Was it really a bupivacaine toxicity?

Abstract

Regional anaesthetic techniques have potential risks of complications due to technique and local anaesthetic solutions. We present a case of spinal anaesthesia complication in a patient with incomplete right bundle branch blockade (RBBB) who had been scheduled for inguinal hernia operation. Subarachnoidal puncture was performed from 13-4 interspace at the first attempt and 3 ml 0.5% bupivacaine solution was injected intrathecally without any complication in our patient. Eleven minutes after injection and a few minutes after initiation of surgery a deep bradycardia (10 bpm) occurred and followed by generalised convulsions. Convulsions and bradycardia were controlled with thiopentone sodium and atropine and this period of bradycardia took approximately 7 minutes. The anaesthesia level was observed at T10 and T8 before and after this period, respectively. Thereafter, operation was completed under spinal anaesthesia and without any additional complication. Clinical presentation of our case mimics systemic toxic reaction as a result of rapid absorption of local anaesthetic solution to the systemic circulation. In spite of possible low plasma concentration of bupivacaine, the perexistance of incomplete RBBB in our patient may be the reason which facilitating the cardiac toxic symptoms, bradycardia, before convulsions. In conclusion; anaesthesiologists have to be aware of that delayed bupivacaine toxicity may occur after nontraumatic spinal anaesthesia, possibly because of the vascular absorption of the local anaesthetic drug, even in small doses especially in susceptible patients.