Effects of low-dose naloxone on morphine analgesia and plasma leveb of opiold peptldes
- VernacularTitle:小剂量纳洛酮对术后吗啡静脉镇痛效果及血浆阿片肽浓度的影响
- Author:
Peng YAO
;
Lingxin MENG
;
Jianjun GUI
- Publication Type:Journal Article
- Keywords:
Morphine;
Naloxone;
Analgesia;
Pain,postoperative;
Opioid peptides
- From:
Chinese Journal of Anesthesiology
1996;0(07):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective Low-dose naloxone has been shown to reduce side-effects of morphine while morphine analgesia is not antagonized and may even be enhanced. The purpose of this study was to evaluate the effects of low-dose naloxone infusion (50 ng? kg-1? h-1 ) on morphine analgesia and plasma levels of opioid peptides in patients after abdominal hysterectomy.Methods Forty-two ASA Ⅰ- Ⅱ patients aged 36-50 yrs, weighing 55-67 kg undergoing abdominal hysterectomy under combined spinal-epidural anesthesia were enrolled in this study. Spinal puncture was performed at L2-3 interspace. The patients received intrathecal 0.75% ropivacaine 2.0-2.6 ml. 2% lidocaine was used for epidural injection. The block height was maintained at T8-6 . For postoperative analgesia the patients were randomized to receive either intravenous morphine infusion at 10 ?g?kg-1 ?h-1 (group M, n = 21) or IV morphine infusion (10 ?g?kg-1?h-1)+ naloxone infusion at 50 ng?kg-1?h-1 (group MN, n = 21). Pain was assessed using VAS (0-10) with 0 representing no pain and 10 representing the worst possible pain. Blood samples were taken from peripheral vein before anesthesia (T0), at the end of surgery (T1) and at 6, 24, 48 h (T2,3,4) after operation for determination of plasma levels of ?-endorphin (?-EP), dynorphin A1-13 (Dyn) and leu-enkepholin (L-EK) .Results The patients were comparable with respect to, age, weight, occupation and duration of operation between the two groups. Two patients (1 patient in each group) were excluded from the study because of their refusal to have repeated blood samples taken. The analgesia was significantly better in group MN than that in group M in terms of VAS scores. Plasma level of ?-EP was significantly lower at 6 h after operation (T2 ) but significantly higher at 24 h postop. (T3 ) in group MN compared with that in group M ( P
