List the likely causes of sudden respiratory distress in a woman in labour, who has no previous history of cardiac or respiratory disease. List 2 cardinal clinical features for each of these conditions.
a) Venous thromboembolism with PE: (Signs of DVT, Rt. Heart failure, ECG, CTPA)
b) Amniotic fluid embolus: Hemodynamic collapse with seizures, DIC
c) Pulm oedema secondary to pre-eclampsia: HT, proteinuria
d) Tocolytic pulmonary oedema: Tocolytic administration, rapid improvement
e) Aspiration pneumonitis – classic features
f) Peripartum cardiomyopathy: cardiomegaly, S3
g) Air embolism: Hypotension, cardiac mill wheel murmur
h) Pneumomediastinum: occurs during delivery
i) Other causes as in the non-pregnant patient
The college has actually only asked for two causes.
The list of causes generated by the college, however, is impressive.
1) Amniotic fluid embolism
Two features: DIC and right heart failure with cyanosis
2) Pulmonary embolism
Two features: increased A-a gradient and right heart strain on ECG
The belowmentioned article gives a list which looks a little like this:
- tocolytic therapy resulting in pulmonary oedema
- blood transfusion reaction
- fluid overload
The college would add:
- peripartum cardiomyopathy
- air embolism
To this list, I would add:
- High epidural with motor block of respiratory muscles
- Excessive peripartum opiate use
|Cause||Cardinal features and brief discussion|
|High epidural/spinal block||
|Amniotic fluid embolism||
|Pre-eclampsia leading to pulmonary oedema||
|Tocolytic-associated pulmonary oedema||
(also known as Hamman's syndrome)
|Accidental magnesium overdose||
|Causes which are not unique to pregnancy, but which commonly co-exist with pregnancy|
|Peripartum opiate use||
Karetzky, Monroe, and Maria Ramirez. "Acute respiratory failure in pregnancy: an analysis of 19 cases." Medicine 77.1 (1998): 41-49. - this is a bit of a "royal sampler" of different causes of respiratory failure.
Chapter 64 (pp. 684) General obstetric emergencies by Winnie TP Wan and Tony Gin
Chapter 65 (pp. 692) Severe pre-existing disease in pregnancy by Jeremy P Campbell and Steve M Yentis
Lapinsky, Stephen E. "Acute respiratory failure in pregnancy." Obstetric Medicine: The Medicine of Pregnancy 8.3 (2015): 126-132.
Samanta, Sukhen, J. Wig, and A. K. Baronia. "How safe is the prone position in acute respiratory distress syndrome at late pregnancy?." (2014).
Rubal, Bernard J., et al. "The'mill-wheel'murmur and computed tomography of intracardiac air emboli." Journal of the American Association for Laboratory Animal Science 48.3 (2009): 300-302.
Lifschultz, Barry D., and Edmund R. Donoghue. "Air embolism during intercourse in pregnancy." Journal of Forensic Science 28.4 (1983): 1021-1022.
Balkan, M. Erkan, and Göknur Alver. "Spontaneous pneumomediastinum in 3rd trimester of pregnancy." Annals of thoracic and cardiovascular surgery 12.5 (2006): 362.
Jain, Vikyath. "Acute respiratory distress syndrome, Respiratory failure, Pregnancy." ACUTE RESPIRATORY DISTRESS SYNDROME IN PREGNANCY 7540 (2015).
Robinson, Julian N., et al. "Inhaled nitric oxide therapy in pregnancy complicated by pulmonary hypertension." American journal of obstetrics and gynecology 180.4 (1999): 1045-1046.