Walter A. Boyle

Hemodynamic and metabolic effects of low-dose vasopressin infusions in vasodilatory septic shock

ObjectiveTo investigate the physiologic effects of exogenous vasopressin as a potential alternative to traditional high-dose catecholamine therapy for septic patients with vascular hyporeactivity to catecholamines. DesignProspective, case-controlled study. SettingIntensive care unit of a university hospital. PatientsVasopressin was infused in 16 critically ill septic patients who remained persistently hypotensive despite infusions of pharmacologic doses of catecholamines. InterventionContinuous intravenous infusion of vasopressin at 0.04 units/min for 16 hrs, in place of escalating the amount of catecholamines being infused. Measurements and Main Results After administration of vasopressin, systemic vascular resistance and mean arterial pressure were immediately and significantly increased in comparison with the values obtained just before vasopressin. When the vasopressin infusions were discontinued, mean arterial pressure decreased immediately and dramatically. We did not detect any obvious adverse cardiac effects during the vasopressin infusions. Vasopressin had no effect on other hemodynamic parameters or any of the metabolic parameters studied, including measures of oxygenation, plasma glucose, or electrolytes. Urine output increased significantly during the administration of vasopressin, although this effect may be nonspecific. Lactate concentrations decreased, particularly in the survival group, but the decreases were not significant. Overall survival was 56%. ConclusionsLow-dose vasopressin infusions increased mean arterial pressure, systemic vascular resistance, and urine output in patients with vasodilatory septic shock and hyporesponsiveness to catecholamines. The data indicate that low-dose vasopressin infusions may be useful in treating hypotension in these patients.

Novel arterial pathology in mice and humans hemizygous for elastin.

Obstructive vascular disease is an important health problem in the industrialized world. Through a series of molecular genetic studies, we demonstrated that loss-of-function mutations in one elastin allele cause an inherited obstructive arterial disease, supravalvular aortic stenosis (SVAS). To define the mechanism of elastins effect, we generated mice hemizygous for the elastin gene (ELN +/-). Although ELN mRNA and protein were reduced by 50% in ELN +/- mice, arterial compliance at physiologic pressures was nearly normal. This discrepancy was explained by a paradoxical increase of 35% in the number of elastic lamellae and smooth muscle in ELN +/- arteries. Examination of humans with ELN hemizygosity revealed a 2. 5-fold increase in elastic lamellae and smooth muscle. Thus, ELN hemizygosity in mice and humans induces a compensatory increase in the number of rings of elastic lamellae and smooth muscle during arterial development. Humans are exquisitely sensitive to reduced ELN expression, developing profound arterial thickening and markedly increased risk of obstructive vascular disease.

Effect of an education program on decreasing catheter-related bloodstream infections in the surgical intensive care unit

Objective The purpose of the study was to determine whether an education initiative aimed at improving central venous catheter insertion and care could decrease the rate of primary bloodstream infections. Design Pre- and postintervention observational study. Setting Eighteen-bed surgical/burn/trauma intensive care unit (ICU) in an urban teaching hospital. Patients A total of 4,283 patients were admitted to the ICU between January 1, 1998, and December 31, 2000. Interventions A program primarily directed toward registered nurses was developed by a multidisciplinary task force to highlight correct practice for central venous catheter insertion and maintenance. The program consisted of a 10-page self-study module on risk factors and practice modifications involved in catheter-related infections as well as a verbal in-service at staff meetings. Each participant was required to take a pretest before taking the study module and an identical test after its completion. Fact sheets and posters reinforcing the information in the study module were also posted throughout the ICU. Measurements and Main Results Seventy-four primary bloodstream infections occurred in 6874 catheter days (10.8 per 1000 catheter days) in the 18 months before the intervention. After the implementation of the education module, the number of primary bloodstream infections fell to 26 in 7044 catheter days (3.7 per 1000 catheter days), a decrease of 66% (p < .0001). The estimated cost savings secondary to the decreased infection rate for the 18 months after the intervention was between

A prospective, randomized study comparing percutaneous with surgical tracheostomy in critically ill patients

185,000 and

Developmental adaptation of the mouse cardiovascular system to elastin haploinsufficiency

2.808 million. Conclusions A focused intervention primarily directed at the ICU nursing staff can lead to a dramatic decrease in the incidence of primary bloodstream infections. Educational programs may lead to a substantial decrease in cost, morbidity, and mortality attributable to central venous catheterization.

Implementation of a mandatory checklist of protocols and objectives improves compliance with a wide range of evidence-based intensive care unit practices.

ObjectiveTo determine the relative cost-effectiveness of percutaneous dilational tracheostomy (PDT) and surgical tracheostomy (ST) in critically ill patients. DesignProspective randomized study. SettingMedical, surgical, and coronary intensive care units at Barnes-Jewish Hospital, a tertiary care medical center. PatientsEighty critically ill mechanically ventilated patients requiring elective tracheostomy. InterventionsRandomization to either PDT performed in the intensive care unit or ST performed in the operating room. Measurements and Main Results Treatment groups were well matched with respect to age (PDT, 65.44 ± 2.82 [mean ± se] years; ST, 61.4 ± 2.89 years, p = Ns), gender (PDT, 45% males; ST, 47.5% males, p = NS), severity of illness (Acute Physiology and Chronic Health Evaluation II score: PDT, 16.87 ± 0.84; ST, 17.88 ± 0.92, p = NS), and principle diagnosis. PDT was performed more quickly (PDT, 20.1 ± 2.0 mins; ST, 41.7 ± 3.9 mins, p < .0001) and was associated with lower patient charges than ST (total patient charges: PDT,

Ventilator-associated tracheobronchitis in a mixed surgical and medical ICU population.

1,569 ±

Effects of volatile anesthetics on acetylcholine-induced relaxation in the rabbit mesenteric resistance artery

157 vs. ST,

Elastin haploinsufficiency induces alternative aging processes in the aorta

3,172 ±

Relation between outer and luminal diameter in cannulated arteries

114; equipment/supply charges: PDT,