Comparative trial of Hexabrix (320 mg iodine/ml), iohexol (300 mg iodine/ml) and iopamiron (300 mg iodine/ml) in cerebral and spinal angiography: a preliminary report.

A comparison has been carried out of results of cerebral and spinal-cord angiography with two non-ionic contrast media, iohexol and Iopamiron, and a low-osmolality contrast medium, Hexabrix. A comparative study of iohexol, Hexabrix, and Iopamiron was carried out in a first group of 41 patients, and Hexabrix was compared with Iopamiron in a second group of 56. Evaluation criteria included local and general safety, as well as quality of angioscopy and angiography. In the first group of patients there were no significant differences in safety between the three agents. On the other hand, quality of visualisation during angioscopy with Hexabrix was clearly better. In the second group, safety and quality of the radiographic images were identical; however, once again, quality of angioscopy was better with Hexabrix than with Iopamiron. We conclude that Hexabrix appears to be the best opacifying agent currently available for cerebral and spinal-cord angiography. While results with Iopamiron were quite similar, the latter agent is slightly more expensive.

[French survey on anesthesia systems and peroperative respiratory monitoring equipment]. / Enquête française sur les systèmes d'anesthésie et l'équipement de surveillance respiratoire peropératoire.

A national inquiry has been carried out in France. It concerned the anaesthetic systems and respiratory monitoring equipment in use at the moment, as well as that wished for. The equipment in use was very stereotyped: an open system with a respirator, for the most volumetric, and with a safety O2/N2O mixer. Monitoring is carried out with the pressure gauges and the measure of expiratory volume; only two thirds of the equipment had an alarm. The O2 and CO2 analysers were little used. Expired CO2 monitoring was only carried out in teaching hospitals and in big centres. Apart from this, the equipment was independent of the hospital and the type of surgery carried out. As for anaesthetic systems, 53% of centres would like obtain open systems, 15% closed systems; 32% did not answer. This increase in number of closed systems is not significant. However, a very strong wish for respirators with flow rate control and safety O2/N2O mixers was observed, whilst the safety parameters of these mixers were open to discussion. Respiratory monitoring was not just confined to the mechanical aspects, as 65% of centres wished to monitor FIO2. The big centres and the teaching hospitals were interested by the expiratory CO2 monitoring. This inquiry showed the interest in respiratory safety in operating theatres. Further studies should confirm or not the increasing interest in closed systems.

[Transcutaneous cerebral electric stimulation by Limoge current during labor]. / Electrostimulation cérébrale transcutanée par les courants de Limoge au cours de l'accouchement.

In order to test the analgesic efficacy of Anesthelec (transcutaneous cranial electrical stimulation with Limoge currents) during labour and delivery, a double blind study was performed in 20 cases for whom analgesia was necessary. In 10 cases Anesthelec was used with the Limoge currents on and in 10 cases as a sham. Labour and delivery were carried out by a medical team different from that which set up the Anesthelec. The results showed that this method, with or without nitrous oxide inhalation, decreased by 80% the number of epidural and general anaesthesias that would otherwise have been unavoidable. To define the effects of this new method, maternal and foetal parameters of 50 deliveries carried out under Anesthelec were compared with 50 deliveries carried out under epidural analgesia. Anesthelec was used only if analgesia was required. This study was a retrospective comparison between two similar non paired series. Despite the fact that analgesia obtained with Anesthelec was less powerful than with epidural analgesia, this method showed many advantages: total safety for the child and the mother, easy utilization, shorter labour time, decreased number of instrumental extractions and potentially reduced costs. Good acceptance and satisfaction for the mother should allow a rapid evolution of this new method.

[Primary-purpose peridural analgesia in labor induction]. / Analgésie péridurale de première intention dans le déclenchement du travail.

21 parturients, showing in most of cases either high blood pressure badly controlled or a "real" out of date term, have undergone a peridural analgesia of first intention in labour induction. All these patients were considered to be uninducable according to Bishop score. After an injection of adrenalinized bupivacaïne, either 0.25% or 0.375% rupture depending on state of cervix of membranes occurred in most cases 6 hours after peridural analgesia. The mean between onset of analgesia and delivery was 17 h and the mean time between induction with ocytocin to birth 5 h 37 min. 16 parturients gave birth per vaginam, 9 of which spontaneously 5 have undergone caesarian section because of a non lack of dilatation or foetal distress. Children at birth, at the 2nd and the 24th hour were all healthy.

[Prevention of anesthesia accidents]. / Prévention des accidents de l'anesthésie

All general anesthetics include a risk to life. The etiology and circumstances of complications with cardiac arrest are studied. Accent is placed on the frequency of fatal accidents for benign operations and on the poor prognosis of accidents with hypoxia. The prevention of accidents and their sequelae, such as encephalopathy, requires one to foresee and treat efficaciously as soon as possible cardiac arrest. To reach these objectives, efforts should be made on preparation of the patients, on the equipment and its maintenance, on the grouping of units where fatal accidents most frequently occur, on the creation of departments of anesthesia with re-awakening wards, on the training of medical and surgical teams with better supervision of young anesthetists.

Effect of analgesia on respiratory muscle function after upper abdominal surgery.

The effects of three methods of analgesia (intravenous morphine, epidural lidocaine and epidural morphine) on vital capacity (VC), forced expiratory volume in 1 s (FEV1) and maximal expiratory and inspiratory pressures (MEP and MIP) at the mouth were studied in 12 high respiratory risk patients following upper abdominal surgery. VC, FEV1, MEP and MIP markedly decreased following laparotomy. VC and FEV1, were partially restored by epidural analgesia and remained unchanged following intravenous morphine. MEP and MIP remained unchanged after each of the three methods of analgesia. This suggests the existence of a non-analgesic dependent dysfunction of inspiratory and expiratory muscles following upper abdominal surgery.

Ventilatory response to CO2 following axillary blockade with bupivacaine.

The systemic effect of bupivacaine on the control of ventilation was studied in eight ASA I (six male, two female) unpremedicated healthy subjects aged 30-55 yr (mean 43.5 yr) and weighing 59-82 kg (mean 69 kg) after axillary blockade with bupivacaine 0.5% without epinephrine, 3 mg/kg. The slope of the ventilatory response to CO2 was significantly increased (P less than 0.05) from its control value (1.77 +/- 1.03 l X min-1 X mmHg-1 [mean +/- SD]) 30 min (+19 +/- 32%) and 60 min (+32 +/- 37%) after axillary blockade, while plasma bupivacaine levels were 1.65 +/- 0.82 and 1.40 +/- 0.60 micrograms/ml, respectively. The correlation between individual plasma bupivacaine levels and the changes in the slope of the ventilatory response to CO2 was significant (r = 0.57, n = 16, P less than 0.05). Resting minute ventilation and end-tidal CO2 values did not change significantly. These results suggest that bupivacaine has a systemic stimulating effect on the ventilatory control mechanisms.

[Post-operative respiratory function after subcutaneous and epidural morphine analgesia (author's transl)]. / Fonction respiratoire post-opératoire après analgésie morphinique par voise sous-cutanée et péridurale.

In 20 elderly patients who underwent cholecystectomy post-operative analgesia was obtained with morphine given either subcutaneously (n = 10) or epidurally (n = 10). Both groups were comparable as to age and pre-operative respiratory function values. On the first post-operative day, vital capacity, forced expiratory volume in one second and and paO2 were significantly higher in the epidural morphine group (respectively 70 +/- 6 p. cent and 68 +/- 6 p. cent of pre-operative values, and 74 +/- 3 mmHg) (mean +/- s.e.m.) than in the subcutaneous morphine group, where the corresponding figures were 52 +/- 4 p. cent, 48 +/- 5 p. cent and 63 +/- 2 mmHg respectively. PaCO2 was unchanged in both groups. These data indicate that epidural morphine analgesia to some extent reduces the post-operative respiratory dysfunction observed after abdominal surgery.

[Tracheobronchial ruptures seen in emergencies. Viewpoint of the anesthesiologist]. / Ruptures trachéobronchiques vues en urgence. Le point de vue de l'anesthésiologiste

At the Marie Lannelongue surgical centre between 1964 and 1975, out of 278 patients with trauma of the thorax, we noted only 10 cases of tracheal-bronchial rupture admitted as an emergency = 9 ruptures due to closed trauma of the thorax, one with division of the lower part of the trachea. Analysis of these cases showed in particular:-the notion of violent trauma in -young subjects (average age: 20 years). In these thoracic injuries suspected of tracheal-bronchial rupture, the anaesthetist intervenes in four early stages: 1) arrival of the injured patient 2) bronchoscopy-diagnosis 3) surgical operation, the anaesthetic problems are linked to various factors, the most important of which are the very precarious cardio-respiratory condition, the lack of information and, sometimes, the lack of time. 4) Post-operative respiratory resuscitation.

[Extraction of intrabronchial foreign bodies in young patients in a surgical unit]. / Extraction des corps étrangers intra-bronchiques chez le sujet jeune en milieu chirurgical

The authors report a study of 35 cases of intra-bronchial foreign bodies in young subjects (average age 6 years). This shows that, more than the age of the child, or the duration of the presence of the object, its nature, has an influence on the possibilities of extraction by bronchoscopy or by thoracotomy. Whatever the nature of the foreign body, the authors emphasize the importance of the quality of the team formed by the endoscopist and the anaesthetist, repeated attempts at bronchoscopy compromise success and may lead to tracheotomy.

Effects of lidocaine on myocardial contractility and baroreflex control of heart rate in conscious dogs.

The effects of intravenous lidocaine (30 and 60 micrograms X kg-1 X min-1 during 30 min) at steady-state plasma levels (1.9 +/- 0.2 and 3.5 +/- 0.2 micrograms/ml, respectively) were investigated in conscious dogs, previously instrumented for measurements of arterial and left ventricular (LV) pressures, isometric myocardial contractility indexes (LV peak rate of tension development [dP/dt] and LV [dP/dt]/DP40), and heart rate. In addition, before and at the end of lidocaine infusions, arterial baroreflex responses were tested by bolus injections of nitroglycerin and phenylephrine. Whereas LV peak dP/dt and LV (dP/dt)/DP40 were significantly decreased after the low dosage of lidocaine, these indexes returned to control values after the 10th min of infusion of the high dosage. Moreover, eight out of 14 dogs exhibited continuous tremors, tachycardia, hypertension, and increase in contractility after the 10th min of lidocaine infusion (60 micrograms X kg-1 X min-1), although their lidocaine plasma levels (3.7 +/- 0.2 micrograms/ml) did not differ from those of the whole group. When these dogs were pretreated by combined alpha- and beta-adrenoceptor blocking drugs, none of them had tremors, and there was a constant depressant effect on cardiac chronotropism and inotropism. A specific enhancement of baroreflex sensitivity after phenylephrine injection was observed at the high lidocaine dosage. It is concluded that a central stimulation of both components of the autonomic nervous system modulates the direct effects of therapeutic plasma levels of lidocaine on cardiac chronotropism and inotropism in conscious dogs.

Diaphragm dysfunction induced by upper abdominal surgery. Role of postoperative pain.

The effects of upper abdominal surgery on diaphragmatic function were studied in 5 patients. During quiet tidal breathing, the volume displacement of the abdomen within the tidal volume (Vab/Vt) and the ratio of abdominal and transdiaphragmatic pressure changes (delta Pab/delta Pdi), taken as an index of the diaphragmatic contribution to the breathing process, decreased significantly on the first postoperative day (p less than 0.001); in 2 patients, a cephalad paradoxical motion of the diaphragm during inspiration was observed. Diaphragmatic dysfunction also occurred during maximal inspiratory efforts as shown by the significant fall in maximal static transdiaphragmatic pressure (Pdimax) and cephalocaudal diaphragmatic displacement on the first (p less than 0.001) and third (p less than 0.001) postoperative days. On the first postoperative day, opiate epidural analgesia did not modify Vab/VT, delta Pab/delta Pdi, and Pdimax. These parameters spontaneously returned towards control values on the seventh postoperative day. We conclude that upper abdominal surgery induces a marked diaphragmatic dysfunction lasting about 1 wk and that it is not suppressed by postoperative pain relief. The mechanism of this dysfunction remains to be determined. It may be the main cause of the postoperative pulmonary restrictive pattern.

Bupivacaine accentuates the cardiovascular depressant effects of verapamil in conscious dogs.

To investigate the potential risk of regional anaesthesia in a verapamil-treated patient, the cardiovascular effects of a combined intravenous infusion of bupivacaine and verapamil were studied in seven conscious and chronically instrumented dogs and were compared to those obtained when each drug was infused separately in the same animals. During verapamil infusion, the decrease in arterial pressure and myocardial contractile force, and the increase in heart rate were constant during the infusion. The lengthening of PR interval correlated with the plasma level of verapamil. During infusion of bupivacaine alone, there was an increase in heart rate and arterial pressure at the end of infusion, whereas the initial depression of myocardial contractile force was compensated. PR interval remained unchanged throughout the infusion of bupivacaine. During combined infusion of bupivacaine and verapamil, there was a time-dependent decrease in heart rate, arterial pressure and myocardial contractile force. A further increase in PR interval correlated with verapamil plasma concentrations which were higher than when verapamil was infused alone; bupivacaine plasma levels were in the same range as during bupivacaine infusion alone. Short periods of second-degree atrioventricular block developed in three out of the seven dogs but no relation was found between QT interval and heart rate in the whole group. Calcium chloride during bupivacaine-verapamil returned heart rate, arterial pressure and myocardial contractile force to their control values within 5 min. Atrioventricular block disappeared and PR interval was shortened following administration of calcium. Bupivacaine and verapamil have additive cardiovascular effects which lead to atrioventricular conduction dysfunction. The effects, at these doses, are reversed by calcium chloride.

Antidiuretic hormone response to osmotic stimulus under fentanyl anaesthesia.

The effect of fentanyl anaesthesia on the plasma antidiuretic hormone (ADH) response to osmotic stimulus was studied in eight patients. Eight g (137 mmol) NaCl were rapidly injected intravenously the day before anaesthesia and blood samples were collected 5, 10, 20 and 30 min after the injection. This protocol was repeated in the same subjects, under anaesthesia with thiopental, nitrous oxide and fentanyl before surgical incision. Plasma ADH markedly increased after NaCl administration and was significantly correlated with plasma sodium (r = 0.67, P less than 0.005) when the patients were awake, whereas it did not change over 30 min and was not correlated with plasma sodium (r = 0.18, P greater than 0.05) under fentanyl anaesthesia. This inhibitory effect of anaesthesia occurred in spite of a significant fall in the mean arterial pressure during the study. In order to eliminate the role of overnight fasting, premedication and fluid load, the same protocol was performed in six control patients who were fasted overnight, premedicated and fluid loaded. These results demonstrate that fentanyl anaesthesia abolishes the plasma ADH response to both osmotic and low arterial pressure stimuli.