Postoperative pulmonary complications: general anesthesia with postoperative parenteral morphine compared with epidural analgesia.

In a prospective study, patients undergoing abdominal cancer surgery were randomly allocated to receive either general anesthesia with fentanyl intravenously and postoperative analgesia with parenteral morphine (GA group) or general anesthesia combined with epidural bupivacaine and epidural morphine for postoperative pain relief (EP group). Analgesia was tested on a visual pain scale. Pulmonary complications were evaluated by clinical complications, blood gas analysis, x-ray film changes, and pulmonary volumes (vital capacity, forced expiratory volume in 1 second). Measurements were performed on the day before the operation and on the first 5 postoperative days. In the EP group the pain relief was significantly better on the first day (p less than 0.03). Whatever the criteria used, the rates of pulmonary complications were similar in the two groups: clinical complications 21% versus 26%, radiologic complications 50% versus 64% for GA and EP groups, respectively. Postoperative PaO2 and spirometric values were similar in the two groups. Postoperative epidural analgesia may improve the patient's comfort but does not decrease the incidence of pulmonary complications.

[Respiratory obstruction during anesthesia in children with malignant mediastinal lymphoma]. / Obstruction respiratoire au cours de l'anesthésie chez des enfants ayant un lymphome malin médiastinal.

In children with a malignant mediastinal lymphoma, acute respiratory occlusion can be a life-threatening complication during general anaesthesia. 26 cases have been reported since 1973, with five deaths. There were 23 boys for 3 girls, aged between 13 months and 18 years. The hazards of anaesthesia in these children are described. The risk of airway obstruction should be assessed preoperatively. General anaesthesia, carried out with the patient half-sitting, should be aimed at maintaining spontaneous breathing, and therefore muscle relaxants should be avoided. The anaesthetist should also be prepared to change the patient rapidly to a lateral or prone position; a rigid bronchoscope should always be at hand. Preoperative awareness of the risk of respiratory occlusion in these patients is essential so that the correct anaesthetic technique can be chosen and the postoperative course prepared.

[Generalized seizure induced by methohexital]. / Convulsion généralisée induite par le méthohexital.

Seizures induced by methohexitone have been reported in epileptic patients. An alcoholic patient without any previous history of epilepsy had grand mal-like seizures after being given an intravenous injection of 4 mg X kg-1 methohexitone. The respective parts played by high doses of methohexitone and chronic alcoholism in the induction of seizures are discussed.

[Evaluation of the risk of pulmonary complications after abdominal surgery]. / Evaluation du risque de complications pulmonaires après chirurgie abdominale.

Pulmonary complications are frequent after abdominal surgery. The object of this study was to evaluate the incidence and the predisposing factors of the postoperative pulmonary complications with a particular attention to their definitions. It included 146 patients. The respiratory complications were separated into clinical complications (bronchitis), radiological complications (atelectasis) and hypoxaemia (PaO2 less than 70 mmHg). Clinical complications (23%) were correlated neither with radiological complications (57%) nor hypoxaemia (46%). They particularly occurred in patients with a preoperative history of respiratory disease. Preoperative risk factors were males, low PaO2 and decreased FEV1. Radiological complications were strongly correlated with postoperative hypoxaemia. Their incidence was not affected by a previous history of respiratory disease. Both radiological complications and hypoxaemia were predicted by age.

Hemodynamic and catecholamine response to isoflurane versus droperidol in complement to fentanyl anaesthesia.

Droperidol (0.03 mg.kg-1 to 0.25 mg.kg-1) with fentanyl has been reported to be less efficient than volatile agents in the prevention of haemodynamic responses to surgery. The aim of this study was to investigate the use of high-dose droperidol in complement to fentanyl in comparison with isoflurane and fentanyl anaesthesia. Thirty patients undergoing laryngectomy were studied. Systolic blood pressure (SBP), heart rate (HR) and plasma catecholamines were analysed both during anaesthesia and during recovery. During surgery, SBP epinephrine (E) levels did not change in either group. HR was slightly lower during droperidol fentanyl anaesthesia. Norepinephrine (NE) levels were significantly higher in the droperidol group than in the isoflurane group (P less than 0.05). During recovery, in both groups, SBP increased by 20% whereas E levels increased by 65%. NE levels increased post-operatively in both groups, but this rise was significantly higher in the droperidol group (P less than 0.01). It is concluded that the two techniques contribute to the haemodynamic stability during surgery, but do not prevent haemodynamic instability during recovery.

Measurement of end-expiratory pressure during transtracheal high frequency jet ventilation for laryngoscopy.

An anaesthetic technique using high frequency jet ventilation has been proposed for direct laryngoscopy, but this may expose the patients to the risk of barotrauma. In order to assess this risk, we have measured end-expiratory airway pressure (EEP) through the injector using two three-way solenoid valves mounted in series. At the end of insufflation the first valve was switched off and the apparatus deadspace connected to atmosphere through a large exit port during an adjustable time (decompression time). Then the second valve was switched off and the injection line connected to a transducer, allowing measurement of EEP through the injector. The accuracy of this measurement was tested against airway pressure measured directly in the trachea (Pt) in a lung model. Provided that the decompression time was long enough (70 ms) and the apparatus deadspace was small (6 ml), the difference between EEP and Pt was less than 1 cm H2O for frequencies up to 5 Hz. A clinical evaluation was performed in 64 patients under general anaesthesia before laryngoscopy. EEP correlated with end-expiratory pulmonary volume above apnoeic FRC inferred from abdominal and thoracic displacements. At jet frequencies up to 5 Hz, the correlations between these two variables were satisfactory (r greater than 0.88), suggesting that EEP is a good indicator of pulmonary overdistension.