CLINICAL-EFFICIENCY OF POSTOPERATIVE ANAL GESIA WITH IVPCA OR CONTINUOUS EPIDURAL ANALGESIA

3,207 patients were treated by the Acute Pain Service of the Clinic of Anaesthesiology, Johannes Gutenberg University Hospital Mainz, from J une 1992 to December 31, 1995. The data recorded during postoperative pain therapy by both nursing staff and physicians were evaluated. Pain therapy after major abdominal, retroperitoneal, peripheral-vascular s urgical interventions as well as after extremity and major joint surge ry consisted of i.v. patient-controlled analgesa (i.v.PCA) (1.5 mg/bol us piritramid, administration interval 10 mins) (n=1,813 or 56.5%) or of lumbar epidural analgesia (EDA) (n=1,181 or 36.8%) with patient; re ceiving continous infusions containing 0.06% bupivacaine + 0.0002% fen tanyl (75% of EDA patients) or 0.125% and 0.1875% bupivacaine, respect ively. In 6.7% (n=213) of patients other systemic or regional methods were used. A standardized management scheme was established and therap y was monitored by the nursing staff of the different surgical special ties according to the instructions of the Pain Service staff. A compar ison of the data recorded for both i.v.PCA and EDA was performed. The analysis of pain intensity showed pain intensity at rest to be signifi cantly lower in patients receiving continuous epidural analgesia than in the i.v. P(CA group-based on the individual relative frequency of r eported pain (> 40 of the Numeric rating scale 0-100). Patients receiv ing EDA reported significantly fewer pain events over a given 12-hour period. The differences in analgesic effectivity between the i.v. PCA and EDA group were clinically acceptable in the majority of cases. How ever, EDA was discontinued in 5.2% (n=61) of patients due to the occur rence of severe pain and in 1.3% (n=15) in the presence of disturbed m otor function, while therapy was discontinued for clinical reasons in only 0.7% (n=13) of patients from the i.v. PCA group. Changes in the r egimen, i.e. increased doses or additional analgesics were more freque ntly required in the EDA than in the i.v. PCA group. The frequency of events recorded in the postoperative period for the cardiovascular and respiratory system, the gastro-intestinal tract and the CNS demonstra tes that the administration of extremely potent drugs for the manageme nt of pain is associated with a large number of potential risk factors . The majority of events was not related to the pain management. Caref ul monitoring is therefore required to avoid the occurrence of complic ations as a result of pain management. Life-threatening events, in par ticular respiratory depression due to the administration of naloxone, did not occur in any of the 2,600 patients receiving opioid with i.v.P CA or epidural infusions. The evalution of the recorded data showed th at both i.v. PCA and lumbar EDA are highly effective as well as safe m ethods for postoperative analgesia. The in-depth analysis revealed tha t a number of events, i.e. hypertension, tachycardia, sedation, SaO(2) less than or equal to 92%, and nausea occurred significantly more oft en in the i.v. PCA than in the EDA group. Furthermore, hypertension an d tachycardia, were observed relatively more frequently in ASA Class I II and IV patients of the i.v. PCA group. The difference was less mark ed regarding an increase in SaO(2) (less than or equal to 92%) or seda tion. This finding is supported by the assessment of the relative risk (odds ratio) in the i.v. PCA group compared to patients receiving EDA . The influence of pain management on perioperative morbidity in sever ely compromised patients can thus not be excluded. The analysis of eve nts occurring as a result of pain therapy confirms the need for routin e measurement of these events as part of everyday clinical practice to allow an accurate assessment of the quality of pain management. Monit oring of pain therapy therefore needs to include consideration of a nu mber of factors in addition to the assessment of pain intensity to pro vide adequate information on factors exerting an influence on morbidit y, e.g. hypertension, tachycardia, sedation and episodes of hypoxaemia . The multivariance analysis of factors influencing the occurrence of hypertension clearly demonstrates that previous illness, pain, the met hod of pain management and the extent of the surgical intervention acq uire a different degree of importance. The data obtained by the presen t study suggest the EDA could be the method of choice in high-risk pat ients undergoing major surgery.