Effects of combined methohexitone-remifentanil anaesthesia in electroconvulsive therapy.

BACKGROUND: Methohexitone is widely used to provide anaesthesia for patients undergoing electroconvulstive therapy (ECT). Short seizure duration, high blood pressures (BP) and heart rates (HR) are usual in elderly patients. In this study, elderly patients undergoing ECT received low dose methohexitone with remifentanil or methohexitone alone and motor seizure duration, haemodynamic response and recovery time were compared. METHODS: Ten patients, of mean age 74.3 years, were enrolled in this double-blind, randomised crossover trial, receiving a total of 38 ECTs. Each patient was given the following two i.v. regimens in random order: A) methohexitone 0.5 mg kg(-1) combined with remifentanil 1.0 microg kg(-1) and B) methohexitone 0.75 mg kg(-1). Additional methohexitone was given, if needed, until loss of consciousness, and then suxamethonium 1.0 mg kg(-1) for muscular paralysis. RESULTS: Mean motor seizure duration was significantly longer with methohexitone-remifentanil (37.6 s (SD 12.0)) than with methohexitone alone (27.1 (SD11.5)) (P=0.0009). Recovery time, time to spontaneous breathing, peak postictal changes in BP and HR were similar with both regimens. CONCLUSION: A reduced dose of methohexitone combined with remifentanil allows prolonged duration of motor seizures in ECT. We conclude that low dose methohexitone combined with a short-acting opioid is a reasonable alternative for elderly patients undergoing ECT, and for other patients with short seizure duration.

Cardiac arrest due to massive pulmonary embolism following caesarean section. Successful resuscitation and pulmonary embolectomy.

A woman developed pulmonary embolism with cardiac arrest after caesarean section. Cardiopulmonary resuscitation was performed for 45 min during which echocardiography showed right ventricular dilatation. After stabilization, but still in a critical condition, the patient was transferred by airambulance to a hospital with facilities for extracorporeal circulation. A massive embolus was removed. Some hours after extubation the patient developed respiratory insufficiency and hypovolaemia. Re-intubation was followed by severe hypotension requiring external cardiac compression for about 15 min. An emergency explorative laparotomy revealed a ruptured liver with a subcapsular haematoma. A critical illness polyneuropathy made prolonged ventilatory support necessary. She recovered without cerebral sequelae.

Mechanical obstruction in the anaesthesia delivery-system mimicking severe bronchospasm.

We present a case where mechanical obstruction in the anaesthesia delivery system caused by plastic wrapping from a filter was misinterpreted as severe bronchospasm. The patient suffered severe hypoxia before the problem was solved by using a free-standing self-expanding ventilation bag. This near-fatal incident emphasises the importance of thorough equipment checking routines, rapid troubleshooting and how equipment failure may be misinterpreted as a medical complication. It also shows how transparent container material can become a medical hazard.

The effects of chewing gum on gastric content prior to induction of general anesthesia.

To study the effects on gastric content and subjective well being of chewing gum in the immediate preoperative period, 60 female nonsmokers were randomized to use regular, sugar-free chewing gum preoperatively or to continue the overnight fast. In a similar fashion 44 habitual smokers were randomized to use nicotine gum 2 mg or not. Nonsmokers using chewing gum had significantly larger gastric fluid volumes than controls (mean 30 +/- 19 mL vs 20 +/- 15 mL; 95% confidence interval (CI) for difference 1-19 mL; P = 0.03), with no difference in gastric fluid acidity. In smokers, neither gastric fluid volume nor acidity differed significantly between those who were or were not chewing gum. Although the use of nicotine gum in smokers was associated with a reduction in dryness of the mouth, thirst, and irritability, nonsmokers chewing regular gum did not report significant improvements in patient well being. In habitual smokers unable to abstain from nicotine, the use of nicotine gum on the morning of surgery may be beneficial. Although it is difficult to prove a direct influence on the incidence of pulmonary aspiration of increased gastric contents, the fact that regular, sugar-free chewing gum increased gastric fluid volumes probably means that it should not be used on the morning of surgery.

Acid aspiration syndrome prophylaxis in gynaecological and obstetric patients. A Norwegian survey.

Clinical practice and attitudes of Acid Aspiration Syndrome (AAS) prevention in connection with gynaecological and obstetric surgery were surveyed in all Norwegian departments of anaesthesia. General anaesthesia with rapid-sequence intubation using succinylcholine and cricoid pressure was the preferred method for all emergency surgery, except Caesarian section (C-section) where 58% of the departments reported use of spinal or epidural anaesthesia if time allowed for its use. Chemoprophylaxis was more often used before emergency C-section (60%) than before emergency gynaecological surgery (14%), and mostly consisted of the antacid sodium citrate given alone. Seventy-six percent of the departments used mechanical emptying of the stomach before emergency gynaecological surgery and 44% before emergency C-section. While all responders considered recent intake of a "light breakfast" in an elective patient to be a risk factor of AAS indicating delay of surgery or use of specific precautions like regional anaesthesia, rapid-sequence intubation, or chemoprophylaxis, 52-72% of the responders considered obesity, dyspepsia, recent water intake, smoking or use of chewing gum to be risk factors as well. We think this survey demonstrates a need for consensus discussions of AAS prophylaxis.

Effects of giving water 20-450 ml with oral diazepam premedication 1-2 h before operation.

We have studied the volume of water which should accompany diazepam 10 mg oral premedication given 1-2 h before induction of anaesthesia in 75 patients undergoing elective gynaecological laparoscopy. Twenty-five patients were given 20 ml (group A), 25 patients 150 ml (group B), and 25 patients 300-450 ml of water (group C). There were no differences between the groups in gastric fluid volume and acidity. All groups reported a reduction in thirst and dryness of the mouth after water intake, while only group B reported significant anxiolysis. Eight patients in group C experienced augmented diuresis, compared with no patients in groups A and B. We conclude that 150 ml is the ideal amount of water given with oral premedication 1-2 h before anaesthesia.

Studies of gastric content: comparison of two methods.

In 20 patients studied under general anaesthesia, we found good agreement between gastric fluid volumes aspirated blindly and total volumes determined by fibreoptic gastroscopy (mean under-estimation 6 ml (22%); range 0-50 ml). Gastric fluid acidity measurements using an electronic pH meter and pH indicator paper also provided results with good agreement (mean difference in pH 0.1; range -0.3 to 0.5). As the use of a standardized blind gastric aspiration technique and pH indicator paper is simpler and provided sufficiently accurate measurements for clinical study purposes, we think this method is preferable.

[Severe, symptomatic hyponatremia]. / Uttalt, symptomgivende hyponatremi.

Severe hyponatremia (serum sodium levels less than 120 mmol/l) is associated with increased morbidity and mortality. We report three cases where patients developed hyponatremia and severe neurological manifestations after medical treatment. The first two patients experienced episodes of general seizures and coma, but recovered in 24 hours without neurologic sequelae after correction of the electrolyte disturbance. The third patient developed the syndrome central pontine myelinolysis with pseudobulbar palsy and quadriparesis. Marked improvement occurred, however, and in three months the patient was almost completely recovered. The development of hyponatremia deserves special attention in connection with the use of diuretics, infusion of sodium-free carbohydrates and immediately after operation.

[Correction of severe hyponatremia]. / Korrigering av alvorlig hyponatremi.

Profound hyponatremia is a life-threatening emergency which can result in permanent neurological damage. The rate at which severe hyponatremia should be corrected is the focus of clinical debate. It is important, however, to differentiate chronic from acute hyponatremia and to develop a plan for correcting hyponatremia. A treatment regime is suggested.

[Jet ventilation]. / Jetventilasjon.

High frequency jet ventilation gives adequate alveolar ventilation with very small tidal volumes, gas exchange at lower airway pressure, reduced risk of pulmonary barotrauma, and less cardiovascular impairment. Use of small insufflation catheters facilitates surgery when access is restricted, as in laryngeal surgery, and makes it possible to ventilate a patient through a cricithyroid membrane puncture in an emergency situation. In intensive care medicine, jet ventilation can have some advantage over conventional ventilation in patients with bronchopleural fistulas, and when it is difficult to wean patients from a respirator. The article describes experience using an Acutronic AMS-1000 Universal Jet Ventilator.

Naloxone: a potent ketobemidone antagonist in man.

Naloxone has been accepted as a potent antagonist towards several narcotic analgesics, e.g. morphine, heroin and pethidin. Its effect as an antagonist and its potency against ketobemidone have not been tested in man. We have described the antagonistic effect of naloxone towards the respiratory depression caused by the administration of ketobemidone to patients anesthetized with N2O/O2 and methohexitone.