Mason Ob Lecture Iv (1St Half)

Front 1

Methods of Pain Relief for L & D....hint Dr. France ;-)

Back 1

Hypnosis
Natural childbirth
Acupuncture
TENS units
Hydrotherapy
Positioning
Systemic medications

Front 2

T or F: All opioids and sedatives can cross placenta and may have some effect on fetus

Back 2

True.....so use limited to early stages or situations where regional not available

Front 3

CNS depression in neonate from opioids and sedatives
can cause

Back 3

-Resp. acidosis
-Prolonged time to sustained resp.
-Abnormal neurobehavioral exam

Front 4

T or F: Loss of beat-to-beat variability in FHR can be caused by opioids and sedatives.

Back 4

True....Degree of depression R/T drug, dose, time from administration to delivery
-Premies more sensitive

Front 5

Sedatives/Tranquilizers...
Primary indication today

Back 5

Used for Sedation when delivery not expected for 12-24 hours

-May be used in first stage of labor
-Barbiturates (Seconal, Nembutal, Amytal)
-No longer popular
-No analgesic action – may cause antianalgesic effect
-All cross placenta and may depress neonate

Front 6

Sedatives/Tranquilizers like Phenothiazine derivatives (Phenergan, Compazine) & hydroxyzine (Vistaril)

Back 6

-Uses - sedation, antiemetic, reduction of opioid requirements
-Cross placenta, so
See decreased variability in FHR but no increased depression of neonate when added to narcotics given to Mom

Front 7

Benzodiazepines uses and effects

Back 7

-May be used as sedatives, narcotic adjuvant, anticonvulsants, premeds
-Decrease FHR variability but do not depress neonate in small doses
-See up to 30 min of antegrade amnesia after 5 mg of midazolam
-Some may not want amnesia
-Teratogenic effects controversial
-Associated with congenital malformations in old studies
-Chestnut says OK if needed for premed

Front 8

Ketamine max dose & uses

Back 8

Crosses placenta
1 mg/kg or less and no neonatal depression
Uses
Emergent induction, hypovolemic C-section
Do not exceed 1 mg/kg
To cover “spotty” block or sedation (0.25 mg/kg)
Give 10-15 mg in 2-5 min intervals (don’t exceed 100mg)
Intense analgesia without resp. depression

Front 9

Ketamine onset and duration

Back 9

Rapid onset (30 sec) and short duration (3-5 min)

Front 10

Ketamine adverse/side effects

Back 10

Undesirable hallucinations can and do occur
Reduced if pleasant verbal reassurance given
Avoid in hypertensive patients

Front 11

What is the most common narcotic used in L&D...dosing

Back 11

Demerol
50-100 mg IM
25-50 mg IV
Peak effect 40-50 min IM and 5-10 IV
Duration of action 3-4 hours

Front 12

Demerol Max tissue uptake__-__ hours after administration

Back 12

2-3
Best time for delivery within one hour of adm. or more than 4 hours after
Neonatal depression after 4 hours if mom get high doses (normeperidine)

Front 13

Fentanyl dosing

Back 13

Effective for IV or IM use
50-100 mcg IM
Peak effect 30 min, lasts 1-2 hours
25-50 mcg IV
Peak effect 3-5 min, duration 30-60 min

Front 14

T or F: neonatal effects are less in pts given fentanyl vs. demerol

Back 14

True
Compared to meperidine, analgesia similar, side effects & neonatal complications less in fentanyl group (100 patients)

Apgar scores in 137 neonates no worse than in moms who received no analgesia

Front 15

Does fentanyl cause ion trapping in the fetus?

Back 15

Rapidly crosses placenta but no effect on uterine tone or blood flow in sheep
Basic drug
More ionized in fetus than mom (ion trapping if fetal acidosis)

Front 16

Which narcotic is least popular? Why?

Back 16

Morphine not popular
Neonate more sensitive to resp. depressant effects than Demerol

Front 17

Butorphanol (Stadol)

Back 17

-Compares to Demerol in efficacy and fetal depression
-May see marked maternal dizziness/drowsiness
Anxiety, loss of control

Front 18

33 vertebrate

Back 18

7 cervical
12 thoracic
5 lumbar
5 sacral
4 coccygeal

Front 19

31 spinal nerves pairs

Back 19

8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Front 20

3 membranes enclose brain and spinal column...
what are they?

Back 20

Dura mater – next to bone
Arachnoid – in the middle
Pia mater – next to nervous tissue

Front 21

Spinal cord ends at ___-___in normal adult
___ in infants until 1 year old

Back 21

L1-L2, L3

Front 22

Contents of Epidural Space

Back 22

-Anterior and posterior nerve roots
-Blood vessels that supply spinal cord
Spinal arteries and vertebral veins
-Fatty tissue

Front 23

Pathways of Labor Pain:
Early first stage is ____
Late first stage is ____

Back 23

visceral, somatic

Front 24

Early first stage of labor pain: Visceral, where do we need to block?

Back 24

Uterus and perineal structures
T10-12 & L1
Need to block T 10

Front 25

Late first stage of labor pain: somatic, where do we need to block?

Back 25

Perineum
Impulses via pudendal nerve to S2-4

Front 26

When are Lumbar Epidurals placed?

Back 26

Placed when 3-4 cm dilated for primipara
3 cm for multipara
Best indication – head of fetus firmly against cervix

*see Page 127, Tables 8.2, 8.3, & 8.4 for techniques

Front 27

Distance from skin to epidural space in 1000 parturients – mean of _____

Back 27

4.23-4.78

Front 28

Ligamentum flavum____ mm thick

Back 28

5.0-6.0, May be “softer” in parturient

Front 29

Why a test dose?

Back 29

To recognize accidental dural or IV puncture

Front 30

significance of Test dose amounts of epi and local

Back 30

-Amount of local
Enough to produce LOW spinal block
Not enough to harm mom or fetus

-Amount of epinephrine
Enough to cause reliable tachycardia
Not enough to harm mom or fetus

-Hyperbaric local ideal but not stable with epi added to dextrose containing solution

Front 31

Usual test dose

Back 31

3 mL lidocaine 1.5% with epi 1:200,000
45 mg lidocaine
Should not reach thoracic dermatomes if SAB
15 mcg epi
Should reliably produce tachycardia in app. 30 sec for about 30 sec

Front 32

Why place a SaO2 monitor during test dose?

Back 32

SaO2 placed for HR not O2 saturation

Front 33

Initial block – loading doses for epidurals

Back 33

Bupivacaine 0.25% (10 mL in divided doses)

Bupivacaine 0.125% - 0.25% 8 mL + 1-2 mL Fentanyl (or 10-15 mcg sufentanil)

Fentanyl 50-100 mcg or sufentanil 10-15 mcg in 10 mL NS

Front 34

epidural Maintenance

Back 34

Intermittent bolus to maintain comfort
Same as with loading dose technique repeated as patient needs

Front 35

Epidural Maintenance – continuous infusion instead of boluses

Back 35

Bupivacaine 0.0625% - 0.125% with Fentanyl 1-3 mcg/mL (or sufentanil 0.1-0.3 mcg/mL) at 10-15 mL/hr

Bupivacaine 0.125% - 0.25% without Fentanyl

Front 36

What should be assessed every 1-2 hrs during continuous infusion with epidurals?

Back 36

VS, FHR, degree of block should be assessed every 1-2 hours

Front 37

What is the dosing if If perineal anesthesia needed

Back 37

10-20 mL of local (lidocaine or Nesacaine) in sitting position

Front 38

most common side effect of epidurals?

Back 38

Hypotension

The higher the level of sympathetic block, the greater the incidence and severity of hypotension

Front 39

Mom will tolerate systolic of 80-90 but fetus may not...Why?

Back 39

Uterus not autoregulated
Blood flow decreases linearly with B/P

Front 40

When do we treat BP if hypotensive during epidural and what can we do to prevent this from occurring?

Back 40

-Treat B/P if less than 100 mm Hg (30% lower than baseline)
-Preload, have vasopressor ready, LUD, monitor mom and fetus

Front 41

Paresthesias

Back 41

*5-25% incidence of transient paresthesia
*5-42/10,000 c/o paresthesia lasting 4-6 weeks
*Don’t use epidural if paresthesia persists after insertion

Front 42

Accidental dural puncture:
Incidence of headache app. ____ in parturient

Back 42

80%

Incidence varies
Most report 1-2% at teaching facilities

Front 43

Puncture by catheter rare, but what happens if this occurs?

Back 43

Total spinal

Front 44

When do we treat BP if hypotensive during epidural and what can we do to prevent this from occurring?

Back 44

-Treat B/P if less than 100 mm Hg (30% lower than baseline)
-Preload, have vasopressor ready, LUD, monitor mom and fetus

Front 45

Treatment of total spinal

Back 45

_Establish AW, ventilate with 100% oxygen
-Maintain B/P:
LUD, fluids, ephedrine
-Treat cardiac arrhythmias and collapse
-CPR and prompt delivery of baby if necessary

Front 46

When do we treat BP if hypotensive during epidural and what can we do to prevent this from occurring?

Back 46

-Treat B/P if less than 100 mm Hg (30% lower than baseline)
-Preload, have vasopressor ready, LUD, monitor mom and fetus

Front 47

Paresthesias

Back 47

*5-25% incidence of transient paresthesia
*5-42/10,000 c/o paresthesia lasting 4-6 weeks
*Don’t use epidural if paresthesia persists after insertion

Front 48

Accidental dural puncture:
Incidence of headache app. ____ in parturient

Back 48

80%

Incidence varies
Most report 1-2% at teaching facilities

Front 49

Paresthesias

Back 49

*5-25% incidence of transient paresthesia
*5-42/10,000 c/o paresthesia lasting 4-6 weeks
*Don’t use epidural if paresthesia persists after insertion

Front 50

Puncture by catheter rare, but what happens if this occurs?

Back 50

Total spinal

Front 51

Accidental dural puncture:
Incidence of headache app. ____ in parturient

Back 51

80%

Incidence varies
Most report 1-2% at teaching facilities

Front 52

Treatment of total spinal

Back 52

_Establish AW, ventilate with 100% oxygen
-Maintain B/P:
LUD, fluids, ephedrine
-Treat cardiac arrhythmias and collapse
-CPR and prompt delivery of baby if necessary

Front 53

Puncture by catheter rare, but what happens if this occurs?

Back 53

Total spinal

Front 54

When do we treat BP if hypotensive during epidural and what can we do to prevent this from occurring?

Back 54

-Treat B/P if less than 100 mm Hg (30% lower than baseline)
-Preload, have vasopressor ready, LUD, monitor mom and fetus

Front 55

Treatment of total spinal

Back 55

_Establish AW, ventilate with 100% oxygen
-Maintain B/P:
LUD, fluids, ephedrine
-Treat cardiac arrhythmias and collapse
-CPR and prompt delivery of baby if necessary

Front 56

Paresthesias incidence

Back 56

*5-25% incidence of transient paresthesia
*5-42/10,000 c/o paresthesia lasting 4-6 weeks
*Don’t use epidural if paresthesia persists after insertion

Front 57

Accidental dural puncture:
Incidence of headache app. ____ in parturient

Back 57

80%

Incidence varies
Most report 1-2% at teaching facilities

Front 58

Puncture by catheter rare, but what happens if this occurs?

Back 58

Total spinal

Front 59

Treatment of total spinal

Back 59

_Establish AW, ventilate with 100% oxygen
-Maintain B/P:
LUD, fluids, ephedrine
-Treat cardiac arrhythmias and collapse
-CPR and prompt delivery of baby if necessary

Front 60

Subdural injection

Back 60

local between dura and arachnoid

Front 61

Incidence of subdural injection

Back 61

0.1-0.82%

Increased during rotation of epidural needle after LOR

Increased in patients with previous back surgery

Front 62

What will you see with subdural injection

Back 62

See wide spread of sensory anesthesia with small amt of local

Usually weak, patchy block with cephalad spread

Delayed onset (10-30 min), faster resolution

Hypotension may be first symptom

Front 63

Massive epidural analgesia

Back 63

More common in massively obese, patients with arteriosclerosis and DM

Onset gradual

Front 64

Accidental IV injection

Back 64

May be at initial dosing or migration of catheter

May see seizures and CV collapse if direct injection of local into epidural vein

Front 65

Backache

Back 65

30-40% incidence

Increased by multiple needle sticks

Some studies show no increase in incidence with or without epidural

Front 66

Broken epidural catheter

Back 66

Most say leave in place if in lumbar epidural space

Implanted catheter in cats in lab covered by fibrous tissue after 3 weeks

Front 67

Neuro problems related to pregnancy or L&D: incidence and causes

Back 67

*1:2600 – 1:6400 (1:40,000-1:100,000 incidence of neuro problems r/t anesthesia)

*Prolapsed disk during labor

*Compression of lumbosacral trunk (L4-L5) by descending fetal head and sacrum
-May be associated with forceps delivery
-Foot drop (peroneal – branch of sciatic)
-Lateral foot and calf numbness (peroneal – branch of sciatic)
-Weakness of hip adductors and quadriceps (obturator)

Front 68

If a L&D pt is on Remifentanil must they be a 1:1 nurse: patient ratio?

Back 68

Yes

Front 69

T or F: Narcan can be given if the neonate is suffering from neonatal depression concerning Demerol administration to mom?

Back 69

True

Front 70

Ketmaine will cause what effects to the patient? HR, BP, etc?

Back 70

Sympathetic (increased HR, BP) unless catecholamine depleted.

Front 71

Is pt able to maintain airway on Ketamine?

Back 71

Yes. It is a powerful analgesic and may cause nystagmus but pt can maintain airway.

Front 72

What happens to the cervix during the early first stage of labor?

Back 72

cervix dilates from 0-10

Front 73

Will you see toxic effects from a test dose?

Back 73

should not....its a small amount of lidocaine and epi.

Front 74

Is it good if the patient can move their legs after 3 mins after the test dose?

Back 74

Yes, you should be in the epidural space.

Front 75

How long should you montior a pt after administering an epidural?

Back 75

20-30 mins

Front 76

Why do obese people have a higher level and massive epidural analgesia sometimes after administration of an epidural?

Back 76

increased intra abdominal pressure