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Biomedical subjects

P Combes

Publications and source records attributed to P Combes.

At least 19 recordsLinked to original sources
PubMed1997

Combined effects of hypocapnia and nicardipine on airway resistance: a pilot study.

OBJECTIVE: The aim of this study was to investigate the modification of the resistive inspiratory properties of the respiratory system associated with hypocapnia in the presence of nicardipine. METHODS: The resistance of the respiratory system, Rrsmin, was studied in two groups of patients who needed mechanical hyperventilation. Group 1 (n = 14; 47 years) was the control group (head injuries); group 2 (n = 12; 53.5 years) included patients treated over a 3 week period with nicardipine (0.5 microgram.kg-1.min-1 i.v.) to prevent arterial vasospasm after subarachnoid haemorrhage. RESULTS: There was no statistical difference between the groups concerning anthropometric and basal respiratory characteristics. In group 1, hypocapnia caused a 20.9% increase in Rrsmin, but no significant increase was observed in group 2. CONCLUSION: Hypocapnic alkalosis had a significant bronchial constrictory effect, which was eliminated in the presence of nicardipine hydrochloride.

Airway Resistance↗
PubMed1996

Severe head injuries: an outcome prediction and survival analysis.

OBJECTIVE: To identify the predictors determined early after admission and associated with unfavorable outcome or early (within 48 h) death after severe head injury. DESIGN: Prospective cohort study. SETTING: A neurosurgical intensive care unit in a university hospital. PATIENTS: 198 consecutive comatose patients hospitalized from 1989 to 1992. RESULTS: Logistic regression showed that a combination of age, best motor response score from the Glasgow Coma Scale, and hypoxia provided a good prediction model of unfavorable outcome (sensitivity = 0.93). The length of participation of survivors was 6 to 61 months (median 27.1). The Cox model demonstrated age, motor score less than 3, mydriasis, and hypoxia as poor prognosis factors. CONCLUSIONS: Clinicians can determine the odds of a good outcome from the combination of three easily measurable factors using a simple diagram constructed from logistic regression. Survival analysis showed that motor score adjusted values greater than 3 had the same prognosis.

Adult↗
PubMed1995

[Prediction of respiratory complications after surgery of the abdominal aorta].

The most frequent type of complication in patients undergoing aortic surgery is respiratory. Preoperative lung function (PFT) and arterial blood gas measurement (ABG) are often carried out to assess the risk more precisely. The aim of the present retrospective study was to determine which value of lung function test could identify patients who developed such complications. "Receiver Operating Characteristic" (ROC) curves and the area beneath the curve for the diagnosis of respiratory complications were calculated for each variable of PFT and ABG. The greatest Youden index for each variable was chosen as indicative pulmonary function criterion of increased risk of pulmonary complications. One hundred and ninety-five patients (age: 65 +/- 10 years) were included. Respiratory complications occurred in 15% of patients. Respiratory complications increased from 12% if the vital capacity (VC) was > or = 77% of the predicted value to 35% if the VC was < 77% (P = 0.002), and from 10% if the FEV1 was > 76% to 34% if the FEV1 was > or = 76% (P = 0.0005). A decreased PaO2 or increased PaCO2 was not correlated with an increased incidence of respiratory complications. Length of stay in ICU or in hospital were increased when VC or FEV1 were low. Frequency of pulmonary complications was 9% in patients without PFT abnormalities, 16% in patients with either diminished VC or FEV1 and 35% in patients with both lowered VC and FEV1. However, all the areas under the ROC curves were < 0.7 and the sensitivity of the different variables was low. It is concluded that routine preoperative PFT and ABG cannot predict respiratory complications after abdominal aortic surgery.

Aged↗
PubMed1993

Pulmonary function tests predict outcome after cardiac surgery.

The aim of this study was to examine the value of systematic preoperative pulmonary function tests (PFTs) in order to reliably predict prolonged stay in I.C.U., prolonged mechanical ventilation and mortality in elective cardiac surgical patients. 149 consecutive adult patients (valvular replacement or coronary bypass graft) were studied retrospectively. We examined the preoperative respiratory data: vital capacity (VC), first second forced expired volume (FEV1), PaCO2 and PO2. Length of stay in I.C.U. (LICU), duration of mechanical ventilation (DMV), incidence of reintubation and survival rate were used as indices of respiratory morbidity. The results of the present study clearly indicate that patients with impaired airway flow rates had a prolonged postoperative recovery following cardiac surgery. Mortality, ICV and DMV increased when FEV1 was less than 1.5 L, VC was less than 2.5 L, or PaO2 was less than 8.5 kPa. Reintubation was associated with impaired flow rates. Pulmonary function tests appeared effective in predicting postoperative complications and the need for prolonged ventilatory support.

Cardiac Surgical Procedures↗
PubMed1992

Systemic vasomotor interaction between nicardipine and hypocapnic alkalosis in man.

The effects of hypocapnic alkalosis on the vasodilating action of nicardipine were studied in 6 patients after cerebral arterial aneurysm surgery. Each patient served as his/her own control during the 6 steps of the study. T0: baseline; T1: hypocapnic alkalosis alone (PaCO2: 3.5 kPa); T2: hypocapnic alkalosis and bolus injection of nicardipine (30 micrograms.kg-1 i.v.); T3: hypocapnic alkalosis and continuous 60 min infusion of nicardipine (0.5 microgram.kg-1.min-1), T4: determination of the infusion rate required to neutralize the effect of hypocapnic alkalosis; T5: same continuous dose of nicardipine as in T4 but reversal of hypocapnic alkalosis. Hypocapnic alkalosis alone caused a significant increase in the systemic vascular resistance index by 20% (T1). The bolus injection of nicardipine reversed this first effect (T2). The continuous infusion of nicardipine in T3 was insufficient to cancel the haemodynamic effect of hypocapnic alkalosis. During T4 the plasma levels required to neutralize completely the effect of hypocapnic alkalosis were twice those at T3. Normalization of the PaCO2 in step T5 induced a significant fall in the systemic vascular resistance index by 27.5% as compared with T0. In this study hypocapnic alkalosis modified the relationship between plasma levels of nicardipine and its expected vasoactive effects. This interaction was reversible.

Aged↗
PubMed1992

[Four cases of tracheoesophageal fistulas in adults in intensive care units].

Four cases of tracheo-oesophageal fistulae following mechanical ventilation are reported. The determining factors, revealing signs, and palliative and curative treatment are discussed based on a review of the literature. In this series, the tracheotomy cannula provided good protection of the upper airways in three cases of upper fistulae. In the other case, the fistula was too close to the carena, requiring the use of high frequency jet ventilation. The management of low, large fistulae is more problematic concerning the choice of technique and timing of the operation.

Adult↗
PubMed1992

Comparison of nicardipine and sodium nitroprusside in the treatment of hypertension after coronary bypass surgery (a pilot study).

Sodium nitroprusside is widely used in the treatment of hypertension after coronary artery bypass surgery despite its toxicity and its deleterious effect on the coronary circulation. The aim of this study was to compare the safety and effectiveness of nicardipine with sodium nitroprusside in a randomized study. Nicardipine and sodium nitroprusside are effective for controlling hypertension after coronary artery surgery. Oxygen myocardial balance was more often improved by nicardipine than by sodium nitroprusside. Hemodynamic stability was better with nicardipine which was also devoid of toxicity and might therefore have advantages over sodium nitroprusside in the management of hypertension after coronary artery surgery.

Aged↗
PubMed1991

Combined effects of nicardipine and hypocapnic alkalosis on cerebral vasomotor activity and intracranial pressure in man.

The effect of hypocapnic alkalosis (HA) on nicardipine-induced cerebral vasodilatation was studied in 2 groups of patients undergoing stereotaxic brain biopsy under general anaesthesia. Arterial diameter (AD) was measured in 16 different locations on a carotid arteriogram (lateral view), and intracranial pressure (ICP) was recorded with an intraventricular catheter. At time T0, in normocapnia an arteriogram was performed in both groups. The first group (GI) was then studied in hypocapnia (T1) and following an injection of nicardipine (T2), while the second group (GII) was studied first after injection of nicardipine (T1) and then in hypocapnia (T2). Groups GI (n = 6; 44 y) and GII (n = 6; 46 y) were similar with regard to age, blood pressure, heart rate and PaO2 at all three phases of the study. HA caused a 9.5% decrease in AD (GI.T1) compared to baseline values, and a 15.2% decrease when preceded by injection of nicardipine (GII.T2). In the latter case the decrease was 3% in comparison with baseline. Nicardipine increased AD by 14.7% (GII.T1) and by 18.5% when preceded by HA (GI.T2), but the rise (7.3%) was not significant in comparison with the baselines value. The changes variations were similar whether the entire arterial trunk or only the supraclinoid region were studied. HA decreased ICP by 44% (GI.T1) and by 50% after nicardipine (GII.T2). Nicardipine did not cause an increase in ICP. Nicardipine and HA antagonise each others vasomotor effects, as previously shown in the baboon using nimodipine.

Adult↗
PubMed1991

[Effect of peroperative analgesia on immediate postoperative oxygen consumption].

Oxygen consumption in the immediate postoperative period was assessed in a series of twelve patients undergoing maxillofacial surgery, randomly assigned to two groups (n = 6 for each). The anaesthetic protocol was the same in all patients: premedication with flunitrazepam 30 micrograms.kg-1, induction with flunitrazepam 20 micrograms.kg-1, fentanyl 5 micrograms.kg-1, thiopentone 5 mg.kg-1, pancuronium bromide 80 micrograms.kg-1, and maintenance during the first three hours with flunitrazepam 10 micrograms.kg-1.h-1 and pancuronium 0.03 micrograms.kg-1.h-1. All the patients were given a continuous infusion of fentanyl during the whole length of the surgery: in Group I (GI), 3 micrograms.kg-1.h-1 and in Group II (GII), 1 microgram.kg-1.h-1. The patients in Group II were also given enflurane 1.2 +/- 0.3 vol %. During the immediate postoperative period, the parameters studied were measured by means of an Engström Metabolism Calculator at the 15th, 30th, 45th, 60th, 120th and 240th minutes, and at the time of extubation. In GII, postoperative heart rate and lactic acid levels were higher than in GI (p less than 0.05). Both groups had oxygen consumption values greater than theoretical resting levels. However, postoperative oxygen consumption was greatly increased in GII with respect to GI during the first 4 hours (p less than 0.01). The respiratory quotient was greater in GI than in GII at the end of the study (p less than 0.05). These data indicate that the intraoperative analgesic technique influences postoperative oxygen consumption. A dose of fentanyl of 3 micrograms.kg-1.h-1 is more efficient than one of 1 microgram.kg-1.h-1 associated with enflurane.

Adult↗
PubMed1990

[Effect of nicardipine on cerebral vasomotor activity in hypocapnia].

Nicardipine, a calcium channel antagonist derivative of dihydropyridine, is a cerebral vasodilatator used in the treatment of cerebral vasospasms induced by subarachnoid hemorrhage after rupture of intracranial aneurysm. Hypocapnia is a powerful vasoconstrictor of cerebral arteries, and antagonizes in the baboon the cerebral vasodilative effect of nimodipine, another derivative of dihydropyridine. The action of nicardipine in presence of hypocapnia was not yet study in human. The study of the interaction of nicardipine and hypocapnia on the cerebral arteries show that hypocapnia antagonizes the cerebral vasodilatator properties of nicardipine.

Adult↗
PubMed1989

[Intraoperative nitroglycerin: value of determining individual doses: (surgery of the abdominal aorta)].

Thirteen patients requiring infrarenal aortic clamping were studied during flunitrazepam, fentanyl, pancuronium and nitrous oxide anaesthesia. Each awake patient was submitted to a volume loading test to determine the haemodynamic status and his optimal left pre-load. Anesthetic induction was well tolerated. Nitroglycerin was administered by continuous infusion before aortic clamping and we determined the dose necessary to decrease the systemic vascular resistance by 20 per cent. This dose was very variable and needed to be increased in five of 13 patients at the time of clamping. With nitroglycerin, we noticed no significant alteration of MVO2 at clamping. Volume loading allowed good stability at declamping.

Aged↗
PubMed1988

Radiotherapy alone in carcinoma of the intact uterine cervix according to G. H. Fletcher guidelines: a French cooperative study of 1383 cases.

A French Cooperative study of 1383 cases with invasive carcinoma of the intact uterine cervix treated with radiation therapy alone, using the guidelines provided by G. H. Fletcher led to the following conclusions: The techniques of treatment were easily reproducible in 9 French centers, working in a prospective cooperative study; Results similar to those of the original study were achieved in Stages I and IIA (MDAH substaging) with a locoregional failure rate of 7%; In Stage IIB, the locoregional failure rate of 16% is also comparable in both studies; Locoregional failures in Stage III are slightly lower than those reported in Houston, probably reflecting differences in patient's prognostic factors in France and Texas; The 5-year survival rate obtained in advanced Stages (UICC FIGO staging) are among the highest in the literature (76% in Stage IIb, 62% in Stage IIIa and 50% in Stage IIIb); The rate of severe complications remains acceptable and decreased throughout the study thanks to a better use of computer dosimetry.

Female↗