Journal of critical care
-
Journal of critical care · Mar 1994
Comparative StudyEffects of dobutamine and prostacyclin on cerebral blood flow velocity in septic patients.
Both dobutamine and prostacyclin (PGI2) have been used to increase oxygen delivery in septic patients, but their effects on cerebral blood flow have not been well studied. ⋯ Dobutamine and PGI2 at the administered doses exert different effects on arterial pressure and middle cerebral artery flow velocity in septic patients. According to these data, dobutamine increases cerebral oxygen delivery more than PGI2.
-
Journal of critical care · Mar 1994
Comparative StudyThe effect of adrenergic agonists on the systemic response to hemorrhage.
Systemic blood loss elicits a variety of reflex cardiovascular responses, which preserve cardiac output as possible and preserve arterial blood pressure when cardiac output decreases. When compensatory venoconstriction is exhausted, hemorrhage reduces oxygen delivery (QO2), and systemic vasoconstriction competes with local metabolic vasodilation to preserve tissue oxygen uptake (VO2). Through their effects on vascular tone and blood flow distribution, adrenergic agents might interfere with the physiological responses to reduced O2 delivery. This study was designed to determine the effects of dobutamine and norepinephrine on oxygen extraction and systemic vascular resistance during progressive hemorrhage. ⋯ Norepinephrine and dobutamine appear to block reflex vasoconstriction, and mechanistic explanations for this finding remain speculative. Despite inhibition of reflex vasoconstriction, neither dobutamine nor norepinephrine significantly impaired oxygen extraction during hemorrhage.
-
Journal of critical care · Mar 1994
Hormonal profiles in a canine model of the brain-dead organ donor.
The aim of the present study was to determine the effect of brain death on the circulating hormone levels. ⋯ The operative procedure alone led to the decrease in the plasma thyroid hormone levels. The inability of the BD group to increase plasma CORT, NE, and EPI may contribute to the hemodynamic deterioration and eventual somatic death.
-
Journal of critical care · Dec 1993
A physical chemical approach to the analysis of acid-base balance in the clinical setting.
We evaluated the clinical application of a model of acid-base balance, which is based on quantitative physical chemical principles (Stewart model). This model postulates that acid-base balance is normally determined by the difference in concentration between strong cations and anions (strong ion difference [SID]), PCO2, and weak acids (primarily proteins). We measured electrolytes and blood gases in arterial blood samples from 21 patients in a medical or surgical intensive care unit or emergency room of a tertiary care hospital. ⋯ It could also be calculated from the difference between the standard Siggaard-Anderson calculation of base excess and base excess attributable to free water, [Cl-], and proteins (ie, base-excess gap). Our results indicate that the SID gap, base excess gap, and anion gap reflect the presence of unmeasured ions, and both the anion-gap and base-excess gap provide readily available estimates of the SID gap. This provides a simple bedside approach for using the Stewart model to analyze the nonrespiratory component of clinical acid-base disorders and indicates that, in addition to unmeasured anions, unmeasured cations can be present.
-
Journal of critical care · Dec 1993
Randomized Controlled Trial Clinical TrialSafety and efficacy of intravenous immunoglobulin prophylaxis in pediatric head trauma patients: a double-blind controlled trial.
Infection is one of the major complications of severe head trauma in children. To assess whether intravenous immunoglobulin (IVIg) decreases the incidence of secondary infection after head injury in children, a randomized, double-blind trial was performed. Thirty-three children (mean age, 6.67 years; mean injury severity score, 32.8; mean Glasgow coma score, 6.1) with severe head injuries were enrolled; 1 child was excluded, 18 received IVIg, and 14 received the placebo preparation. ⋯ There was no difference in the number of days on mechanical ventilation or in number of hospital days. There were no side effects. It is concluded that prophylactic administration of commercial IVIg at a dose of 400 mg/kg, although safe, had no effect on the incidence of secondary infections in children with severe head injuries.