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216 Cards in this Set
- Front
- Back
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Mallampati Class I
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visualise soft palate, uvula, tonsillar pillars
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Mallampati Class II
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visualise soft palate, uvula but NOT tonsillar pillars
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Mallampati Class III
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only visually soft palate and BASE of uvula
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Mallampati Class IV
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only soft palate (uvula cannot be seen)
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American Society of Anaesthesiology (ASA) classification for predictor of overall outcome.
6 classes |
ASA 1: health, fit
ASA 2: mild systemic disease e.g controlled DM/HTN ASA 3: severe systemic disease that limits activity e.g angina, COPD ASA 4: incapacitating disease that is a constant threat to life e.g CHF, renal failure ASA 5: moribund - not expected to survive 24h with or without surgery e.g ruptured AAA, head trauma with raised ICP ASA 6: organs harvested Add E for emergency |
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Malignant hyperthermia:
mechanism |
decr reuptake of Ca++ by sarcoplasmic reticulum=> i/c Ca++ accumulation => muscle contraction => incr aerobic + anaerobic metabolism
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Malignant hyperthermia:
triggering drugs |
suxamethonium
+ potent volatile agents |
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Does previous uneventful anaesthesia preclude Malignant hyperthermia?
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no
75% have had anaesthesia before |
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Malignant hyperthermia:
2 early signs |
incr end tidal CO2
tachycardia |
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Malignant hyperthermia:
14 late signs |
1. incr temp
2. rhabdo 3. myoglobinuria 4. metabolic + resp acidosis 5. muscle rigidity 6. dysrhythmias 7. HTN 8. cardiac arrest 9. masseter spasm 10. hypoxia 11. hyperkalaemia 12. high CK 13. renal failure 14. DIC |
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What might be the first indication of a previously unsuspected Dx of Malignant hyperthermia ?
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masseter muscle spasm after being given sux
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Malignant hyperthermia:
drug Rx What is it? How does it work? |
DANTROLENE
muscle relaxant interferes with release of Ca++ from SR => uncouples the excitation contraction of skeletal m |
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Malignant hyperthermia:
Rx (4) |
hyperventilate with 100% FiO2
dantrolene sodium bicarb for acidosis cool patient with IV fluids, lavage in stomach + bladder |
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Can patients with Malignant hyperthermia ever get an anaesthetic?
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yes, use a "safe technique" and avoid sux and volatile agents
There are 'vapour free' machines that can be used |
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What does GORD do to gastric emptying of food?
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slows solids
no effect on liquid emptying |
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Pts with GORD: what meds can be used before induction?
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Antacid: sodium citrate - just before induction
or PPI/H2 blocker - night before and 2hr before op |
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If a Pt is at high risk of cardiac event during surgery, what can they prophylactically be put on?
What is the aim? |
beta-blockers
cardioselective: atenolol/metoprolol aim: PR 70 |
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Which antihypertensives should patients withhold/continue taking perioperatively?
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ACEi - STOP 1/7 before unless severe HTN (intraop hypotension with anaesthetic agents)
Diuretics: stop that day, unless CHF B-blockers, CCB: CONTINUE |
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At what stage of the day should diabetics have their surgery scheduled?
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morning
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Metformin is assoc w/ development of ________ ___________ under GA => stop night before op and monitor BSL
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metabolic acidosis
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Pts with insulin-dependent DM should be commenced on __________________
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IV infusion regime
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Pre-op fasting guidelines for adults with no RFs for aspiration
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8h meat, fatty foods
6h solid food (incl milk) 2h clear fluids 1-2h for pre-op meds w/ sips of H2O |
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What does trauma do to gastric emptying?
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delays
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What do opioids do to gastric emptying?
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delays
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What med can be given to increase gastric emptying (in a healthy Pt)
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metoclopramide
(dopamine antagonist = pro-kinetic) |
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Which agents should be given to a pregnant woman to avoid aspiration? (2)
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Ranitidine
Sodium citrate (antacid) |
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3 aims of GA
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1. unconsciousness (anaesthesia)
2. analgaesia 3. loss of reflexes (muscle relaxants) |
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3 stages of GA
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1. induction
2. maintenance 3. emergence/recovery |
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Usually, which sorts of GA agents are used for induction and maintenance
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induction: IV agents
maintenance: volatile |
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Conscious sedation: rousable?
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yes
independently maintain airway and response to appropriate physical stimulation and verbal command |
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Making a Pt unrousable by use of propofol/volatile gases still have reflexes, both motor and autonomic (coughing, motor reflexes, eyelash flutter)
=> what is given to decrease motor reflexes? autonomic reflexes? |
motor: muscle relaxants
autonomic: opioids |
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LMA: what does the cuff surround?
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glottic structures
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4 IV induction agents?
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propofol
thiopental ketamine benzos |
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What are the two types of inhaled anaesthetics agents?
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1. volatile: ____flurane. these are liquids that are vapourised
2. gas: NO - usually given with volatile; reduces amount of volatile needed |
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What can occur if Pt extubated too early (during twilight zone b/t unconsciousness + wakefulness)
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laryngospasm
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What does MAC stand for?
What does it mean? It is inversely proportional to what? |
Minimal Alveolar Concentration
= conc reqd to abolish the response to surgical incision in 50% of subjects inversely proportional to potency |
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Mech of action: most anaesthetics enhance the activity of _________
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inhibitory GABA(A) receptors
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anaesthetic agents:
__________ cardiac contractility broncho___________ ________________respiration _______________ arterial PCO2 |
decrease
dilation decrease (increase RR and decr tidal vol => decr net minute ventilation) increase |
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What class of drugs does thiopental belong to?
MOA? |
barbituate
(it's an induction agent) decrease time Cl channels open facilitating GABA and suppressing glutamic acid |
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How does propofol work?
What is the class of drug? |
inhibitory at GABA synapse
prolongs GABA Cl- channel opening => hyperpolarisation and neuronal inhibition Alkylphenol - hypnotic |
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Induction dose of propofol?
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2.0-2.5 mg/kg
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What does propofol do to peripheral resistance?
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decreases
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What other good property other than anaesthesia does propafol have?
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anti-emetic
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What is used as premedication to provide anxiolysis and sedation before GA or local/regional anaesthetic?
MOA? |
benzo: midazolam
increased freq of Cl- channel opening time, facilitating GABA |
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For anaesthesia induction; dose of midazolam?
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0.1-0.2mg/kg IV
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What is suxamethonium (succinylcholine)?
How does it work? |
muscle relaxant
Depolarising blocking drug --> activates AChR => muscle depol => continued presence at motor endplate desensitises AChR => cease to respond to nerve impulses Membrane remains depolarised -> neuromuscular transmission blocked --> voltage dependent Na channels inactivated due to sustained depol |
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4 SEs of sux
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1. fasciculations
2. increased ICP 3. hyperkalaemia 4. malignant hyperthermia |
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Patients are considered "non-fasted" if there has been <____hr b/t last meal and operation => are at risk of _______________ and require ______________
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6
aspiration RSI |
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Anything that ______________ abdo pressure such as pregnancy, obesity, emergency abdo trauma are at risk of aspiration
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increases
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To intubate, patient position = head _________ and neck _________
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extension
flexion ie atlanto-occipital extension; C-spine flexion |
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___________________ pressure (aka _______________ manoevre) is applied during RSI to obstruct the _________________ between cartiladge and C__ to prevent aspiration of gastric contents
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cricoid; Sellick's
oesophagus C6 |
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LMA is positioned __________________________ so does not protect against pulmonary aspiration to the same degree as LMA
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supraglottic
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When using direct laryngoscopy before intubating, you visualise the pt's glottis through their mouth be aligned the axes of... (3)
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1. oral cavity
2. pharynx 3. larynx |
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Why are diabetics at increased risk of aspiration?
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delayed gastric empying
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Sux is usually used during RSI to facilitate intubation, except in burns patients are spinal cord injury patients where __________________ is used to avoid hyperkalaemia
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rocuronium
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RSI: do they do face mask ventilation?
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no
to avoid stomach distension |
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Airway risk is LOW if thyromental distance >_____ finger breadths
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3
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What condition is associated with instability of the atlanto-occipital joint => may make a difficult airway
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Rheumatoid Arthritis
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Sizing the guedel
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corner of mouth to angle of mandible
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LMA inserted into ____________________________ within the pharynx
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piriform fossa
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True or false: LMA protects against aspiration
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false
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Ideal position for intubation
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Pt supine with head on pillow, head flexed, neck extended (sniffing position)
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Typical size ETT for men
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8-8.5
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Typical size ETT for women
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7-7.5
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What will you see (2) if you accidentally intubate the oesophagus?
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1. capnography may show initial burst of CO2 from gas in stomach, but then nothing
2. abdo will rise |
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What happens if you insert ETT too far?
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goes into R main bronchus
ventilate only one lung => ventilate only 1 lung stats start to fall |
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When extubating, what two things do you have to remember to do first?
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1. suction oropharynx
2. deflate cuff |
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Rapid pulse or high BP while under may indicate 2 things
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1. ineffective analgaesia
2. emersion from anaesthesia |
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Why is temp monitored during long op?
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1. detect malignant hyperthermia
2. prevent hypothermia which often happens b/c of cool OT, evaporative heat loss, conduction of heat to cooler instruments that touch the body --- prevent with body warmers, blankets, warm IV fluids |
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Aim for U/O?
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0.5mL/kg/hr
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Most common type of periop eye injury?
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corneal abrasion
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When an operation is happening in supine position (most common), the arm position should be less than 90 deg; why?
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minimise brachial plexus injury from pressure of humerus head in the axilla
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What position can you make the theatre bed in case of hypotension?
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Trendelenberg
(head down) - increases venous return Risk = raised ICP This also decreases lung compliance due to abdo viscera pressure against diaphragm |
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2 risks of anaesthetic in sitting position
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1. venous embolism
2. air embolism |
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4 contraindications to mechanical devices used for VTE prophylaxis
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1. severe peripheral arterial disease
2. recent skin grafts 3. severe peripheral neuropathy 4. severe leg deformity |
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Duration of VTE prophylaxis:
high risk Pts |
10 days
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Duration of VTE prophylaxis:
knee replacement |
14 days
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Duration of VTE prophylaxis:
hip replacement/# |
28-35 days
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Blood transfusion appropriate when Hb < ____g/L
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70
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Which blood group is the universal recipient?
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AB
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Which blood group is the universal donor?
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O
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Blood group A can receive blood from who?
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A
O |
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Blood group B can receive blood from who?
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B
O |
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Blood group AB can receive blood from who?
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A
B AB O |
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Blood group O can receive blood from who?
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O
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Plt transfusion is required if platelet levels are <______x10^9/L and they are having a procedure with associated blood loss or major blood loss (>500mL expected loss)
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50
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6 indications for FFP
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1. warfarin OD
2. DIC 3. massive transfusion rxn 4. isolated coag def 5. TTP 6. HUS |
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Define massive blood transfusion
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replacement of >1 blood volume (5L) is <24h
OR >50% blood volume in 4h |
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5 causes of DIC
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1. tissue damage
2. hypoxia 3. acidosis 4. sepsis 5. haemolytic transfusion |
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4 things that may require massive blood transfusion
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1. dilution/consumption (e.g replacement with flids lacking coag factors of plts e.g crystalloids)
2. DIC 3. systemic fibrinolysis: assoc with liver disease in partiuclar (causes rapid lysis of thrombi at surgical sites) 4. platelet dysfn |
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What do you think of 4-30 days post transfusion, p/w fever, diarrhoea, liver fn abnormalities, pancytopaenia
Which cells are involved |
graft vs host disease
T cells |
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Acute haemolytic blood transfusion rxn:
what causes it when does it occur |
ABO incompatibility ==> intravascular haemolysis
occurs immediately |
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Febrile non-haemolytic blood transfusion rxn:
what causes it when does it occur |
alloAbs to WBC, plt or other donor plasma Ag + release of cytokines from blood products
within 0-6h |
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Allergic non-haemolytic blood transfusion rxn:
what causes it how does it present? Rx? |
alloAbs (IgE) to proteins in donor plasma --> mast cell activation --> histamine
p/w urticaria, sometimes as anaphylaxis with bronchospasm, laryngeal oedema, hypotension (but this is usually with IgA def Pts) Rx: anti-histamine (diphenhydramine) |
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Transfusion related acute lung injury (TRALI):
what causes it when does it occur how does it present? |
binding of donor Abs to WBC of recipient and release of mediators --> incr capillary permeability in lungs
2-4h p/w acute resp distress, APO |
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Delayed haemolytic blood transfusion rxn:
what causes it when? p/w |
alloAbs to minor Ag e.g Rh, kell, duff, kidd (level of Ab at time of transfusion too low to cause haemolysis, then later increases and --> extravascular haemolysis)
5-7d post-infusion p/w anaemia, mild jaundice |
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Where is the chemoreceptor triggering zone for vomiting?
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base of 4th Ventricle
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Which NTs work at the chemoreceptor triggering zone for vomiting (2)
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5HT3
D2 |
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MOA: metoclopramide
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D2 receptor antagonist
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MOA: Ondansetron/Tropisetron
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5HT3 receptor antagonist
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MOA: prochloroperazine (anti-emetic)
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D2 receptor antagonist
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What is scopolamine, what is it used for?
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anticholinergic agent that blocks binding of ACh => blocks neuronal pathways from vestibular system
acts as an anti-emetic |
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What is dolasetron?
MOA? |
anti-emetic
5HT3 receptor antagonist |
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Which corticosteroid has an anti-emetic property?
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dexamethasone
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Which receptors in the CNS do opioids work on?
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µ agonist
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MOA tramadol
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weak µ receptor agonist
+ inhibits reuptake of serotonin and NAd |
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What is the advantage of using tramadol over opioid?
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doesn't --> resp depression or decr GI motility
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MOA ketamine
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NMDA antagonist
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What are 5 differences between morphine and fentanyl?
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1. morphine = hydrophilic; fentanyl = lipophilic
2. morphine = delayed onset; fentanyl = rapid onset 3. morphine = longer duration; fentanyl = shorter duration 4. N+V -> higher incidence in morphine 5. pruritis -> higher incidence in morphine |
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What does morphine O.D do to pupils?
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constrict: pinpoint pupils
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What can be given in morphine O.D if clinically significant resp or CV depression?
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Naloxone
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Dose: Fentanyl
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30-75mcg IV
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Dose: Morphine
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2-5mg IV
2.5-10mg S/C |
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Dose: Oxycodone
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2.5-15mg PO q4h
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Dose: Ibuprofen
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200-400mg PO q8h
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Dose: Paracetamol
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1g PO q4-6h
max 4g/d |
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Under normal physiological conditions, how much water is lost?
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30-35mL/kg/day
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Rule for maintenance fluids
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4-2-1:
1st 10kg: 4mL/kg/hr 2nd 10kg: 2mL/kg/hr Next kg over 20kg: 1mg/kg/hr |
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What is the difference (in placement) of a spinal vs epidural anaesthetic?
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spinal: local injected directly into subarachnoid space
epidural: local diffuse into the subarachnoid space from the epidural spcae |
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Which layers do you have to get through (in order) before reaching the epidural space (5)
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1. skin
2. s/c tissue 3. supraspinous lig 4. interspinous lig 5. ligamentum flavum |
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How do local anaesthetics work?
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blocking conduction of afferent nociceptive impulses
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What, other than analgaesia, do you get by using epidural?
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motor nerve block
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What is the opioid of choice for epidural infusion?
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Fentanyl
(best used in combo with local; improves the quality of epidural analgesia compared to local anaesthetic alone) |
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Which 2 local anaesthetics are most commonly used in an epidural infusion
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bupivacaine and ropivacaine
- often in combo w/ fentanyl |
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____________ _____________ plus ___________ in a patient who has recently had an epidural block represents a medical emergency.
Could indicate an _________________ ______________ What Ix do you do? Who do you refer to? |
back pain
fever epidural abscess MRI neurosurgeon |
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For a spinal anaesthesia, how do you confirm that the placement is in the subarachnoid space?
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free flow of CSF out of the hub of the needle
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What can you add to a local anaesthesia to decrease the rate of absorption and therefore prolong the duration of the anaesthetic?
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vasoconstrictor; adrenaline
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What is the difference between hyperbaric and hypobaric solutions used in local anaesthetics?
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hyperbaric: spreads to dependent areas eg. if head is down, the anaesthetic moves up spine; if sitting up, it moves down spine
hypobaric (less commonly used): does opposite and floats up |
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MOA: local anaesthetics
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inhibit sodium channels --> membrane unable to depolarise sufficiently to reach the threshold potential and generation of an AP is prevented
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S.Es of local anaesthetic (split into systems)
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CNS: numb tongue, peri-oral tingling, metallic taste, tinnitus, visual dysfn, tremors, LOC, seizure, resp depression
CVS: bind to myocardial Na channels --> arrthymia, decr contractility, cardiac arrest Neurotoxicity: "Transient Neurological Symptoms {TNS}" = hyper/paraesthesias, motor weakness legs/bum - usually resolve w/i 3d Hypersensitivity/allergy |
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Ventilatory support (oxygen) indicated if RR > ____
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30
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Ventilatory support (oxygen) indicated if PaO2 <____kPa on FiO2 > ______
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11
0.4 |
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Ventilatory support (oxygen) indicated if PaCO2 high with significant resp distress (e.g pH <______)
5 other indications for O2 |
7.2
1. exhaustion 2. confusion 3. severe shock 4. severe LVF 5. raised ICP |
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Type I Respiratory Failure
What is it? Failure of ____________ Causes: Rx: |
hypoxia (PaO2 < 60mmHg) with normal or low PaCO2
oxygenation acute diseases of lung (fluid filling of collapse of alveolar units): cardiogenic/noncardiogenic pulmonary oedema, pneumonia, pulmonary haemorrhage O2 therapy |
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Type II Respiratory Failure
What is it? Failure of ____________ Causes: Rx: |
hypoxia AND hypercapnoea (>50mmHg)
ventilation + oxygenation (cost alveolar vent is inversely prop to PCO2) drug OD, neuromuscular disease, chest wall abno, severe airway disease (eg COPD) Rx: ventilatory assistance + S' O2 |
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Symptoms of cerebral hypoxia (3)
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anxiety
agitation depression consciousness |
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What happens to BV during hypoventilation?
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dilate
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Other than malignant hyperthemia, what is another familial disease that can cause adverse anaesthetic rxns?
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atypical cholinesterase (prolonged duration of muscular blockade)
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Fasting guidelines: meat, fried or fatty foods, how many hours can they be eaten before surgery?
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8
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If someone is taking regular opioids (e.g MS contin) for chronic pain, can they keep taking them before the surgery?
Why? |
yes
keep dose consistent to prevent withdrawal |
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At the beginning of a GA, what happens to the eyes and when can you say the Pt is properly unconscious and ready for surgery?
What happens to pupils when ready? |
eyes initially are rolling
then become fixed when ready dilate |
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What do volatile anaesthetic agents (e.g --fluranes) do to ICP?
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raise
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What does propofol do to ICP
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decrease
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Can you use thiopental for maintenance anaesthetic?
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no - it accumulates with increased dosing
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How long does propofol last for?
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4-6mins
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Antagonist for Benzos
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Flumazenil
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Which of the inhalation agents has the most rapid onset?
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N.O
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In a semi-conscious Pt, is guedel (oropharyngeal) or nasopharyngeal airway better tolerated?
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nasopharyngeal
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2 contraindications to nasopharyngeal airway
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1. c-spine injury
2. base of skull # |
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At least how many ppl required to do an intubation of a trauma pt with potential C-spine injury?
What does each do? |
3:
1. pre-oxygenate + intubate 2. cricoid pressure 3. manual in-line immobilisation of head and neck (counters forces made by moving laryngoscope) |
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What drug can you give to decrease salivation and bronchial secretions?
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Atropine
= muscarinic antagonist |
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What are the two different sorts of muscle relaxants, how do they work? E.g of each?
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DEPOLARISING: Suxamethonium
- mimics ACh and binds to ACh-Rs => prolonged depol. NON-DEPOLARISING: Rocuronium, Vercuronium - inhibis postsynaptic ACh Rs => prevent depol. |
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Is Sux long or short acting?
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short (5-10mins)
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What effect can sux have on K+?
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increase
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Some Pts have abnormal or missing plasma cholinesterase therefore have decreased sux metabolism so will be ________________ for longer and need to be ventilated til sux is fully metabolised (what is this called?)
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paralysed
sexamethonium apnoea |
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What drugs are given to reverse neuromuscular blockade?
MOA? |
Cholinesterase inhibitors (NEOSTIGMINE)
inhibit enzymatic degrad of ACh => incr ACh at nicotinic and muscarinic Rs which deplace NON-DEPOLARISING muscle relaxants |
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What does an arterial line measure?
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BP
MAP (aim >60) |
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What sort of monitoring do you need to measure preload?
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central venous line
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What sort of monitoring do you need to measure afterload?
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arterial line
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3 locations for central venous cannulation
*Which has highest risk of DVT and bacterial colonisation? |
1. internal jugular
2. subclavian 3. femoral (*highest risk) |
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7 potential complications of central venous cannulation
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1. pneumo/haemo/chylothorax
2. venous thrombosis 3. thrombophlebitis 4. infection 5. haemorrhage 6. catheter or guidewire embolisation 7. cardiac arrhythmias |
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Define Hypothermia
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<36 deg
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5 adverse effects of hypothermia
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1. risk of wound infection (imp immune fn)
2. delayed healing 3. reduced Plt fn and imp activation of coag cascade => incr blood loss 4. incr risk arrhythmia (particularly VT) 5. decr metabolism anaesthetic agents => prolongs post-op recovery |
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Where in the brainstem are the two centres of vomiting found?
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medulla
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Mechanism of vomiting
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Chemoreceptor trigger detects circulating toxins in blood and CSF and relays stimuli to the Integrative Vomiting Centre which produces the act of emesis
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3 ways in which the vomiting centre can be activated
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1. nerve impulses from stomach/intestinal tract -> reflexive activation (mechanoreceptors from contraction/dilation, chemoreceptors from chemical stimuli)
2. stimulation from higher brain centres 3. chemoreceptor trigger zone sending impulses (detects toxins) |
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Which two sorts of surgeries tend to increase post-op N+V?
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1. abdo
2. gynae |
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Which anaesthetic agents (3) increase post-op N+V?
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1. inhalational agents (NO>fluranes)
2. opioids 3. neostigmine (large dose) |
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S.Es ondansetron (3)
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1. H/A
2. flushing 3. seizures |
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Lignocaine, bupivocaine, ropivocaine:
order from time to onset and duration of action safe dose of each? |
1. lignocaine fastest/shortest 5mg/kg
2. bupivocaine 2.5mg/kg 3. ropivocaine lasts longest 3-4mg/kg |
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Safe dose lignocaine?
max dose w/ adrenaline? |
5mg/kg
7mg/kg |
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Local anaesthetic toxicity: Seizure
What can be given? |
diazepam, propofol, thiopental
--> all lower Sz threshold |
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What is meant by the term "high spinal"?
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when spinal anaesthetic drifts up to block thoracic level (T2-T4) => cardiac sympathetic block
(adverse outcome to spinal) |
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Where is the epidural space?
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between the ligamentum flavum and the dura
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Nasal prongs:
fixed/variable? max flow? max FiO2? |
variable
5L/min 40% |
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Hudson mask:
fixed/variable? max flow? max FiO2? |
variable
10L/min 55% |
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Venturi mask:
fixed/variable? max flow? max FiO2? |
fixed
FiO2 = 24-50% depending on nozzle |
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Non-rebreather mask:
fixed/variable? max flow? max FiO2? |
variable
15L/min 70% |
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Self-inflating Laerdal mask:
fixed/variable? max flow? max FiO2? |
fixed
15L/min 100% |
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Define hypoxic hypoxia
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decr O2 saturation of Hb
e.g low inspired partial pressure of O2 (high altitude), hypoventilation, V-Q mismatch |
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Define stagnant hypoxia
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blood flow through capillaries is insufficient to supply the tissues e.g poor C.O, vasoconstriction
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Define anaemic hypoxia
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low [PaO2] due to low [Hb] in blood
e.g bleeding, haemolytic anaemia, iron def, renal failure, BM failure |
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Histotoxic hypoxia
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inability of cells to take up or use O2, despite normal delivery e.g cyanide poisoning
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Where does crystalloid soln distribute?
Requires ___:1 replacement |
ECF
3:1 (i.e 1L of i/v replacement requires 3L N/S due to distribution into interstitial fluid) |
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Where does colloid soln distribute?
Requires ___:1 replacement |
intravascular volume
1:1 (stays within i/v space) |
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What are the % breakdown of distribution of body water?
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2/3 intracellular
1/3 extracellular - 3/4 interstitial - 1/4 intravascular (plasma) |
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Total body water = ____% of total body weight
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60%
(i.e in 70kg person = 42L water) |
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Starling forces:
Capillary hydrostatic pressure - ______ fluid ___________ capillary Interstitial hydrostatic pressure - _______ fluid ________ capillary Plasma colloid osmotic pressure - _________ fluid__________ capillary Interstitial colloid osmotic pressure - ____________ fluid _________ capillary |
Starling forces:
Capillary hydrostatic pressure - pushes fluid out of capillary Interstitial hydrostatic pressure - pushes fluid into capillary Plasma colloid osmotic pressure - pulls fluid into capillary Interstitial colloid osmotic pressure - pulls fluid out of capillary |
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How does CHF cause oedema? (in terms of starling forces)
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increase capillary hydrostatic pressure
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How does nephrotic syndrome/liver failure cause oedema? (in terms of starling forces)
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decrease plasma proteins
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How do toxins/infection/burns cause oedema?
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increase capillary permeability
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How does lymphatic blockage cause oedema? (in terms of starling forces)
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increased interstitial colloid osmotic pressure
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ADH secretion is influenced by:
1. receptors in hypothal that are sensitive to increasing plasma osmolarity --> __________ ADH secretion 2. stretch receptors in atria of heart; activated by larger than normal volume of blood returning to heart --> ______________ ADH secretion 3. stretch receptors in aorta and carotid aa; stimulated when BP falls --> ______________ ADH secretion |
stimulate
inhibit stimulate |
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Low BP --> decreased GFR as lower flow through tubule in kidney => _________________ cells --> renin --> _________ --> stimulates the adrenal cortex to produce _______________ => increase sodium reabsorption --> increase H2O reabsorption => conserve volume and raise BP
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juxtaglomerular
angiotensin II aldosterone |
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What maintenance electrolytes are required for sodium and potassium?
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Na: 3mEq/kg/day
K: 1mEq/kg/day |
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What % body weight is fluid deficit in mild dehydration (dry mucous membranes, thirsty)
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3%
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What % body weight is fluid deficit in moderate dehydration (skin turgor decr, sunken eyes, oliguric)
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5%
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What % body weight is fluid deficit in severe dehydration (tachycardic, hypotensive, mottled skin, cap refill reduced)
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10%
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How do you estimate blood volume in an adult?
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estimated blood vol = weight (kg) x average blood vol
average blood vol: males = 75mL females = 65mL |
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Grade I-IV blood loss
%? |
I: <15%
II: 15-30% III: 30-40% IV: >40% |
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Grade IV blood loss
HR? SBP? U/O? LOC? |
>120
<90 none lethargic |
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When giving a blood transfusion, should administer it within ____mins of arrival
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30
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4 types of shock
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1. hypovolaemic
2. septic/anaphylactic 3. cardiogenic 4. neurogenic |
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Rx hypovolaemic shock
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fluid resus
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Rx cardiogenic shock
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improve cardiac perfusion and CO:
NORADRENALINE |
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What happens to vascular resistance and cardiac output in neurogenic shock?
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resistance decreases
C.O increases |
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Mgmt anaphylactic shock
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1:1000 adrenaline 0.3-0.5mg SC
Antihistamines (diphenhydramine or phenergin) Salbutamol if severe: (in addition to above) ABCs, may need ETT Steroids Crystalloid resus |
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Major fn of alpha 1 Rs
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increase vascular smooth muscle contraction
increase intestinal and bladder sphincter contraction |
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Major fn of alpha 2 Rs
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decrease sympathetic outflow
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Major fn of beta 1 Rs
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increase HR, increase contractility
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Major fn of beta 2 Rs
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vasodilation
bronchodilation increase HR increase contractility |
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Which adrenoceptors does adrenaline work on
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all alpha and beta
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Which adrenoceptors does noradrenaline work on
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primarily alpha
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Which adrenoceptors does dobutamine work on
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mainly beta 1
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Which adrenoceptors does dopamine work on
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alpha 1, alpha 2, beta 1
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Which adrenoceptors does Metaraminol work on
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alpha 1, alpha 2, beta 1
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