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Biomedical subjects

B Delafosse

Publications and source records attributed to B Delafosse.

At least 37 records · Page 2Linked to original sources

The effects of norepinephrine infusion on oxygen consumption in a patient with septic shock.

A 65-year-old man developed postsurgical septic shock, unresponsive to plasma volume expansion and administration of dopamine and dobutamine. A continuous norepinephrine infusion was then started and the dose increased to 0.62 micrograms.kg-1.min-1 until the mean arterial pressure was 70 mmHg. Prior to and during the norepinephrine infusion, oxygen consumption was continuously measured with a mass spectrometer system. There was a parallel increase in mean arterial pressure and oxygen consumption (+ 35%). There was also an increase in cardiac index and oxygen delivery. Systemic vascular resistance was only transiently increased. In this case with septic shock, norepinephrine infusion improved hemodynamic variables with an associated increase in oxygen consumption.

Aged↗

[Measurement of gas exchange in anesthesia and during resuscitation: principles and applications].

Pulmonary gas exchange measurements can be performed in ICU with commercially available devices. During open-circuit anaesthesia, measurement of VO2 and VCO2 requires the acquisition of fractional concentration of inspired and expired nitrogen, the appropriate calibration of sensors according to the use of anaesthetic gases and to take into account the unsteady state of nitrogen body stores after a change in FiN2. This technique can be readily used to measure energetic expenditure or to specific applications as oxygen cost of breathing, respiratory effects of parenteral nutrition or the metabolic effects of various anaesthetic procedures in man.

Anesthesia↗

[Fatal fulminant hepatitis in 2 women taking toloxatone (Humoryl)].

We report two cases of fulminant hepatitis which might be due to toloxatone, a new type-A monoamine oxidase inhibitor. Hepatitis occurred 20 days after the beginning of toloxatone administration in the first case and 138 days after the reintroduction of treatment in the second case. Clinical features included vomiting and jaundice, followed by asterixis and coma. Histologically, hepatic cell necrosis was predominant in the centrilobular area in the first case, and affected the entire lobule in the second case. Both patients died despite emergency liver transplantation.

Acute Disease↗

Effects of protein intake on pulmonary gas exchange and ventilatory drive in postoperative patients.

The effects of different protein regimens on pulmonary gas exchange and ventilatory drive were examined in eight postoperative patients receiving inspiratory pressure support ventilation. They were studied during 60 consecutive hours, which included two 12-h periods of high protein intake (33%) of total caloric intake provided as protein), each of them being preceded and followed by a 12-h period of standard protein intake (14% of total caloric intake provided as protein). Throughout the study, total caloric intake was 1.5 times the predicted resting energy expenditure. Nitrogen was provided as a 24% branched chain amino acid (BCAA) solution during the period of standard protein intake. During the periods of high protein intake, it was provided as a 24% and a 41% BCAA solution. Pulmonary gas exchange was continuously measured during the second half of each period, with the use of a mass spectrometer system. Measurements of the ventilatory response to CO2 (FICO2 0, 1.5, and 3%) were achieved at the end of each dietary regimen. O2 consumption, CO2 production, respiratory quotient, minute ventilation, and PaCO2 were the same for the three protein regimens. Changing protein intake failed to affect the ventilatory response to CO2. The authors conclude that, in postoperative patients having inspiratory pressure support ventilation, the administration of a high protein intake does not affect the ventilatory drive and the pulmonary gas exchange.

Carbon Dioxide↗

A case of sotalol poisoning with fatal outcome.

The case of a 58 year old woman who died after ingestion of 14.4 g of sotalol and 50 mg of triazolam is described. Despite medical treatment, intracardiac pacing and hemodialysis, cardiovascular failure persisted and became irreversible. High sotalol concentrations were observed in plasma (65 micrograms/ml) and in post mortem tissues samples. Tissue to plasma ratios ranged from 2.5 to 6. The high drug concentration found in heart tissue (104.4 micrograms/g) explains the difficulties experienced in the sotalol poisoning.

Chromatography, High Pressure Liquid↗

Energy expenditure in the acute renal failure patient mechanically ventilated.

Twenty mechanically ventilated patients with acute renal failure were studied on 31 occasions to determine their energy expenditure (EE) during a 2 h period before a hemodialysis. Oxygen consumption and CO2 elimination were measured continuously with a mass spectrometer system. EE (1660 +/- 48 kcal day-1) was close to the total caloric intake (1682 +/- 83 kcal day-1) and represented 1.19 +/- 0.03 times the predicted resting energy expenditure (PREE) with large inter-individual variations (0.7-1.7 PREE). EE/PREE was higher when sepsis was present (1.31 +/- 0.03 versus 1.14 +/- 0.02; p less than 0.05). Glucose oxidation rate (4.35 mg kg-1 min-1) exceeded glucose intake (2.6 mg kg-1 min-1). Respiratory quotient was 1.02 +/- 0.01. Nitrogen loss was 17.3 +/- 1.7 g day-1 and nitrogen balance -11.9 +/- 1.9 g day-1. In conclusion, EE values were scattered but never exceeded 1.7 times the PREE. Sepsis increased EE. With a nutritional support covering EE, nitrogen balance remained markedly negative and a preferential utilisation of glucose and lipogenesis occurred.

Acute Kidney Injury↗

[Methanol poisoning].

The neurological signs, the cerebral CAT scan aspects and the ocular problems seen in five cases of acute methanol poisoning are reported; these were, respectively, coma requiring assisted ventilation, convulsions, hypotonicity, hypodensity of the putamen, and amaurosis and papillary oedema. The simplified acute physiologic score varied from 11 to 26; the value of 26 was observed in the only death of the series. Pathogenesis of the metabolic acidosis, as well as the different parts played by formic acid, lactic acid and ketone bodies are discussed. A normal or lowered serum potassium in a case of unexplained metabolic acidosis associated with an osmotic gap should make one think of the diagnosis. Macrocytosis, an indirect sign of folic acid deficiency, was in favour of a poor prognosis. The treatment included early gastric lavage, alkalinization, blocking of the metabolism of methanol by ethanol and haemodialysis with a bicarbonate dialysate enriched in ethanol; this corrected the acidosis and permitted the elimination of the toxic metabolites (clearance of methanol: 159 ml X min-1; half-life of methanol during purification: 3.46 +/- 1.32 h; quantity extracted: 246 g). The possible advantages of 4-methyl-pyrazol and alkyldiol derivatives need further confirmation.

Acidosis↗

[Myocardial infarction during postoperative peridural analgesia with opiates].

A case of postoperative myocardial infarction is reported. It occurred seven days after intra-abdominal surgery (left hemicolectomy), in a patient with coronary heart disease. Diagnosis was delayed because of lack of pain; it was suggested by cardiogenic shock occurring 48 h after the initial phase. The patient had been receiving postoperative epidural analgesia with an opioid (pethidine); this may explain the pain was missing, so delaying the diagnosis.

Analgesia↗

[Continuous measurement of gas exchange during artificial ventilation].

A system for on-line measurement of respiratory gas exchange in patients undergoing artificial ventilation is described. Fractional concentrations were measured by a mass spectrometer and expired flow by a pneumotachometer; signals processing was carried out by a microcomputer. The accuracy of the measurement of the burning methanol RQ was within 1.6% at FIO2 lower or equal to 0.4. When compared to a reference method (the Douglas bag method), correlation was found to be excellent. The major problem in measuring gas exchange in a ventilated patient is that physiological signals are contaminated by artefacts which may lead to erroneous computations. An algorithm was developed in order to identify and disregard artefacted periods or ventilatory unsteady state in the patients. The technique used for data processing gave reliable continuous measurements of respiratory gas exchange for periods up to 24 h, without interfering with the nursing of the ventilated patients.

Algorithms↗

[Acute amiodarone poisoning. Clinical and pharmacokinetic study].

A 73 years old patient, treated with Amiodarone for ventricular tachycardia, ingested 6 000 mg of Amiodarone. This did not induce hemodynamic troubles or aggravation of ventricular arrhythmia. Treatment included a gastric lavage and purging at the third hour. Plasma assay revealed a concentration of 3.69 mg/l at the fourth hour. Their evolution can be described as the sum of two exponentials. The half-life of the first exponential is 4.9 hours ; the half-life of the second one is 544 hours. Amiodarone is an antiarrhythmic agent of high safety.

Aged↗