[Indomethacin enema in treatment of postoperative pain after knee arthrotomy. A double-blind controlled trial]. / Indometacin-klysma til behandling af postoperative smerter efter knaeartrotomi. En dobbeltblind kontrolleret undersøgelse.

Twenty-three patients subjected to arthrotomy of the knee were in a double-blind trial randomly allocated to either: 1) Indomethacin 100 mg (Confortid) administered as an enema immediately before induction of anaesthesia and repeated morning and evening for the next two days, or: b) a placebo. The patients' demand for postoperative pain treatment were registered. Survival analysis was applied to the time passed from recovery from anaesthesia until patients first asked for postoperative pain treatment. A significant difference was found (p less than 0.05). The indomethacin treated group required significantly less postoperative pain treatment than did the placebo group. 36% of the patients in the indomethacin group had no additional pain treatment during the two days of observation. Indomethacin as an enema proved to be an easy and effective way of reducing postoperative pain.

Prophylactic ephedrine during spinal anaesthesia: double-blind study in patients in ASA groups I-III.

Forty-eight patients scheduled to undergo spinal anaesthesia were allocated to three groups of 16 each according to ASA classification I-II-III. Each patient received a fluid load of 7 ml kg-1 and either ephedrine 12.5 mg i.v. and 37.5 mg i.m., or placebo. Twelve patients in the placebo groups developed a maximal decrease in mean arterial pressure exceeding 20%. Five of these (one in ASA II and four in ASA III) developed a decrease exceeding 33% and required treatment. In ASA risk group III, all patients in the placebo group had a decrease in mean arterial pressure exceeding 20%; in 50% of these patients, the decrease exceeded 33%. We conclude that prophylactic ephedrine is desirable for spinal anaesthesia, especially in ASA III patients.

Prediction of severe postoperative complications in patients admitted to neuroanaesthesia.

The purpose of this study was to identify factors which will predict the risk of severe postoperative complications in individual patients in a neurosurgical unit. Eleven risk factors were investigated in 363 neurosurgical patients, of whom 40 (11%) developed postoperative complications requiring mechanical ventilation for more than 24 h in an intensive care unit, 16 were found to be severely disabled or in a vegetative state at follow-up 1 month after admission, and 28 patients died. By applying stepwise, logistic regression analysis to the patient's data, we were able to select two significant risk variables, i.e. the Glasgow Coma Scale (GCS) 8 or less preoperatively and emergency anaesthesia. The presence of GCS 8 or less on the consciousness scale was associated with postoperative complications in approximately 40% of the cases. Emergency patients with severe neurological damage had the greatest risk of postoperative complications (93%). Fatal outcome for patients with postoperative complications was seen in 40% of the cases.

Buprenorphine antagonism of ventilatory depression following fentanyl anaesthesia.

In order to compare the effect of buprenorphine and naloxone on respiratory depression after fentanyl anaesthesia (25 micrograms/kg), 32 women scheduled for elective abdominal hysterectomy participated in a double-blind randomized investigation. At termination of anaesthesia, after antagonizing residual neuromuscular blockade, 20 normocapnic patients with a respiratory rate of 4 breaths/min or less entered the study, receiving either buprenorphine (0.6 mg in 20 ml NaCl) or naloxone (0.4 mg in 20 ml NaCl) 2 ml/min until 20 ml was given or until the respiratory rate exceeded 8 breaths/min. Respiratory rate, PaCO2, sedation score, and pain intensity were evaluated during a 3-h study period. Fifteen min after beginning the treatment, all the patients in both groups had their ventilatory depression antagonized. There were no statistically significant differences in respiratory rates between groups except at 15 min. On no occasion did either PaCO2 or a sedation score differ statistically significantly between the groups. At 15 min all patients in the buprenorphine group had no or mild pain, compared to the patients in the naloxone group, of whom 50% had moderate to severe pain (P less than 0.05). It seems as if buprenorphine is as effective as naloxone in antagonizing respiratory rate depression following fentanyl anaesthesia.

Peroperative buprenorphine: do high dosages shorten analgesia postoperatively?

Fifty-two patients undergoing biliary surgery were investigated in a prospective randomized study, in which they received buprenorphine 10, 20, 30, and 40 micrograms X kg-1, respectively, as sole intravenous analgesic as a bolus 15 min before induction of anaesthesia. The anaesthetic was uneventful in all four groups, although when receiving 10 and 20 micrograms X kg-1 almost two-thirds of the patients needed supplemental analgesics during the operation. When receiving buprenorphine in the dosage of 30 and 40 micrograms X kg-1, 50% of the patients requested an analgesic within 5 min of extubation. In contrast, when receiving 10 and 20 micrograms X kg-1 none of the patients requested an analgesic within 1 h of the operation. These findings accord to a certain extent with the presence of a bell-shaped dose-response curve for buprenorphine in humans.

Comparison of oral controlled release morphine and epidural morphine in the management of postoperative pain.

Oral controlled release morphine (CRM) was compared in a double-blind study with epidural morphine (EM) for postoperative pain relief in 20 patients undergoing knee arthrotomy under epidural anesthesia. Ten patients received 30 mg CRM orally and saline epidurally (CRM group), and ten patients received placebo tablets orally and 4 mg morphine epidurally (EM group), both at the time of skin incision and then every 8 hr for 48 hr during which patients evaluated pain intensity using a visual analog scale. Nine of the ten patients in the EM group had good relief of pain throughout the study period. Seven of the ten patients in the CRM group needed rescue analgesics within 6 hr of the initiation of the study (P less than 0.01). We conclude that CRM is not suitable for the control of early postoperative pain, whereas epidural morphine is excellent.

Postoperative pain relief with naloxone. Severe respiratory depression and pain after high dose buprenorphine.

Buprenorphine 30 and 40 micrograms/kg was given as the sole intravenous analgesic in balanced anaesthesia to 12 patients undergoing cholecystectomy. Significant and severe respiratory depression was found 15 minutes after preoperative loading with buprenorphine. In the immediate postoperative period six patients were in pain. They were treated with naloxone 0.08-0.4 mg leading to a long lasting period of pain relief (median 22 hours).

Sublingual buprenorphine for premedication and postoperative pain relief in orthopaedic surgery.

The effect of sublingual buprenorphine (Temgesic) as a premedicant and for postoperative pain relief compared with morphine/pethidine was studied in 50 patients scheduled for elective surgery of the knee joint. Twenty-five patients received buprenorphine 0.4 mg sublingually 1 h before surgery and the same dose on demand postoperatively. Twenty-five patients were given morphine intramuscularly (7.5 mg or 10 mg to females and males respectively) 1 h preoperatively. This group received pethidine (75 mg) intramuscularly on demand postoperatively. All the patients were anaesthetized with halothane N2O/O2 after induction with thiopentone. No significant differences were found with regard to sedation, dizziness, nausea and vomiting during the study period. Emergence shivering, confusion and restlessness just after termination of the operation were equal in the two groups. In the recovery room, however, there was a higher frequency of shivering (P less than 0.05) in the morphine group. During the first 24 h postoperatively the buprenorphine group was given an average of 3.8 doses compared with 2.3 in the pethidine group (P greater than 0.05). It is concluded, that buprenorphine sublingually is as good as morphine intramuscularly for premedication and therefore should be recommended to patients who wish to avoid injections. For postoperative pain relief the initial dose of buprenorphine should be given intravenously. Only minor and unimportant side effects were seen.

Peroral diazepam compared with parenteral morphine/scopolamine with regard to gastric content.

In a prospective study, 62 adult patients were studied with respect to the volume and pH of their gastric contents after receiving randomly one of three different premedications. One group received flunitrazepam 2 mg perorally on the night before operation and diazepam 0.2 mg per kg body weight perorally at 7.00 a.m. on the day of operation. The patients in the second group were given flunitrazepam 2 mg perorally the night before operation and morphine/scopolamine i.m. 1 h prior to operation. In the third group no flunitrazepam was given on the night before operation, and the patients were premedicated with morphine/scopolamine i.m. 1 h preoperatively. No statistically significant difference was found between the groups with respect to the volume and pH of gastric contents after induction of anaesthesia.

Catecholamine response to the clinical use of alpha adrenergic receptor blocking agents.

Treatment with alpha adrenergic receptor blocking agents has been used clinically for many years to obviate peripheral vasoconstriction in patients suffering from circulatory or thermoregulatory distress. Various reports indicating that administration of these agents may be followed by an increased plasma concentration of catecholamines, and subsequently an increased oxygen demand, led to 29 investigations on humans who were placed in a horizontal position in a thermoneutral environment and given 25 mg chlorpromazine intravenously, dissolved in 500 cc low molecular weight dextran. Blood pressure and heart rate remained unchanged during the infusions and significant changes in plasma noradrenaline (average fall: 4.42 nmol X 1(-1), range: -31.9- + 5.1) and in plasma adrenaline (average fall: 1.06 nmol X 1(-1), range: -16.3- + 5.11) were observed (P less than 0.01). The results indicate that as long as any baro-reflex activation of the sympathetic nervous system and acceleration of the nonshivering thermogenesis is avoided, the recommended treatment with alpha adrenergic receptor blocking agents can be performed without any increase in plasma concentration of catecholamines.

Impaired platelet aggregation and increased bleeding time during general anaesthesia with halothane.

A significant correlation was found between the inhibition produced by 1% halothane with nitrous oxide and oxygen on platelet aggregation in vitro and the increase in bleeding time during anaesthesia with halothane, nitrous oxide and oxygen in 10 patients. It is suggested that halothane in nitrous oxide with oxygen inhibits platelet aggregation in vivo and in vitro. The inhibition is not seen when platelet aggregation is studied in platelet-rich plasma from anaesthetized patients because the agents evaporate during preparation of platelet-rich plasma and during analysis in the aggregometer.

Human body temperature and controlled cold exposure during moderate and severe experimental alcohol-intoxication.

In an attempt to obtain more conclusive data, especially concerning the condition in many cases of very high alcohol concentration, two groups of healthy volunteers were exposed to controlled cold surroundings in a climate chamber after i.v. infusion of 96% ethyl alcohol, 1-2 1/2 ml per kg bodyweight, supplemented with alcohol perorally; the maximum blood alcohol concentration measured was 57 mmol/l, corresponding to 2.62%. One group was not habituated to drinking; the other group was habituated to heavy drinking, but functioned well socially. During the stay in a neutral environment, the alcohol infusion caused a rapid elevation of skin temperature with a short, but significant delay in temperature elevation in the alcohol-habituated group. After controlled exposure to cold, a rapid fall in surface temperature back to pre-alcoholic infusion values was seen in both groups. During cold exposure, core temperature remained unchanged in both groups. No changes in plasma catecholamines were found. A 12-18% increase in metabolic rate was seen in both groups during cold exposure, probably as an expression of the specific dynamic effect of alcohol. That the observed vasoconstriction was sufficient to prevent an undue fall in core temperature is further supported by the fact that neither shivering, nor non-shivering thermogenesis was activated, as no visible shivering occurred and no rise in plasma catecholamines was seen.

Carbamezepine poisoning, a surprisingly severe case.

A case of carbamazepine (Tegretol) poisoning is presented. The symptoms and signs were surprisingly severe after ingestion of only 10g. Treatment and unusual features of the case are discussed.