Intraarticular morphine after arthroscopic ACL reconstruction: a double-blind placebo-controlled study of 40 patients.

We compared analgesic effects and pharmacokinetics of intraarticular versus intravenous administration of morphine after arthroscopic anterior cruciate ligament surgery. In a double-blind placebo-controlled study, 40 patients were randomly allocated to one of four treatment groups. Group I received 1 mg morphine intraarticularly and saline intravenously; group II received 5 mg morphine intraarticularly and saline intravenously; group III received 5 mg saline intraarticularly and morphine intravenously and group IV, the control group, received saline both intraarticularly and intravenously. The pain scores were significantly lower in groups I and II at 24 hours postoperatively than in group IV, and in group II during the rest of the postoperative period, as compared to groups III and IV. After intraarticular injection of 1 mg and 5 mg morphine, respectively, low concentrations of morphine-6-glucuronide (M6G) were found in the circulation, while morphine-3-glucuronide (M3G) appeared late after the injection in concentrations that considerably exceeded those of morphine in groups I and II. The analgesic effect of intraarticular morphine together with the low levels of morphine and morphine-6-glucuronide in plasma further strengthens the view that opioids have a peripheral mechanism of action.

Analgesic effects of intra-articular morphine during and after knee arthroscopy: a comparison of two methods.

The objective of this study was to compare the analgesic effects of intra-articularly administered bupivacaine with bupivacaine/morphine during and after therapeutic knee arthroscopy. In a prospective, randomized study, 50 patients with clinical signs of medial meniscal injury were allocated to two groups, A and B. The patients in group A received 40 mL of 0.25% bupivacaine while the same dose of bupivacaine combined with 1 mg of morphine sulphate was administered in group B. Pain was estimated using the visual analogue scale (VAS) during surgery and at 2, 4, 6, and 24 hours after the operation was completed. Supplementary analgesic requirements were also registered, as well as the patients' overall rating of the entire procedure. The pain scores were significantly lower in Group B throughout the whole postoperative observation period. However, no significant differences were found between the two groups in terms of intraoperative pain scores, supplementary analgesic requirements, or the overall rating of the procedure. This study provides evidence that arthroscopic surgery can be performed in a safe manner after intra-articularly administered bupivacaine with or without low-dose morphine. The combination of low-dose morphine and bupivacaine did, however, produce a superior postoperative analgesic effect during the 24 hours following knee arthroscopy compared with bupivacaine alone.

Postoperative analgesic effects of an external cooling system and intra-articular bupivacaine/morphine after arthroscopic cruciate ligament surgery.

The aim of this study was to evaluate the analgesic effect of an external cooling system with or without the combined effect of intra-articularly administered bupivacaine/morphine after arthroscopic anterior cruciate ligament (ACL) reconstruction. Fifty patients with isolated ACL insufficiency operated on under general anaesthesia were randomized to three different postoperative treatment groups. Group I was treated with the cooling system during the first 24 h after surgery and an intra-articular injection of 20 ml of physiological saline given at the completion of surgery; in group II, the cooling system was combined with an intra-articular injection of 20 ml bupivacaine 3.75 mg/ml and 1 mg of morphine at the end of the operation; while group III (placebo group) received an intra-articular injection of 20 ml of physiological saline at the completion of surgery. Pain was assessed using a visual analogue scale (VAS) at 1, 2, 4, 6, 24 and 48 h postoperatively. Supplementary analgesic requirements were registered. In group I 80% (16/20) and in group II 90% (18/20) of the patients were satisfied with the postoperative pain control regimen (NS). This was significantly better than in group III, where 30% (3/10) were satisfied. The pain scores were significantly lower in the two treatment groups compared with the placebo group during the entire postoperative period. The pain score was significantly lower in group II than in group I at 24 and 48 h after surgery. The supplementary analgesic requirements were also lower in the two treatment groups compared with the placebo group. No complications due to the use of the cooling system or the intra-articular injections of bupivacaine/morphine were observed. The external cooling system used in this study provides an effective method of obtaining pain relief after arthroscopic surgery. The combination with an intra-articular injection of morphine and bupivacaine results in a slightly greater analgesic effect than the cooling system alone.

Postoperative analgesic effects of intra-articular bupivacaine and morphine after arthroscopic cruciate ligament surgery.

Intra-articular administration of local anaesthetics such as bupivacaine can produce short-term postoperative analgesia in patients undergoing diagnostic arthroscopy or arthroscopic meniscectomy. A peripheral anti-nociceptive effect may also be induced by the administration of intra-articular opiates interacting with local opioid receptors in inflamed peripheral tissue. In the present study we aimed to study the analgesic effects of intra-articularly given bupivacaine and morphine sulphate (as well as the combination of both drugs) on postoperative pain. In a prospective, randomized, double-blind manner 40 patients received one of the following: (a) morphine (1 mg in 20 ml NaCl), (b) bupivacaine (20 ml, 0.375%), (c) combination of both or (d) saline (20 ml, control group) intra-articularly at the end of arthroscopic anterior cruciate ligament (ACL) reconstruction. The postoperative pain was assessed via a visual analogue scale (VAS) during the first 48 h after surgery, and supplemental analgesic requirements were noted. All comparisons were made versus the control group receiving saline. The pain scores were significantly lower in the morphine group at 24 and 48 h, and in the bupivacaine group at 2, 4 and 6 h after surgery. In the group that received a combination of both bupivacaine and morphine, the pain scores were significantly reduced throughout the whole postoperative observation period. No side-effects or complications from therapy were seen in any of the groups. The conclusion of this study is that intra-articular morphine is effective in the postoperative period after arthroscopic ACL reconstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic effects in dogs of nitrous oxide-meperidine and meperidine, respectively, in comparison with nitrous oxide.

The aim of this investigation on dogs, was to examine the hemodynamic effects of nitrous oxide (N2O) plus meperidine and of meperidine with room air ventilation, respectively, compared with those of N2O on its own. When meperidine (bolus dose 3 mg.kg-1 and continued infusion 4 mg.kg-1.h-1) was added to 80% N2O, mean arterial blood pressure fell from about 20 to 10 kPa (150 to 75 mmHg), as a result of a decrease in peripheral vascular resistance, but no compensatory changes in cardiac output were seen. When N2O was withdrawn, during continued meperidine infusion, cardiac output and stroke volume increased, while peripheral resistance remained low. Coronary vasodilation was noted when meperidine was added to N2O, and persisted when N2O was withdrawn. In the pulmonary circulation a different response was found. Here, no effects were observed when meperidine was added to N2O, while pressure and resistance decreased when N2O was withdrawn and meperidine continued.

Carnitine in maternal and neonatal plasma.

Total plasma carnitine was analysed in 19 women, with uncomplicated pregnancies, who underwent elective caesarean section, and in their neonates. The women were given a balanced glucose (glucose group) or saline (saline group) infusion, group allocation being on a random basis. The carnitine levels in maternal or infant plasma did not differ between these two groups. At delivery, the mean maternal carnitine value, 17.4 +/- 1.25 mumol/l, was lower than the mean infant value, 25.9 mumol/l +/- 2.67 (mean +/- SE, p less than 0.005) and lower than the mean value in non-pregnant, fertile women, i.e. 40.9 +/- 1.22 mumol/l. The mean carnitine value in the unfed neonate had not changed when the infant was 4 hours old. A positive correlation was found between carnitine levels in maternal and infant plasma (p less than 0.01). At delivery, the levels of non-esterified fatty acids and 3-OH-butyrate in infant plasma were different in the two groups, but not at 4 hours of age. The results suggest that the maternal carnitine level is the most important factor governing plasma carnitine levels in the neonate.

Maternal haemodynamic changes during caesarean section: a comparison of epidural and general anaesthesia.

Haemodynamic measurements were performed on 20 healthy women before and during elective caesarean section under epidural (10 women) or general anaesthesia (10 women). The influence of the two anaesthetic techniques on the haemodynamic changes associated with operative delivery was compared. The following haemodynamic variables were studied: cardiac output (CO), stroke volume (SV) determined non-invasively with impedance cardiography, heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), pulse pressure, mean arterial pressure (MAP) and total peripheral vascular resistance (TPR). During epidural anaesthesia, SV was largely unchanged before delivery but increased (P less than 0.05) following delivery. However, CO increased (P less than 0.05) prior to delivery due to an increase (P less than 0.01) in HR. A further increase (P less than 0.05) in CO was recorded following delivery. SBP, DBP, MAP and TPR decreased (P less than 0.01) during epidural anaesthesia. In the patients undergoing general anaesthesia, SV decreased (P less than 0.05) prior to delivery. However, CO remained largely unchanged due to an increase (P less than 0.01) in HR. Following delivery, CO (P less than 0.05) and SV (P less than 0.01) increased whereas HR decreased (P less than 0.01). SBP, DBP and MAP increased (P less than 0.01) prior to delivery, returning to the same level as prior to induction of anaesthesia following delivery. TPR was largely unchanged prior to delivery but decreased (P less than 0.01) following delivery.