Pulmonary-artery versus central venous catheter to guide treatment of acute lung injury.

BACKGROUND: The balance between the benefits and the risks of pulmonary-artery catheters (PACs) has not been established. METHODS: We evaluated the relationship of benefits and risks of PACs in 1000 patients with established acute lung injury in a randomized trial comparing hemodynamic management guided by a PAC with hemodynamic management guided by a central venous catheter (CVC) using an explicit management protocol. Mortality during the first 60 days before discharge home was the primary outcome. RESULTS: The groups had similar baseline characteristics. The rates of death during the first 60 days before discharge home were similar in the PAC and CVC groups (27.4 percent and 26.3 percent, respectively; P=0.69; absolute difference, 1.1 percent; 95 percent confidence interval, -4.4 to 6.6 percent), as were the mean (+/-SE) numbers of both ventilator-free days (13.2+/-0.5 and 13.5+/-0.5; P=0.58) and days not spent in the intensive care unit (12.0+/-0.4 and 12.5+/-0.5; P=0.40) to day 28. PAC-guided therapy did not improve these measures for patients in shock at the time of enrollment. There were no significant differences between groups in lung or kidney function, rates of hypotension, ventilator settings, or use of dialysis or vasopressors. Approximately 90 percent of protocol instructions were followed in both groups, with a 1 percent rate of crossover from CVC- to PAC-guided therapy. Fluid balance was similar in the two groups, as was the proportion of instructions given for fluid and diuretics. Dobutamine use was uncommon. The PAC group had approximately twice as many catheter-related complications (predominantly arrhythmias). CONCLUSIONS: PAC-guided therapy did not improve survival or organ function but was associated with more complications than CVC-guided therapy. These results, when considered with those of previous studies, suggest that the PAC should not be routinely used for the management of acute lung injury. (ClinicalTrials.gov number, NCT00281268.).

Comparison of two fluid-management strategies in acute lung injury.

BACKGROUND: Optimal fluid management in patients with acute lung injury is unknown. Diuresis or fluid restriction may improve lung function but could jeopardize extrapulmonary-organ perfusion. METHODS: In a randomized study, we compared a conservative and a liberal strategy of fluid management using explicit protocols applied for seven days in 1000 patients with acute lung injury. The primary end point was death at 60 days. Secondary end points included the number of ventilator-free days and organ-failure-free days and measures of lung physiology. RESULTS: The rate of death at 60 days was 25.5 percent in the conservative-strategy group and 28.4 percent in the liberal-strategy group (P=0.30; 95 percent confidence interval for the difference, -2.6 to 8.4 percent). The mean (+/-SE) cumulative fluid balance during the first seven days was -136+/-491 ml in the conservative-strategy group and 6992+/-502 ml in the liberal-strategy group (P<0.001). As compared with the liberal strategy, the conservative strategy improved the oxygenation index ([mean airway pressure x the ratio of the fraction of inspired oxygen to the partial pressure of arterial oxygen]x100) and the lung injury score and increased the number of ventilator-free days (14.6+/-0.5 vs. 12.1+/-0.5, P<0.001) and days not spent in the intensive care unit (13.4+/-0.4 vs. 11.2+/-0.4, P<0.001) during the first 28 days but did not increase the incidence or prevalence of shock during the study or the use of dialysis during the first 60 days (10 percent vs. 14 percent, P=0.06). CONCLUSIONS: Although there was no significant difference in the primary outcome of 60-day mortality, the conservative strategy of fluid management improved lung function and shortened the duration of mechanical ventilation and intensive care without increasing nonpulmonary-organ failures. These results support the use of a conservative strategy of fluid management in patients with acute lung injury. (ClinicalTrials.gov number, NCT00281268 [ClinicalTrials.gov].).

Pathophysiology of pulmonary arterial hypertension.

The mechanisms leading to elevations in precapillary pulmonary vascular resistance are complex and likely involve multiple pathways, but the histopathologic sequelae of these processes are restricted to a few findings, primarily neoangiogenesis, intimal and smooth muscle proliferation, vasoconstriction, and/or in situ thrombosis. Regardless of the etiology of pulmonary hypertension, abnormalities in endothelial function are often observed and likely play a central role in mediating structural changes.

Education does pay off: pneumococcal vaccine screening and administration in hospitalized adult patients with pneumonia.

Streptococcus pneumoniae-associated infections are an important cause of hospitalization and mortality in high-risk and elderly patients. Even in the setting of appropriate therapy, the case fatality rate of invasive pneumococcal disease in the elderly may approach 40%. Since approximately 40,000 people die annually from pneumococcal-associated disease, it represents a substantial target for vaccine-preventable, bacterial fatalities. The 23-valent pneumococcal polysaccharide vaccine has proven consistently effective in preventing invasive pneumococcal disease. Despite its endorsement by numerous specialty societies, the pneumococcal vaccine is underutilized in the inpatient setting. In a recent report of quality indicators for Medicare beneficiaries, the percentage of Medicare beneficiaries in Louisiana admitted with pneumonia who were screened or received the pneumococcal vaccination prior to discharge was only 4%, the lowest percentage in the United States. The Louisiana State University-New Orleans Internal Medicine Department and its house staff embarked upon a retrospective study to determine its baseline pneumococcal vaccination or screening rates for all patients with pneumonia on its inpatient services at the The Medical Center of Louisiana in New Orleans from July 2000 through June 2001. From July 2001 through June 2002 an intensive educational intervention concentrating on the indications and benefits of pneumococcal vaccination was directed toward the Louisiana State University Internal Medicine house staff assigned to the inpatient service. Retrospective analysis for pneumococcal vaccine screening and administration of charts of all patients with pneumonia on the LSU Medicine service from July 2001 through June 2002 was performed in order to determine the effects of the intervention. Data from the pre-educational intervention period revealed a baseline pneumococcal vaccine screening or administration rate of 11% for all patients with pneumonia on the LSU Internal Medicine inpatient service. During the one-year intervention period, the pneumococcal vaccine screening or administration rate increased to 71%, a clinically and statistically significant increase (p-value < 0.0001). Data targeting patients 65 years of age and older revealed a baseline pneumococcal vaccine screening or administration rate of 10% for patients with pneumonia on the LSU Internal Medicine inpatient service which increased to 82% during the one year educational intervention (p-value < 0.0001). House officer scores (possible range 0-100) on a questionnaire assessing their understanding of the indications and benefits of pneumococcal vaccination were significantly higher after the educational intervention compared to before the intervention (means +/- standard deviations, 68 +/- 9 vs. 59 +/- 10, p < 0.0001). The findings from this study highlight the importance of education in increasing compliance with widely-accepted practice guidelines such as pneumococcal vaccine screening or administration in patients hospitalized with pneumonia.