Respiratory changes in aortic blood velocity as an indicator of fluid responsiveness in ventilated patients with septic shock.

STUDY OBJECTIVE: To investigate whether the respiratory changes in peak velocity (Vpeak) of aortic blood flow could be related to the effects of volume expansion on cardiac index. DESIGN: Prospective clinical study. SETTING: Medical ICUs of a university hospital (20 beds) and of a nonuniversity hospital (15 beds). PATIENTS: Nineteen sedated septic shock patients who were receiving mechanical ventilation and who had preserved left ventricular (LV) systolic function. INTERVENTION: Volume expansion. MEASUREMENTS AND RESULTS: Analysis of aortic blood flow by transesophageal echocardiography allowed beat-to-beat measurement of Vpeak before and after volume expansion. Maximum values of Vpeak (Vpeakmax) and minimum values of Vpeak (Vpeakmin) were determined over one respiratory cycle. The respiratory changes in Vpeak (Delta Vpeak) were calculated as the difference between Vpeakmax and Vpeakmin divided by the mean of the two values and were expressed as a percentage. The indexed LV end-diastolic area (EDAI) and cardiac index were obtained at the end of the expiratory period. The volume expansion-induced increase in cardiac index was > or = 15% in 10 patients (responders) and < 15% in 9 patients (nonresponders). Before volume expansion, Delta Vpeak was higher in responders than in nonresponders (20 +/- 6% vs 10 +/- 3%; p < 0.01), while EDAI was not significantly different between the two groups (9.7 +/- 3.7 vs 9.7 +/- 2.4 cm(2)/m(2)). Before volume expansion, a Delta Vpeak threshold value of 12% allowed discrimination between responders and nonresponders with a sensitivity of 100% and a specificity of 89%. Volume expansion-induced changes in cardiac index closely correlated with the Delta Vpeak before volume expansion (r(2) = 0.83; p < 0.001). CONCLUSION: Analysis of respiratory changes in aortic blood velocity is an accurate method for predicting the hemodynamic effects of volume expansion in septic shock patients receiving mechanical ventilation who have preserved LV systolic function.

[Validity of pretransfusion bedside agglutination tests for pretransfusional control]. / Etude régionale de validité, dans les services de soins, du test d'agglutination du contrôle ultime prétransfusionnel.

The incidence rate of ABO hazards of transfusion remains high in France. In this country, bedside pretransfusion controls include an agglutination test for red cells only, although its validity has scarcely been assessed in the practice. 847 nurses from 9 public hospitals and private clinics in a French region participated in a study aimed at measuring the sensitivity and specificity of pretransfusion bedside agglutination tests within hospital wards. Sensitivity was found to be 93.9% +/- 3%. Nondetection of mismatching was increased by two risk factors only: having worked more than 4 years in the same ward, and not having been trained to use this test. The sensitivity of this test might still be improved. This test is found sensitive enough to be kept. Nevertheless, if used alone, it is not a safe protection against recipient's mismatch. Authors recommend both to improve agglutination test sensitivity and to link it strongly to the bedside checking of both transfusion information and the recipient's identity.

[Acute respiratory distress syndrome in the initial phase of myocardial infarction in adults]. / Le syndrome de déstresse respiratoire aiguë de l'adulte à la phase initiale de l'infarctus du myocarde.

Four patients developed an acute respiratory distress syndrome characterised by clinical and radiological signs of pulmonary oedema, a protein-rich oedema, severe hypoxemia refractory to oxygen therapy, contrasting with normal left ventricular filling pressures and indicating increased permeability of the alveolo-capillary membrane, 24 to 72 hours after the onset of acute myocardial infarction. After having excluded the usual causes of the acute respiratory distress syndrome, the authors suggest that acute myocardial infarction, especially when extensive, may cause a lesion of the alveolo-capillary membrane by an unknown mechanism. Treatment consisted in mechanical ventilation with positive expiratory pressures in 3 cases and with continuous positive pressure during spontaneous respiration in the third patient and in relay with controlled ventilation in the other two. These techniques of ventilation improved the hypoxemia and led to complete cure in all cases without evolution to pulmonary fibrosis. In addition to mechanical ventilation, all patients were given systematic antibiotic therapy because of the possibility of an infectious etiology while waiting for the results of microbiological and serological testing and because of the high risk of superinfection which plays an essential part in the outcome of the condition. The immediate response to treatment was favourable in all cases. One patient died suddenly of cardiogenic shock two weeks after this episode. The other patients are still alive 39, 38 and 20 months after infarction. The importance of the diagnosis of the acute respiratory distress syndrome in the acute phase of myocardial infarction resides in its therapeutic implications which are quite different to those of cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

[Risk evaluation of oxygen desaturation after buprenorphine or morphine administration during the early postoperative period]. / Evaluation du risque de désaturation en oxygène après administration de buprénorphine ou de morphine en période postopératoire immédiate.

The purpose of this study, conducted in a PACU in the early recovery period of orthopaedic procedures under general anaesthesia, was to compare the time course of O2 arterial saturation (SpO2), measured by pulse oximetry, after the intramuscular administration of either buprenorphine (0.30 mg) or morphine (10 mg). The rate of patients who had an episode of O2 desaturation (defined as a SpO2 under 95%) was similar in both groups: 73% after buprenorphine vs 67% after morphine. The cumulative duration of desaturation episodes was higher following buprenorphine (p < 10(-5). Finally, in patients who had at least one episode of arterial desaturation, the mean duration of these episodes was identical in both groups. However the average number of episodes per patient was significantly higher in the buprenorphine group. These results should lead us to be cautious with the use of buprenorphine during the early recovery period, especially as this as this agent has specific characteristics such as a long duration of action and resistance to naloxone.

Nadroparin in the prevention of deep vein thrombosis in acute decompensated COPD. The Association of Non-University Affiliated Intensive Care Specialist Physicians of France.

Low molecular weight heparins are as effective as unfractionated heparin in deep-vein thrombosis (DVT) prophylaxis for major surgery. However, there is no evidence nor consensus for prophylaxis in medical patients. We compared the efficacy and safety of nadroparin calcium (nadroparin) with placebo in medical patients at high risk of DVT. A total of 223 patients mechanically ventilated for acute, decompensated chronic obstructive pulmonary disease, were randomized to treatment with subcutaneous nadroparin adjusted for body weight (0.4 ml, i.e., 3,800 AXa IU, or 0.6 ml, i.e., 5,700 AXa IU) or placebo. The average duration of treatment was 11 d. The incidence of DVT in patients receiving nadroparin was significantly lower than that in patients receiving placebo (15.5 versus 28.2%; p = 0.045). Although the incidence of adverse events was high in both groups, there were no significant differences between nadroparin and placebo for total adverse events (46.3 versus 39.8%; p = 0.33), serious adverse events (25.0 versus 19.5%; p = 0.32), or those resulting in early permanent discontinuation of treatment (12.0 versus 8.8%; p = 0.44). The most common adverse event was hemorrhage. There was the same number of deaths in both treatment groups. Subcutaneous nadroparin resulted in 45% decrease in incidence of DVT compared with placebo.