Elevated Red Cell Distribution Width Is Associated With Decreased Ventilator-Free Days in Critically Ill Patients.

INTRODUCTION: Elevated red cell distribution width (RDW) is associated with mortality in a variety of respiratory conditions. Recent data also suggest that RDW is associated with mortality in intensive care unit (ICU) patients. Although respiratory failure is common in the ICU, the relationship between RDW and pulmonary outcomes in the ICU has not been previously explored. Therefore, our goal was to investigate the association of admission RDW with 30-day ventilator-free days (VFDs) in ICU patients. METHODS: We performed a retrospective analysis from an ongoing prospective, observational study. Patients were recruited from medical and surgical ICUs of a large teaching hospital in Boston, Massachusetts. The RDW was assessed within 1 hour of ICU admission. Poisson regression analysis was used to investigate the association of RDW (normal: 11.5%-14.5% vs elevated: >14.5%) with 30-day VFD, while controlling for age, sex, race, body mass index, Nutrition Risk in the Critically Ill score, the presence of chronic lung disease, Pao2/Fio2 ratio, and admission levels of hemoglobin, mean corpuscular volume, phosphate, albumin, C-reactive protein, and creatinine. RESULTS: A total of 637 patients comprised the analytic cohort. Mean RDW was 15 (standard deviation 4%), with 53% of patients in the normal range and 47% with elevated levels. Median VFD was 16 (interquartile range: 6-25) days. Poisson regression analysis demonstrated that ICU patients with elevated admission RDW were likely to have 32% lower 30-day VFDs compared to their counterparts with RDW in the normal range (incidence rate ratio: 0.68; 95% confidence interval: 0.55-0.83: P < .001). CONCLUSIONS: We observed an inverse association of RDW and 30-day VFD, despite controlling for demographics, nutritional factors, and severity of illness. This supports the need for future studies to validate our findings, understand the physiologic processes that lead to elevated RDW in patients with respiratory failure, and determine whether changes in RDW may be used to support clinical decision-making.

The association of macronutrient deficit with functional status at discharge from the intensive care unit: a retrospective study from a single-center critical illness registry.

BACKGROUND: Nutrition is often thought to influence outcomes in critically ill patients. However, the relationship between macronutrient delivery and functional status is not well characterized. Our goal was to investigate whether caloric or protein deficit over the course of critical illness is associated with functional status at the time of intensive care unit (ICU) discharge. METHODS: We performed a retrospective analysis of surgical ICU patients at a teaching hospital in Boston, MA. To investigate the association of caloric or protein deficit with Functional Status Score for the ICU (FSS-ICU), we constructed linear regression models, controlling for age, sex, race, body mass index, Nutritional Risk in the Critically Ill score, and ICU length of stay. We then dichotomized caloric as well as protein deficit, and performed logistic regressions to investigate their association with functional status, controlling for the same variables. RESULTS: Linear regression models (n = 976) demonstrated a caloric deficit of 238 kcal (237.88; 95%CI 75.13-400.63) or a protein deficit of 14 g (14.23; 95%CI 4.46-24.00) was associated with each unit decrement in FSS-ICU. Logistic regression models demonstrated a 6% likelihood (1.06; 95%CI 1.01-1.14) of caloric deficit ≥6000 vs. <6000 kcal and an 8% likelihood (1.08; 95%CI 1.01-1.15) of protein deficit ≥300 vs. <300 g with each unit decrement in FSS-ICU. CONCLUSION: In our cohort of patients, macronutrient deficit over the course of critical illness was associated with worse functional status at discharge. Future studies are needed to determine whether optimized macronutrient delivery can improve outcomes in ICU survivors.

Vitamin D Status Is Associated With Development of Hospital-Acquired Pressure Injuries in Critically Ill Surgical Patients.

BACKGROUND: Hospital-acquired pressure injuries (HAPIs) typically develop following critical illness due to immobility and suboptimal perfusion. Vitamin D helps to maintain epithelial cell integrity, particularly at barrier sites such as skin. It is unclear whether vitamin D status is a modifiable risk factor for HAPIs in critically ill patients. Our goal was to investigate the relationship between admission 25-hydroxyvitamin D (25OHD) levels with the development of HAPIs in surgical intensive care unit (ICU) patients. METHODS: We performed a retrospective cohort study of patients admitted to surgical ICUs at a major teaching hospital in Boston, Massachusetts. To investigate the association of 25OHD levels with subsequent development of HAPIs, we performed logistic regression analyses, controlling for body mass index, Nutrition Risk in the Critically Ill score, ICU length of stay, and cumulative ICU caloric or protein deficit. RESULTS: A total of 402 patients comprised our analytic cohort. Each unit increment in 25OHD was associated with 11% decreased odds of HAPIs (odds ratio [OR] 0.89; 95% CI 0.840.95). When vitamin D status was dichotomized, patients with 25OHD <20 ng/mL were >2 times as likely to develop HAPIs (OR 2.51; 95% CI 1.065.97) compared with patients with 25OHD >20 ng/mL. CONCLUSION: In our cohort of critically ill surgical patients, vitamin D status at ICU admission was linked to subsequent development of HAPIs. Randomized, controlled trials are needed to assess whether optimizing 25OHD levels in the ICU can reduce the incidence of HAPIs and improve other clinically relevant outcomes in critically ill patients.

Elevated red cell distribution width at initiation of critical care is associated with mortality in surgical intensive care unit patients.

PURPOSE: Recent evidence suggests that red cell distribution width (RDW) is associated with mortality in mixed cohorts of critically ill patients. Our goal was to investigate whether elevated RDW at initiation of critical care in the intensive care unit (ICU) is associated with 90-day mortality in surgical patients. METHODS: We performed a retrospective, single-center cohort study. Normal RDW was defined as 11.5%-14.5%. To investigate the association of admission RDW with 90-day mortality, we performed a logistic regression analysis, controlling for age, sex, race, body mass index, Nutrition Risk Screening 2002 score, Acute Physiology and Chronic Health Evaluation II score, hospital length of stay, as well as levels of creatinine, albumin, and mean corpuscular volume. RESULTS: 500 patients comprised the analytic cohort; 47% patients had elevated RDW and overall 90-day mortality was 28%. Logistic regression analysis demonstrated that patients with elevated RDW had a greater than two-fold increased odds of mortality (OR 2.28: 95%CI 1.20-4.33) compared to patients with normal RDW. CONCLUSIONS: Elevated RDW at initiation of care is associated with increased odds of 90-day mortality in surgical ICU patients. These data support the need for prospective studies to determine whether RDW can improve risk stratification in surgical ICU patients.