Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1987
Randomized Controlled Trial Clinical TrialHemodynamic effects of esmolol in chronically beta-blocked patients undergoing aortocoronary bypass surgery.
The hemodynamic effects of esmolol were studied in 40 patients scheduled for elective coronary artery surgery to determine whether the administration of esmolol in chronically beta-blocked patients would result in additional attenuation of sympathetically mediated hemodynamic stress responses to noxious stimuli. Patients were randomly assigned to receive IV infusions of esmolol or 5% dextrose in water (D5W). All received their regular dose of beta-adrenergic blocker within 6 hr of surgery and were anesthetized with diazepam, pancuronium, and enflurane. ⋯ However the incidence and magnitude of SNP use in the control group was significantly (P less than 0.05) greater. Thus, the lower blood pressure, in the absence of changes in systemic vascular resistance, cardiac index, heart rate, and pulmonary capillary wedge pressure points toward a decrease in myocardial contractility, suggesting that the addition of esmolol to chronically used beta-blockers resulted in an additional negative inotropic effect. We conclude that in patients with coronary artery disease in whom chronic beta-blocker therapy is continued until the time of surgery, esmolol does not further attenuate the heart rate response but does attenuate the increase in blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Feb 1987
Hypertonic saline as a resuscitation solution in hemorrhagic shock: effects on extravascular lung water and cardiopulmonary function.
To determine the effect of resuscitation with hypertonic saline on extravascular lung water, seven adult sheep were endotracheally intubated; mean arterial pressure (MAP), pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), and central venous pressure (CVP) were monitored. A 5-French, thermistor-tipped catheter was used to measure extravascular lung water (EVLW). Colloid oncotic pressure (COP), serum electrolytes and osmolality, and arterial and mixed venous blood gas tensions were measured. ⋯ Throughout the study, EVLW did not vary despite a COP-PCWP gradient less than 4 mm Hg. Serum sodium levels and serum osmolality were significantly above baseline values after resuscitation. In this animal model of hemorrhagic shock, infusion of hypertonic saline effected resuscitation without compromising cardiopulmonary function or increasing EVLW.
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Anesthesia and analgesia · Feb 1987
The neuromuscular blocking effect of vecuronium on the human diaphragm.
This study compares the neuromuscular blocking effect of vecuronium (0.1 mg/kg) on the diaphragm and the adductor pollicis in nine anesthetized patients. Monitoring of the diaphragm consisted of measurement of the transdiaphragmatic pressure after bilateral phrenic nerve stimulation. Onset time for neuromuscular blockade of the diaphragm was 1.6 +/- 0.3 min (+/-SD) compared to 2.5 +/- 0.3 min in the adductor pollicis (P less than 0.001). ⋯ The twitch height (TH) returned to 25% of its control value after 27 +/- 8 min for the diaphragm, compared to 41 +/- 11 min for the adductor pollicis (P less than 0.01). Complete TH recovery was achieved after 49 +/- 14 min for the diaphragm and after 74 +/- 22 min for the adductor pollicis (P less than 0.01). The recovery index of 12 +/- 4 min for the diaphragm was significantly shorter (P less than 0.05) than for the adductor pollicis (20 +/- 9 min.) We conclude that monitoring of peripheral muscles in anesthetized patients given vecuronium provides adequate information about the degree of paralysis of the diaphragm.
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Anesthesia and analgesia · Feb 1987
Low-dose enflurane as adjunct to high-dose fentanyl in patients undergoing coronary artery surgery: stable hemodynamics and maintained myocardial oxygen balance.
The effects of enflurane (end-tidal concentration 0.7%) on central and coronary hemodynamics and myocardial oxygenation were studied during steady state, high-dose fentanyl anesthesia in ten patients undergoing coronary artery bypass grafting operations. Compared with the response in ten patients receiving the same fentanyl anesthesia (100 micrograms/kg) without enflurane supplementation, enflurane caused a moderate reduction in mean arterial pressure, systemic vascular resistance, and left ventricular stroke work index. No patient showed signs of myocardial ischemia, and mean coronary sinus flow and calculated coronary resistance remained unchanged. ⋯ Myocardial oxygen extraction decreased in the enflurane supplemented group although it increased in the fentanyl group after surgical stimulation. Three fentanyl group patients and one enflurane-fentanyl group patient had a low myocardial lactate extraction as a sign of myocardial ischemia during surgery. We conclude that a 0.7% enflurane supplementation of 100 micrograms/kg fentanyl anesthesia does not endanger myocardial oxygenation and effectively prevents central and coronary hemodynamic responses to skin incision and sternotomy in patients undergoing coronary artery surgery.