Search PubMed⌕ Search

Biomedical subjects

M Pinaud

Publications and source records attributed to M Pinaud.

At least 91 records · Page 5Linked to original sources
PubMed1990

Effects of propofol on cerebral hemodynamics and metabolism in patients with brain trauma.

The authors determined the effect of propofol on cerebral blood flow, intracranial pressure, and cerebral arteriovenous oxygen content difference in severely brain-injured patients during orthopedic treatment of fractures of the extremities. The Glasgow Coma Scale score was 6 or 7 at the time of the study. Data were collected in the operating room before and during (5 and 15 min) administration of propofol (2 mg/kg iv bolus immediately followed by a 150 micrograms.kg-1.min-1 infusion) before surgical stimulation. Propofol was infused during 41.4 +/- 7.3 min. After operation, the last set of measurements was made 15 min after propofol was stopped. The study was performed on 10 adults (age range, 15-40 yr) whose lungs were mechanically ventilated (air/O2) and who were sedated (phenoperidine, 1 mg/h), and was conducted using a radial artery cannula; a 7.5-Fr, thermodilution, flow-directed, pulmonary artery catheter; an intraventricular catheter; and a catheter in the jugular venous bulb. The 133xenon intra-internal carotid artery injection technique was used to determine regional cerebral blood flow (rCBF). Anesthetic blood concentration of propofol (3-5 micrograms/ml) was associated with decreases in cerebral perfusion pressure (CPP; from 82 +/- 14 to 59 +/- 7 mmHg; P less than 0.001), rCBF (from 35 +/- 6 to 26 +/- 5 ml.100 g-1.min-1; P less than 0.001), and intracranial pressure (ICP; from 11.3 +/- 2.6 to 9.2 +/- 2.5 mmHg; P less than 0.001). Cerebrovascular resistance and cerebral arteriovenous oxygen content difference were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Continuous propofol infusion versus enflurane in children operated on for strabismus. Comparison of the quality of anesthesia and recovery conditions].

In children, the use of a continuous infusion of propofol has not yet been reported. A study was therefore designed to compare the characteristics of anaesthesia and recovery when either propofol or enflurance was used as the main anaesthetic agent. All 42 children (14 girls, 28 boys), ASA I and scheduled for corrective squint surgery under general anaesthesia, received 350 micrograms.kg-1 midazolam and 40 micrograms.kg-1 atropine intrarectally 20 min before induction, which was carried out with 3 mg.kg-1 propofol intravenously in 20 s. The patients were then randomly assigned to two groups, according to the drug used for maintenance: group P (n = 21) received a continuous intravenous infusion of propofol, 18 mg.kg-1.h-1 for the first 30 min and 15 mg.kg-1.h-1 thereafter; group E (n = 21) received 2.5%, then, after 30 min, 2% enflurane. Both groups were given 15 micrograms.kg-1 dextromoramide and 0.09 mg.kg-1 vecuronium. During anaesthesia, the following parameters were monitored: systolic (Pasys), diastolic (Padia) and mean arterial (Pa) pressures, heart rate (fc), the presence or not of an oculocardiac reflex with or without a 20% fall in fc which responded to 10-15 micrograms.kg-1 atropine, the appearance of a cardiac dysrhythmia, duration of anaesthesia and the delay before extubation. Recovery was assessed 1, 2, 4 and 6 h postoperatively by using both clinical and psychomotor criteria, the latter being adapted to children having one or both eyes occluded.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia Recovery Period↗
PubMed1989

[Comparison in healthy volunteers of the systemic beta adrenergic receptor blockade by beta blockader eye drops].

The isoproterenol dose-response curve was used to assess quantitatively the degree of systemic beta-adrenoceptor blockade induced by metipranolol (Bétanol) and betaxolol (Bétoptic) eye drops. The study was carried out in twelve healthy volunteers, aged 22 +/- 1.4 yr. In a randomized double-blind trial, each volunteer received, on separate occasions at least one week apart, one drop in each eye of either placebo (physiological saline) or either of the ophthalmic beta-blockers. The intraocular pressure (Pio), heart rate (fc), arterial systolic (Pasys) and diastolic (Padia) pressures were measured before instillation of the eye drops after 15 to 30 min rest, and 3 h afterwards. The isoproterenol dose-response curve was studied 3 h after instillation of the drops. The CD25 (the amount of isoproterenol needed to increase fc by 25 b.min-1) was obtained by extrapolation on the least square linear regression curve. Both beta-blockers gave a significant fall in Pio compared with placebo, metipranolol more than betaxolol (p less than 0.02). There was also a significantly greater fall in fc with both metipranolol and betaxolol than with placebo. There were no changes in Pasys and Padia. CD25 was significantly increased with both beta-blocker eye drops as compared with placebo (p less than 0.05 for betaxolol; p less than 0.01 for metipranolol), but there was no difference between the two. Systemic absorption after topical application of ocular beta-blockers was thus confirmed for both metipranolol and betaxolol. However, the degree of beta-adrenoceptor blockade was weaker than that observed with other older ocular beta-blockers (timolol and carteolol).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1989

Cerebral blood flow and cerebral oxygen consumption during nitroprusside-induced hypotension to less than 50 mmHg.

The authors determined the effect of profound induced hypotension (i.e., mean arterial blood pressure less than 50 mmHg) during craniotomy for cerebral aneurysm on cerebral blood flow and cerebral metabolic rate for oxygen before, during, and after (20 min and 40 min after) the hypotensive period. The study was performed on nine adults (mean age, 29.2 yr) who were awake and conscious without peripheral neurologic deficits at the time of surgery. The study was conducted with the dura open with the use of a radial artery cannula, a 7-Fr thermodilution flow-directed pulmonary artery catheter, and an internal jugular vein catheter. The 133xenon intraarterial injection technique was used to determine regional cerebral blood flow (rCBF) in the nonoperated hemisphere. rCBF remained unchanged (from 22.8 +/- 4.1 ml.100 g-1.min-1 to 23.8 +/- 4.6 ml.100 g-1.min-1) during the hypotensive period (MAP from 87.8 +/- 10.4 mmHg to 40.0 +/- 4.4 mmHg; P less than 0.001) despite an increase in cardiac index since cerebral perfusion pressure and cerebrovascular resistance decreased to a similar degree. No gross cerebral metabolic disturbances were observed. A period of decreased cerebrovascular resistance and increased rCBF followed induced hypotension. rCBF increased from 23.8 +/- 4.6 ml.100 g-1.min-1 to 30.0 +/- 5.8 ml.100 g-1.min-1 (P less than 0.001) 20 min after sodium nitroprusside (SNP) was stopped without rebound hypertension. These modifications disappeared 20 min later. Reduction of mean arterial blood pressure to 40 mmHg by SNP was apparently safe for the brain, although the possibility of low perfused regions and local brain and cerebrospinal fluid lactoacidosis, particularly in the retracted hemisphere, cannot be excluded.

Adult↗
PubMed1989

Norepinephrine therapy has no deleterious renal effects in human septic shock.

We investigated 25 patients (aged 20 to 70 yr) in septic shock with low systemic vascular resistance in order to assess the effects on renal function of prolonged (24 to 240 h) norepinephrine (NE) infusion (range 0.5 to 1.5 micrograms/kg.min). Two sets of renal function tests were made: a) control study before NE therapy after the initial intravascular loading and on dopamine infusion (mean dosage 14 +/- 2 micrograms/kg.min); b) in the last 24 h of NE infusion associated with dopamine (2 to 3 micrograms/kg.min). The following renal function tests were measured: urine flow rate, creatinine, osmolar and free water clearances, and fractional excretion of sodium (FENa). Data were collected only in 22 nonanuric patients: urine flow rate, creatinine, and osmolar clearance increased (p less than .001), and free water clearance (p less than .001) and FENa (p less than .02) decreased. These results suggest that NE (0.5 to 1.5 micrograms/kg.min) may be used in the treatment of human septic shock without deleterious renal effects.

Adult↗
PubMed1989

Hypotensive anesthesia with isoflurane and enflurane during total hip replacement: a comparative study of catecholamine and renin angiotensin responses.

Catecholamine and renin-angiotensin responses to enflurane- or isoflurane-hypotensive anesthesia were compared in a randomized study. Two groups of 10 patients undergoing total hip arthroplasty were premedicated with morphine hydrochloride (0.1 mg/kg). Anesthesia was induced with thiopental and the trachea intubated after pancuronium. Equal concentrations of each volatile agent (1.3 MAC) were administered until mean arterial blood pressure decreased to 50-60 mm Hg. Hemodynamic data and blood samples for measurements of plasma renin activity (PRA) and plasma epinephrine (E) and norepinephrine (NE) concentrations were collected 1) after induction and intubation but before the start of isoflurane or enflurane; 2) 15 min (T15) after the start of isoflurane or enflurane administration; and 3) 45 min (T45) after the start of isoflurane or enflurane administration. The desired level of hypotension was achieved at T15 with isoflurane and at T45 with both anesthetics. When hypotension was achieved, cardiac index and stroke index were significantly lower in the enflurane group while systemic vascular resistance index was lower in the isoflurane group. Increases in E and NE levels above baseline levels were significantly greater in the isoflurane group than in the enflurane group. Use of isoflurane to induce hypotension is associated with more rapid induction of hypotension, less depression of cardiac output, and better preservation of homeostatic responses than is use of enflurane.

Enflurane↗
PubMed1988

Additive effects of dihydralazine during enflurane or isoflurane hypotensive anaesthesia for spinal fusion.

Sixteen patients (13-38 yr) undergoing spinal fusion for scoliosis under controlled hypotension were studied to determine the haemodynamic and neuroendocrine responses to IV dihydralazine (1.0 mg.kg-1) followed by 0.5 and 1 MAC of enflurane or isoflurane. Twenty minutes after dihydralazine administration mean arterial pressure (-20 per cent) and systemic vascular resistance (-50 per cent) decreased, and cardiac index (+57 per cent), heart rate (+37 per cent) and intrapulmonary shunt increased. Plasma renin activity and aldosterone and norepinephrine levels increased. Further decreases in mean arterial pressure and in systemic vascular resistance were observed when 0.5 MAC enflurane or isoflurane were added. With 1 MAC anaesthetic levels a further decrease in mean arterial pressure was observed in both groups, but pressure fell to a lower level with isoflurane than with enflurane (p less than 0.01). The reduction of arterial blood pressure to a level of 50-60 mmHg for three to four hours was easy to control and was free of complications. The preliminary IV administration of dihydralazine allowed a reduced volatile agent concentration which attenuated undesirable haemodynamic effects, in spite of renin and norepinephrine release, and permitted a rapid intraoperative awakening.

Adolescent↗