The Effects of Epidural Injection of Local Anesthetic on Pulmonary Function Tests of the Patients with the Upper Abdominal Operation

Shin, Woo Jong; Seung, Ik Sang

Abstract

In addition to premedicants, adjuvants and inhalation of dried anesthetic gas mixture during anesthesia, pain after upper abdominal operation may cause obtundation of cough reflex, limitation of lung function, and decreased movement of respiratory cilia, resulting in postoperative pulmonary complications such as pneumonia and atelectasis. Epidural injection of local anesthetic may produce enough analgesic action without depression of pulmonary function for the majority of upper abdominal surgery cases, while intramuscular injection of analgesic which has been applied for postoperative pain relief might cause depression of pulmonary function and increase of mortality and morbidity of pulmonary complications. This study was designed to compare the effects of above two pain-relief methods on pulmonary function at the postoperative 24 hour and 44 adult patients who have been operated in upper abdomen which were allocated randomly with either epidural injection group (10 of male, 9 of female) or intramuscular injection group (17 of male, 8 of female). The results were as follows; 1) All patients have markedly decreased pulmonary function in the preoperative period, comparing with the predictive values. 2) The results of postoperative pulmonary function test of all patients in intramuscular injection group was similar to the results of preoperative pulmonay function test and not improved. 3) Patients in epidural injection group have markedly improved in nearly all pulmonary functions after operation. The degree of improvement was increased in order as following; MEF50> MEF75> IRV (or TV)> FEV1/FVC. And there was no difference of results between male and female. 4) Vital capacity in epidural injection group was increased to about 25~42% from the preoperative period, while it was decreased to about 22~29% in intramuscular injection group. With the above results, we suggest that single or continuous epidural injection of local anesthetic will be an appropriate way of postoperative pain-relief methods, especially in the patients who has markedly decreased pulmonary function and upper abdominal surgery.