What is A 30 year old woman with coarctation of aorta is admitted to the labour room for elective caesarean section. Which of the following is the anaesthesia technique of choice - and explain in detail?
Ans. is 'c' i.e., General anaesthesia In coarctation of Aorta, Aorta narrows anywhere along its course.The most common site for coarctation of Aorta isJust distal to origin of left subclavian arteryNear the insertion of ligamentum arteriosusSo, the common clinical presentation in coarctation of Aorta isHypotension, ischemia, distal to the obstruction, (circulation is usually diminished in abdominal organs and pulses are absent in lower extremities)Hypertension proximal to the site of obstruction (the B.P. in upper extremities and head and neck is increased)Effect of coarctation of Aorta on Pregnancy.Coarctation of Aorta may lead to compromise of placental circulation, because the placental circulation is derived from uterine artery, which is a branch of internal iliac artery (all the vessels originating distal to coarctation will have diminished perfusion)So, the fetal circulation is in a compromised state in coarctation of Aorta.Anaesthetic considerations that should be taken into account in case of coarctation of Aorta.In coarctation of Aorta, am decrease in cardiac output or cardiac return is deleterious to the fetus because the placental circulation is already compromised on account of coarctation.So any anaesthetic procedure or drug which causes hypotension should be avoided in these patients.Regional anaesthetic procedures such as spinal anaesthesia and epidural anaesthesia should be avoided in these patients because hypotension is the most common side effect of these procedures. The consequence of decreased venous return and decreased systemic vascular resistance as a result of these procedures would be hazardous to the patientGeneral anaesthesia is the preferred technique for performing ceasarean section in a patient with coarctation of Aorta as it has the advantage ofmore rapid inductionless hypotensionbetter airway and ventilation.Here are the quoted lines from an internet site further supporting our answerUncorrected coarctation is rare in pregnancy but when present tends to be exacerbated by normal physiologic changes with fixed aortic outflow obstruction and distal hypoperfusion. These patients are at increased risk of left ventricular failure, aortic dissection and rupture, endocarditis and cerebrovascular accident. Anesthetic goals should center on maintaining normal to slightly elevated SVR and heart rate and adequate preload. Regional anesthesia is relatively contraindicated. General anesthesia is the preferred technique for cesarean section with invasive hemodynamic monitoring with post ductal intraarterial catheter, CVP or PA catheters to guide fluid administration and to assess left ventricular function and use of ephedrine and dopamine as vasopressors of choice.