Prognostic factors of spinal cord decompression sickness in recreational diving: retrospective and multicentric analysis of 279 cases.

BACKGROUND: This study aims to determine the potential risk factors associated with the development of severe diving-related spinal cord decompression sickness (DCS). METHODS: Two hundred and seventy nine injured recreational divers (42 ± 12 years; 53 women) presenting symptoms of spinal cord DCS were retrospectively included from seven hyperbaric centers in France and Belgium. Diving information, symptom latency after surfacing, time interval between symptom onset and hyperbaric treatment were studied. The initial severity of spinal cord DCS was rated with the Boussuges severity score, and the presence of sequelae was evaluated at 1 month. Initial recompression treatment at 2.8 ATA with 100% oxygen breathing or deeper recompression up to 4 or 6 ATA with nitrogen or helium-oxygen breathing mixture were also recorded. RESULTS: Twenty six percent of DCS had incomplete resolution after 1 month. Multivariate analysis revealed several independent factors associated with a bad recovery: age ≥ 42 [OR 1.04 (1-1.07)], depth ≥ 39 m [OR 1.04 (1-1.07)], bladder dysfunction [OR 3.8 (1.3-11.15)], persistence or worsening of clinical symptoms before recompression [OR 2.07 (1.23-3.48)], and a Boussuges severity score >7 [OR 1.16 (1.03-1.31)]. However, the time to recompression and the choice of initial hyperbaric procedure did not significantly influence recovery after statistical adjustment. CONCLUSIONS: Clinical symptoms of spinal cord DCS and their initial course before admission to the hyperbaric center should be considered as major prognostic factors in recovery. A new severity score is proposed to optimize the initial clinical evaluation for spinal cord DCS.

Recovery of [13C]bicarbonate as respiratory 13CO2 in mechanically ventilated patients.

Measurement of the nutrient oxidation rate with 13C as a tracer requires knowledge of the value of its coefficient of fractional recovery in the expired gas (FR). We measured FR in nine intensive care patients who were mechanically ventilated and received total parenteral nutrition. NaH13CO3 was administered at a priming dose (3.75 mumol.kg-1.min-1) followed by a continuous infusion (0.05 mumol.kg-1.min-1). Metabolic rate and pulmonary carbon dioxide elimination (VCO2) were measured by using a mass-spectrometer system. The 13C-12C ratio was measured in the expired gas with an isotopic-ratio mass spectrometer and FR was calculated by using standard equations. The average value of FR was 0.899 +/- 0.026 (means +/- SE) and remained stable for each patient on 2 consecutive days. Between patients, the coefficient of variation of FR was 8.6%. Metabolic rate was the only physiological factor found to affect the FR value.

Oxygen cost of breathing in postoperative patients. Pressure support ventilation vs continuous positive airway pressure.

In seven postoperative patients with normal preoperative pulmonary function tests, we evaluated the oxygen cost of breathing (VO2resp) during continuous positive pressure ventilation (CPAP) and during a 15 cm H2O inspiratory pressure support ventilation (IPSV). For both periods, VO2 resp was estimated as the difference between total oxygen uptake of the period (VO2tot), measured by a mass-spectrometer system, and that during controlled ventilation. During CPAP ventilation, VO2resp was found to be 11.2 +/- 1.4 percent of VO2tot. During IPSV, VO2resp was found insignificant. It is concluded that a 15 cm H2O IPSV takes over the major part of the work of breathing in postoperative patients without preexisting pulmonary disease.

Oxygen cost of breathing and diaphragmatic pressure-time index. Measurement in patients with COPD during weaning with pressure support ventilation.

The oxygen cost of breathing and the time integral of the transdiaphragmatic pressure were measured at the onset of the weaning period in eight patients with chronic obstructive pulmonary disease requiring mechanical ventilation. Measurements were achieved during continuous positive airway pressure ventilation and during 15 cmH2O pressure support ventilation. For both periods, the O2COB was estimated as the difference between oxygen uptake of the period and that during controlled ventilation. During CPAP ventilation, the O2COB was 16.9 +/- 1.5 percent. During PSV, it was only 6.3 +/- 1.3 percent, and PTdi decreased by 73 percent compared to the CPAP period. Both effects illustrate the ability of PSV to facilitate spontaneous breathing during weaning from mechanical ventilation. However, we found these measurements to be of no help in predicting the duration of the weaning process.

Neuron-specific enolase as a marker of neuronal lesions during various comas in man.

The detection of neuron-specific enolase in biological fluids has been investigated as an indirect marker of neuronal damage in man. This protein was measured by a sandwich enzymoimmunoassay in serums and cerebrospinal fluids from patients with consciousness disorders of various aetiologies. Neuron-specific enolase level was significantly increased in sera from patients with comas resulting from anoxemia, head injury, septic state, cirrhosis and fulminant hepatitis. On the other hand, patients with meningitis (affection not normally accompanied with neuronal lesion) exhibited no change of this marker level. The statistical analysis of our results suggests that, in neurological disorders, the neuron-specific enolase levels in cerebrospinal fluid could have some prognostic value. The correlation between its level in cerebrospinal fluid and in serum was also demonstrated. Neuron-specific enolase increase in biological fluids thus represents a useful and promising marker to biochemically characterize various strokes possibly resulting in neuronal damage.

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.

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.

Clinical validation of the Deltatrac monitoring system in mechanically ventilated patients.

OBJECTIVE: To evaluate a monitor of pulmonary gas exchange (Deltatrac, Datex) in a clinical setting. DESIGN: After in vitro evaluation, comparison over 2 min between VO2 and VCO2 values measured by the Deltatrac and the Douglas bag technique. Comparisons were also achieved over 8 h periods between the Deltatrac and a system using a mass-spectrometer. SETTING: Polyvalent intensive care unit (ICU 15 beds) in a 1200 bed general hospital. PATIENTS: Comparison with the Douglas bag technique in 10 patients undergoing controlled ventilation. Comparison with the mass-spectrometer system in 25 other patients undergoing controlled or pressure support ventilation. MEASUREMENTS AND RESULTS: Compared to the results obtained by the Douglas bag technique, the bias (+/- 2 SD) for VO2 and VCO2 was -3.5 +/- 26.6 and 6.1 +/- 12.7 ml.min-1, respectively. By comparison with the mass-spectrometer system, the bias for VO2 and RQ was -5.8 +/- 16.0 ml.min-1 and 0.018 +/- 0.048, respectively. No drift between the two systems was observed over time. CONCLUSIONS: The Deltatrac appears suitable for VO2 and VCO2 measurements in ventilated patients and equivalent to a mass-spectrometer system for long term measurements.

Time course of oxidative stress after major burns.

OBJECTIVE: To evaluate oxidative stress resulting from major burns in humans. DESIGN: Prospective clinical study with control group. SETTING: Mechanically ventilated adult patients admitted with more than 30% total burn surface area. PATIENTS AND PARTICIPANTS: 20 patients with a mean body surface burned area of 54%. MEASUREMENTS AND RESULTS: The oxidative stress evaluation was based on measurements of trace elements, vitamins, antioxidant enzymatic activity and end-products of lipid peroxidation. During the first 5 days after injury burn patients exhibit a decrease in selenium and antioxidant vitamins (C, beta-carotene, lycopene) and an increase in lipid peroxidation products (TBARS). CONCLUSION: Our results suggest that major burn is associated with oxidative stress during the 5 days after the initial injury, as demonstrated by a simultaneous decrease in antioxidant vitamins and a large increase in TBARS.

Successful treatment of hepatic hydrothorax with octreotide.

Hepatic hydrothorax is a rare complication of cirrhosis. Controlling ascites formation is the goal of therapy. We report the case of an adult patient presenting with alcoholic cirrhosis who developed first a symptomatic hydrothorax, refractory to diuretics and fluid and sodium restriction, and then an hepatorenal syndrome. Treatment consisted of chest tube insertion and 5 days' intravenous infusion of octreotide. Complete clinical and biological data were reviewed. Octreotide administration resulted in an increased urinary outflow and sodium output, concomitant with improved renal function. The patient has been free of symptoms after discharge from hospital for a follow-up period of 5 months. This observation raises interesting issues regarding the possible utility of splanchnic vasoconstrictors, reducing portal hypertension, in the treatment of refractory hepatic hydrothorax.

Energy expenditure during severe acute pancreatitis.

Energy expenditure (EE) was measured, during 3 consecutive days, in six patients suffering from acute pancreatitis. Measurements were achieved postoperatively, under mechanical ventilation, using a mass spectrometer system. EE represented 1.49 times (range: 1.08-1.78) the predicted resting energy expenditure (PREE) according to the reevaluated Harris-Benedict equation. There was a weak positive correlation between EE and core temperature and a negative correlation between EE and nitrogen balance. EE/PREE was not different between septic and nonseptic patients (1.58 +/- 0.06 vs. 1.39 +/- 0.07). The calculations of nutrient oxidation rate indicated a high protein catabolic rate, a neoglucogenesis, and a lipolysis.

[Acute amiodarone poisoning. Clinical and pharmacokinetic study]. / Intoxication aiguë à l'amiodarone. Etude clinique et pharmacocinétique.

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.

[Fatal fulminant hepatitis in 2 women taking toloxatone (Humoryl)]. / Hépatites fulminantes mortelles chez deux femmes prenant de la 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.

[Systemic air embolism after CT-guided transthoracic biopsy using a cutting needle]. / Embolie gazeuse compliquant une ponction transthoracique à l'aiguille à couperet.

The authors report a case of systemic air embolism after CT-guided transthoracic needle biopsy using an 18G cutting needle. CT performed immediately after the occurrence of neurological signs showed air within the left ventricle but no air within the cerebral arteries. Radiologists must be aware of this extremely rare but potentially severe complication to provide accurate diagnosis and treatment.

[How to assess and monitor postoperative artificial nutrition?]. / Comment évaluer et surveiller la nutrition artificielle postopératoire?

Quantitative and qualitative nutritional requirements depend on the level of energetic expenses. Various formulas, especially the tables by Harris and Benedict allow the estimation of the level of energetic expenses with an approximation of 14%. Corrective factors permit an adjustment of the figures, according to the level of body aggression. In complex cases, indirect calorimetry allows a more accurate appraisal of energetic expenses. This technique provides also indications on the utilisation of each substrate and allows therefore to determine the optimal carbohydrate-lipid ratio for each patient. The assessment of the direct benefit of artificial nutritional support relies on anthropometric techniques and at present on body composition appraisal by determination of its impedance. The changes in muscular strength are difficult to assess. Moreover the time course of body weight is not specific for nutritional status. Therefore other biological indicators such as the nitrogen balance, the concentration of plasma proteins and albumin are more often assessed; proteins with a short half-life depend on the body aggression level. The potassium balance, which is easy to obtain in clinical practice, is a relevant indicator for nitrogen balance and protein synthesis. Clinical monitoring includes the checking of hydratation and its impact on the circulatory, respiratory and renal functions. The tolerance of enteral nutrition is appraised by the quality of gastrointestinal function. Biological monitoring includes the electrolyte balance and various variables of carbohydrate, lipidic and proteic metabolisms. It allows to check the absence of hyperglycaemia, hyperlipidaemia and cholestasis. The daily checking of catheters is part of the monitoring of nutritional support.(ABSTRACT TRUNCATED AT 250 WORDS)

[Methanol poisoning]. / Intoxication au méthanol.

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.

[Posttraumatic fat embolism]. / Embolies graisseuses post-traumatiques.

Between 1977 and 1982, fifty cases of post-traumatic fat embolism were treated in a general intensive care unit. Average age of patients was 25.5 +/- 13 years; there was no male majority. Mean free interval was 39 +/- 27 h. 12 cases (24%) had single fractures and 38 (76%) multiple fractures. Forty-four patients had a fractured femur. Thirty-two patients presented the complete clinical syndrome with general, respiratory, neurological and cutaneous signs. Thrombocytopaenia and hypocholesterolaemia were the biological signs most often seen. In forty-four patients, orthopaedic treatment consisted of immediate immobilization, usually with traction. Twenty-six patients were reoperated on: intramedullary nail for twenty patients, plate for the other six. Fat embolism appeared in spite of surgery in six cases; it worsened after surgery in six others. Seven patients had per- or postanaesthetic problems. Fourteen per cent of patients died. The decrease in mortality was mainly due to an improvement in mechanical ventilation techniques. Early surgical fixation remained the rule if there was no serious respiratory distress or haemodynamic instability, although it did not seem to change the mortality rate in this group of patients.

[Myocardial infarction during postoperative peridural analgesia with opiates]. / Infarctus myocardique au cours d'une analgésie péridurale postopératoire aux opiacés.

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.

[Continuous measurement of gas exchange during artificial ventilation]. / Mesure en continu des échanges gazeux au cours de la ventilation artificielle.

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.

[Orthotopic liver transplantation for severe amanita phalloides poisoning]. / Transplantation orthotopique du foie pour intoxication grave par amanite phalloïde.

Forty-eight hours after a women was poisoned by ingesting Amanita phalloides mushrooms, she developed fulminant hepatic failure with collapse, pH 7.24, lactic acidosis 7.6 mmol/l, hypoglycaemia 3.5 mmol/l, anuria and stage IV coma requiring tracheal intubation and mechanical ventilation. Transaminase level was up to 8,000 UI/l. Prothrombin and factor V levels were below 10 percent, with an APT time of 86 s versus a 29 s control time. Twenty-four hours after her admission, the patient underwent orthotopic liver transplantation. The postoperative period was uneventful, with return to consciousness and rapid normalization of hepatic biochemistry values, without signs of acute rejection. This 10th published case of orthotopic liver transplantation for Amanita phalloides poisoning with acute hepatic necrosis confirms that this type of treatment must be systematically envisaged in all such cases.