Helium-oxygen breathing in the early emergency care of acute severe asthma: a randomized pilot study.

The aim of this study was to establish whether a clinical trial, comparing helium-oxygen (HeO2) breathing to standard therapy, would be feasible during the out-of-hospital care of adult patients with severe asthma. Although the primary outcome in a definitive trial will be a decrease in morbidity, the present study primarily examined: (1) if the strategy could be successfully implemented in emergency ambulatory units; (2) if the research staff could enroll enough patients, given the resources. Nine patients were included in the conventional treatment group, and seven patients in the HeO2 group. Patients randomized to the HeO2 group breathed the mixture for a 12-hour period. Clinical and biological parameters improved for all patients. There was no trend towards a HeO2 benefit, whether during the initial out-of-hospital nor the ICU care. No patient was intubated within the study period. HeO2 breathing was considered to be simple to initiate, and no side effects were reported. In conclusion, while HeO2 breathing is easy to apply, even in the out-of-hospital setting, the few enrolled patients did not appear to benefit from this treatment. Regarding our low inclusion rate and the lack of positive effect trend, we believe that a large definitive trial will be difficult to initiate in such an emergency care setting.

[Is the direct admission to the recovery service or to the intensive care unit of patients cared for by the Smur system justified?]. / L'admission directe en service de réanimation ou de soins intensifs des patients pris en charge par le Smur est-elle justifiée?

STUDY DESIGN: The French system of Samu-Smur allows the admission of patients directly in intensive care unit (ICU). The aim of this study is to examine the utility of the Samu-Smur with regard to such direct admission (DA). PATIENTS AND METHODS: This retrospective study was performed by the Samu of Paris. Patient details were gathered from three reports: namely hospitalization, transport and regulation reports. These were analysed to decide whether the admission diagnostic was exact, whether the patient's condition was serious, whether the prehospital treatment justified direct admission into an ICU and whether the management was coherent. RESULTS: In 1997, 409 (31%) cases were studied among the 1,350 admitted patients in ICU. Three groups of patients were classified according to admission to surgical (n = 54), medical (n = 180), cardiological ICU (n = 175). The prehospital diagnosis was confirmed by the hospitalization report in 91% of patients in the all three groups. The patient's condition was found to the serious in all cases. Justification of the treatment was respectively found in 96, 88 and 84% of patients. The coherence of management was confirmed in 94, 96 and 89%. DISCUSSION: This study has shown that Samu-Smur management lead to justified DA in ICU for all patients in the study. Prospective studies are needed to show the advantages of this strategy in term of speed of management and outcome.

[Initial resuscitation of closed thoracic trauma]. / Réanimation initiale des traumatismes fermés du thorax.

Blunt thoracic trauma are frequent and often severe. Their management is improved in the prehospital settings by the involvement of a medical team, and the admission in a specialized trauma center. Diagnostic and therapeutic steps are closely linked. They are based on the stabilization of life threatening problems and the appropriate use of recent advances in medical imaging. Endotracheal intubation and mechanical ventilation are indicated for respiratory distress. Immediate surgical management is mandatory for an hypovolemic shock related to massive hemothorax. On the contrary, multiple ribs fractures and flail chest without major pulmonary contusion are managed with regional analgesia allowing effective physiotherapy and avoiding the infectious complications related to prolonged mechanical ventilation.

Myocardial effects of propofol in hamsters with hypertrophic cardiomyopathy.

BACKGROUND: Propofol is a short-acting intravenous induction agent that induces cardiovascular depression but without significant effect on intrinsic myocardial contractility in various species. However, its effects on diseased myocardium remain unknown. METHODS: The effects of propofol (1, 3, and 10 micrograms.ml-1) on the intrinsic contractility of left ventricular papillary muscles from normal hamsters and those with hypertrophic cardiomyopathy (strain BIO 14.6, aged 6 months) were investigated in vitro (Krebs-Henseleit solution, 29 degrees C, pH 7.40, Ca++ 2.5 mmol.l-1, stimulation frequency 3/min). RESULTS: Cardiac hypertrophy (143 +/- 13%, P < 0.001) was observed in cardiomyopathic hamsters. The contractility of papillary muscles from hamsters with cardiomyopathy was less than that of controls, as shown by the decrease in maximum shortening velocity (-29%, P < 0.03) and active isometric force (-51%, P < 0.001). Propofol did not induce any significant effect on contraction, relaxation, and contraction-relaxation coupling under low and high loads in normal hamsters. The effects of propofol were not significantly different between normal hamsters and those with cardiomyopathy. A slight but significant increase in maximum unloaded shortening velocity was observed in cardiomyopathic hamsters at 3 micrograms.ml-1 (4 +/- 6%, P < 0.05) and 10 micrograms.ml-1 (7 +/- 6%, P < 0.05). CONCLUSIONS: Propofol did not modify intrinsic myocardial contractility in normal hamsters, and no significant differences were observed between normal and cardiomyopathic hamsters. These results may be useful because, unlike propofol, most anesthetics decrease myocardial contractility. Nevertheless, indirect cardiac effects of propofol may be more important than its direct cardiac effects in patients with impaired cardiac function.

Modifications of the inotropic responses to alpha- and beta-adrenoceptor stimulation by propofol in rat myocardium.

UNLABELLED: Propofol induces cardiovascular depression but without significant effect on intrinsic myocardial contractility in many species. However, its interactions with adrenoceptor stimulation are unknown. We studied the effects of propofol (1 and 10 microg/mL) and its solvent on the inotropic response induced by phenylephrine (10(-8)-10(-4) M) or isoproterenol (10(-8)-10(-4) M) in rat left ventricular papillary muscles in vitro (Krebs-Henseleit solution, 29 degrees C, pH 7.40, calcium 0.5 mM, stimulation frequency 12 pulses/min). We also studied the lusitropic effects in isotonic and isometric conditions. In control groups, phenylephrine (127% +/- 3% of baseline; P < 0.05) and isoproterenol (169% +/- 11% of baseline; P < 0.05) induced a positive inotropic effect. Propofol (10 microg/mL) completely abolished the positive inotropic effect of phenylephrine (100% +/- 3% of baseline; P = not significant). In contrast, at the lowest concentration (1 microg/mL), propofol did not modify the positive inotropic effect of phenylephrine. Propofol did not modify the inotropic effect of isoproterenol. Propofol (10 microg/mL) enhanced the positive lusitropic effect of isoproterenol under low-load (P < 0.05) but not under high-load conditions. IMPLICATIONS: A high concentration of propofol abolished the positive inotropic effect of alpha- but not beta-adrenoceptor stimulation and enhanced the positive lusitropic effect of beta-adrenoceptor stimulation.

Postal survey of cuffed or uncuffed tracheal tubes used for paediatric tracheal intubation.

A postal survey of the use of cuffed or uncuffed tracheal tubes for tracheal intubation in children and infants was performed to investigate the criteria used for deciding the choice of tube and the manner of inflating the cuff in the case of use of a cuffed tracheal tube (CTT). From 200 questionnaires despatched, replies were received from 130 paediatric anaesthesiologists (response rate 65%). In paediatric practice, the CTT was routinely used by 25% of respondents for more than 80% of their patients, while more than 37% of respondents use them in less than 20% of the cases. The three main criteria used for inflating a cuff were: (i) the presence of a leak, (ii) the type of surgery associated with the presence of a leak and (iii) the patient's age associated with the type of surgery and the presence of a leak. These criteria were specified, respectively, by 32%, 24% and 18% of the respondents. The cuff was inflated in response to a leak in 18% of the cases and as a response to a pressure manometer in 15% of the cases. Few paediatric anaesthesiologists use a cuffed tracheal tube routinely for tracheal intubation in children, and fewer actually use a pressure monitoring device, while it is suggested that the cuff pressure should be monitored in case of CTT.