David A. Kaufman

Early Identification of Patients at Risk of Acute Lung Injury: Evaluation of Lung Injury Prediction Score in a Multicenter Cohort Study

RATIONALE Accurate, early identification of patients at risk for developing acute lung injury (ALI) provides the opportunity to test and implement secondary prevention strategies. OBJECTIVES To determine the frequency and outcome of ALI development in patients at risk and validate a lung injury prediction score (LIPS). METHODS In this prospective multicenter observational cohort study, predisposing conditions and risk modifiers predictive of ALI development were identified from routine clinical data available during initial evaluation. The discrimination of the model was assessed with area under receiver operating curve (AUC). The risk of death from ALI was determined after adjustment for severity of illness and predisposing conditions. MEASUREMENTS AND MAIN RESULTS Twenty-two hospitals enrolled 5,584 patients at risk. ALI developed a median of 2 (interquartile range 1-4) days after initial evaluation in 377 (6.8%; 148 ALI-only, 229 adult respiratory distress syndrome) patients. The frequency of ALI varied according to predisposing conditions (from 3% in pancreatitis to 26% after smoke inhalation). LIPS discriminated patients who developed ALI from those who did not with an AUC of 0.80 (95% confidence interval, 0.78-0.82). When adjusted for severity of illness and predisposing conditions, development of ALI increased the risk of in-hospital death (odds ratio, 4.1; 95% confidence interval, 2.9-5.7). CONCLUSIONS ALI occurrence varies according to predisposing conditions and carries an independently poor prognosis. Using routinely available clinical data, LIPS identifies patients at high risk for ALI early in the course of their illness. This model will alert clinicians about the risk of ALI and facilitate testing and implementation of ALI prevention strategies. Clinical trial registered with www.clinicaltrials.gov (NCT00889772).

Outcomes of critically ill patients who received cardiopulmonary resuscitation.

RATIONALE Studies examining survival outcomes after in-hospital cardiopulmonary arrest (CPA) among intensive care unit (ICU) patients requiring medications for hemodynamic support are limited. OBJECTIVES To examine outcomes of ICU patients who received cardiopulmonary resusitation. METHODS We identified 49,656 adult patients with a first CPA occurring in an ICU between January 1, 2000 and August 26, 2008 within the National Registry of Cardiopulmonary Resuscitation. Survival outcomes of patients requiring hemodynamic support immediately before CPA were compared with those of patients who did not receive hemodynamic support (pressors), using multivariable logistic regression analyses to adjust for differences in demographics and clinical characteristics. Pressor medications included epinephrine, norepinephrine, phenylephrine, dopamine, dobutamine, and vasopressin. MEASUREMENTS AND MAIN RESULTS The overall rate of survival to hospital discharge was 15.9%. Patients taking pressors before CPA were less likely to survive to discharge (9.3 vs. 21.2%; P < 0.0001). After multivariable adjustment, patients taking pressors before pulseless CPA were 55% less likely to survive to discharge (adjusted odds ratio [OR], 0.45; 95% confidence interval [CI], 0.42-0.48). Age equal to or greater than 65 years (adjusted OR, 0.77; 95% CI, 0.73-0.82), nonwhite race (adjusted OR, 0.58; 95% CI, 0.54-0.62), and mechanical ventilation (adjusted OR, 0.60; 95% CI, 0.56-0.63) were also variables that could be identified before CPA that were independently associated with lower survival. More than half of survivors were discharged to rehabilitation or extended care facilities. Only 3.9% of patients who had CPA despite pressors were discharged home from the hospital, as compared with 8.5% of patients with a CPA and not taking pressors (adjusted OR, 0.53; 95% CI, 0.49-0.59). CONCLUSIONS Although overall survival of ICU patients was 15.9%, patients requiring pressors and who experienced a CPA in an ICU were half as likely to survive to discharge and to be discharged home than patients not taking pressors. This study provides robust estimates of CPR outcomes of critically ill patients, and may assist clinicians to inform consent for this procedure.

Lung Injury Prediction Score in Hospitalized Patients at Risk of Acute Respiratory Distress Syndrome.

Objective:The Lung Injury Prediction Score identifies patients at risk for acute respiratory distress syndrome in the emergency department, but it has not been validated in non-emergency department hospitalized patients. We aimed to evaluate whether Lung Injury Prediction Score identifies non-emergency department hospitalized patients at risk of developing acute respiratory distress syndrome at the time of critical care contact. Design:Retrospective study. Setting:Five academic medical centers. Patients:Nine hundred consecutive patients (≥ 18 yr old) with at least one acute respiratory distress syndrome risk factor at the time of critical care contact. Interventions:None. Measurements and Main Results:Lung Injury Prediction Score was calculated using the worst values within the 12 hours before initial critical care contact. Patients with acute respiratory distress syndrome at the time of initial contact were excluded. Acute respiratory distress syndrome developed in 124 patients (13.7%) a median of 2 days (interquartile range, 2–3) after critical care contact. Hospital mortality was 22% and was significantly higher in acute respiratory distress syndrome than non-acute respiratory distress syndrome patients (48% vs 18%; p < 0.001). Increasing Lung Injury Prediction Score was significantly associated with development of acute respiratory distress syndrome (odds ratio, 1.31; 95% CI, 1.21–1.42) and the composite outcome of acute respiratory distress syndrome or death (odds ratio, 1.26; 95% CI, 1.18–1.34). A Lung Injury Prediction Score greater than or equal to 4 was associated with the development of acute respiratory distress syndrome (odds ratio, 4.17; 95% CI, 2.26–7.72), composite outcome of acute respiratory distress syndrome or death (odds ratio, 2.43; 95% CI, 1.68–3.49), and acute respiratory distress syndrome after accounting for the competing risk of death (hazard ratio, 3.71; 95% CI, 2.05–6.72). For acute respiratory distress syndrome development, the Lung Injury Prediction Score has an area under the receiver operating characteristic curve of 0.70 and a Lung Injury Prediction Score greater than or equal to 4 has 90% sensitivity (misses only 10% of acute respiratory distress syndrome cases), 31% specificity, 17% positive predictive value, and 95% negative predictive value. Conclusions:In a cohort of non-emergency department hospitalized patients, the Lung Injury Prediction Score and Lung Injury Prediction Score greater than or equal to 4 can identify patients at increased risk of acute respiratory distress syndrome and/or death at the time of critical care contact but it does not perform as well as in the original emergency department cohort.

Severe Hypoxemia and Orthodeoxia following Right Pneumonectomy

A 57-year-old woman presented with severe hypoxemia 2 months after right pneumonectomy. Orthodeoxia was noted: PaO2 on 100% oxygen was 41 mm Hg while upright and 71 mm Hg while supine. Electrocardiography showed increased right atrial forces (Figure 1). Right heart catheterization revealed normal pressures. Transesophageal echocardiography showed an aneurysmal interatrial septum, patent foramen ovale (PFO), a large Eustachian valve, and a compressed right atrium (Figure 2; see also video E1 in the video supplement). Doppler imaging revealed a large right-to-left shunt across the PFO (Figure 3; video E2). Shunting decreased in the supine position (Figures 4 and 5, video E3). Hypoxemia resolved after closure of the PFO. PFO and persistent Eustachian valve are common anomalies, found in approximately 25% and 57% of adults, respectively; their presence is associated with increased risk of stroke from paradoxical emboli (1, 2). After pneumonectomy, mediastinal shift and right atrial compression by hydrothorax combined with these anomalies to cause shunt as venous inflow hit the Eustachian valve and was directed across the PFO. Figure 1. Twelve-lead electrocardiograms before pneumonectomy (top) and afterward (bottom). Note the increase in the amplitude of the P-waves (leads I and II ) as well as the leftward shift of the mean electrical axis of the P-waves throughout.

Letter to Tuon et al.

I congratulate Tuon et al. authors of ‘‘Time-dependent behavioral recovery after sepsis in rats,’’ on their intriguing results [1]. Completing long-term, complex follow up testing in rats is impressive. More impressive is the application of methods from the behavioral sciences to a clinically important question in intensive care—what factors may contribute to long-term cognitive sequelae? One important factor, however, appears to have been unexplored. In rats, the cecal-ligation and puncture (CLP) model of induced sepsis is associated with hyperglycemia [2]. The use of ketamine-xylazine for anesthesia in various strains is also associated with hyperglycemia [3, 4]. Whether the use of ketamine– xylazine in conjunction with CLP may result in more severe hyperglycemia than either intervention alone is unknown. Van den Berghe et al. [5] reported better long-term functional status and improved peripheral and central nervous system outcomes in surgical ICU patients who received intensive insulin therapy. In CLP-induced sepsis, ketamine–xylazine anesthesia might result in exacerbated hyperglycemia, contributing to the delayed behavioral recovery Tuon et al. observed; blood glucose levels, however, were not reported. The role of hyperglycemia in delayed behavioral recovery after CLP-induced sepsis is an important potential mechanism worth exploring.

IgG4-related disease presenting as a lung mass and weight loss: Case report and review of the literature

We describe a case of IgG4-related lung disease presenting as a lung mass with associated weight loss. IgG4-related disease is a systemic sclerosing disorder that causes fibrotic, often tumor-like manifestations that variably effect different organ systems. The clinical presentation of IgG4-related disease is protean. Timely recognition and diagnosis requires awareness on the part of clinicians and pathologists to the variable manifestations of this newly recognized disorder. We offer a concise review of the pulmonary manifestations, diagnosis and treatment of IgG4-related lung disease.

Can Transcutaneous CO2 Tension Be Used to Calculate Ventilatory Dead Space? A Pilot Study

Dead space fraction (V d/V t) measurement performed using volumetric capnography requires arterial blood gas (ABG) sampling to estimate the partial pressure of carbon dioxide (PaCO2). In recent years, transcutaneous capnography (PtcCO2) has emerged as a noninvasive method of estimating PaCO2. We hypothesized that PtcCO2 can be used as a substitute for PaCO2 in the calculation of V d/V t. In this prospective pilot comparison study, 30 consecutive postcardiac surgery mechanically ventilated patients had V d/V t calculated separately using volumetric capnography by substituting PtcCO2 for PaCO2. The mean V d/V t calculated using PaCO2 and PtcCO2 was 0.48 ± 0.09 and 0.53 ± 0.08, respectively, with a strong positive correlation between the two methods of calculation (Pearsons correlation = 0.87, p < 0.05). Bland-Altman analysis showed a mean difference of −0.05 (95% CI: −0.01 to −0.09) between the two methods. PtcCO2 measurements can provide a noninvasive means to measure V d/V t, thus accessing important physiologic information and prognostic assessment in patients receiving mechanical ventilation.

Implementation of routinely checked laboratory test results into the national early warning score (NEWS) significantly improves its prognostic ability

with RDW, and 0.764 with RIFLE classification. AU-ROC for NEWS improved from 0.748 to 0.771 when combined with both RDW and RIFLE classification. Based on NEWS alone, there were 128 patients with moderate and high risk scores, while this number increased to 170 when RDW and RIFLE were added to the tool. Conclusions