Journal of critical care
-
Journal of critical care · Jun 1994
Implications of a biphasic two-compartment model of constant flow ventilation for the clinical setting.
To investigate the theoretical effects of changing frequency (f), duty cycle (D), or end-inspiratory pause length on the distribution of ventilation and compartmental pressure in a heterogeneous, two compartment pulmonary model inflated by constant flow. ⋯ In a linear, two compartment model of the respiratory system, disparity of compartmental end-expiratory pressures is the primary mechanism by which changes of f, D, or pause alter the distribution of ventilation during inflation with constant flow. Ventilation is less evenly distributed than peak alveolar pressure, and there are limits to the beneficial effects on the distribution of ventilation to be gained from manipulations of machine settings.
-
Journal of critical care · Mar 1994
ReviewRole of neutrophil-endothelial cell adhesion in inflammatory disorders.
Polymorphonuclear leukocytes are armed with an impressive arsenal of bactericidal agents that allow these cells to play a vital role in host defense against invading pathogens. However, these same agents can produce extensive cellular damage in host tissues when leukocytes are activated during inflammatory conditions. ⋯ NECA also appears to play an important role in the pathobiology of airway inflammation and asthma, pulmonary oxygen toxicity, arthritis, bacterial meningitis, and cerebral malaria. The aim of this review is to summarize the evidence implicating NECA in the pathogenesis of these inflammatory conditions.
-
Journal of critical care · Mar 1994
Comparative StudyThe effects of intravenous L-arginine supplementation on systemic and pulmonary hemodynamics and oxygen utilization during group B streptococcal sepsis in piglets.
In these investigations, three questions were addressed. First, to what extent did inhibition of endothelium-derived relaxation factor (EDRF) mimic the hemodynamic disturbances noted in a piglet model of neonatal group B streptococcal (GBS) sepsis? Second, to what extent would an attempt to augment EDRF production reverse the hemodynamic effects of continued GBS infusion in septic piglets? Third, to what extent would an attempt to augment EDRF production affect hemodynamics in piglets who were not septic. ⋯ EDRF inhibition with NNLA appeared to model GBS infusion partially but not completely. L-ARG appeared to produce desirable hemodynamic effects during GBS sepsis when compared with the consequences of ongoing GBS infusion without L-ARG. Given the constellation of increased pulmonary and systemic vascular resistance often observed during neonatal GBS sepsis in human infants, all these effects of L-ARG, if extrapolated from our piglets to the clinical arena, would appear to be beneficial. Particularly in the context of deleterious consequences resulting shunting or right ventricular decompensation from increased afterload), L-ARG administration might prove clinically useful.
-
Journal of critical care · Mar 1994
Nimodipine after circulatory arrest: effects on oxygen delivery and consumption.
Evaluation of the effects of nimodipine administration during and after cardiopulmonary resuscitation (CPR) on oxygen delivery and consumption was the aim of this study. ⋯ Our findings suggest that in nimodipine-treated animals, a lower oxygen deficit or a better redistribution of regional blood flow occurred after circulatory arrest and resuscitation.
-
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.