Critical care medicine
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Critical care medicine · Jul 1987
Continuous arteriovenous hemofiltration in critically ill children with acute renal failure.
Last year, five critically ill children with acute renal failure were treated by continuous arteriovenous hemofiltration. Mean treatment duration was 326 +/- 89 (SD)h, for a total of 1632 h. ⋯ In the four surviving patients, urinary output started between 12 and 42 days after the onset of acute renal failure. Continuous arteriovenous hemofiltration is a very effective extracorporeal therapeutic system to control azotemia, fluid, and electrolyte balance in critically ill children with acute renal failure and hemodynamic instability.
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Critical care medicine · Jul 1987
Comparative StudyMethoxamine versus epinephrine on regional cerebral blood flow during cardiopulmonary resuscitation.
The improvement in cerebral blood flow (CBF) during CPR after epinephrine administration has been attributed to epinephrine's alpha-adrenergic properties. Methoxamine, a pure alpha-1 agonist, has only been shown to be comparable to epinephrine in restoring circulation after cardiac arrest in a canine model. This study compares the effectiveness of equipotent doses of epinephrine and methoxamine in improving CBF during CPR after a prolonged cardiac arrest in a swine model. ⋯ This study demonstrated that, after a 10-min cardiac arrest, CBF was extremely low, averaging less than 7 ml/min X 100 g during external CPR. There were no clinically significant improvements in regional CBF after 0.02 mg/kg of epinephrine, or the two lowest doses of methoxamine. The addition of 10 mg/kg of methoxamine clinically improved blood flow only to the most caudal CNS structures, including the pons, medulla, and cervical spinal cord.(ABSTRACT TRUNCATED AT 250 WORDS)
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Critical care medicine · Jul 1987
Comparative StudyComparison of high-frequency chest wall compression with conventional mechanical ventilation in cats.
Six anesthetized paralyzed cats with normal lungs were ventilated by high-frequency chest wall compression (HFCWC) at 5 Hz using a single-chamber circumferential cuff enclosing the thorax from the axillae to the xiphisternum. PaCO2 during HFCWC + PEEP (3 cm H2O) was significantly (p less than .0005) lower compared with conventional mechanical ventilation (CMV). End-expiratory lung volume (VL) during HFCWC + PEEP was significantly (p less than .001) lower than VL during CMV + PEEP but was higher than VL during CMV without PEEP. ⋯ A significant decrease in PaCO2 (p less than .02) during HFCWC occurred but no significant differences were observed in PaO2, VL, or compliance. Arterial BP and cardiac output were similar between CMV + PEEP and HFCWC + CPAP. In cats with normal lungs, VL can be maintained by applying CPAP during HFCWC, and in those with injured lungs, HFCWC + CPAP produces comparable gas exchange at a Paw equal to or lower than that used during CMV + PEEP.
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Critical care medicine · Jul 1987
Comparative StudyHemodynamic effects of continuous norepinephrine infusion in dogs with and without hyperkinetic endotoxic shock.
We compared, at constant preload maintained by polygeline (gelatin) infusion, the hemodynamic effects of continuous infusion of norepinephrine (0.5, 1, and 1.5 micrograms/kg X min) in anesthetized dogs with and without hyperdynamic endotoxic shock. In both groups, norepinephrine infusion increased systolic, diastolic and mean aortic BP, cardiac index, stroke index, index of myocardial contractility, and mean pulmonary artery pressure. No significant change in right atrial pressure, left ventricular end-diastolic pressure, heart rate, systemic vascular resistance, or pulmonary vascular resistance was observed. ⋯ Stroke index increased as contractility improved. The slight alpha-adrenergic effect of continuous, low-dose norepinephrine infusion did not impede the beneficial effects of the marked beta-adrenergic stimulation on cardiac function. The combination of these two effects improved hemodynamic disturbances of hyperdynamic endotoxic canine shock.
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Critical care medicine · Jun 1987
Randomized Controlled Trial Comparative Study Clinical TrialRestoration of volume by crystalloid versus colloid after coronary artery bypass: hemodynamics, lung water, oxygenation, and outcome.
We compared Ringer's acetate-gluconate solution with 6% dextran-70 infused during rewarming after coronary bypass surgery. In a randomized study, 18 patients received 56 +/- 15 ml/kg of crystalloid (group 1), and 14 patients received 16 +/- 6 ml/kg of dextran (group 2). Data were taken at the following intervals: 4 to 5 h after terminating the cardiopulmonary bypass, after rewarming, the next morning on controlled ventilation and continuous positive airway pressure (CPAP) breathing, and after extubation. ⋯ After transition to the CPAP mode, hydrostatic pressures increased, more in group 2, doubling the pulmonary shunt flow. Pulmonary extravascular thermal volume did not change in either group. We conclude that hemodynamic stability occurred faster with dextran, and ventilatory weaning was somewhat easier with crystalloid.