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P Montravers

Publications and source records attributed to P Montravers.

48 records · Page 3Linked to original sources
PubMed1993

Pilot study of cardiopulmonary risk from pentoxifylline in adult respiratory distress syndrome.

Neutrophils and cytokines are directly involved in the pathophysiology of adult respiratory distress syndrome (ARDS). Pentoxifylline (PTX) has been shown in vitro to protect against the inflammatory effects of neutrophils and cytokines. The same protective effects have been demonstrated on animal models of lung injury. These results suggested that PTX might be useful in patients with ARDS. The cardiopulmonary effects of large doses of PTX were evaluated in a pilot study performed in six patients with severe ARDS. PTX was administered with an initial 1-mg/kg bolus, followed by infusion of 1.5 mg/kg/h over 6 h. No significant change was observed in the gas exchange and hemodynamic parameters, except for a 10 percent increase in the heart rate during the infusion period. Our results demonstrate that large doses of PTX induced only minor hemodynamic changes without worsening in pulmonary gas exchange. Further studies are warranted to evaluate human safety and ultimately the effectiveness of PTX in the treatment of ARDS.

Aged↗
PubMed1993

Cardiopulmonary effects of bronchoalveolar lavage in critically ill patients.

Bronchoalveolar lavage (BAL) has been proposed as a useful procedure for bacteriologic diagnosis of lower respiratory tract infection in mechanically ventilated patients. To determine the cardiopulmonary effects of this procedure and to identify the patients at risk of poor tolerance, 30 critically ill ventilated patients suspected of having pneumonia were studied. Hemodynamic and gas exchange parameters were continuously recorded using an arterial catheter, a Swan-Ganz catheter with SvO2 display, and a pulse oximeter. In addition to the basal sedation required by these patients, midazolam, 0.1 mg/kg intravenously, was administered 5 min prior to bronchoscopy. A moderate increase (10 percent from basal values) in heart rate, mean arterial pressure, and cardiac index was recorded at each measurement during the procedure. A marked decrease in PaO2 was observed during bronchoscopy associated with an increase in oxygen consumption. Maximal changes in SaO2 and SvO2 were recorded at the end of BAL. Two hours after the end of BAL, PaO2 values were still 20 percent lower than pre-BAL values in 40 percent of the patients. We conclude that BAL can be performed safely in most critically ill ventilated patients who have stable hemodynamic and ventilatory parameters. However, none of the recorded parameters allows identification of the patients at risk of poor tolerance of the procedure.

Analysis of Variance↗
PubMed1993

[State of activation of polynuclear neutrophils and cytokines in acute respiratory distress syndrome in adults].

To gain further insight into the pathogenesis of the adult respiratory distress syndrome (ARDS), the authors studied possible relationships among the activation status of circulating polymorphonuclear neutrophils (PMN), cytokine levels, and the severity of lung injury in 31 patients: 15 with ARDS, 9 with severe pneumonia uncomplicated by ARDS, and 7 mechanically ventilated patients with neither ARDS nor pneumonia. Nine healthy subjects served as controls. Using flow cytometry, the authors identified a subpopulation of PMN with an increased capacity to generate hydrogen peroxide after stimulation ex vivo in all three patient groups; significantly higher values were found in those with ARDS. The PMN stimulation index, a reflection of the degree of hyperresponsiveness, correlated with elevated levels of tumor necrosis factor alpha (TNF-alpha) in plasma, and both spontaneous and lipopolysaccharide (LPS)-induced TNF-alpha production by cultured monocytes. These biological expressions of PMN activation and cytokine generation both correlated with indices of the severity of lung injury, but not with the overall clinical severity. In contrast, IL-6 and IL-1 beta showed little or no relationship with either the degree of lung injury or PMN hyperresponsiveness. We conclude that TNF alpha-primed PMN may play a major role in the pathogenesis of ARDS-associated lung injury.

Adult↗
PubMed1992

[Impairment of deglutition reflex after prolonged intubation].

This study was designed to assess the swallowing reflex after an endotracheal intubation of more than 24 h, as well as the influence of age and duration of intubation on swallowing. Twenty patients (aged 58 +/- 17 years) who had been intubated for more than 24 h were compared with fifteen others (63.1 +/- 16.7 years), who had never been intubated. All had a nasogastric tube. Swallowing was assessed after administration of 0.25, 0.5, 0.75 and 1 ml volumes of normal saline, in a random sequence, into the epipharynx through a thin catheter passing through the nostril after extubation (E0), and then at 1 (E1), 8 (E8), 24 (E24) and 48 h (E48) in the extubated patients, and once in the control patients. Swallowing responses were identified by an electromyogram of the floor of the oral cavity. The efficiency of the swallowing reflex was assessed by the delay between instillation and the first swallowing response obtained, and the number of swallows recorded during the first 15 seconds following each injection. There was a significant increase in swallowing delay in intubated patients for volumes less than 1 ml during the first three measurements. Recovery occurred for 0.5 and 0.75 ml at E24 and E48, when compared with the control group. However, delay remained increased throughout the study for 0.25 ml. The number of swallows was the same in both groups for each volume tested. There was no correlation between increased delay and age or duration of intubation. These data confirmed that prolonged endotracheal intubation impairs the swallowing reflex.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effects of i.v. midazolam on upper airway resistance.

We have measured changes in supraglottic airway resistance (Rsg) produced by midazolam. Ten subjects were studied on two occasions, receiving in a random order either midazolam 0.1 mg kg-1 or placebo. Supraglottic pressures were measured using a balloon-tipped catheter and air flow with a pneumotachograph. Rsg were calculated at a flow rate of 0.3 litre s-1 during inspiration. No changes in Rsg and no apnoeic events were noted following placebo injection. Mean Rsg increased from 0.23 (SEM 0.07) kPa litre-1 s to 1.29 (0.38) kPa litre-1 s 5 min after injection of midazolam (P less than 0.01), and remained increased significantly for 20 min. Twenty-two apnoeic events were recorded in six subjects, including 11 obstructive events. We conclude that midazolam in sedative doses increases Rsg markedly and induces central apnoea during the first few minutes after i.v. administration and this is followed by obstructive apnoea.

Adult↗
PubMed1992

Subpopulation of hyperresponsive polymorphonuclear neutrophils in patients with adult respiratory distress syndrome. Role of cytokine production.

To gain further insight into the pathogenesis of the adult respiratory distress syndrome (ARDS), we studied possible relationships among the activation status of circulating polymorphonuclear neutrophils (PMN), cytokine levels, and the severity of lung injury in 31 patients: 15 with ARDS, nine with severe pneumonia uncomplicated by ARDS, and seven mechanically ventilated with neither ARDS nor pneumonia. Nine healthy subjects served as controls. Using flow cytometry, we identified a subpopulation of PMN with an increased capacity to generate hydrogen peroxide after stimulation ex vivo in all three patient groups; significantly higher values were found in those with ARDS. The PMN stimulation index, a reflection of the degree of hyperresponsiveness, correlated with elevated levels of tumor necrosis factor-alpha (TNF alpha) in plasma, and both spontaneous and lipopolysaccharide-induced TNF alpha production by cultured monocytes. These biologic expressions of PMN activation and cytokine generation both correlated with indices of the severity of lung injury, but not with the overall clinical severity. In contrast, IL-6 and IL-1 beta showed little or no relationship with either the degree of lung injury or PMN hyperresponsiveness. We conclude that TNF-alpha-primed PMN may play a major role in the pathogenesis of ARDS-associated lung injury.

Flow Cytometry↗
PubMed1986

[Renovascular hypertension with renal failure: value of renal revascularization].

The purpose of this work was to determine the effects of renal revascularization on blood pressure and renal function in 9 patients with arterial stenosis involving both kidneys (7) or a solitary kidney (2). There were five women and four men with a mean (SD) age for 64.5 +/- 7 years. The duration of hypertension ranged from 2 to 28 years (mean = 12 +/- 8). Blood pressure ranged from 210/100 to 260/150 mmHg, despite the use of three or more antihypertensive agents in 7 cases. The serum creatinine level, on presentation, ranged from 160 to 265 mumol/l (mean = 198 +/- 30 mumol/l). Intravenous pyelograms were not suggestive of renovascular disease in 4 of 7 cases. Digital angiography or arteriography demonstrated severe stenosis of the artery of the solitary kidney in 2 patients, severe bilateral atherosclerotic disease in 7 patients, three of them had complete occlusion of a main renal artery. During hospitalization, therapy with captopril (5 patients) or minoxidil (1 patient) lowered blood pressure in 3 cases, but induced a marked increase in serum creatinine level in 4 cases. In two patients, medically treated, severe and rapidly progressive impairment of renal function was observed. The seven remaining patients underwent surgical revascularization (two after unfructuous percutaneous transluminal angioplasty). One died 45 days later. Blood pressure control with diastolic blood pressure of 100 mmHg or less was achieved in the other six, although each patient continued to require antihypertensive medication (bitherapy: 2, monotherapy: 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

[Value of the kidney revascularization in renovascular hypertension with kidney failure].

The effects of renal revascularization on blood pressure and renal function were evaluated in 8 hypertensive patients with renal impairment and renal artery stenosis in both kidneys (6 cases) or in a solitary kidney (2 cases). Mean age was 66 +/- 7 years. The mean duration of arterial hypertension was 13 +/- 8 years. In spite of treatment with 3 antihypertensive drugs (or more in 5 cases) blood pressure values ranged from 170-90 to 260-150 mmHg. Adding captopril (in 3 cases) or minoxidil (in 1 case) resulted in control of hypertension in 1 patient and further deterioration of renal function in 2. Two patients underwent surgery after failure of percutaneous transluminal angioplasty. There were 6 revascularizations and 2 nephrectomies with contralateral revascularization. One patient died post-operatively. In the remaining 7 patients, the hypertension was controlled with one or two drugs and the renal function remained stable or improved over a mean follow-up period of 2 years. We consider that these results warrant radiological exploration in all patients, even old, with renal impairment and drug-resistant hypertension. Renal revascularization must be performed as early as possible in view of the rapid degradation of renal function under medical treatment in these patients.

Acute Kidney Injury↗