Lokendra Thakur

Acute lung injury prediction score: derivation and validation in a population-based sample.

Early recognition of patients at high risk of acute lung injury (ALI) is critical for successful enrolment of patients in prevention strategies for this devastating syndrome. We aimed to develop and prospectively validate an ALI prediction score in a population-based sample of patients at risk. In a retrospective derivation cohort, predisposing conditions for ALI were identified at the time of hospital admission. The score was calculated based on the results of logistic regression analysis. Prospective validation was performed in an independent cohort of patients at risk identified at the time of hospital admission. In a derivation cohort of 409 patients with ALI risk factors, the lung injury prediction score discriminated patients who developed ALI from those who did not with an area under the curve (AUC) of 0.84 (95% CI 0.80–0.89; Hosmer–Lemeshow p = 0.60). The performance was similar in a prospective validation cohort of 463 patients at risk of ALI (AUC 0.84, 95% CI 0.77–0.91; Hosmer–Lemeshow p = 0.88). ALI prediction scores identify patients at high risk for ALI before intensive care unit admission. If externally validated, this model will serve to define the population of patients at high risk for ALI in whom future mechanistic studies and ALI prevention trials will be conducted.

Long-Term Survival and Quality of Life After Transfusion-Associated Pulmonary Edema in Critically III Medical Patients

BACKGROUND Transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO) commonly complicate transfusion in critically ill patients. Prior outcome studies of TACO and TRALI have focused on short-term morbidity and mortality, but the long-term survival and quality of life (QOL) of these patients remain unknown. METHODS In a nested case-control study, we compared survival and QOL between critically ill medical patients who developed pulmonary edema after transfusion (TRALI or TACO) and medical critically ill transfused controls, matched by age, gender, and admission diagnostic group. QOL in survivors was assessed with a 36-item short form health survey 1 year after initial hospitalization. RESULTS Hospital, 1-year, and 2-year mortality among the 74 TRALI cases and 74 matched controls were 43.2% vs 24.3% (P = .020), 63.8% vs 46.4% (P = .037) and 74.3% vs 54.3% (P = .031), whereas among the 51 TACO cases and 51 matched controls these values were 7.8% vs 11.8% (P = .727), 38.0% vs 28.0% (P = .371), and 44.9% vs 38.8% (P = .512). When adjusted for age and baseline severity of illness in a Cox proportional hazard analysis, the development of TRALI remained associated with decreased survival (hazard ratio 1.86; 95% CI, 1.19-2.93; P = .006). Both TRALI (P = .006, P = .03) and TACO (P = .03, P = .049) were associated with prolonged ICU and hospital lengths of stay. CONCLUSIONS In critically ill medical patients, development of TRALI, but not TACO, is independently associated with decreased long-term survival.

Ephrin B2/EphB4 pathway in hepatic stellate cells stimulates Erk-dependent VEGF production and sinusoidal endothelial cell recruitment

Chemotaxis signals between hepatic stellate cells (HSC) and sinusoidal endothelial cells (SEC) maintain hepatic vascular homeostasis and integrity and also regulate changes in sinusoidal structure in response to liver injury. Our prior studies have demonstrated that the bidirectional chemotactic signaling molecules EphrinB2 and EphB4 are expressed in HSC. The aim of our present study was to explore whether and how the EphrinB2/EphB4 system in HSC could promote SEC recruitment, which is essential for sinusoidal structure and remodeling. Stimulation of human HSC (hHSC) with chimeric agonists (2 microg/ml) of either EphrinB2 or EphB4 (EphrinB2 Fc or EphB4 Fc, respectively) significantly increased VEGF mRNA levels in hHSC as assessed by quantitative PCR, with respective small interfering RNAs for EphrinB2 and EphB4 inhibiting this increase (P < 0.05, n = 3). EphrinB2 agonist-induced increase in VEGF mRNA levels in hHSC was associated with increased phosphorylation of Erk and was significantly blocked by U0126 (20 microM), an inhibitor of MEK, which is a kinase upstream from Erk (P < 0.05, n = 3). The EphB4 agonist also significantly increased human VEGF promoter activity (P < 0.05, n = 3) as assessed by promoter reporter luciferase assay in transfected LX2-HSC. This was associated with upregulation of the vasculoprotective transcription factor, Kruppel-like factor 2 (KLF2). In Boyden chamber assays, conditioned media from hHSC stimulated with agonists of EphrinB2 or EphB4 increased SEC chemotaxis in a VEGF-dependent manner, compared with control groups that included basal media with agonists of EphrinB2, EphB4, or HSC-conditioned media from HSC in absence of agonist stimulation (P < 0.05, n = 3). EphB4 expression was detected in situ within liver sinusoidal vessels of rats after carbon tetrachloride-induced liver injury. In summary, activation of the EphrinB2/EphB4 signaling pathway in HSC promotes chemotaxis of SEC through a pathway that involves Erk, KLF2, and VEGF. These studies identify EphrinB2 or EphB4 as a key intermediary that links HSC signal transduction pathways with angiogenesis and sinusoidal remodeling.

Towards the prevention of acute lung injury: a population based cohort study protocol

BackgroundAcute lung injury (ALI) is an example of a critical care syndrome with limited treatment options once the condition is fully established. Despite improved understanding of pathophysiology of ALI, the clinical impact has been limited to improvements in supportive treatment. On the other hand, little has been done on the prevention of ALI. Olmsted County, MN, geographically isolated from other urban areas offers the opportunity to study clinical pathogenesis of ALI in a search for potential prevention targets.Methods/DesignIn this population-based observational cohort study, the investigators identify patients at high risk of ALI using the prediction model applied within the first six hours of hospital admission. Using a validated system-wide electronic surveillance, Olmsted County patients at risk are followed until ALI, death or hospital discharge. Detailed in-hospital (second hit) exposures and meaningful short and long term outcomes (quality-adjusted survival) are compared between ALI cases and high risk controls matched by age, gender and probability of developing ALI. Time sensitive biospecimens are collected for collaborative research studies. Nested case control comparison of 500 patients who developed ALI with 500 matched controls will provide an adequate power to determine significant differences in common hospital exposures and outcomes between the two groups.DiscussionThis population-based observational cohort study will identify patients at high risk early in the course of disease, the burden of ALI in the community, and the potential targets for future prevention trials.

Alcohol consumption and development of acute respiratory distress syndrome: a population-based study.

This retrospective population-based study evaluated the effects of alcohol consumption on the development of acute respiratory distress syndrome (ARDS). Alcohol consumption was quantified based on patient and/or family provided information at the time of hospital admission. ARDS was defined according to American-European consensus conference (AECC). From 1,422 critically ill Olmsted county residents, 1,357 had information about alcohol use in their medical records, 77 (6%) of whom developed ARDS. A history of significant alcohol consumption (more than two drinks per day) was reported in 97 (7%) of patients. When adjusted for underlying ARDS risk factors (aspiration, chemotherapy, high-risk surgery, pancreatitis, sepsis, shock), smoking, cirrhosis and gender, history of significant alcohol consumption was associated with increased risk of ARDS development (odds ratio 2.9, 95% CI 1.3–6.2). This population-based study confirmed that excessive alcohol consumption is associated with higher risk of ARDS.

Risk factors for the development of acute lung injury in patients with infectious pneumonia

IntroductionAlthough pneumonia has been identified as the single most common risk factor for acute lung injury (ALI), we have a limited knowledge as to why ALI develops in some patients with pneumonia and not in others. The objective of this study was to determine frequency, risk factors, and outcome of ALI in patients with infectious pneumonia.MethodsA retrospective cohort study of adult patients with microbiologically positive pneumonia, hospitalized at two Mayo Clinic Rochester hospitals between January 1, 2005, and December 31, 2007. In a subsequent nested case-control analysis, we evaluated the differences in prehospital and intrahospital exposures between patients with and without ALI/acute respiratory distress syndrome (ARDS) matched by specific pathogen, isolation site, gender, and closest age in a 1:1 manner.ResultsThe s tudy included 596 patients; 365 (61.2%) were men. The median age was 65 (IQR, 53 to 75) years. In total, 171 patients (28.7%) were diagnosed with ALI. The occurrence of ALI was less frequent in bacterial (n = 99 of 412, 24%) compared with viral (n = 19 of 55, 35%), fungal (n = 39 of 95, 41%), and mixed isolates pneumonias (n = 14 of 34, 41%; P = 0.002). After adjusting for baseline severity of illness and comorbidities, patients in whom ALI developed had a markedly increased risk of hospital death (ORadj 9.7; 95% CI, 6.0 to 15.9). In a nested case-control study, presence of shock (OR, 8.9; 95% CI, 2.8 to 45.9), inappropriate initial antimicrobial treatment (OR, 3.2; 95% CI, 1.3 to 8.5), and transfusions (OR, 4.8; 95% CI, 1.5 to 19.6) independently predicted ALI development.ConclusionsThe development of ALI among patients hospitalized with infectious pneumonia varied among pulmonary pathogens and was associated with increased mortality. Inappropriate initial antimicrobial treatment and transfusion predict the development of ALI independent of pathogen.

Long Term Survival in Patients with Tracheostomy and Prolonged Mechanical Ventilation in Olmsted County, Minnesota

BACKGROUND: An increasing number of patients require prolonged mechanical ventilation (PMV), which is associated with high morbidity and poor long-term survival, but there are few data regarding the incidence and outcome of PMV patients from a community perspective. METHODS: We retrospectively reviewed the electronic medical records of adult Olmsted county, Minnesota, residents admitted to the intensive care units at the 2 Mayo Clinic Rochester hospitals from January 1, 2003, to December 31, 2007, who underwent tracheostomy for PMV. RESULTS: Sixty-five patients, median age 68 years (interquartile range [IQR] 49–80 y), 39 male, underwent tracheostomy for PMV, resulting in an age-adjusted incidence of 13 (95% CI 10–17) per 100,000 patient-years at risk. The median number of days on mechanical ventilation was 24 days (IQR 18–37 d). Forty-six patients (71%) survived to hospital discharge, and 36 (55%) were alive at 1-year follow-up. After adjusting for age and baseline severity of illness, the presence of COPD was independently associated with 1-year mortality (hazard ratio 3.4, 95% CI 1.4–8.2%). CONCLUSIONS: There was a considerable incidence of tracheostomy for PMV. The presence of COPD was an independent predictor of 1-year mortality.

Ketamine and Propofol Combination (“Ketofol”) for Endotracheal Intubations in Critically Ill Patients: A Case Series

Case series Patient: Male, 77 • Male, 25 • Male, 63 • Male, 70 • Male, 70 • Female, 61 Final Diagnosis: — Symptoms: Hypotension • respiratory failure Medication: Ketamine • Propofol • Etomidate Clinical Procedure: Endotracheal intubation Specialty: Critical Care Medicine Objective: Educational Purpose (only if useful for a systematic review or synthesis) Background: Endotracheal intubation is a common procedure performed for critically ill patients that can have immediate life-threatening complications. Induction medications are routinely given to facilitate the procedure, but most of these medications are associated with hypotension. While etomidate is known for its neutral hemodynamic profile, it has been linked with increased mortality in septic patients and increased morbidity in trauma patients. Ketamine and propofol are effective anesthetics with counteracting cardiovascular profiles. No data are available about the use of this combination in critically ill patients undergoing endotracheal intubation. Case Series: We describe 6 cases in which the combination of ketamine and propofol (“ketofol”) was used as an induction agent for endotracheal intubation in critically ill patients with a focus on hemodynamic outcomes. All patients received a neuromuscular blocker and fentanyl, while 5 patients received midazolam. We recorded mean arterial pressure (MAP) 1 minute before induction and 15 minutes after intubation with the combination. Of the 6 patients, 5 maintained a MAP ≥65 mmHg 15 minutes after intubation. One patient was on norepinephrine infusion with a MAP of 64 mmHg, and did not require an increase in the dose of the vasopressor 15 minutes after intubation. No hemodynamic complications were reported after any of the intubations. Conclusions: This case series describes the use of the “ketofol” combination as an induction agent for intubation in critically ill patients when hemodynamic stability is desired. Further research is needed to establish the safety of this combination and how it compares to other induction medications.

Preliminary noise reduction efforts in a medical intensive care unit

Abstract Noise is a significant contributor to sleep disruption in the intensive care unit (ICU) that may result in increased patient morbidity such as delirium and prolonged length of stay in ICU. We conducted a pre-post intervention study in a 24-bed tertiary care academic medical ICU to reduce the mean noise levels. Baseline dosimeter recordings of ICU noise levels demonstrated a mean noise level of 54.2 A-weighted decibels (dBA) and peak noise levels of 109.9 dBA, well above the Environmental Protection Agency’s recommended levels. There were 1735 episodes of “defects” (maximum noise levels > 60 dBA). Following implementation of multipronged interventions, although the mean noise levels did not change significantly between pre- and post-intervention (54.2 vs 53.8 dBA; p = 0.96), there was a significant reduction in the number of “defects” post-intervention (1735 vs 1289, p ≤ 0.000), and the providers felt that the patients were sleeping longer in the ICU post-intervention.