Delayed Onset of Spinal Anesthesia in a Chronic Opioid User Undergoing Cesarean Section.

Delayed onset of spinal anesthesia can pose challenges during cesarean section (CS) in patients with a history of chronic opioid use. We present a case of delayed onset of spinal anesthesia in a patient with chronic opioid use undergoing CS, highlighting the clinical implications and management strategies. Delayed onset of spinal anesthesia in chronic opioid users can result from neurophysiological adaptations and pharmacokinetic interactions in the central nervous system. Previous studies have suggested chronic opioid users display a delayed onset and shorter duration of action of neuraxial blockade. This can have great implications in pregnant women who require anesthesia for CS. Delayed onset can lead to misconception of a failed spinal block and conversion to general anesthesia. In reality, additional time may be needed for the block to rise to an adequate level. Additionally, delayed time to incision can lead to poor outcomes for the mother and baby in urgent scenarios. When providing anesthesia for chronic opioid users undergoing CS, it is important to understand the possibility of delayed onset of neuraxial blockade which can impact patient care.