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Biomedical subjects

M Saussine

Publications and source records attributed to M Saussine.

At least 19 recordsLinked to original sources
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1991

[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↗
PubMed1989

Myosin: a highly sensitive indicator of myocardial necrosis after cardiac operations.

Plasma levels of ventricular myosin fragments, determined with monoclonal antibodies to myosin heavy chains, were studied in 27 patients after cardiac operations (17 aorta-coronary bypass grafts and 10 valve replacements) to assess their possible role as a marker of perioperative myocardial necrosis. Five patients had perioperative myocardial necrosis after aorta-coronary bypass grafts as indicated by changes in the electrocardiogram and elevated levels of the MB isoenzyme of creatine kinase. Six more patients were also studied after thoracic operations performed by the same sternotomy approach. After cardiac operations, myosin levels increased from postoperative day 3 and reached peak values on day 7. Peak myosin values in patients with perioperative myocardial necrosis after aorta-coronary bypass grafting were significantly higher than in patients after an identical operation but without perioperative myocardial infarction (3793 +/- 592 versus 369 +/- 47 ng/ml; p less than 0.001). These results suggest that plasma myosin is a sensitive marker of myocardial necrosis. Furthermore, peak plasma levels of ventricular myosin after coronary bypass grafting without myocardial infarction (mean value 369 +/- 47 ng/ml) were not significantly different from peak levels after thoracic operations (mean value 253 +/- 52 ng/ml), whereas they were significantly higher after valve replacement (mean value 794 +/- 149 ng/ml; p less than 0.01). These results indicate that a certain degree of myocardial necrosis occurs during value replacement that is undetectable by the usual diagnostic criteria for perioperative myocardial infarction. We conclude that the plasma level of ventricular myosin fragments is a more specific and accurate marker of perioperative myocardial necrosis than changes in the electrocardiogram or elevated creatine kinase MB levels. Therefore the detection of myosin fragments, which appear in the serum on the third day after cardiac operations, may be useful for precise comparisons of different techniques of myocardial protection.

Biomarkers↗
PubMed1988

[Pulse oximetry and thoracopulmonary surgery].

Arterial blood gases are invasive and they provide intermittent information only. On the other hand, pulse oximetry is non invasive, providing continuous monitoring of SaO2 (SpO2). A study was therefore carried out in twelve patients undergoing lung and intrathoracic surgery to determine whether pulse oximetry was a reliable method of monitoring. The SpO2 values obtained using a Physiocontrol Oximeter (Lifestat 1600) were compared with those given by blood gas measurements (SaO2). When ventilation was switched to one-lung ventilation, PaO2 fell in all cases, whatever the method of monitoring, with PaCO2 remaining constant. 46 paired values of SaO2 were compared using linear regression analysis. Correlation between the two methods was good (r = 0.95; p less than 0.001). Pulse oximetry would therefore seem to provide a reliable method of continuous noninvasive and accurate monitoring of oxygenation during lung surgery.

Adult↗
PubMed1988

Comparison of myoglobin and creatine kinase MB levels in the evaluation of myocardial injury after cardiac operations.

Myoglobin was studied in 40 patients before, during, and after cardiac operations and was compared to the MB isoenzyme of creatine kinase to identify its possible role as a marker of perioperative myocardial damage. Myoglobin reached peak values during cardiac arrest in all patients and was significantly higher immediately after administration of the anesthetics, during cardiac arrest, and until the sixth postoperative hour in eight patients with a perioperative myocardial infarction. By contrast, the MB isoenzyme of creatine kinase reached peak values at the fourth postoperative hour and was significantly higher in patients with perioperative myocardial infarction from the fourth to the tenth postoperative hours. We conclude that myoglobin is a valuable marker of perioperative myocardial damage and is an earlier and more specific marker of perioperative myocardial infarction than creatine kinase MB.

Clinical Enzyme Tests↗
PubMed1987

[Myoglobin: an early indicator of myocardial infarction during heart surgery].

Plasma myoglobin was measured in 40 patients before, during and after cardiac surgery under cardiopulmonary bypass, in order to study its value as an indicator of intra-operative myocardial damage. Myoglobin levels rose at cannulation, further increased during the operation and reached a peak 2 hours later; they began to decrease 6 hours after surgery and were back to normal 24 hours later. Myoglobin levels from induction of the anesthetics to the 6th post-operative hour were significantly higher in the 8 patients who developed intra-operative myocardial infarction than in the other patients. Thus, myoglobin is an early indicator of intra-operative myocardial ischaemia. An abnormal rise of myoglobin at induction of the anesthetics characterizes a group of patients at high risk of myocardial infarction during surgery.

Cardiac Surgical Procedures↗
PubMed1987

[Complement activation in extracorporeal circulation. Comparison of nylon versus polyester bubble oxygenators].

Complement activation during cardiopulmonary bypass is well known and may influence postoperative morbidity. As nylon can particularly induce complement activation, its influence was assessed by measuring total haemolytic complement and B, C3 and C4 factors, during cardiopulmonary bypass with bubble oxygenators for coronary surgery, comparing "nylon" circuits (20 patients, Bentley BOS 10) versus "polyester" circuits (19 patients, Shiley S 100 A). Complement activation began with induction of anaesthesia and surgical procedures, B, C3 and C4 levels falling significantly (respectively 15, 17 and 20% from baseline values). The alternative pathway was activated before the classical pathway. Complement activation continued during cardiopulmonary bypass, with no more consumption of complement factors (slight variations of about 0 to 3% of the levels found after anaesthetic induction and surgical procedures). No statistically significant difference appeared between the two groups. This suggested that nylon did not significantly increase complement activation during cardiopulmonary bypass. The bubble oxygenator material cannot therefore be considered as a criterion for choosing the type of equipment.

Complement Activation↗