The Influence of Varying Dose and Lockout Interval on Patient-controlled Analgesia Using Meperidine. |
Chang Sung Kim, Jong Ho Choi, Jae Yong Shim, Keon Hee Ryu, Yoon Ki Lee, Dong Wook Kim, Cheol Joo Park, Sung Nyeon Kim |
Department of Anesthesiology, Catholic University Medical College, Seoul, Korea. |
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Abstract |
BACKGROUND The lockout interval is a safe guard to prevent patients from taking additional dose before the full effect of the preceding dose. Therefore, it should correlate with the time-to-peak effect of the opioid selected. The time-to-peak effect of meperidine is known to be different from that of morphine and fentanyl. But there have been few reports about the influence of varying lockout interval on IV-PCA using meperidine. So we studied the influence of varying lockout interval with constant hourly maximum dose on IV-PCA using meperidine. METHODS This study included sixty patients undergoing low abdominal surgery under general anesthesia. After administration of initial dose of meperidine (0.5 mg/kg) they were randomly assigned to three groups according to the lockout interval; Group 1 (6-min lockout interval, 0.2 mg/kg bolus dose), Group 2 (9-min lockout interval, 0.3 mg/kg bolus dose), Group 3 (12-min lockout interval, 0.4 mg/kg bolus dose). We examined NRS pain score, sedation score, satisfaction score, PCA measurements and the incidence of side effects during 24 hours. RESULTS There were no significant differences in NRS pain score, sedation score, satisfaction score, the amount of meperidine consumed, injections/attempts ratio and the incidence of side effects among three groups. The numbers of injections and attempts were significantly higher in Group 1 than in Group 2 and Group 3 (P<0.05). CONCLUSIONS The lockout intervals chosen for this study (6-min, 9-min, 12-min) do not influence pain, side effects, satisfaction and meperidine consumption in IV-PCA using meperidine when hourly maximum dose is constantly 2 mg/kg. |
Key Words:
Analgesia: patient-controlled; lockout interval; Analgesics: meperidine; Pain: postoperative |
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