Hypotension Following Spinal Anesthesia

Overview

Spinal anesthesia is less complicated then epidural anesthesia. However, spinal anesthesia by itself can also cause complications if not monitored or managed carefully. Addition of opioids provides longer analgesic effect postoperatively however it carries a higher risk of respiratory depression. The most important complication to look out for in spinal anesthesia is hypotension. Hypotension can be due to autonomic sympathetic blockage especially if the level of block is above T10. The reason behind the spinal anesthesia-induced hypotension is due to an increased venous capacity because of sympathectomy causing vasodilation in the lower part of the body. Together with higher-level spinal block inhibit cardio accelerator fibers causing decrease heart rate and drop in cardiac output. A combination of low cardiac output and decreased systemic vascular resistance increase the risk of hypotension after spinal anesthesia. It can be worsened even more if the patient is hypovolemic and has underlying cardiovascular disease. However, there are ways to counter the complications such as administering intravenous fluids, giving medications such as ephedrine, phenylephrine, and ondansetron or by leg compression.