Effect of preoperative oral dextromethorphan on immediate and late postoperative pain and hyperalgesia after total abdominal hysterectomy.

Dextromethorphan is a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist known to inhibit wind-up and NMDA-mediated nociceptive responses of dorsal horn neurons. Experimental and clinical studies indicate that NMDA-receptor antagonists may potentiate the effect of analgesics such as morphine, local anesthetics and NSAIDs. Results from previous clinical studies of dextromethorphan in postoperative pain are conflicting, possibly related to administration of insufficient doses of the drug. Fifty patients scheduled for non-malignant elective abdominal hysterectomy in general anesthesia were randomized to receive oral dextromethorphan 150 mg, or placebo 1 h before surgery. The patients received patient-controlled analgesia with morphine for 24 h postoperatively as the only analgesic. Patient-controlled analgesia (PCA) morphine consumption was reduced with 30% from 0-4 h after operation in patients receiving dextromethorphan compared with placebo (P=0.02); no differences were observed from 5-24 h postoperatively. There were no significant differences between groups for visual analogue scale scores at rest, during cough, or during mobilization, pressure pain detection thresholds, von Frey hair pain detection thresholds, or peak flow. At 24 h after operation, hyperalgesia to von Frey hair stimulation proximal to the surgical wound was easily detected in 23 of 25 patients receiving dextromethorphan, and in 22 of 25 patients receiving placebo, with no significant difference between groups. Pooled data from both groups showed a weak but significant correlation between the extent of hyperalgesia at 24 h after operation, and total 24 h postoperative PCA morphine consumption (Rs=0.28, P=0.05). Three months postoperatively, hyperalgesia was still detectable in 18 of 22 examined patients in the dextromethorphan group, and in 16 of 23 patients in the placebo group, without statistical differences between groups. There were no significant differences in side-effects (nausea, vomiting, sedation). In conclusion, oral dextromethorphan 150 mg reduced PCA morphine consumption immediately (0-4 h) after hysterectomy, without prolonged effects on pain or wound hyperalgesia. A positive correlation between the magnitude of wound hyperalgesia at 24 h after operation, and total 24 h postoperative PCA morphine consumption was demonstrated.

[Inguinal paravascular block (3-in-1 block)]. / Den ingvinale paravaskulaere blokade ("3-i-1" blok).

The three main nerves from the lumbar plexus may be blocked by injection of local anesthetic into the facial envelope of the femoral nerve ("three-in-one block"). The femoral nerve may be localized by obtaining paresthesia, by employing a nerve stimulator or by the loss of resistance technique. We prefer the use of a nerve stimulator. The "three-in-one block" may be employed for immediately pain relief of pain and for treatment of postoperative pain from fractures in the hip, femur and knee. Introduction of a catheter into the femoral nerve sheath is recommended to provide continuous block of the lumbar plexus for relief of postoperative pain.

Long- and short-term mortality rates in patients who primarily survive cardiac arrest compared with a normal population.

This is a follow-up study of 180 survivors after cardiac arrest outside intensive care and coronary care units. The follow-up extended over 0.5 to 8.5 years (averaged 4.3 years) after the primary cardiac arrest. Of the patients, 72 (40%) were discharged from hospital, 13 with anoxic brain damage. Thirty-ourred in 43% after 2 years, and in 50% after 3 years. After that time, the mortality was similar to that of a comparable normal population. At the end of the study, 34 patients were still alive, including eight with neurological sequelae. Their present cardiac function was satisfactory in the majority (59%) of the patients falling into group I or II of the American Heart Association classification. Their social situation, however, left much to be desired, as only 50% had fully or partly regained their previous level of activity.

Prevalence and prognostic significance of coma after cardiac arrest outside intensive care and coronary units.

In 181 patients resuscitated from cardiac arrest, the prevalence and duration of coma were registered and related to the site of occurrence of cardiac arrest, cardiac rhythm during arrest, age and clinical outcome of the patients. Coma was most frequent after cardiac arrest outside the hospital, as 84% of these patients were comatose for more than 1 h and 56% for more than 24 h; the corresponding values for patients with cardiac arrest in general wards were 63% and 30%, respectively, and for patients with cardiac arrest during ambulance transport, 80% and 44%. Permanent brain damage was extremely rare if the coma lasted less than 6 h (1 out of 62 patients), and relatively rare with a coma duration between 6 and 24 h (5 out of 34 patients). Of the patients, 85 remained comatose for more than 24 h and only 7 of them were discharged alive, all with cerebral impairment of a severity increasing with the duration of the coma. None regained consciousness after more than 7 days' coma, and a total of 80 patients died in coma, 20 with signs of cerebral death. Older patients were more vulnerable to coma than younger ones, but coma as such was not more frequent. We found no differences in coma after asystole and ventricular fibrillation. Problems concerning the selection of patients who have a chance of survival, although comatose after cardiac arrest, are discussed.

Prognosis after cardiac arrest occurring outside intensive care and coronary units.

Emergency calls to a total of 1686 patients with verified cardiac arrest in the University Hospital, Arhus, were made in the 8-year period 1969-1977. Among the patients, cardiac arrest occurred outside the hospital in 1347, in the general wards in 240, while it was present on arrival at the emergency room in 99. Resuscitation was attempted in 1172 patients; 181 survived for at least 24 hours, and 72 were discharged alive, including 13 with residual brain damage. The prognosis was best when cardiac arrest occurred in the general wards (13% discharged) and poorest when it occurred outside the hospital (4% discharged). However, in the latter group, the prognosis showed considerable improvement when resuscitation was initiated at once by a doctor or by laymen present at the accident site (16% discharged). As regards the mechanism of cardiac arrest, ventricular fibrillation was found to be a relatively favourable prognostic sign (10% discharged), whereas almost none of the patients with asystole or severe bradycardia survived. The possibility of improving the prognosis of cardiac arrest occurring outside hospital by the establishment of mobile coronary care units and by instructing lay people in the technique of cardiopulmonary resuscitation is discussed.

Prognostic significance of alpha frequency EEG rhythm in coma after cardiac arrest.

Sixty-five patients who remained in coma for more than 24 hours after resuscitation from cardiac arrest were divided into two groups according to their EEGs. Thirteen patients were found to have rhythm of alpha frequency while 52 had the usual EEG findings after cerebral anoxia. Three patients from the group with alpha frequency EEG rhythms regained full consciousness but showed severe sequelae. Our results suggest that the prognosis of comatose patients with EEG rhythm of alpha frequency is no poorer than that of other individuals who are comatose after cardiac arrest.

Prognosis after cardiac arrest based on age and duration of coma.

In an attempt to determine the relation between duration of coma and neurologic recovery following cardiac resuscitation 163 survivors of cardiac arrest from Winnipeg, Manitoba and Aarhus, Denmark were studied. The age of the patients did not influence the outcome. Of the 153 patients who had awakened from the coma within 24 hours, only 11 suffered brain damage, compared with all of the 10 patients who wakened after 24 hours. The three who wakened after 72 hours had severe brain damage and required permanent care in an institution. It was concluded that recovery of communicative brain function is unlikely if coma persists longer than 72 hours after cardiac arrest and that full recovery cannot be expected after 24 hours of coma.

A comparison between reaction time measurement and critical flicker fusion frequency under rising nitrous oxide inhalation in healthy subjects.

Ten subjects volunteered to inhale a test gas containing 0, 10, 20 and 30% nitrous oxide. After equilibration at each nitrous oxide concentration, the reaction time was measured using both the single-hand and the double-hand methods, and then the critical flicker fusion frequency was measured. Using the flicker funsion frequency test, significant changes from the normal range were found at 20 and 30% nitrous oxide in the test gas, whereas no significant changes were found with the fusion flicker frequency test. No significant prolongation was found with either double-hand or single-hand reaction time measurements until 30% nitrous oxide in the test gas was reached. It is concluded that critical flicker fusion frequency measurement is a simpler, more time-saving and more sensitive method for the estimation of the changes which nitrous oxide produces in healthy subjects than reaction time measurement, and that critical flicker fusion frequency measurement will presumably be a useful supplement to clinical examination as an objective method for the estimation of postanaesthetic recovery in patients.

Preoperative starvation and blood glucose concentrations in children undergoing inpatient and outpatient anaesthesia.

Blood glucose concentrations were measured in 82 children undergoing inpatient anaesthesia and in 46 children undergoing anaesthesia as outpatients. The children were aged between 6 months and 9 yr. Outpatients were fasted from bedtime, while inpatients were randomly allocated to two groups. In group A the children were fasted from bedtime, whereas in group B the children were fed 6 h before anaesthesia. There was no difference in mean blood glucose concentration between the fasted inpatients and outpatients nor between children younger than, or older than, 4 years of age. A blood glucose concentration of less than 40 mg dl-1 was found in only one of the fasted children (1%). The mean blood glucose concentration was greater in group B than A, but only significantly so for children older than 4 yr. It is concluded that to minimize the risks of hypoglycaemia and inhalation of vomit on induction of anaesthesia children older than 6 months should be fasted overnight and operated on in the morning.