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Biomedical subjects

G Vourc'h

Publications and source records attributed to G Vourc'h.

At least 19 recordsLinked to original sources
PubMed1988

Prediction of outcome of anaesthesia in patients over 40 years: a multifactorial risk index.

The prediction of outcome of anaesthesia in patients over 40 years of age was assessed using a multifactorial index based on current preoperative factors recorded prospectively. The study was conducted using a representative sample of anaesthetizations (except for cardiac surgery) including 517 cases with major complication (occurring during or within 24 hours of anaesthesia) and a one in fifty random sample comprising 1538 cases without complication. A split sample approach was adopted and a logistic regression model was applied to two subsets of similar size. Four preoperative factors were significantly associated with the occurrence of complications: ASA physical status, age, surgical procedure (major/minor) and type (elective/emergency). Goodness-of-fit of the model was assessed using another sample of 332 cases with complication and a different subset of 987 cases without complication. The model fitted the data well (p = 0.15).

Age Factors↗
PubMed1988

[Relation of the fall in PO2 in ventilation of the lower lung in pulmonary surgery and the preoperative distribution of respiratory function].

Hypoxaemia during one-lung ventilation is influenced by the anatomic distribution of lung perfusion and hypoxic vasoconstriction. This study aimed to assess whether preoperative selective bronchospirometry could predict the degree of peroperative hypoxaemia. Twelve patients scheduled for pneumonectomy, lobectomy, wedge resection or decortication were included in the study. Preoperative data included the usual spirometric parameters, oxygen consumption, minute ventilation of each lung and arterial blood gases. A Carlens or Robertshaw tube was inserted in each case; the patients were ventilated with 100% oxygen and halothane was used for anaesthesia. Blood gases were measured during surgery before and after upper lung exclusion. When both lungs were ventilated, mean PaO2 was 390.5 +/- 92.4 mmHg; during one-lung ventilation, it fell to 210.8 +/- 109.2 mmHg. Routine spirometry could not predict the magnitude of fall in PaO2; however, it was correlated with the bronchospirometric oxygen consumption of each lung (r = 0.83; p less than 0.01). The anatomical distribution of lung perfusion seemed to be the predominant factor influencing the decrease in PaO2 during one-lung ventilation.

Aged↗
PubMed1988

[Development of anesthetic technics for resection-anastomosis of the trachea].

A series is reported of 109 patients, 45 +/- 18 yr old, undergoing tracheal sleeve resection. 101 patients had iatrogenic tracheal stenosis, 5 tracheal cylindroma, 2 tracheal cancer and 1 tracheal trauma. 84 patients underwent preoperative laser coagulation to increase the airway internal diameter. Anaesthesia for the sleeve resection was induced by thiopentone, and maintained by an opiate, nitrous oxide and, if necessary, a volatile anesthetic. Patients were intubated, after having been given a muscle relaxant, with either a normal length and diameter tube with a low pressure cuff, or a narrow (internal diameter less than 6 mm) 50 cm long tube with or without a low pressure cuff. Patients with long tubes were ventilated with intermittent positive pressure, and the others with high frequency jet ventilation (HFJV) via a urethral catheter within the endotracheal tube. 20% of the long tubes had to be replaced during surgery because of perforation of the cuff by a tracheal stitch. In all, six patients died, one as a result of a pneumothorax and air embolus due to HFJV. Preoperative photocoagulation reduced the risk of induction and intubation; the choice of endotracheal tube no longer depended on the tracheal diameter, but on the method of ventilation chosen. However, HFJV has tended to be phased out, except for the surgery of lesions close to the carena; it has been replaced by intermittent positive pressure ventilation via long tubes. Because laser photocoagulation can completely cure small stenoses, these patients requiring surgery were those with long stenoses which were difficult to treat.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Hypoxia secondary to the failure of an oxygen-air-nitrous oxide mixer].

A case is reported of hypoxia occurring during anaesthesia in a spontaneously breathing ASA I patient. The patient became cyanotic twice when breathing a gas mixture delivered by a safety mixer. Changing the machine solved the immediate problem. The diagnosis was difficult to make because the rotameters all showed normal delivery of oxygen and nitrous oxide. Oximetry elucidated the cause, which was found to be a defective rapid oxygen control. Because these machines do not appear to be absolutely reliable, the use of gas analysers should become more systematic.

Adult↗
PubMed1988

Complications related to anaesthesia in infants and children. A prospective survey of 40240 anaesthetics.

A prospective survey of anaesthesia-related mortality and morbidity in infants and children was carried out in a representative sample of anaesthetics performed in 440 institutions chosen at random in France. A total of 40240 anaesthetics were administered to patients younger than 15 yr, 2103 (5%) involving infants (younger than 1 yr). Twenty-seven major complications related to anaesthesia occurred during or within 24 h of the anaesthesia--an incidence of 0.7 per 1000 anaesthetics. Nine, of which four were associated with cardiac arrest, were observed in infants, whereas in children there were 18 complications of which eight were associated with cardiac arrest, one with fatal outcome. The risk of complications was significantly higher (P less than 0.001) in infants (4.3 per 1000) than in children (0.5 per 1000). Accidents observed in infants mainly occurred during maintenance of anaesthesia and were the result of respiratory failure. In children, circulatory failure was as frequent as respiratory failure and complications were observed almost equally during induction and maintenance and on recovery. The rate of complications increased significantly with the ASA score and the number of co-existing diseases. The incidence was also higher when a previous history of anaesthesia was present, when the procedure was an emergency, and when the duration of preoperative fasting was less than 8 h.

Adolescent↗
PubMed1986

Complications associated with anaesthesia--a prospective survey in France.

A prospective survey of complications associated with anaesthesia was carried out in France from 1978 to 1982 in a representative sample of 198,103 anaesthetics performed in 460 public and private institutions chosen at random in the country as a whole. There were 268 major complications associated with anaesthesia occurring during or within 24 hours of anaesthesia (one per 739 anaesthetics), among which 67 were followed by death within 24 hours and 16 by coma persistent after the 24th hour. The incidence of death and coma was one per 2387 anaesthetics. The incidence of death and coma totally attributable to anaesthesia was one per 7924 anaesthetics. Fifty-eight per cent of complications occurred during anaesthesia while 42 per cent were observed during the recovery period. Mortality was lower following complications during anaesthesia than for those during the recovery period. Half of the deaths and cases of coma totally attributable to anaesthesia were due to postanaesthetic respiratory depression. The rate of complications appeared to be dependent upon several risk factors: the patient's age, the number of associated diseases, the preoperative status, whether the operation was an emergency and the duration of procedure.

Adolescent↗
PubMed1986

Changes in intrathoracic pressures induced by positive end-expiratory pressure ventilation after cardiac surgical procedures.

The consequences of controlled ventilation with positive end-expiratory pressure (PEEP) were studied, after cardiac surgical procedures, in two groups of patients supposed to have different lung and chest wall mechanical properties. The first group included 6 patients who had undergone coronary artery graft surgical procedures (CGS). The second group included 5 patients who had undergone a mitral valve replacement (MVR). Postoperatively, static lung and chest wall compliance was measured by stepwise inflation and deflation of the thorax. Esophageal, pericardial, and pleural pressures were then measured, and cardiac output was determined while PEEP was increased from 0 to 20 cm H2O. Lung and chest wall compliance values sharply decreased in MVR patients. This accounts for the lower values for pleural and pericardial pressures in this group than in the CGS patient group, but the transmission of airway pressure was identical in the two groups when PEEP was increased. The decrease in cardiac output induced by PEEP was similar in the two groups. The results suggest that the opposing influences of lung and chest wall compliance on airway pressure transmission could at least partly explain the hemodynamic effects of PEEP in patients in whom the mechanical properties of the lung and thorax are impaired. PEEP ventilation should be used cautiously in patients suspected of having thoracic rigidity.

Cardiac Output↗
PubMed1986

What changes can be expected during high frequency jet ventilation when the rate of ventilation, the I:E ratio and the driving pressure are modified? A laboratory study.

Changes in minute ventilation, tracheal airway pressure and lung volume have been measured using a jet ventilator (VS 600) during different rates of ventilation, I:E ratios and driving pressures. A lung model with a slightly increased compliance and an increased airway resistance was used. Five rates of ventilation (from 60 to 230 b.p.m.), three I:E ratios (0.25, 0.43, 0.67) and three driving pressures (200, 300 and 400 kPa) were studied. The increases in the rate of ventilation did not modify minute ventilation significantly, decreased peak airway pressure only slightly and increased end-expiratory pressure and lung volume. The increases in I:E ratio produced increases in minute ventilation, peak airway pressure, end-expiratory pressure and lung volume. The increases in driving pressure induced changes similar to those produced by the alterations in I:E ratio.

Airway Resistance↗
PubMed1986

The pharmacokinetics of droperidol in anesthetized patients.

A pharmacokinetic study of droperidol was performed in ten anesthetized patients receiving an intravenous bolus dose of 150 micrograms/kg of droperidol. Plasma concentrations were measured using a specific radioimmunoassay method. The pharmacokinetics of droperidol can be described according to a three-compartment open model. The mean (+/- SD) half-life for the rapid (t 1/2 pi) and slow distribution t 1/2 alpha) phases was 1.4 +/- 0.5 min and 14.3 +/- 6.5 min, respectively. The mean elimination half-life, t 1/2 beta was 103.8 +/- 20.2 min. The mean (+/- SD) total body clearance was 14.1 +/- 4.4 ml X min-1 X kg-1, and the total apparent volume of distribution (Vd beta) was 2.04 +/- 0.50 l/kg. The short terminal half-life of droperidol does not correlate with the well-known, relatively prolonged duration of its pharmacologic action.

Adult↗
PubMed1986

Indications and technique for endoscopic laser resections in bronchology. A critical analysis based upon 2,284 resections.

Over a period of 6 years, we have treated 1,310 patients in 2,284 sessions using a neodymium-yttrium aluminum garnet laser. Indications are more often palliative than curative, with the primary goal to relieve an obstructed airway in a single treatment. The effectiveness of such resections is widely recognized, but indications for such a technique with its limitations deserve emphasis. The use of a rigid bronchoscope is important to provide satisfactory operating conditions and especially to manage hemorrhage rapidly while maintaining a satisfactory airway.

Adolescent↗
PubMed1985

Jet ventilation using low or high frequencies, during bronchoscopy.

Jet ventilation, through a bronchoscope, was evaluated using a lung model (normal compliance and increased airway resistance). Three I/E ratios (0.25, 0.43, 0.67) and seven rates of ventilation (from 20 to 230 cycles per min (c min-1) were studied with the bronchoscope either unoccluded or partially occluded by a telescope. Increases in I/E ratio induced increases in minute ventilation, peak airway pressure, end-expiratory pressure and lung volume. Increase in the rate of ventilation decreased peak airway pressure, increased end-expiratory pressure and lung volume; minute ventilation increased in parallel with the increase in the rate of ventilation or remained constant when a high I/E ratio was used. The introduction of the telescope reduced minute ventilation, as a result of a decrease in the amount of air entrained, and increased end-expiratory pressure and lung volume. The risk of barotrauma as a result of high peak pressure is reduced during high frequency jet ventilation, but the increase in lung volume, particularly when the telescope is introduced, may be of clinical importance.

Bronchoscopy↗
PubMed1985

Circulatory responses to thiopentone and tracheal intubation in patients with coronary artery disease. Effects of pretreatment with labetalol.

The haemodynamic responses to induction and tracheal intubation have been studied in patients with coronary artery disease randomly assigned to a labetalol pretreatment group (n = 14) or to a placebo group (n = 16). Twelve hour before operation, treated patients received a bolus dose of labetalol 0.5 mg kg-1 followed by a constant infusion of 0.1 mg kg-1 h-1 i.v. Anaesthesia was induced with thiopentone and phenoperidine, and intubation performed following the administration of suxamethonium. At intubation, the changes in heart rate (P less than 0.01), mean arterial pressure (P less than 0.05) and rate-pressure product (P less than 0.01) were significantly smaller in the labetalol group compared with the placebo group. Labetalol pretreatment appears satisfactory and may be useful in patients with coronary artery disease who have a normal left ventricular ejection fraction.

Anesthesia, General↗
PubMed1985

Pharmacokinetics of phenoperidine in anaesthetized patients undergoing general surgery.

The pharmacokinetics of phenoperidine have been studied in five anaesthetized patients receiving a 2-mg bolus dose i.v. Plasma concentrations were measured using a sensitive radioimmunoassay method. The distribution of phenoperidine was described according to a two-compartment open model. The mean distribution half-life (T1/2 alpha) for the five patients was short (2.2 min); the mean elimination half-life (T1/2 beta) was 193 min. The mean whole body clearance was 22 ml min-1 kg-1 and the apparent steady state distribution volume (VSS) was 5.7 litre kg-1. Secondary concentration peaks occurred in all patients; in two patients these were substantial and occurred 80 min after injection.

Anesthesia, General↗
PubMed1985

Pharmacokinetics of phenoperidine in patients undergoing cardiopulmonary bypass.

Phenoperidine concentrations were studied, using radioimmunoassay, in five patients submitted to coronary artery bypass graft surgery. Administration of phenoperidine consisted of a 5-mg bolus dose followed by constant infusion of 5 mg h-1. Before cardiopulmonary bypass, phenoperidine concentrations were stable in an individual patient, but there was a large scatter between patients. The concentrations decreased immediately following the start of the bypass, but this decrease was short. During cardiopulmonary bypass, the phenoperidine concentrations increased progressively and were greater at the end of the bypass than before it. The increase in concentration continued following the discontinuation of bypass. The ratios of change of the observed results were in accord with a theoretical evaluation, although the observed concentrations were all greater than those calculated, except at one point. This difference in phenoperidine concentration is probably related to an alteration of liver plasma flow. Haemodilution as a result of the priming of the cardiopulmonary bypass circuit played only a transient role.

Adult↗