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Biomedical subjects

M Pinaud

Publications and source records attributed to M Pinaud.

At least 127 records · Page 7Linked to original sources
PubMed1985

[Plasma renin activity and prostaglandin E2 in hypotension induced by nicergoline].

The hypotensive actions of nicergoline, a new alpha 1-adrenoreceptor blocking agent, were studied in six dogs during stable anaesthesia under mechanical ventilation. Systemic haemodynamic parameters were measured before the infusion of nicergoline (500 micrograms X kg-1 in 5 min), and regularly after it during 2 h. Plasma renin activity (PRA), right atrial (V PGE2) and arterial (A PGE2) prostaglandin E2 concentrations measured by radio-immunoassay were collected before, and 10 and 20 min after nicergoline infusion. The mean aortic pressure fell to its lowest figure (-30%) at the 5th min, this being maintained for 45 min. Heart rate and cardiac output remained unchanged. Pulmonary wedge pressure (p less than 0.01) and central venous pressure (p less than 0.05) decreased. All parameters reached their control values in 120 min. PRA was unchanged. V PGE2 (p less than 0.01) and pulmonary extraction in PGE2 (V PGE2 - A PGE2/V PGE2) (p less than 0,05) increased whilst A PGE2 was unmodified. The fall in mean aortic pressure was linked (p less than 0.001) to the increase in V PGE2. Nicergoline infusion induced hypotension by reducing vascular tone of resistance and capacitance beds. Hypotension was related to the vasoplegia and to an inhibition of the rapid pressor control mechanisms. The reasons for the lack of renin release were unknown. V PGE2 release was stimulated by the hypotension. The increase in pulmonary extraction in PGE2 was involved in the maintenance of A PGE2 concentration. Nicergoline gave mild hypotension without reflex sympathetic activation. Its alpha-adrenoreceptor blocking properties were similar to those of prazosin.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1985

[Plasma renin activity and prostaglandin E2 in hypotension induced by sodium nitroprusside].

Sodium nitroprusside (SNP) is a potent, effective and readily reversible vasodilating agent frequently used in anaesthesia for deliberate hypotension. Moderate hypotension induced by SNP activated catecholamine and vasopressin secretions, and the renin-angiotensin system, resulting in partial antagonism of the hypotensive response to SNP. Furthermore, this increase in renin release was involved in the hypertensive rebound after SNP withdrawal. This activation of vasoconstrictor systems led to pharmacological associations aimed at reducing the risk of cyanide poisoning. The physiological interrelationship between prostaglandins and renin secretion has now been well established but, as far as we know, no paper existed concerning prostaglandins during SNP-induced hypotension. In such hypotension (Pa: -30%), monitored by invasive and non invasive haemodynamic techniques (pulsed Doppler), the variations in plasma renin activity (PRA) and in venous and arterial plasma PGE2 concentrations (V PGE2 and A PGE2), determined by radioimmunoassay, were studied in anaesthetized dogs. Invasive haemodynamic data were similar to previous reports. Common carotid diameter increased (p less than 0.05), with a constant common carotid blood flow. PRA (p less than 0.05), V PGE2 (p less than 0.05) and A PGE2 (p less than 0.05) increased. PRA and V PGE2 were highly correlated before and after SNP. SNP resulted in hypotension with reflex sympathetic activation and dilatation of large arteries. Carotid blood flow autoregulation was maintained. Whilst pulmonary removal of PGE2 remained unchanged, an increase in A PGE2 may have been involved in the vasodilator mechanisms.

Animals↗
PubMed1985

[An original intubation technic in a child with Pierre Robin syndrome].

Infants with Pierre Robin syndrome often present the anaesthesiologist with the challenge of upper airway obstruction and difficult tracheal intubation. An unconventional method for solving this problem was used in a 2 week old 2.2 kg term male infant who presented with severe micrognathia, a widely cleft palate and extreme glossoptosis. Hyperextension of the head in the prone position distracted the epiglottis from the glottis. Blind nasotracheal intubation was then used. The curve of the nasotracheal tube made it pass behind the epiglottis into the larynx.

Anesthesia, General↗
PubMed1985

Preoperative acute volume loading in patients with pheochromocytoma.

Ten patients with pheochromocytoma underwent preoperative acute volume loading to determine whether fluid infusion severely increased pulmonary capillary wedge pressure without improving forward flow, and to provide a guide for intraoperative volume replacement. In one patient, volume loading confirmed baseline pressure data suggesting a discrepancy between right and left ventricular filling pressures. In a second patient with normal baseline wedge pressure, volume loading revealed an unsuspected ventricular dysfunction. During subsequent surgery, both volume and speed of fluid infusion were adapted to the preoperative ventricular response.

Adrenal Gland Neoplasms↗
PubMed1985

Bilateral phaeochromocytomas in pregnancy: anaesthetic management of combined caesarean section and tumour removal.

A 25-year-old primigravida with bilateral phaeochromocytomas was managed from 6 weeks' gestation until 2.5 years following combined Caesarean section and removal of adrenal tumours. Pre-operative alpha-blockade was achieved by oral prazosin without deleterious effects. Intra-operative management comprised neuroleptanalgesia, arterial and pulmonary pressure monitoring, adequate heart loading with fluid replacement and sodium nitroprusside. Post-operatively, mother and baby remained normotensive.

Adrenal Gland Neoplasms↗
PubMed1985

[Preoperative vascular loading. A guide for the management of volume expansion in the surgery of pheochromocytoma].

The most acurate fluid replacement is needed for the operative management of patients with pheochromocytoma. Pulmonary capillary wedge pressure monitoring must be incorporated into routine practice for assessing left ventricular filling pressure because discrepancies between central venous pressure and left-sided filling pressure may occur, even in patients apparently free of cardiopulmonary dysfunction. The response to preoperative acute volume loading was used in 11 patients--to detect preoperatively patients in whom fluid infusion was associated with a dangerous increase in pulmonary wedge pressure without improvement in forward flow and--to provide a guide for intraoperative volume replacement. This method confirmed informations suspected from baseline pressure data in one patient: distorsion between right and left ventricular filling pressures. Furthermore it showed an unsuspected ventricular dysfunction in a second patient with normal baseline pulmonary capillary wedge pressure. Both volume and speed of operative fluid challenge were adapted to this preoperative ventricular response.

Adrenal Gland Neoplasms↗
PubMed1984

[Spinal anesthesia with bupivacaine in lower urologic surgery. Our experience apropos of 500 cases].

Rachianesthesia was used for 500 lower urinary tract operations, including 50 repeat procedures, the anesthetic employed being bupivacaine. Patients were frequently hypertensive and presented cardiopathies, usually ischemic in origin. The surgical procedure generally involved transurethral prostate resection for adenoma or carcinoma, or endoscopic resection of a bladder tumor, and all patients received preventive heparin therapy using Kakkar's method. Induction of anesthesia occurs between 30 seconds and one minute after completing the injection a procedure lasting 2 to 5 minutes. Full anesthesia is obtained after 2 to 3 minutes, and is maintained during the mean operation period of 69 +/- 32 minutes by regular intraspinal injections of anesthetic. Results were perfect in 425 cases, 48 patients required additional sedatives, 23 a potent analgesic and 4 a general anesthetic after an operating time extending beyond 100 minutes heart rate remained fairly regular while diminishing slightly in frequency (an average of 4 beats/min). The fall in blood pressure was globally moderate (296 patients) and was unaltered in 204 cases. Hemodynamic modifications lasted for 3 à 4 minutes only and were corrected by appropriate therapy. Postoperative complications were mainly of the headache type (26 cases: 5%), but three patients developed angina from a coronary ischemic accident. Myocardial infarction was not observed, and no particularly incidents were reported in the 32 patients requiring repeat rachianesthesia. The simple execution and efficacy of this mode of anesthesia is emphasized, an additional need for general anesthesia being a rare event. The compound is well tolerated, hemodynamic modifications are moderate and neurological sequelae lacking. Rachianesthesia with bupivacaine appears to be among the methods of choice for lower urinary tract surgery.

Adolescent↗
PubMed1984

Pharmacokinetics of intravenous and intramuscular methohexitone in dogs.

Twenty-four dogs received methohexitone, either intravenously injected (2 mg kg-1 of a 1% solution) or intramuscularly (10 mg kg-1 of a 2% solution). Plasma methohexitone concentrations were measured by gas/liquid chromatography and pharmacokinetics were obtained from the general equations of a multicompartment model. Peak blood concentrations were equivalent following i.v. (18.2 +/- 9.9 mg 1(-1); at 30 s) and i.m. (19.1 +/- 5.6 mg 1(-1); at 3 min) injections. After i.v. injection a rapid distribution phase (half-life t 1/2 lambda 1; 1.3 +/- 0.5 min) was followed by an elimination phase (elimination half-life t 1/2 lambda z; 26.4 +/- 7.8 min). After i.m. injection the distribution phase was followed by two further phases (half-lives: 10.1 +/- 3.6 min and 75.6 +/- 22.6 min). The authors conclude that an i.m. dose five times as great as the i.v. dose produces equivalent peak blood concentration 30 s after i.v. injection and 3 min after i.m. injection. In addition, after i.m. injection of 10 mg kg-1 an additional compartment was apparent, indication substantial drug uptake by poorly perfused tissues.

Animals↗
PubMed1983

[Electroencephalographic study of pediatric anesthesia with intramuscular methohexital].

Intramuscular methohexital was used in pediatric anesthesia to carry out special investigations. There seemed to be few side effects but twitches or seizures have been reported. An electroencephalographic study was performed in normal children. The electroencephalogram showed periods of increased amplitude. The authors discussed the problem of side effects following the intramuscular administration of methohexital in the normal child, and prescribed its use in the epileptic.

Anesthesia, General↗
PubMed1983

Influence of cardiac rhythm on the haemodynamic effects of fazadinium in patients with heart failure.

The haemodynamic effects of fazadinium were compared in two groups of elderly patients with class III functional heart failure about to undergo gastrointestinal surgery. Four patients were in sinus rhythm and four in atrial fibrillation. Following the assessment of baseline values fazadinium 1 mg kg-1 was injected i.v. and measurements obtained every 1 min for 15 min. In patients in sinus rhythm, fazadinium produced a decrease in total peripheral resistance, which was maximum at the 1st min (delta TPRI -738 +/- 88 dyn s cm-5 m2) and accompanied by a moderate decrease in arterial pressure (MAP -27 +/- 2.4 mm Hg) and cardiac index (delta CI -0.23 +/- 0.17 litre min-1 m-2) and a moderate increase in heart rate (delta HR +16 +/- 5.7 beat min-1). In patients in atrial fibrillation, a similar decrease in total peripheral resistance (delta TPRI -1160 +/- 174 dyn cm-5 m2) was accompanied by a significantly more pronounced tachycardia (delta HR +71 +/- 5.1 beat min-1) (P less than 0.001) and decreases in arterial pressure (delta MAP -51.7 +/- 5.9 mm Hg) (P less than 0.01) and stroke index (P less than 0.02).

Aged↗
PubMed1983

Echocardiography and left ventricular function on recovery from anaesthesia in patients with coronary artery disease.

Eight patients with coronary artery disease and eight age-matched patients without coronary artery disease undergoing noncardiac surgery were submitted to M-mode echocardiography and haemodynamic measurements. In the patients with coronary artery disease, but not in the controls, recovery from anaesthesia was associated with echocardiographic and haemodynamic changes suggestive of impaired cardiac pump function. This impairment seems to result from an imbalance between myocardial oxygen availability and demand in patients with coronary artery disease.

Acid-Base Imbalance↗