The use of continuous spinal anesthesia in high risk elderly patients undergoing lower abdominal or tower extremity surgery / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the feasibility and safety of using continuous spinal anesthesia (CSA) in high risk elderly patients undergoing lower abdominal or lower extremity surgery. Methods Sixty-four ASA III or IV patients aged 70-101 yr weighing 38-55 kg undergoing lower abdominal or lower extremity surgery were randomized to receive epidural anesthesia (EA) (n = 32) or CSA ( n = 32). The patients were complicated with cerebral embolism and/or hypertension, coronary artery disease and/or COPD and/or diabetes mellitus. The patients were unpremedicated. EA was performed at I2.3 or L1.2. A test dose of 2 ml of 2% lidocaine was given. When no signs of spinal block was observed, 1 % ropivacaine was given in small increments until the block height reached T6-8 . CSA was performed at L3,4 using Spinocath (B. Braun). A 2-cm catheter segment was left in subarachnoid space. 0.5% bupivacaine was given in 0.5 ml increments every 3 min until satisfactory block level was reached. The onset time of anesthesia was recorded. The degree of motor block was assessed using modified Bromage scale. Arterial blood samples were obtained before anesthesia (T0 , baseline), when satisfactory block level was reached ( T1), 1 h after skin incision (T2) and at the end of operation (T3) for determination of lactate concentration. The amount of ephedrine and innovar ( droperidol-fentanyl mixture) used during operation and the recovery of motor function of lower extremities were also recorded. Results The demographic data including sex, age, height, body weight, ASA physical status and types of operation were not significantly different between the two groups. BP and HR were significantly decreased after anesthesia as compared to the baseline values at T0 in group EA, whereas in CSA group there were no significant changes in BP and HR after anesthesia. Significantly more patients received ephedrine in EA group (98% ) than in CSA group (15%) and the mean dose of ephedrine was significantly higher in EA group [(34.5?3.1) mg] than in CSA group [(4.3?0.5) mg ]. The onset of block was significantly faster in CSA group than in EA group. Motor blockade was less intense in EA group as assessed by modified Bromage scale. Analgesia was more satisfactory in CSA group and less patients received innovar during operation in CSA group (20% ) than in EA group (51% ). The recovery of motor function of lower extremities was faster in CSA group than in EA group. Blood lactate was significantly higher at T1 , T2 , T3 in EA group than in CSA group. No late complications related to CSA was observed. Conclusion CSA is safe and effective and provides better analgesia with better hemodynamic stability and faster onset of block than EA in elderly patients.