Obstetrics Anesthetic Emergency

Question 1

What are the cardiovascular changes seen in Pregnancy?(5)

Answer 1

1.Increase in blood volume by an increase plasma volume
2Increase in Red Cell mass
3.Hypercoagulability
4.Aorto-caval compression
5.Increase in cardiac output

Question 2

What causes physiological anemia in Pregnancy? And by how much does the Hb decrease?

Answer 2

There is an increase in plasma volume and red cell mass but not at the same rate.
10-20%

Question 3

By how much does the blood volume increase? When does it start and when does it peak.

Answer 3

From 65-75ml/kg to 80-85ml/kg
It starts at birth and peaks at around 30-32 weeks

Question 4

What are the physiological respiratory changes seen in Pregnancy?

Answer 4

1.Increase in oxygen consumption
2. Reduction in functional Residual Capacity and Residual Volume due to the displacement of the diaphragm
3. Interstitial Edema of the upper airway

Question 5

By how much does the oxygen consumption increase in Pregnancy?

Answer 5

From 200-250ml/min to 500mls/min

Question 6

What are the physiological renal changes seen in pregnancy? And why?

Answer 6

Decrease in urea and creatinine levels
Because there is an increase in renal blood flow and GFR as a result increase in clearance of urea and creatinine and ureal levels.

Question 7

By how does the GFR increase by? and when does this usually peak?

Answer 7

By 100-150%
It peaks at 13 weeks

Question 8

What are the physiological gastrointestinal changes seen in pregnancy? And how will they affect the anesthesia?

Answer 8

-Slow gastric emptying which increases risk of reflux and regurgitation especially during labor.
-Risk of aspiration especially during general anesthesia

Question 9

Describe the Obstetric Pre-Op assessment?

Answer 9

Medical and family history
Allergies to anaesthetic drugs
Establish when was last solids and fluids taken.
Assessment of airway and prediction of difficult intubation
Physical examination
Lab investigations; FBC, G&X match

Question 10

What is the choice for anesthesia in Pregnancy?

Answer 10

1st choice: Spinal Anesthesia
2.General Anesthesia only under certain conditions.

Question 11

What are the contraindications for Spinal Anesthesia?

Answer 11

1.Maternal refusal
2.Skin infection at needle injection site
3.Severe maternal sepsis
4.Coagulopathies

Question 12

What are the indications for General Anesthesia in obstetrics ?

Answer 12

Maternal request
Failed Spinal Anaesthesia
Emergency c/s e.g cord prolapse.
Contra-indication to Spinal Anaesthesia

Question 13

What are the complications of Spinal Anesthesia in obstetrics?

Answer 13

1.Hypotension
2.High Spinal/Total Spinal
3.Local anaesthetic toxicity
4.Post dura puncture headache

Question 14

What are the signs of local anesthetic toxicity?

Answer 14

Dizziness
Confusion
Agitated
Convulsions

Question 15

What are the signs of Post-dural puncture headache?

Answer 15

Visual disturbances(Diplopia, photophobia, )
nausea,tinnitus, 6th cranial nereve palsy.
Bifrontal,occipital headache worse in the upright positioning,when straining and coughing.

Question 16

List 4 Anesthetic Emergencies?

Answer 16

Obstetric hemorrhages
Failed intubation
High spinal/Total Spinal
Cardiac arrest