecal. Try again.
The block is one-sided or is not high enough on one side.

what do you do?
When using a hyperbaric solution, lie the patient on the side that is inadequately blocked for a few minutes and adjust the table so that the patient is slightly "head down". When using an isobaric solution, lie the patient on the side that is blocked. (Moving a patient around in any way at all in the first 10-20 minutes following injection will tend to increase the height of the block).
Block not high enough

what do you do?
When using a hyperbaric solution, tilt the patient head down whilst they are supine (lying on the back), so that the solution can run up the lumbar curvature. Flatten the lumbar curvature by raising the patient's knees. When using a plain solution turn the patient a complete circle from supine to prone (lying on the front) and back to supine again.
Block too high.

what do you do?
The patient may complain of difficulty in breathing or of tingling in the arms or hands. Do not tilt the table "head up". (See later under Treatment of a total spinal).
Nausea or vomiting

what do you do?
This may occur with high spinal blocks that may be associated with hypotension. Check the blood pressure and treat accordingly

what do you do?
This occurs occasionally. Reassure the patient and give oxygen by mask.
Temperature sensation level is the same as _______ level
It is essential to monitor the respiration, pulse and blood pressure closely. The _____ can fall precipitously following induction of spinal anaesthesia, particularly in the elderly and those who have not been adequately preloaded with fluid.
blood pressure
Warning signs of falling blood pressure include
pallor, sweating, nausea or feeling generally unwell
A moderate fall in systolic blood pressure to say ______ in a young, healthy patient or _______ in an older patient is acceptable, provided the patient looks and feels well and is adequately oxygenated.
80-90mm Hg
_______ is quite common during spinal anaesthesia particularly if the surgeon is manipulating the bowel or uterus.

If the patient feels well, and the blood pressure is maintained, then it is not necessary to give atropine. If, however, the heart rate drops below 50 beats per minute or there is hypotension, then atropine 300-600mcg should be given intravenously. If the heart rate does not increase try ephedrine (see below
It is generally considered good practice for all patients undergoing surgery under spinal anaesthesia to be given ________ at a rate of 2-4 litres/minute, especially if sedation has also been given
supplemental oxygen by facemask
Hypotension is due to _______ and a _______.

functional decrease in the effective circulating volume.

The treatment is, therefore, to reverse the vasodilatation with vasoconstrictor drugs and increase the circulating volume by giving fluids. All hypotensive patients should be given oxygen by mask until the blood pressure is restored.

Increase the speed of the intravenous infusion to maximum until the blood pressure is restored to acceptable levels and, if the pulse is slow, give atropine intravenously. Vasoconstrictors should be given immediately if the hypotension is severe, and to patients not responding to fluid therapy.
A simple and effective way of rapidly increasing the patient's circulating volume is _______thus increasing the return of venous blood to the heart.
by raising their legs

This can either be done manually by an assistant or by tilting the lower half of the operating table. Tilting the whole operating table head down will also achieve the same effect, but is unwise if a hyperbaric spinal anaesthetic has been injected as it will result in the block spreading higher and the hypotension becoming more severe. If an isobaric spinal solution has been used, tilting the table at any time will have very little effect on the height of the block.
umbilicus level?,
zyphoid level?
nipple level?
is probably the vasopressor of choice. It causes peripheral blood vessels to constrict and raises the cardiac output by increasing the heart rate and the force of myocardial contraction. It is safe for use in pregnancy, as it does not reduce placental blood flow. Ephedrine is generally available in 25 or 30mg ampoules. It is best diluted to 10mls with saline and then given in increments of 1-2ml (2.5-6mg) titrated against the blood pressure. Its effect generally lasts about 10 minutes and it may need repeating. Alternatively, the ampoule may be added to a bag of intravenous fluid and the rate of infusion altered to maintain the desired blood pressure. It can also be given intramuscularly but its onset time is delayed although its duration is prolonged. Larger doses are necessary when it is given intramuscularly.
Methoxamine (Vasoxine).
It is available in 20mg ampoules and must be diluted before injection. A suitable adult dose is 2mg intravenously or 5-20mg by intramuscular injection. It is a pure peripheral vasoconstrictor and reflex bradycardia, needing treatment with atropine can occur. It is particularly useful to treat hypotension during spinal anaesthesia when the patient has a tachycardia.
A pure peripheral vasoconstrictor which is available in 10mg ampoules; it must be diluted before use. Suitable adult doses for intravenous use are 100-500mcg repeated after 15 minutes if necessary, or 2-5mg intramuscularly. It lasts about 15 minutes. A reflex bradycardia may occur.
Metaraminol (Aramine).
It is supplied in 10mg ampoules and should be diluted and used incrementally (1-5mg) as with ephedrine. Alternatively, it can be added to 500ml of fluid and titrated against the blood pressure. It has a slower onset time (at least 2 minutes after intravenous injection) but lasts longer (20-60 minutes).
Available as 1mg/ml (1:1,000) and 1mg/10ml (1:10,000) ampoules. Dilute 1ml of 1:1,000 adrenaline to at least 10ml with saline and give increments of 50mcg (0.5ml of 1:10,000) repeating as necessary. Monitor the effect of epinephrine/adrenaline closely - it is a very powerful drug but only lasts a few minutes. It may be used during spinal anaesthesia if hypotension does not respond to first line drugs listed above or when they are not available.
Norepinephrine/Noradrenaline (Levophed
A powerful vasoconstrictor available in 2mg ampoules which must be diluted in 1000ml of intravenous fluid before use. It is then given at an initial rate of 2-3ml/minute and thereafter titrated against the blood pressure. Control the infusion with the utmost care taking particular care that to avoid extravasation.
Treatment of Total Spinal
Although rare, total spinals can occur with frightening rapidity and result in the death of the patient if not quickly recognised and treated. They are more likely to occur when a planned epidural injection is, inadvertently, given intrathecally. The warning signs that a total spinal block is developing are:
Hypotension - treat as detailed above. Remember that nausea may be the first sign of hypotension. Repeated doses of vasopressors and large volumes of fluid may be necessary.
Bradycardia - give atropine. If this is not effective give ephedrine or adrenaline.
Increasing anxiety - reassure.
Numbness or weakness of the arms and hands, indicating that the block has reached the cervico-thoracic junction.
Difficulty breathing - as the intercostal nerves are blocked the patient may state that they can't take a deep breath. As the phrenic nerves (C3,4,5) which supply the diaphragm become blocked, the patient will initially be unable to talk louder than a whisper and will then stop breathing.
Loss of consciousness.
Call for help - several pairs of hands may be useful!
ABC Resuscitation
Intubate and ventilate the patient with 100% oxygen.
Treat hypotension and bradycardia with intravenous fluids, atropine and vasopressors as described earlier. If treatment is not started quickly the combination of hypoxia, bradycardia and hypotension may result in a cardiac arrest.
Ventilation will need to be continued until the spinal block recedes and the patient is able to breathe again unaided. The time this will take will depend on which local anaesthetic has been injected.
Once the airway has been controlled and the circulation restored, consider sedating the patient with a small dose of a benzodiazepine as consciousness may return before muscle power and the patient will find it distressing to be unable to breathe properly.
General Postoperative Care
The patient should be admitted to the recovery room as with any other anaesthetised patient. In the event of hypotension in the recovery room, the nurses should elevate the patients' legs, increase the rate at which intravenous fluids are being administered, give oxygen and summon the anaesthetist. Further doses of vasoconstrictors or fluids may be required, as previously discussed. Patients should be advised as to how long their spinal block will last and be told to remain in bed until full sensation and muscle power has returned.
Complications of Spinal Anaesthesia
Headache. A characteristic headache may occur following spinal anaesthesia. It begins within a few hours and may last a week or more. It is postural, being made worse by standing or even raising the head and relieved by lying down. It is often occipital and may be associated with a stiff neck. Nausea, vomiting, dizziness and photophobia frequently accompany it. It is more common in the young, in females and especially in obstetric patients. It is thought to be caused by the continuing loss of CSF through the hole made in the dura by the spinal needle. This results in traction on the meninges and pain.
The incidence of headache is related directly to the size of the needle used. A 16 gauge needle will cause headache in about 75% of patients, a 20 gauge needle in about 15% and a 25 gauge needle in 1-3%. It is, therefore, sensible to use the smallest needle available especially in high-risk obstetric patients. As the fibres of the dura run parallel to the long axis of the spine, if the bevel of the needle is parallel to them, it will part rather than cut them and therefore, leave a smaller hole. Make a mental note of which way the bevel lies in relation to the notch on the hub and then align it appropriately. It is widely considered that pencil-point needles (Whiteacre or Sprotte) make a smaller hole in the dura and are associated with a lower incidence of headache (1%) than conventional cutting-edged needles (Quincke) (figure 7).
Treatment of spinal headache
Patients with spinal headaches prefer to remain lying flat in bed as this relieves the pain. They should be encouraged to drink freely or, if necessary, be given intravenous fluids to maintain adequate hydration. Simple analgesics such as paracetamol, aspirin or codeine may be helpful, as may measures to increase intra-abdominal and hence epidural pressure such as lying prone. Sumatriptan, normally used in the treatment of migraine, is said to be effective. Caffeine containing drinks such as tea, coffee or Coca-Cola are often helpful. Prolonged or severe headaches may be treated with epidural blood patch performed by aseptically injecting 15-20ml of the patient's own blood into the epidural space. This then clots and seals the hole and prevents further leakage of CSF.
It used to be thought that bedrest for 24 hours following a spinal anaesthetic would help reduce the incidence of headache, but this is now no longer believed to be the case. Patients may get up once normal sensation has returned, if surgical considerations so allow.
Urinary retention. As the sacral autonomic fibres are among the last to recover following a spinal anaesthetic, urinary retention may occur. If fluid pre-loading has been excessive, a painful distended bladder may result and the patient may need to be catheterised.
Permanent neurological complications are extremely rare. Many of those that have been reported were due to the injection of inappropriate drugs or chemicals into the CSF producing meningitis, arachnoiditis, transverse myelitis or the cauda equina syndrome with varying patterns of neurological impairment and sphincter disturbances. Damage to an epidural vein can lead to the formation of an epidural haematoma that compresses the spinal cord. This is most unlikely in a patient with a normal clotting profile. If inadequate sterile precautions are taken, bacterial meningitis or an epidural abscess may result although it is thought that most such abscesses are caused by the spread of infection in the blood. Finally, permanent paralysis can occur due to the "anterior spinal artery syndrome". This is most likely to affect elderly patients who are subjected to prolonged periods of hypotension and may result in permanent paralysis of the lower limbs.