Obstetrics

Question 1

What BP target are you aiming at post spinal for obstetric anaesthesia?

Answer 1

90% or above of baseline. Avoidance of <80% is important.

Question 2

Outline management of spinal induced hypotension.

Answer 2

Phenylephrine infusion 25-50mcg/min. Ephedrine/glyco/atropine boluses Fluid load (1L crystalloid or 500mL colloid) and left lateral tilt. Consideration of leg elevation if insufficient fluid load.

Question 3

How do you manage spinal induced hypotension in the pre eclamptic/PIH?

Answer 3

Phenylephrine infusion again. reduce the infusion rate.

Question 4

what is the pathophysiology behind spinal induced hypotension?

Answer 4

decreased tpr secondary to small artery vasodilation and mild venodilation

Question 5

What is the usual hemodynamic response to spinal anaesthesia?

Answer 5

decreased BP, increased HR

Question 6

What causes hypotension and bradycardia post spinal blockade?

Answer 6

Normal response with vasovagal OR high spinal blockade with Cardio respiratory failure

Question 7

Management of low bp low HR post spinal blockade?

Answer 7

Continue phenylephrine infusion, bolus ephedrine/anticholinergic AND rule out high spinal block as it progresses

Question 8

Management of persistent refractory hypotension post spinal blockade?

Answer 8

Review cardiovascular status immediatey- rule out sig hypovolemia, cardiac disease and pre eclampsia induced heart failure/AFE

Question 9

Outline management of low BP with normal HR

Answer 9

BP <90% –》phenylephrine increas rate by 10mL/hr. BP <80% –》bolus 100mcg and increase rate by 10mL/hr

Question 10

Outline management of spinal induced low bp/hr

Answer 10

Decreased HR + BP <90% –》ephedrine 3-6mg. Decreased HR (<60) + BP <80% –> glyco 200mcg or atropine 600mcg

Question 11

What are the signs of a high spinal? (in order of likelihood;low to high)

Answer 11

Unlikely; weak cough, hypotension. Early signs; progressive dyspnoea, weak grip strength (C8/T1), can’t touch nose (C5/6), ineffective cough, sats <90% Likely; unable to speak, hypoventilation, Sats <90%, hypotension + brady Confirmed; Unable to speak/breathe. Hypotension/brady

Question 12

Management of early signs of high spinal?

Answer 12

Monitor, high flow O2

Question 13

Management of likely high spinal?

Answer 13

PPV 100%. Reassure + cricoid. Ephedrine 10mg if needed + IVF

Question 14

Management of total spinal

Answer 14

RSI with low dose thio. Support circulation with phenylephrine and ephedrine. Atropine/adrenaline if needed.

Question 15

What are the effects of an ascending neuraxial block at T1-4

Answer 15

sympathetic fibres–> brady and hypotensive

Question 16

What are the effects of an ascending neuraxial block at C6-8?

Answer 16

hands and arms–> tingling and weakness. accessory muscles od respiration affected.

Question 17

What are the effects of an ascending neuraxial block at C3-5?

Answer 17

Diaphragm and shoulder- apnoea. Shoulder weakness is a warning sign of impending diaphragmatic compromise. slurred speech/sedation, LOC.