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Biomedical subjects

P Barash

Publications and source records attributed to P Barash.

At least 19 recordsLinked to original sources

High-dose nitrates in the immediate management of unstable angina: optimal dosage, route of administration, and therapeutic goals.

Nitrates are commonly used for rapid relief of ischemia in the initial management of unstable angina. However, their optimal dosage, route of administration, and therapeutic goals have not been fully established. This study was conducted to determine the optimal dosage and mode of administration (intravenous bolus versus sublingual spray) of nitrates and the therapeutic goals of their use in the immediate management of unstable angina. In a single-center prospective trial, 72 consecutive patients with unstable angina accompanied by typical ST-segment depression on electrocardiogram were randomly assigned to receive isosorbide dinitrate either as repeated intravenous boluses or as sublingual sprays while being delivered to the hospital by a mobile intensive care unit. Optimal nitrate dosage was tailored to pain relief while monitoring mean blood pressure reduction to an optimal range (5% to 20%) without dosage restriction. The mean nitrate dosage needed for ischemia control during the first hour of treatment was 7.8 +/- 3.8 mg. Optimal blood pressure reduction was achieved by significantly more intravenously treated patients than sublingually treated patients (68% v 41%, P = .037). Intravenously treated patients also experienced a more pronounced therapeutic effect, as assessed by reduction in chest pain score (67% v 39%, P = .0004) and decrease in ST-segment depressions (57% v 27%, P = .004). These results show that higher doses of nitrates than previously recommended are required for ischemia control during the initial management of unstable angina. The use of repeated intravenous boluses is safe and more easily controlled and, therefore, more efficacious than sublingual sprays in inducing the maximal anti-ischemic effect while avoiding significant hypotension.

Administration, Sublingual↗

Ventricular fibrillation in the patient with blunt trauma: not always exsanguination.

Three cases of successful prehospital resuscitation of blunt trauma patients sustaining cardiac arrest resulting from ventricular fibrillation are reported. Although probably uncommon, ventricular fibrillation not caused by severe hypovolemia, exsanguination, or severe hypoxia in the setting of blunt trauma might be a treatable cause of cardiac arrest. Early electrocardiographic monitoring of patients with blunt trauma, including those with cardiac arrest, can detect this small, yet easily salvageable group of patients.

Adolescent↗

An initial multicenter, randomized controlled trial on the safety and efficacy of acadesine in patients undergoing coronary artery bypass graft surgery. SPI Research Group.

Acadesine (5-amino-4-imidazole carboxamide riboside) is a purine nucleoside analog that has been shown in animals to reduce myocardial ischemic injury by selectively increasing the availability of adenosine in ischemic tissues. Because patients undergoing coronary artery bypass graft (CABG) surgery are especially vulnerable to developing myocardial ischemia, we investigated whether perioperative use of this adenosine-regulating drug with potential anti-ischemic properties could modify the incidence and severity of perioperative myocardial ischemia. The goals of this study were to evaluate safety and the effects of acadesine on myocardial ischemia, left ventricular function, and, secondarily, on adverse clinical outcomes (myocardial infarction, heart failure, life-threatening dysrhythmias, and death) in patients undergoing CABG surgery. One hundred sixteen patients were randomized to receive one of three continuous intravenous dosing regimens (placebo [control] or one of two doses of acadesine [high- and low-dose infusion]) in double-blind fashion intraoperatively and in the early postoperative period (total infusion time was 7 h). Multidose cold crystalloid cardioplegia (each containing either acadesine or placebo) was used for myocardial protection. All were monitored for potentially drug-related adverse events and the presence of myocardial ischemia was assessed by continuous Holter electrocardiography (ECG) and transesophageal echocardiography (TEE). All patients received standardized anesthetic, surgical, and hemodynamic management during the intraoperative period. All research data (ECG, TEE, outcome data) were evaluated at the coordinating center (San Francisco) in blinded fashion to ensure that uniform data analysis criteria were employed. The administration of acadesine was safe: mild increases in plasma uric acid (a metabolite of acadesine) occurred only in patients receiving high doses (mean increase 1.6 +/- 0.2 mg/dL) and were without clinical sequelae. Before drug administration in the preoperative period (baseline), the incidence and severity of ECG ischemia did not differ among the three groups (placebo = 18%; low-dose = 14%; high-dose = 14%). During prebypass, the incidence of ECG ischemia was similar in all three groups (0%, 3%, 3%, respectively). The incidence of TEE ischemia was numerically lower in the two acadesine groups (high-dose = 6%, low-dose = 15%) than in the control group (19%), but this was not statistically significant (P = 0.22). During postbypass, the incidence of ECG ischemia was 11% in the high-dose group, 22% in the low-dose group, and 18% in the control group (P = 0.42), and TEE ischemia was similar in incidence in all groups (placebo = 29%; low dose = 27%; high-dose = 24%) (P = 0.86).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗

Anesthesiology.

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Anesthesiology↗

Measurement of ejection fraction by thermal dilution techniques.

The reproducibility, accuracy, and clinical applicability of ventricular ejection fraction derived by a thermal dilution technique were assessed in 22 dogs and 18 patients. Results obtained by the thermal technique were compared to simultaneous results obtained by radionuclide angiography. Right ventricular ejection fraction, measured in 9 dogs (1014 determinations) and 8 patients (744 determinations) was reproducible +/- 5%. Left ventricular ejection fraction, measured in 10 patients, was reproducible +/- 5%. Correlation between thermal and radionuclear measurements varied from 0.86 to 0.93 (all P less than 0.02). We conclude that, because of its low cost, ease of use, and accuracy, thermally derived ejection fraction determinations can be helpful in hemodynamic monitoring of critically ill patients.

Angiography↗

Intranasal cocaine: dose relationships of psychological effects and plasma levels.

We compared the psychological effects of three doses of intranasal cocaine hydrochloride (.2, .75, and 1.5 mg/kg) with cocaine plasma concentrations in four volunteers. Intranasal lidocaine hydrochloride (.2 mg/kg) was used as a topically active placebo. Peak "high" ratings were related to both dose and peak plasma concentrations. At a given plasma concentration, "high" ratings were greater when plasma levels were increasing than when they were decreasing. This indicates that acute tolerance by tachphylaxis occurred after single doses. The cocaine "high" was a pleasant feeling but was without distinctive sensations. The dramatic effects of intranasal cocaine on the street may be related to larger or repeated doses as well as the setting.

Administration, Intranasal↗

Intranasal and oral cocaine kinetics.

Plasma cocaine levels were determined in 7 subjects after intranasal and oral cocaine. Intranasal doses of 0.19, 0.38, 0.75, 1.5, and 2.0 mg/kg were given as a 10% aqueous solution; 0.38 mg/kg was given as crystalline cocaine HCl. Oral cocaine was administered in doses of 2.0 and 3.0 mg/kg. Intranasal cocaine kinetics were described by a 1-compartment open model with 2 consecutive first-order input steps and first-order elimination. Oral cocaine disposition was described by a 1-compartment open model with a lag time followed by a single first-order input phase and first-order elimination. The mean elimination half-life (t 1/2) for cocaine by the intranasal route to 7 subjects was 75 +/- 5 min (mean +/- SE). The mean t 1/2 after oral administration to 4 subjects was 48 +/- 3 min. The relative bioavailability [as determined by the area under the concentration-time curve (AUC)] for the 2.0-mg/kg dose by the intranasal and oral routes was not different. There was a linear increase in AUC with increasing intranasal dose.

Administration, Intranasal↗

Measurement of benzoylecgonine and cocaine in urine, separation of various cocaine metabolites using reversed-phase high-performance liquid chromatography.

The application of reversed-phase high-performance liquid chromatography to the measurement of benzoylecgonine and cocaine in urine is described. Following a simple extraction and clean-up procedure, chromatography is performed using a column containing an octadecylsilica coated packing, elution with 17% acetonitrile in pH 2.7 phosphate buffer and ultraviolet detection at 200 or 235 nm. The detection limit is ca.0.1 microgram of drug per ml urine, and using the ethyl ester of benzoylecgonine as an internal standard, benzoylecgonine and cocaine are quantified with coefficients of variation of 7.0 and 2.8%, respectively. The procedure has been applied to urines from subjects receiving intranasal cocaine, and compared to the enzyme multiplied immunoassay technique. The chromatography procedure also permits the separation of norcocaine and benzoylnorecgonine.

Chromatography, High Pressure Liquid↗

Objective assessment of the trauma patient in a surgical intensive care unit.

A 6-month study using the Therapeutic Intervention Scoring System (TISS) to evaluate trauma patients admitted to a surgical intensive care unit showed a correlation between severity of illness and TISS score at the same time. The TISS is useful in the ICU, where numerous complex interventions are made in caring for acutely ill and injured patients.

Adolescent↗

Cor triatriatum: masked by complex congenital cardiac anomalies.

The radiographic, angiographic, hemodynamic, and surgical features of 2 cases of cor triatriatum complicated by other cardiac anomalies are presented. In the first case, the patient had tetralogy of Fallot, the scimitar syndrome, and left ventricular obstruction. In the second case the patient had truncus arteriosus. The first case was revealed only after augmentation of pulmonary flow by an aorta-pulmonary artery anastomosis. In the second case, the diagnosis was retrospectively suggested by certain angiographic and hemodynamic clues. The prospective diagnosis was made only after a modified Rastelli procedure for truncus arteriosus. The difficulties encountered in making the diagnosis in both cases are discussed. It is stressed that a high index of suspicion, thorough accumulation and examination of hemodynamic data, and excellent angiograms and plain film radiography are all necessary to an early diagnosis of cor triatriatum when the latter is complicated by other congenital heart anomalies.

Abnormalities, Multiple↗