Perioperative myocardial ischaemia in patients undergoing surgery for fractured hip randomized to incremental spinal, single-dose spinal or general anaesthesia

Abstract

Quantitative assessment of myocardial ischaemia during incremental spinal, single-dose spinal and general anaesthesia may provide guidelines for the choice of anaesthetic technique for osteosynthesis of hip fractures in the elderly atherosclerotic individual. Forty-three patients with coronary artery disease were allocated to receive either incremental spinal anaesthesia (bupivacaine 0.5% plain) (A), single-dose spinal anaesthesia (2.5 mL of bupivacaine 0.5% plain) (B) or general anaesthesia (fentanyl, thiopentone, atracurium, enflurane, N2O/O2) (C) for hip surgery. ST segment monitoring was performed from the induction of anaesthesia and for the following 48 h, and perioperative hypotension, blood loss and fluid therapy were recorded. ST depression developed in two out of 14 (A), seven out of 15 (B) and six out of 14 (C) patients (P = 0.14). In (A), a total of seven ST depressions occurred in the observation period as opposed to 125 in (B) and 16 in (C) (P < 0.05). Intra-operative ST depression only occurred in (B). Three (A), 33 (B) and 40 (C) hypotensive events were recorded (P < 0.002). Altogether, 56% of hypotensive patients developed ST depression compared with 10% of normotensive patients (P < 0.003). In (A), 1.6 mL of 0.5% bupivacaine were used as opposed to the fixed 2.5 mL dose in (B) (P < 0.001). In the first post-operative week, mortality was higher in (B) (P < 0.05) but, after 1 month, there was no significant difference in mortality between the three groups. The incidence of hypotension and myocardial ischaemia was lowest in the group receiving incremental spinal anaesthesia.