Biomedical subjects

I Gratz

Publications and source records attributed to I Gratz.

25 records · Page 2Linked to original sources

PubMed1992

The effect of desmopressin acetate on postoperative hemorrhage in patients receiving aspirin therapy before coronary artery bypass operations.

It has been suggested that desmopressin acetate has been effective in reducing hemorrhage after coronary artery bypass grafting in patients receiving aspirin before operation. We conducted a prospective, randomized, placebo-controlled, double-blind trial to determine the effectiveness and safety of desmopressin in these patients. Sixty-five patients pretreated with aspirin within 7 days before their scheduled elective coronary artery bypass grafting were randomized to receive desmopressin (0.3 micrograms/kg) or placebo after cessation of bypass and reversal of heparin with protamine. The demographic characteristics and last dose of aspirin were similar in both groups. There was a significant reduction in postoperative blood loss noted between groups for both chest tube blood loss (833 +/- 311 ml for the 1-desamino-8-D-arginine vasopressin [desmopressin] group versus 1176 +/- 674 ml for the placebo group; p = 0.016) and total blood loss (1215 +/- 381 ml for the desmopressin group versus 1637 +/- 761 ml for the placebo group; p = 0.0097). Despite the differences in blood loss between the two groups, the red cell transfusions were not significantly different, but the use of platelets was less in the desmopressin group and almost achieved statistical significance (p = 0.053). Neither was there a difference in the occurrence of thrombotic complications between groups. It appears that desmopressin in this specific subgroup of patients receiving preoperative aspirin is effective as a prophylactic agent for reduction of postsurgical hemorrhage.

Aged↗

PubMed1992

Does desmopressin acetate prophylaxis reduce blood loss after valvular heart operations? A randomized, double-blind study.

The effectiveness of prophylactic desmopressin acetate in reducing hemorrhage after cardiopulmonary bypass operations is controversial. We conducted a prospective, randomized, placebo-controlled, double-blind trial to determine its effectiveness and safety in such patients. Eighty-three evaluable patients undergoing valvular heart operations were randomized to receive desmopressin (0.3 microgram/kg) (41) or placebo (42) after cardiac bypass. Demographic characteristics were similar in both groups. There was no significant difference in total 24-hour blood loss between groups (desmopressin 1064.8 +/- 647.1 ml versus placebo 844.4 +/- 507.6 ml; p greater than 0.05), or in the requirement for red blood cell, platelet, or fresh frozen plasma transfusion, or for reexploration for control of hemorrhage. Neither was there a difference in the occurrence of thrombotic complications between groups. Analysis of factor VIII activity, von Willebrand factor, or von Willebrand factor multimers failed to show significant correlations with blood loss or differences between groups except for factor VIII activity, which was significantly higher in the desmopressin group 1 hour after operation than in the placebo group. A detailed comparative analysis of similar trials to determine the reasons for different outcomes suggests that desmopressin should not be used routinely as a prophylactic agent to reduce postsurgical hemorrhage, but that it may be beneficial when used in patients who already manifest excessive bleeding postoperatively.

Blood Loss, Surgical↗

PubMed1991

Clinical pharmacology of the neuromuscular blocking agents.

Neuromuscular blocking agents are among the most commonly used drugs during general anesthesia. They compete with acetylcholine and interfere with the transmission of nerve impulses resulting in skeletal muscle relaxation. Based on their mechanism of action, neuromuscular blocking agents are classified as either depolarizing or nondepolarizing. Succinylcholine is a short-acting depolarizing agent. Commonly used nondepolarizing agents are curare (long-acting), pancuronium (long-acting), atracurium (intermediate-acting), and vecuronium (intermediate-acting). Neuromuscular blocking agents are used clinically to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery. This article provides an overview of the physiology of the neuromuscular transmission and summarizes our current knowledge on the use of these agents during general anesthesia.

Atracurium↗

PubMed1991

Treatment of postoperative nausea and vomiting with ondansetron: a randomized, double-blind comparison with placebo.

Postoperative nausea and vomiting are common after recovery from general anesthesia. The antiemetic effect and safety of ondansetron, a selective serotonin type 3 (5-HT3) receptor antagonist, was determined in 36 patients suffering from nausea or vomiting during recovery from intravenous anesthesia by giving either a single intravenous dose of ondansetron (8 mg, n = 18) or placebo (n = 18) over 2-5 min in a randomized, double-blind manner. A "rescue" antiemetic was provided in case of continued vomiting or at the patient's request. Antiemetic efficacy was defined as no request for rescue antiemetic and/or no vomiting episode during the next 4 h. There was no significant difference in the demographic data between the groups. Administration of ondansetron or placebo had no significant effect on vital signs. Ondansetron was an effective antiemetic in 78% (14/18) and placebo was effective in 28% (5/18) of the patients. Laboratory studies 24 h later showed no signs of hematologic, hepatic, or renal alterations. Ondansetron at a dose of 8 mg administered intravenously over 2-5 min appears to be a safe and effective antiemetic for the treatment of nausea and/or vomiting after intravenous anesthesia.

Adolescent↗

PubMed1991

The effectiveness of labetalol in treating postoperative hypertension.

During the postanesthesia recovery period, surgical patients often exhibit an increased arterial blood pressure. Although these transient increases in blood pressure are usually benign, significant morbidity and mortality may result from complications of postoperative hypertension. The purpose of this study was twofold: to determine the frequency of postoperative hypertension in one particular recovery room, and to determine the efficacy of labetalol as an antihypertensive drug in this setting. This study included both a retrospective and prospective component. The retrospective portion involved review of 465 records of patients admitted to the recovery room at a large, private eastern medical college. Nearly 20% of patients admitted were found to have blood pressures in the range of our study's criteria for hypertension. Records were also reviewed for types of therapeutic interventions used to treat hypertension and determinations of their success or failure. The prospective portion of the study evaluated treatment protocols for postoperative hypertension with graduated intravenous injections of labetalol in 30 patients. Blood pressure was effectively controlled with an average of 25 minutes for all patients and remained effective for 24 hours postoperatively.

Adult↗

PubMed1989

Clinical pharmacology of propofol: an intravenous anesthetic agent.

Propofol is a 2,6-diisopropylphenol with sedative-hypnotic properties. Because of its slight solubility in water, the drug is formulated as an emulsion for clinical use. It is highly lipophilic and distributes extensively in the body. The blood concentration-time profile of propofol after an iv bolus injection follows a three-compartment model with half-lives of 2-4 min, 30-45 min, and 3-63 h, respectively. Propofol is extensively metabolized by the liver prior to its elimination by the kidney. Following an iv dose of 2-2.5 mg/kg, loss of consciousness occurs in less than one minute and lasts for approximately five minutes. Hypnosis can be maintained by propofol blood concentrations of 1.5-6 micrograms/mL in the presence of N2O/O2 (60:40 ratio) or other anesthetic agents. During induction, propofol decreases the systolic and diastolic blood pressure by approximately 20-30 percent with minimal change in heart rate; apnea is also common. The cardiovascular and respiratory effects of propofol, however, should not cause major concern in otherwise healthy patients. By virtue of its pharmacokinetic profile, the drug lends itself to continuous infusion for maintenance of anesthesia. When used as the main anesthetic agent, it produces satisfactory anesthesia with rapid recovery and without major adverse effects in healthy individuals. In continuous infusion propofol can be used as an alternative to inhalation anesthetics.

Anesthesia, Intravenous↗

PubMedDate not supplied

The effect of isoflurane versus balanced anesthesia on rocuronium's pharmacokinetics and infusion requirement.

STUDY OBJECTIVE: To compare the effects of two anesthetic techniques, balanced and isoflurane anesthesia, on the response to an intubating dose and an infusion of rocuronium, and on rocuronium's pharmacokinetics. DESIGN: Randomized, open-label study. SETTING: A university-affiliated hospital. PATIENTS: Twenty-two healthy adults undergoing elective surgery. INTERVENTIONS: The patients were anesthetized with a balanced technique (nitrous oxide, fentanyl, midazolam) or isoflurane (nitrous oxide, isoflurane 0.5-1.0%). Rocuronium was administered initially as a 500-micrograms/kg bolus, then by infusion to maintain approximately 86-94% depression of twitch tension. Plasma samples to determine rocuronium concentrations were obtained before, during, and after the infusion. Pharmacokinetics were determined using a population-based approach. MEASUREMENTS AND MAIN RESULTS: Onset time and initial recovery after the bolus dose were similar for the two groups. Infusion requirements also were similar. Plasma clearance was greater during isoflurane than during balanced anesthesia (4.48 vs 3.49 ml/kg/min). Distribution clearances and volumes of distribution were similar for the two groups. CONCLUSIONS: The similarity of response to an intubating dose and an infusion of rocuronium suggests that clinicians need not alter the dose or rate of rocuronium administration during isoflurane anesthesia with a of duration less than 1 hour. However, the greater clearance of rocuronium, in light of the similarity of infusion requirements, suggests that isoflurane potentiates rocuronium compared with balanced anesthesia.

Adult↗