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Biomedical subjects

B Roquefeuil

Publications and source records attributed to B Roquefeuil.

At least 19 recordsLinked to original sources

A comparative study of controlled-release morphine (CRM) suspension and CRM tablets in chronic cancer pain.

This study compared the efficacy and the adverse effects of controlled-release morphine (CRM) suspension (SAR 213) and CRM tablets (Moscontin) in the treatment of cancer pain. This multicenter, randomized, double-blind, double-dummy, crossover study was carried out on 52 patients. Each patient received both study treatments given at an equivalent dosage of morphine during each of two 7-day periods. The primary outcome variable was the severity of pain assessed three times daily by means of a visual analogue scale. Secondary criteria of efficacy were the severity of pain assessed by verbal rating scale, the need for "rescue" doses of immediate-release morphine, treatment preference, and indices of quality of life (activity, mood, sleep). There were no statistically significant differences in the parameters assessed when comparing the two groups. This study shows that, when prescribed at the same doses, CRM suspension and CRM tablets have similar efficacy and adverse effects, as well as the same duration of action. The results of this first clinical study carried out on CRM suspension are especially relevant for patients with cancer pain who have difficulty swallowing.

Delayed-Action Preparations

Hemodynamic effect of calcium channel blockade during anesthesia for coronary artery surgery.

Because the choice of anesthetic technique does not influence the incidence of perioperative myocardial ischemia, reduction of ischemic risk may require specific antianginal therapy. Calcium entry blockers are effective drugs in antianginal therapy. Diltiazem reduces myocardial oxygen demand through decreases in heart rate, inotropy, and systolic function, while increasing myocardial oxygen delivery through coronary vasodilation. These potentially beneficial effects of diltiazem were evaluated in 15 of 29 patients (diltiazem v placebo, double-blind study) scheduled for coronary artery bypass graft surgery. Continuous infusion of diltiazem (0.15 mg/kg bolus followed by 2 micrograms/kg/min), during anesthesia and surgery before cardiopulmonary bypass, significantly reduced the major MVO2 determinants during anesthesia with moderate doses of fentanyl and a benzodiazepine (midazolam in 8 of 14 control patients and 9 of 15 treated patients, or flunitrazepam in the others). Heart rate, mean arterial pressure, and inotropy were decreased during the most stressful events of surgery when plasma diltiazem concentrations were in the therapeutic range (greater than 96 ng/mL). The number of patients with perioperative ischemia was 2 of 15 in the treated group and 4 of 14 in the control group. Provided that diltiazem plasma concentrations are sufficient, it can contribute to lowering the ischemic burden during anesthesia for coronary artery surgery.

Anesthesia, Intravenous

Effects of halothane and isoflurane on transient renal dysfunction associated with infrarenal aortic cross-clamping.

Aortic cross-clamping for reconstructive aortic surgery is associated with impairment of renal function. Halothane or isoflurane was used to assess the influence of volatile anesthesia on renal hemodynamics during aortic surgery. Nineteen patients with normal preoperative creatinine clearances who were scheduled for reconstructive aortic surgery were randomly divided into two groups: halothane group (n = 9) and isoflurane group (n = 10). Induction of anesthesia consisted of midazolam, fentanyl, and pancuronium. Anesthesia was maintained with fentanyl and halothane or isoflurane in nitrous oxide and oxygen (50/50). Systemic hemodynamics were similar in both groups throughout surgery. Before aortic cross-clamping, effective renal plasma flow (ERPF) (131I-hippuran clearance) and glomerular filtration rate (GFR) (99Tc-DTPA clearance) were significantly lower in the halothane group (118.4 +/- 25.6 and 19.7 +/- 5.2 mL/min, respectively) than in the isoflurane group (253.4 +/- 51.5 and 44.9 +/- 8.4 mL/min) (P less than 0.05 for both). During cross-clamping, the renal variables were not markedly affected in either group and remained higher in the isoflurane-anesthetized patients (232.9 +/- 47.1 and 49.5 +/- 1.2 mL/min for ERPF and GFR, respectively) than in the halothane-anesthetized patients (132.4 +/- 31.6 and 14.8 +/- 3.7 mL/min, respectively) (P less than 0.05). After aortic unclamping, ERPF increased markedly in both groups (467.8 +/- 122 and 362.5 +/- 57.7 mL/min in the halothane and isoflurane groups, respectively), as did GFR (74.8 +/- 22 and 71.8 +/- 13.1 mL/min, respectively). These results suggest that anesthesia with halothane is associated with transient renal vasoconstriction during abdominal surgery. In contrast, aortic cross-clamping during isoflurane anesthesia was not associated with renal hemodynamic impairment.

Adult

Myocardial depressant effect of nitrous oxide after coronary artery bypass graft surgery.

We have studied the cardiovascular effects of nitrous oxide after cardiac ischaemia-reperfusion injury caused by aortic cross-clamping and unclamping during coronary artery bypass grafting (CABG). At the time of chest closure, 20 patients were allocated randomly to receive oxygen and air (FIO2 = 0.5) or 50% nitrous oxide in oxygen in addition to anaesthesia with fentanyl. Nitrous oxide significantly decreased mean arterial pressure (P less than 0.01) and cardiac index (P less than 0.05), which suggests that nitrous oxide with fentanyl may significantly depress left ventricular performance after CABG. Although ischaemia-reperfusion cardiac injury did not appear to increase the myocardial depressant effect of nitrous oxide, the use of nitrous oxide is not recommended immediately after CABG.

Aged

Does choice of the anesthetic influence renal function during infrarenal aortic surgery?

Reconstructive infrarenal aortic surgery is associated with impairment of renal function owing to vasoconstriction during and after aortic cross-clamping. To assess the influence of anesthetic technique on renal hemodynamics during aortic surgery, 34 patients received one of four anesthetics: isoflurane (n = 10), halothane (n = 9), droperidol (n = 8), and flunitrazepam (n = 7). Supplemental anesthesia consisted of midazolam, fentanyl, nitrous oxide in oxygen (50%), and pancuronium. Before aortic cross-clamping, effective renal plasma flow (ERPF) (131iodohippuran clearance) and glomerular filtration rate (GFR) (99technetium-DTPA clearance) were low in the halothane and flunitrazepam groups (118.4 +/- 25.6 and 170 +/- 35 mL/min for ERPF; 19.7 +/- 5.2 and 26.9 +/- 5.8 mL/min for GFR, respectively) and better preserved in the isoflurane group (253.4 +/- 51.5 and 44.9 +/- 8.4 mL/min, respectively; P less than 0.05 between isoflurane and halothane groups) or in the droperidol group as regards GFR (75.4 +/- 9.4 mL/min, P less than 0.05). During clamping, both renal variables were not markedly affected in any group except in the droperidol group in whom GFR significantly decreased from preclamp value. The GFR was then significantly higher in the isoflurane group (49.5 +/- 9.2 mL/min) than in the halothane and flunitrazepam groups (14.8 +/- 3.7 and 26.5 +/- 10.1 mL/min, respectively; P less than 0.05). After aortic declamping, ERPF and GFR increased markedly in the halothane group, and there was no significant difference between the groups. These results suggest that renal hemodynamics are less altered with droperidol-fentanyl anesthesia during abdominal surgery but not during aortic cross-clamping.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Hemodynamic effects of anesthesia in patients chronically treated with angiotensin-converting enzyme inhibitors.

Angiotensin-converting enzyme inhibitors (ACEIs) are increasingly used in the treatment of cardiovascular disease, but recent reports have warned of some hemodynamic risk (hypotension and bradycardia) when associated with anesthesia. To assess the hemodynamic effects of induction of anesthesia in patients chronically treated with ACEIs, 16 hypertensive patients scheduled for coronary artery bypass graft surgery (n = 12) or vascular surgery (n = 4) were studied. Eight of them were chronically treated (for at least 1 mo) with ACEIs (ACEI group), and the remaining eight (control group) were treated with other classes of antihypertensive drugs. Induction of anesthesia, which consisted of flunitrazepam (0.03 mg/kg), fentanyl (0.006 mg/kg), and pancuronium (0.1 mg/kg) IV, was followed by a significant decrease in mean arterial blood pressure from baseline in both groups (by 16.8% in controls [P = 0.001] and 33.5% in ACEI-treated patients [P = 0.001] [P = 0.041 between groups]). In control patients, mean arterial blood pressure decrease was only associated with a significant decrease in cardiac index (-18%, P = 0.014). In ACEI-treated patients, the arterial blood pressure decreases were associated with consistent reductions in pulmonary capillary wedge pressure (-26.4%; P = 0.035) and cardiac index (-23.9%; P = 0.001). Systemic vascular resistance index and heart rate were moderately changed (-14.2% and -4.5%, respectively). Rapid restoration of arterial blood pressure was obtained in all ACEI-treated patients, mainly with the intravenous administration of 0.4 to 0.7 L of lactated Ringer's solution. Phenylephrine (0.38 +/- 0.9 mg) was, however, required in four patients when mean arterial blood pressure was less than 60 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Mechanisms of renal hemodynamic impairment during infrarenal aortic cross-clamping.

Infrarenal aortic cross-clamping is associated with impairment of renal hemodynamics due to vasoconstriction, the mechanism of which remains under debate. To assess the renal effect of two potent renal vasodilators (enalapril, a converting enzyme inhibitor, and nicardipine, a calcium antagonist), 24 patients scheduled for reconstructive aortic surgery were randomly allocated to one of three treatment groups (n = 8 each) and received either a placebo, nicardipine, or enalapril. Anesthesia consisted of flunitrazepam, fentanyl, pancuronium, and, occasionally, droperidol. Although aortic cross-clamping was associated with no change in mean arterial blood pressure, decreased cardiac output and increased systemic vascular resistance occurred in control patients (33% and 43%, respectively, both P less than 0.05 versus baseline) and nicardipine-treated patients (51.7% and 67.7%, respectively, both P less than 0.05 versus baseline); however, changes in cardiac output and systemic vascular resistance failed to reach significance in enalapril-treated patients. Glomerular filtration rate (technetium 99-diethylenetriaminepentacetic acid clearance) and effective renal plasma flow (iodo-Hippuran 131 clearance) decreased for the duration of aortic cross-clamping in control patients (42.9% and 18.5%, respectively, both P less than 0.05 versus baseline) and enalapril-treated patients (34.0% and 38.1%, respectively, both P less than 0.05 versus baseline), but no change was observed in nicardipine-treated patients. These results suggest that the reninangiotensin system is not an important determinant of the renal vasoconstriction associated with aortic cross-clamping. In contrast, renal dysfunction may be alleviated by the dihydropyridine derivative nicardipine, which probably acts at the level of the preglomerular resistance vessels.

Adult

[Comparison of the effects of epsilon-aminocaproic acid and aprotinin on intra- and postoperative bleeding in heart surgery].

Excessive bleeding during and after cardiac surgery with cardiopulmonary bypass is a real problem in this kind of surgery. The use of prophylactic high doses of aprotinin (APROT) reduces blood loss in this context but this treatment is expensive. Some investigators have advocated that epsilon-aminocaproic acid (EACA), a cheaper antifibrinolytic drug, could reduce blood loss in cardiac surgery. The goal of this prospective study was to determine if EACA is as effective as APROT for this clinical condition. Sixty patients undergoing elective surgery for cardiac disease were randomly allocated to one of the two groups. Drugs were administered after induction of anesthesia at a dose of 2.10(6) UIK in the APROT group or 5 g in the EACA group. The same dose was added to the priming of the cardiopulmonary bypass circuit. Until the skin closure the patients received 5.10(5) UIK/h of APROT or 2 g/h of EACA. Bleeding during and after surgery was not different between the two groups. No complication, directly due to the treatment administered, was observed. EACA seems to be as effective as APROT to reduce intra and post cardiac surgery blood loss. EACA has the advantage of being cheaper (treatment is approximately 200 times cheaper), therefore allowing a wider use.

Aminocaproic Acid

[Vascular effects of adenosine-triphosphate].

This study assessed the effects of adenosine triphosphate (ATP) on systemic vascular resistances during the hypothermic cardiopulmonary bypass phase of cardiac surgery. Twenty patients scheduled for cardiac surgery were randomly divided into an ATP group (n = 10), and a placebo group (n = 10). Anaesthesia was similar for all the patients (diazepam, fentanyl and pancuronium). During the heart arrest phase, and as soon as the arterial pressure, the level in the venous return reservoir, and the pump flow rate had all been in steady state for 5 min, ATP or placebo was injected into the venous line of the oxygenator. Injection speed was doubled every three minutes, twice. The following ATP doses were administered: 0.012, 0.025 and 0.05 mg.kg-1.min-1. The level in the venous return reservoir was kept constant. Mean arterial pressure (MAP) and pump flow rate (DP) were assessed every half minute. Systemic vascular resistances were calculated with the relationship MAP/DP. Changes in vascular capacitance were directly proportional to changes in DP as the heart had been excluded, and all the blood returned to the pump, the blood volume being kept constant. MAP and DP remained unchanged in the placebo group. In the opposite ATP induced a dose-related systemic vasodilation: MAP decreased from 82.8 +/- 12.5 mmHg (control) to 66.0 +/- 14.8 mmHg, 59.8 +/- 10.6 mmHg, and 49.0 +/- 4.7 mmHg with 0.012, 0.025 and 0.05 mg.kg-1.min-1 ATP respectively. The MAP returned to preinfusion control levels when the ATP infusion was discontinued (90.0 +/- 17.8 mmHg). The DP, and therefore venous return, did not change, neither during ATP infusion, nor after its discontinuation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate

[The use of opioids by the regional route in the treatment of pain].

The decision to administer regional opioids either by an epidural or a subarachnoid route (intrathecal or intraventricular) necessitates a prior multiparametric analysis. When opiate therapy is definitively indicated regional opiate administration usually relays an insufficient or poorly tolerated oral route. The epidural route seems to be the best way for transient indications; the choice of the opioid drug then depends on the local or disseminated character of pain. For definitive opioid treatment, morphine is the only substance which can be used for long periods of time; the choice of the route depends on the life expectancy; epidural way combined with "open devices or half open devices" chiefly concerns patients with a poor life expectancy and a rather low daily morphine regime: a subarachnoid approach is best indicated in cases with good life expectancy, however, other criteria--intellectual, socioeconomical levels and quality of the "support system"--are important factors for the choice of the route and of the type of administration devices.

Analgesia, Epidural

Effect of angiotensin converting enzyme inhibition on blood pressure and renal function during open heart surgery.

Activation of the renin-angiotensin system during open heart surgery may have consequences both beneficial in sustaining blood pressure and deleterious in compromising renal hemodynamics. The influence of short-term pretreatment with captopril on blood pressure and renal function was assessed double-blind versus placebo in 18 patients without pre-existing cardiac or renal failure, and undergoing coronary artery bypass. No difference in blood pressure and fluid requirement during the surgical period was observed between groups receiving captopril or placebo. Effective renal plasma flow and glomerular filtration rate decreased in the placebo group whereas they remained unaltered in the captopril group; during cardiopulmonary bypass, urinary excretion of sodium was greater in patients receiving captopril than those receiving placebo. These results suggest that captopril pretreatment does not compromise the control of blood pressure and renal function during open heart surgery; additional studies on the protective value of angiotensin-converting enzyme inhibitors are warranted in patients at higher risk for developing renal failure.

Angiotensin-Converting Enzyme Inhibitors

[Pre- and postoperative antihypertensive treatment with calcium antagonist in pheochromocytoma].

Medical preparation for pheochromocytoma surgery requires adrenergic blockade and restoration of euvolemia. Usually, this preoperative preparation consisted essentially of sequential and progressive adrenergic antagonism, alpha then beta blockade. This therapy is not easy to introduce and exposes to blood pressure collapses after tumor removal. By contrast, calcium channel blocking drugs like dihydropyridines offer efficacy and safety. Moreover, new intravenous (IV) agents (nicardipine, diltiazem) provide useful therapeutic tools to control, rapidly and with a dose-dependent effect, any undesired hemodynamic event during surgery. As a demonstration of this new therapeutic strategy for management of pheochromocytoma resection, we report here the cases of two patients who were exclusively treated with dihydropyridines. A 61 year-old woman and a 41 year-old man were scheduled for pheochromocytoma resection (left and right adrenal tumors, respectively). Both patients received dihydropyridines for preoperative preparation (nicardipine and nifedipine, respectively, 60 mg/day). This treatment allowed a good control of arterial blood pressure (BP) (from 210/110 to 170/90 and 180/100 to 140/80 mmHg, respectively) and was maintained up to the morning of the operative day. After patient installation on the operating-table, IV nicardipine infusion was started (2 mg/hour). Anesthesia consisted of high doses of fentanyl, flunitrazepam and vecuronium. Hemodynamic measurements (radial artery and Swan ganz catheters) allowed adjustment of nicardipine infusion rate to maintain peripheral arterial resistances under 1,000 dynes.s.cm-5, and adequate volume loading. A hypertensive crisis (270/130 mmHg) occurred at the time of the intubation in the first case but responded to higher infusion rate of nicardipine (5 mg/10 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Gland Neoplasms

[Value of etomidate for the temporary clamping in early surgery, in normotension, of ruptured intracranial aneurysms. Preliminary study of 8 cases].

For 8 cases of aneurysmal ruptures in patients between twenty two and sixty-six years old, with clinical grade I or II, without diabetes neither high blood pressure, all of them underwent before the third day, with EEG monitoring, the surgical technic requires a temporary clipping of the carrying vessel (extreme times: 2 min 30 and 16 min), with a normal mean blood pressure. mean (ASBP) The circulatory cerebral brain protection is obtained with vascular filling before the clipping time and administration of Etomidate, (0.4 mg.kg-1) as soon as the aneurysm is exposed. For etomidate the posology is. The total required dose of Etomidate was about 98 mg. In all cases this protocol well tolerated (no neurological deficit) enables a good brain protection without cardio-vascular inconveniences of high barbiturate posologies. The waking up is very quick and allows a very early neurological check-up and a return to the presurgery tensional pattern too.

Adult