Effects of patient-controlled upper and lower epidural analgesias on postoperative respiratory and circulatory...

OBJECTIVE: To compare the effects of patient-controlled high thoracic epidural analgesia (PCHEA) and low thoracic epidural analgesia (PCLEA) on respiratory and circulatory functions after operation. METHODS: Thirty-six patients were divided into 2 groups with 18 in each, and one group (Group H) received PCHEA during thoracic operations and the other (Group L) received PCLEA during abdominal operations. Postoperative patient-controlled analgesia (PCA) was performed in all the patients with 0.125% bupivacaine and 0.01% morphine delivered through the same epidural space for PCHEA or PCLEA. RESULTS: Postoperative analgesia did not produce significant differences in the respiration rate (Rr), tidal volume (Vt), vital capacity (VC) and oxygen saturation (SpO2) between the groups, but in both groups, Vt and VC were significantly improved compared with those before starting patient-controlled epidural analgesia (PECA) (P<0.01). In group H, its effects on systolic and diastolic blood pressure and heart rate were more obvious than in group L (P<0.05), and both groups showed these improvements after PCA started(P<0.01). CONCLUSION: PCHEA shows more marked effects on the respiratory and circulatory functions of the patients, which may mainly result from its blocking the cardiac sympathetic nerves. PCEA is able to improve postoperative respiratory function but both PCHEA and PCLEA necessitate individual-based adjustment of the PCA pump for the safety of the patient.