Does Spinal Anesthesia Affect Cerebral Oxygenation During Transurethral Prostatectomy?

Background and ObjectivesTransurethral resection of the prostate (TURP) is associated with the unique complication of transurethral resection of prostate syndrome (TURS), which is attributed to the absorption of irrigating fluid. This study was initiated to investigate the effects of spinal anesthesia and TURP on cerebral oxygen balance.MethodsThirty patients scheduled for TURP were included. Jugular bulb oxygen saturation (SjbO2) was measured via retrograde cannulation of jugular venous bulb. Spinal anesthesia was initiated by 3 mL hyperbaric 0.5% bupivacaine injected at L3-L4 in the sitting position, producing a block to the T10 dermatome. Hemodynamic measurements and arterial and jugular bulb blood gasometry were performed before and after spinal anesthesia, throughout surgery, and during the postoperative period.ResultsA significant decrease of cerebral perfusion pressure after spinal anesthesia was accompanied by a significant decrease of SjbO2 below a preoperative value of 61% ± 1. Eight patients developed yawning, irritability, restlessness, and nausea toward the end of surgery, and these were considered to be early signs of TURS. These patients demonstrated SjbO2 below 55% and 50% in 63% and 42% of respective data set points.ConclusionThe neurologic symptoms in patients undergoing TURP during spinal anesthesia might not only be caused by absorption of irrigating fluid but also by impairment of cerebral oxygenation.