Fluid balance and colloid osmotic pressure in acute respiratory failure: emerging clinical evidence

Available evidence suggests that both hydrostatic and osmotic forces are important in the development of acute respiratory distress syndrome (ARDS) or, more broadly, acute lung injury (ALI). More than 80% of ARDS patients in a large-scale randomized controlled trial (RCT) exhibited, at least intermittently, pulmonary artery wedge pressures (PAWP) above 18 mmHg. Retrospective analyses have shown that PAWP elevation is associated with increased mortality. Reduction in serum total protein (STP) has been shown, in a recent retrospective analysis of data from a sepsis patient population with a high frequency of ARDS, to be highly predictive of positive fluid balance, weight gain, development of ARDS, prolonged mechanical ventilation, and mortality. These findings suggest that therapy with diuretics and colloids might be of benefit in the prevention or treatment of ALI. A prospective RCT was designed and conducted to evaluate combination therapy with furosemide and albumin over a 5-day period in 37 ALI patients. Both mean serum albumin and mean STP increased promptly and substantially in furosemide + albumin recipients. The furosemide + albumin group also achieved a mean weight loss of 10 kg by the end of the treatment phase, and their weight loss exceeded that of placebo patients throughout. Hemodynamics improved in the treatment group during the 5-day protocol. Oxygenation, as assessed by the ratio between the fraction of inspired oxygen and the partial pressure of oxygen in arterial blood (PaO2/FiO2), was significantly higher within 24 h after commencement of treatment in the furosemide + albumin than the placebo group. No clinically important adverse effects of furosemide + albumin therapy were encountered. These results provide evidence that combined therapy with furosemide and albumin is effective in augmenting serum albumin and STP levels, promoting weight loss, and improving oxygenation and longer-term hemodynamic stability. Although mortality did not differ between groups, the RCT showed a trend toward reduced duration of mechanical ventilation and length of stay in the intensive care unit in patients receiving furosemide + albumin. The findings of the RCT further highlight the importance of both hydrostatic and osmotic forces in hypoxemic respiratory failure, a subject that requires further investigation

Rational or rationalized choices in fluid resuscitation?

The war between colloids and crystalloids wages on. In a large multinational survey of fluid prescribing practices in critically ill patients, we have a new and intriguing snapshot of global fluid resuscitation practices. Colloids are more often used for impaired perfusion or low cardiac output, and the choice of colloid or crystalloid varies enormously between countries. Why are some ICUs prescribing colloids more often than crystalloids when there is little convincing evidence that colloids are superior for fluid resuscitation? Are colloids advantageous in certain diseases, or in specific regional patient populations that have not yet been elucidated? Perhaps we should look inwards: the answer may not be more randomized clinical trials, but better adherence to current guidelines and treatment recommendations

Effect of sepsis therapies on health-related quality of life

Sepsis is one of the most common conditions encountered in the intensive care unit and is the 10th leading cause of death overall in the United States. Both long-term survival and health-related quality of life are reduced in survivors of sepsis, yet there is little knowledge of the effect of sepsis-specific interventions on either long-term survival or health-related quality of life. The present article discusses the importance of studying health-related quality of life as it relates to sepsis management strategies, particularly in the context of pharmacologic therapy with recombinant human activated protein C

Extending international sepsis epidemiology: the impact of organ dysfunction

In the previous issue of Critical Care, Blanco and colleagues contributed to a growing body of literature on the international epidemiology of severe sepsis. Taken together, these studies confirm that the sepsis incidence is high, that the development of organ dysfunction is a major determinant of mortality and that the occurrence of organ dysfunction is influenced by chronic comorbid medical conditions. It is clear that early detection of organ dysfunction and serial sequential organ dysfunction scoring provides us with the best chance to optimize clinical care. Identifying factors that contribute to the development of organ dysfunction in sepsis will lead to the development of new treatment modalities that will reduce mortality. Future studies must therefore focus on the impact of new treatment modalities for preventing progression to multiple organ dysfunction syndrome and consequent mortality in sepsis

Polarization Observations with the Cosmic Background Imager

We describe polarization observations of the CMBR with the Cosmic Background Imager, a 13 element interferometer which operates in the 26-36 GHz band from Llano de Chajnantour in northern Chile. The array consists of 90-cm Cassegrain antennas mounted on a steerable platform which can be rotated about the optical axis to facilitate polarization observations. The CBI employs single mode circularly polarized receivers which sample multipoles from ℓ~400 to ℓ~4250. The instrumental polarization of the CBI was calibrated with 3C279, a bright polarized point source which was monitored with the VLA

Extravascular lung water in patients with severe sepsis: a prospective cohort study

INTRODUCTION: Few investigations have prospectively examined extravascular lung water (EVLW) in patients with severe sepsis. We sought to determine whether EVLW may contribute to lung injury in these patients by quantifying the relationship of EVLW to parameters of lung injury, to determine the effects of chronic alcohol abuse on EVLW, and to determine whether EVLW may be a useful tool in the diagnosis of acute respiratory distress syndrome (ARDS). METHODS: The present prospective cohort study was conducted in consecutive patients with severe sepsis from a medical intensive care unit in an urban university teaching hospital. In each patient, transpulmonary thermodilution was used to measure cardiovascular hemodynamics and EVLW for 7 days via an arterial catheter placed within 72 hours of meeting criteria for severe sepsis. RESULTS: A total of 29 patients were studied. Twenty-five of the 29 patients (86%) were mechanically ventilated, 15 of the 29 patients (52%) developed ARDS, and overall 28-day mortality was 41%. Eight out of 14 patients (57%) with non-ARDS severe sepsis had high EVLW with significantly greater hypoxemia than did those patient with low EVLW (mean arterial oxygen tension/fractional inspired oxygen ratio 230.7 ± 36.1 mmHg versus 341.2 ± 92.8 mmHg; P < 0.001). Four out of 15 patients with severe sepsis with ARDS maintained a low EVLW and had better 28-day survival than did ARDS patients with high EVLW (100% versus 36%; P = 0.03). ARDS patients with a history of chronic alcohol abuse had greater EVLW than did nonalcoholic patients (19.9 ml/kg versus 8.7 ml/kg; P < 0.0001). The arterial oxygen tension/fractional inspired oxygen ratio, lung injury score, and chest radiograph scores correlated with EVLW (r(2 )= 0.27, r(2 )= 0.18, and r(2 )= 0.28, respectively; all P < 0.0001). CONCLUSIONS: More than half of the patients with severe sepsis but without ARDS had increased EVLW, possibly representing subclinical lung injury. Chronic alcohol abuse was associated with increased EVLW, whereas lower EVLW was associated with survival. EVLW correlated moderately with the severity of lung injury but did not account for all respiratory derangements. EVLW may improve both risk stratification and management of patients with severe sepsis

The role of body mass index and diabetes in the development of acute organ failure and subsequent mortality in an observational cohort

INTRODUCTION: Several studies have shown a correlation between body mass index (BMI) and both the development of critical illness and adverse outcomes in critically ill patients. The goal of our study was to examine this relationship prospectively with particular attention to the influence of concomitant diabetes mellitus (DM). METHODS: We analyzed data from 15,408 participants in the Atherosclerosis Risk in Communities (ARIC) study for this analysis. BMI and the presence of DM were defined at baseline. We defined 'acute organ failure' as those subjects who met a standard definition with diagnostic codes abstracted from hospitalization records. Outcomes assessed included the following: risk of the development of acute organ failure within three years of the baseline examination; in-hospital death while ill with acute organ failure; and death at three years among all subjects and among those with acute organ failure. RESULTS: At baseline, participants with a BMI of at least 30 were more likely than those in lower BMI categories to have DM (22.4% versus 7.9%, p < 0.01). Overall, BMI was not a significant predictor of developing acute organ failure. The risk for developing acute organ failure was increased among subjects with DM in comparison with those without DM (2.4% versus 0.7%, p < 0.01). Among subjects with organ failure, both in-hospital mortality (46.5% versus 12.2%, p < 0.01) and 3-year mortality (51.2% versus 21.1%, p < 0.01) was higher in subjects with DM. CONCLUSION: Our findings suggest that obesity by itself is not a significant predictor of either acute organ failure or death during or after acute organ failure in this cohort. However, the presence of DM, which is related to obesity, is a strong predictor of both acute organ failure and death after acute organ failure