Journal of clinical anesthesia
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Randomized Controlled Trial Clinical Trial
Attenuation of hemodynamic responses to rapid sequence induction and intubation in healthy patients with a single bolus of esmolol.
The effectiveness of a single preinduction intravenous (IV) bolus of esmolol in blunting hemodynamic responses to rapid sequence induction and tracheal intubation was evaluated. In a randomized double-blind study, 32 ASA I and II healthy patients scheduled for surgery were monitored with electrocardiography (EKG) lead V5, arterial cannulation, and impedance cardiography. After preoxygenation and a priming dose of vecuronium (0.01 mg/kg), patients received either saline (n = 12), esmolol 100 mg (n = 10), or esmolol 200 mg (n = 10) as an IV bolus (20 ml volume). ⋯ Plasma norepinephrine levels at 1.5 minutes after intubation increased in the esmolol groups about 130% above that measured in the placebo group. This finding was associated with a more gradual return of peripheral resistance to baseline following tracheal intubation. However, both doses of esmolol effectively attenuated heart rate (HR), SP, and rate pressure product (RPP) increases (p less than 0.05 vs placebo) produced by laryngoscopy and tracheal intubation.
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Randomized Controlled Trial Clinical Trial
Intraoperative use of bolus doses of esmolol to treat tachycardia.
A randomized, double-blind, parallel, placebo-controlled study was conducted to determine the safety and efficacy of intravenous (IV) bolus administration of esmolol in treating intraoperative tachycardia in patients undergoing noncardiac general surgery. Forty-eight ASA II-IV patients were randomized into three equal groups to receive either placebo, esmolol 50 mg, or esmolol 100 mg. Premedication (lorazepam) and anesthetic induction techniques (thiopental sodium and succinylcholine) were identical between groups. Approximately 20 minutes after intubation, during isoflurane/N2O/O2 maintenance anesthesia, patients with systolic pressure (SBP) greater than or equal to 110 mmHg were advanced into a 10-minute study drug period if one of two conditions were met: (1) heart rate (HR) was greater than or equal to 95 beats/minute, or (2) an increase in HR of greater than 20% above preinduction baseline occurred. After two consecutive recordings of HR and blood pressure (BP), the study drug (or placebo) was injected. HR was recorded every 30 seconds and BP was recorded every minute during the ensuing 10-minute period. Compared to placebo responses, HR was significantly reduced with both doses of esmolol within 1 minute of bolus injection and remained below placebo levels for 5 minutes after 50 mg of esmolol and for 9.5 minutes after 100 mg of esmolol. There were, however, only minor differences among groups with respect to SBP, diastolic blood pressure (DBP), and mean blood pressure (MBP) changes. ⋯ Bolus administration of esmolol can produce a rapid reduction of HR with relatively few adverse effects in an unhealthy surgical population.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
A single bolus dose of esmolol in the prevention of intubation-induced tachycardia and hypertension in an ambulatory surgery unit.
The efficacy of a single bolus dose of esmolol in the prevention of intubation-induced tachycardia and hypertension was studied in a double-blind manner. Thirty patients from the Ambulatory Surgery Unit at Rush-Presbyterian-St. Luke's Medical Center were prospectively randomized to receive a placebo, 100 mg of esmolol, or 200 mg of esmolol immediately prior to induction (2.5 to 3.0 minutes before intubation). ⋯ The average maximum BP increase was 47% in the placebo group versus 22% and 19% in the esmolol 100 mg and esmolol 200 mg groups, respectively. There were no significant differences between the two esmolol groups. This study demonstrates the efficacy of a single bolus dose of esmolol in blunting the tachycardic and hypertensive responses to laryngoscopy and intubation in an ambulatory surgery setting.
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Administration of vecuronium by infusion is an increasingly common technique, both in the operating room and in the intensive care unit (ICU), for patients requiring prolonged neuromuscular blockade and mechanical ventilation. The major advantage of vecuronium over older neuromuscular blocking agents is its rapid excretion and intermediate duration of action. ⋯ A case of an 81-year-old patient with renal failure and subclinical chronic cirrhosis of the liver, who remained paralyzed for 13 days following a vecuronium infusion, is described. Intensive monitoring of neuromuscular function is recommended whenever muscle relaxants are administered by continuous infusion.
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Review Case Reports
The cardiac, obstetric, and anesthetic management of pregnancy complicated by acute myocardial infarction.
Myocardial infarction (MI) occurring during pregnancy is a rare but potentially lethal event for both mother and fetus, particularly when it occurs in the third trimester or peripartum period. The authors report two cases of MI occurring in the third trimester of pregnancy and review the literature. ⋯ The preferred method of delivery in the pregnant MI patient is addressed, with emphasis on the need for individualization of care and coordination between the cardiac, obstetric, and anesthetic teams. Finally, the authors review the risks of subsequent pregnancy in this patient population.