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Biomedical subjects

J J Rouby

Publications and source records attributed to J J Rouby.

At least 19 recordsLinked to original sources
PubMed1992

Continuous positive airway pressure (CPAP) vs. intermittent mandatory pressure release ventilation (IMPRV) in patients with acute respiratory failure.

Intermittent Mandatory Pressure Release Ventilation (IMPRV) is a positive pressure spontaneous breathing ventilatory mode in which airway pressure is released intermittently and synchronously with patient's spontaneous expiration in order to provide ventilatory assistance. Eight critically ill patients free of any factor known to alter chest wall mechanics (group 1) and 8 critically ill patients whose spontaneous respiratory activity was markedly altered by a flail chest, or by a C5 quadraplegia and/or by the administration of opioids (group 2) were studied prospectively. CPAP and IMPRV were administered to each patient in a random order during a 1 h period using a CESAR ventilator. Gas flow, tidal volume, tracheal pressure, esophageal pressure, end-expiratory lung volume and hemodynamic parameters were measured. In group 1 patients, the ventilatory assistance provided by IMPRV was associated with a significant decrease in spontaneous tidal volume whereas all other respiratory parameters remained unchanged. In group 2 patients, IMPRV increased minute ventilation from 8.0 +/- 2.61/min to 12.2 +/- 1.81/min (p less than 0.05), decreased PaCO2 from 46 +/- 7.3 mmHg to 38 +/- 6.8 mmHg (p less than 0.05) and reduced respiratory frequency from 21 +/- 10 bpm to 14 +/- 5.7 bpm (p less than 0.07). These results show that IMPRV provides significant ventilatory assistance to patients with mild acute respiratory failure either by decreasing patient's contribution to minute ventilation or by increasing alveolar ventilation in presence of respiratory depression of central or peripheral origin.

Acute Disease↗
PubMed1992

Nosocomial bronchopneumonia in the critically ill. Histologic and bacteriologic aspects.

To provide a comprehensive description of the histologic and bacteriologic characteristics of human nosocomial bronchopneumonia (BPN), the lungs of 83 critically ill patients decreased after a period of mechanical ventilation were examined in the immediate postmortem period. In addition, the accuracy of the protected minibronchoalveolar lavage (BAL) technique in the diagnosis of nosocomial BPN was evaluated. In each patient, a surgical pneumonectomy was performed at the bedside within 30 min following death. Each pulmonary lobe was sampled and bacteriologically analyzed using semiquantitative cultures in 50 patients and quantitative cultures in 33 patients. The entire lung was histologically analyzed using 5 to 10 slices per lung segment. In 69 patients, the bacteriologic result of a protected mini-BAL performed within 48 h preceding death was compared with histologic and bacteriologic results of study of the lung tissue itself. Histologic lesions of BPN were found in 43 of the 83 lungs examined. These lesions were (1) severe in the majority of patients (confluent BPN, n = 23; lung abscess, n = 6), (2) preferentially found in dependent lung segments, (3) often associated with nonspecific alveolar damage, (4) associated with positive lung cultures in 65% of patients (53% with gram-negative bacteria), (5) polymicrobial in 28% of patients, (6) characterized by a lobar bacterial burden greater than 10(3) cfu/g in 32% of cases. Using semiquantitative bacteriologic analysis, the sensitivity and the specificity of the protected mini-BAL in the diagnosis of nosocomial BPN were found to be 70 and 69%, respectively. Protected mini-BAL identified 77% of causative microorganisms of BPN.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchoalveolar Lavage Fluid↗
PubMed1991

Peripheral vascular effects of thiopental and propofol in humans with artificial hearts.

The peripheral vascular effects of thiopental 5 mg/kg and propofol 2.5 mg/kg were compared in five patients whose lungs were being ventilated and in whom a Jarvik-7 artificial heart had been implanted. The patients were monitored, using catheters that had been surgically inserted into the radial artery, the right and left atria, and the pulmonary artery. The Jarvik-7 settings were modified to render the artificial heart "preload independent" and to maintain cardiac output constant. Each patient received both drugs, with the interval between each drug ranging from 16 to 28 h. Hemodynamic parameters and catecholamine and atrial natriuretic peptide plasma concentrations were measured before drug administration and 5, 10, 15, 30, and 45 min later. Both drugs significantly decreased arterial pressure, systemic vascular resistance index, pulmonary arterial pressure (PAP), and right and left atrial pressures (RAP and LAP, respectively). However, propofol 2.5 mg/kg induced a significantly greater and more prolonged decrease in arterial pressure, systemic vascular resistance index, and RAP than that after administration of thiopental 5 mg/kg (P less than 0.05). Five minutes after drug injection, mean arterial pressure decreased by 21% after thiopental and by 39% after propofol (P less than 0.01); systemic vascular resistance index decreased by 21% after thiopental and by 44% after propofol (P less than 0.05); RAP decreased by 20% after thiopental and by 50% after propofol (P less than 0.05); mean PAP decreased by 18% after thiopental and by 32% after propofol (P less than 0.09); and LAP decreased by 40% after thiopental and by 46% after propofol (P less than 0.2). With both drugs, atrial natriuretic peptide, norepinephrine, and epinephrine plasma concentrations remained stable throughout the study period. Because cardiac output was maintained constant throughout the study, these results suggest that propofol 2.5 mg/kg is a more potent vasodilator of venous and arterial beds than is thiopental 5 mg/kg.

Adult↗
PubMed1990

Functional and metabolic activity of polymorphonuclear leukocytes from patients with adult respiratory distress syndrome: results of a randomized double-blind placebo-controlled study on the activity of prostaglandin E1.

Indirect and experimental evidence suggests that polymorphonuclear leukocytes, responding to an activating signal presumably related to the complement cascade activation, are involved in the pathogenesis of the adult respiratory distress syndrome (ARDS). The pathologic changes seem to be result of the polymorphonuclear leukocyte margination within the pulmonary capillary vessels and their activation with subsequent release of vasoactive peptides (thromboxane A2, prostaglandin E2) and toxic intracellular compounds. This study confirms that adherence, chemotaxis, and chemiluminescence are increased in polymorphonuclear leukocytes from patients with ARDS. Enhanced chemotactic and chemiluminescence capacities are likely specific to ARDS, whereas increased polymorphonuclear leukocyte adherence seems to be nonspecific. If increased polymorphonuclear leukocyte activation is important in the pathogenesis of ARDS, the inhibition of this phenomenon could play a therapeutic role. This double-blind prospective study was undertaken to assess if polymorphonuclear leukocyte activity is inhibited in vivo by the iv administration of prostaglandin E1 (PGE1) in patients with ARDS. A continuous infusion of PGE1 at a dose of 30 ng.kg-1.min-1 for 7 days did not modify the functional activity of polymorphonuclear leukocytes in patients with ARDS. Because hemodynamic instability was seen during infusion of this dose of PGE1, an increased dose was not tested. At the dose of PGE1 tested, no significant effect upon the function activity of polymorphonuclear leukocytes in patients with ARDS could be demonstrated.

Adult↗
PubMed1990

Peripheral vascular effects of halothane and isoflurane in humans with an artificial heart.

The peripheral vascular effects of isoflurane and halothane were compared in five critically ill patients in whom a Jarvik-7 artificial heart had been implanted. The lungs of all patients were mechanically ventilated in the postoperative period and the patients were monitored with an arterial catheter and with catheters that had been surgically inserted into the right and left atria and into the pulmonary artery. Norepinephrine and epinephrine plasma concentrations were measured using a radioenzymatic assay. The Jarvik-7 settings were modified to render the artificial heart "preload independent" and to maintain cardiac output constant. Each patient was anesthetized twice using halothane and isoflurane at two different MAC levels, 1 and 1.5 (Datex vapour analyzer), with the interval between each anesthetic ranging from 12 to 26 h. Both anesthetics significantly decreased mean arterial pressure (from 100 +/- 11 mmHg to 66 +/- 13 mmHg for halothane and from 102 +/- 17 mmHg to 48 +/- 11 mmHg for isoflurane; mean +/- SD) and systemic vascular resistance index (from 27 +/- 11 Wood units/m2 to 18 +/- 6 Wood units/m2 for halothane and from 30 +/- 6 Wood units/m2 to 13 +/- 3 Wood units/m2 for isoflurane; mean +/- SD), but with isoflurane to a significantly greater extent than with halothane (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Three mixed venous saturation catheters in patients with circulatory shock and respiratory failure.

Thirty-one critically ill patients with acute respiratory failure and circulatory shock were divided into three groups. Group 1 included 11 patients with an inserted mixed venous saturation (SvO2) catheter using three-reference wavelengths and characterized by one transmitting and one detecting fiberoptic filament (Oximetrix opticath catheter); group 2 included eight patients with an inserted SvO2 catheter using two-reference wavelengths and characterized by one transmitting and one detecting fiberoptic filament; (Edwards sat-one catheter); group 3 included 12 patients with an inserted SvO2 catheter using two-reference wavelengths and characterized by one transmitting and two detecting fiberoptic filaments. Once calibration procedures were performed, SvO2 measured by the catheter and by an hemoximeter OSM 3 (reference value) were compared following each therapeutic intervention. Over a period of 1.5 to 6 hours during which the hematocrit value remained unchanged, 119 measurements were obtained in group 1, 91 in group 2 and 181 in group 3. The dispersion of SvO2 values was much more pronounced with the two-reference wavelength systems using either one or two detecting fiber optic filaments, and the correlation coefficient was significantly higher with the three-reference wavelength system (r = 0.970 for the Oximetrix catheter vs r = 0.855 for the Edwards catheter and r = 0.826 for the Spectramed catheter, p less than 0.001). After 24 hours, the spontaneous drifts in the two-reference wavelength systems, using either one or two detecting fiber optic filaments (expressed as the SvO2 value measured by the catheter minus the reference SvO2 value) were significantly higher than the spontaneous drift in the three-reference wavelength system (9.3 +/- 7 percent for the Edwards catheter and +/- 6 +/- 4.1 percent for the Spectramed catheter vs 3.3 +/- 3.1 percent for the Oximetrix catheter, p less than 0.05). This study shows that a three-wavelength system is more accurate than a two-wavelength system for measuring acute changes in SvO2. The addition of a second detecting fiber optic filament does not seem to improve the accuracy of the system when SvO2 changes occur in conditions of stable hematocrit.

Carboxyhemoglobin↗
PubMed1990

Characteristics of atrial natriuretic hormone receptors in human pheochromocytomas.

The presence of functional receptors for human atrial natriuretic hormone in human pheochromocytomas was recently reported. The present study reports the binding of hANH as measured by Scatchard analysis in 4 human adrenal glands and in 5 human pheochromocytomas. Binding assays using [3H]ANH revealed a single class of high-affinity binding sites for hANH in both tissues. Human pheochromocytomas present a lower number of binding sites than normal human adrenal gland (Bmax of 7.1 +/- 2.1 vs 33.6 +/- 6.9 fmol/mg protein, respectively). However, the decreased number of ANH receptors was not paralleled by modifications of tissular cyclic GMP (cGMP). Moreover, plasma hANH concentrations in 7 patients with pheochromocytomas (20.2 +/- 2.7 pmol/l) were statistically higher than those obtained in 25 normal control humans (8.1 +/- 0.6 pmol/l, p less than 0.001). We also demonstrated the presence of immunoreactive ANH in the tumour itself.

Adrenal Gland Neoplasms↗
PubMed1989

[Comparative evaluation of 2 fiber optic catheters for the continuous measurement of Svo2].

Nineteen intensive care patients with shock and acute respiratory failure were studied using two different fiber-optic catheters used for the continuous measurement of mixed venous blood oxygen saturation (SVO2). In groupe I patients (n = 11), a Swan-Ganz catheter with optic fibres emitting light characterized by three different wavelengths was used (Opticath Oximetrix). In groupe II patients (n = 8), a Sat-one Edwards catheter was used instead (only two different wavelengths). All the patients were studied in the early stages of shock, once all the calibration procedures had been carried out. An increase in FIO2, using PEEP, fluid replacement therapy and vasoactive drugs or diuretics all improved the cardio-respiratory status of each patient. After each new therapeutic procedure, SVO2 was measured in blood samples obtained from these catheters, and from the pulmonary artery (to give the reference value, using an OSM3 Hemoximeter). Over a period of 1.5 to 6 h, 119 measurements were carried out in Group I, and 91 in Group II. The correlation coefficient was higher with the Oximetrix catheter than with the Edwards one (r = 0.970 and 0.855 respectively; p less than 0.001). Moreover, the 24 h spontaneous drift of the former catheter was less than that of the latter (+3.3 +/- 3.1% vs. +9.3 +/- 7%, p less than 0.05). This study showed that a catheter with optic fibres emitting a light with three wavelengths is more accurate than one emitting only two for the measurement of changes in SVO2 in critically ill patients.

Adult↗
PubMed1989

[Factors influencing mixed venous oxygen saturation in intensive care].

Changes in mixed venous blood oxygen saturation (SvO2) were studied in 2 groups of patients. Group I patients (n = 10) were all hypoxaemic, suffering from acute respiratory failure, requiring that FIO2 be maintained at 1 throughout the study; respiratory and haemodynamic conditions were improved using PEEP and cardiovascular support. On the other hand, Group II patients (n = 13) were non-hypoxaemic patients with circulatory shock in whom FIO2 was gradually increased, and the haemodynamic status was improved using positive inotropic drugs (dopamine, dobutamine, adrenaline, amrinone). All 23 patients had a Swan-Ganz catheter set up for monitoring; all the usual haemodynamic and respiratory parameters were measured. Haematocrit values were kept at the same level throughout the study. Haemodynamic parameters were measured each time a new therapeutic procedure was carried out. No close relationship between SvO2 changes and changes in cardiac index or O2 consumption were found. However, a close relationship existed between changes in SvO2 and changes in O2 extraction (EAO2): SvO2 = -EAO2 + 102 (Group I; r = 0.90, n = 54); SvO2 = -1.2 EAO2 + 103 (Group II; r = 0.93, n = 66). A strong relationship was also found between changes in SvO2 and in FIO2 in each patient of Group II. In the complicated physiological set-up of an intensive care patient, SvO2 reflects oxygen extraction. A fall in SvO2 is related to an altered oxygen demand: oxygen supply ratio. In the most seriously ill patients, there is no relationship between changes in SvO2 and cardiac index.

Adult↗
PubMed1989

A prospective study of protected bronchoalveolar lavage in the diagnosis of nosocomial pneumonia.

The value of a new technique of protected bronchoalveolar lavage not requiring bronchoscopy was prospectively evaluated for the diagnosis of nosocomial pneumonia in two groups of critically ill patients. The control group was comprised of 29 patients free of any pulmonary disease whose lungs were ventilated for a mean time of 14 +/- 9 days (mean +/- SD). The pneumonia group was comprised of 30 patients with histologically proven nosocomial pneumonia whose lungs were ventilated for a mean time of 11 +/- 8 days. All patients of the pneumonia group died, and postmortem lung biopsies were taken for bacteriologic and pathologic examination. Twice a week in the control group or within the day preceding death in the pneumonia group, distal bronchial samples were obtained by a technique of protected bronchoalveolar lavage performed at the bedside. Fifty-one distal bronchial samples were bacteriologically analyzed in the control group and 30 in the pneumonia group. The sensitivity of a positive protected bronchoalveolar lavage for diagnosing nosocomial pneumonia was 80%, whereas the specificity was 66%. In 73% of the patients of the pneumonia group, the microorganisms isolated in the protected bronchoalveolar lavage and in the lung culture were partially (16%) or completely in agreement (57%). Among the 43 microorganisms isolated in the lung cultures, 74% were recovered by the protected bronchoalveolar lavage technique. This study shows that the protected bronchoalveolar lavage is an accurate technique for the diagnosis of nosocomial pneumonia. Because the technique is simple, noninvasive, easily repeatable at the bedside, and enables gram staining, it represents an attractive alternative to the fiberoptic bronchoscopy technique using a plugged double-sheathed brush.

Biopsy↗
PubMed1989

Respiratory effects of the Jarvik-7 artificial heart.

In five anesthetized patients with a Jarvik-7 artificial heart, pulmonary volume displacements generated by cardiogenic oscillations were measured using an indirect spirometric method. Consequences on gas exchange were also evaluated during a 15-min period of apnea by use of a tracheal insufflation of pure O2 at a constant flow rate of 20 l/min. The Jarvik-7 artificial heart generated a mean pulmonary volume displacement of 105 +/- 29 (SD) ml/heart beat. After 15 min of apnea, arterial PCO2 (PaCO2) significantly increased from 29 +/- 5 to 47 +/- 6 (SD) Torr. PaCO2 increased by 0.8 Torr/min from the 5th to the 15th min of apnea. Mean arterial PO2, mean pulmonary shunt, mean O2 consumption, and mean metabolic production of CO2 did not change significantly during the apnea period. Because cardiac output was kept constant during the study, O2 transport was adequately maintained throughout the apnea period. In patient 1, where the period of apnea was continued for 60 min, PaCO2 progressively increased until the 45th min and then remained stable at 61 Torr during the last 15 min of apnea. This "plateau" corresponded to an alveolar ventilation of 3,907 ml/min, representing 69% of the alveolar ventilation calculated during conventional mechanical ventilation. In conclusion, the Jarvik-7 artificial heart provides a potent respiratory support through the cardiogenic oscillations it generates.

Adult↗