BACKGROUND: Subjects with severe hypoxemic respiratory failure have shown a high mortality in previous studies. METHODS: All adult ICU patients requiring mechanical ventilation from 2005 to 2010 at Mayo Clinic were screened for severe hypoxemia (Murray lung injury score of ≥ 3). Extracorporeal membrane oxygenation, prone positioning, high-frequency oscillatory ventilation (HFOV), and inhaled vasodilators were considered as rescue strategies. A propensity-based scoring was created for the indication or predilection to use each strategy. A model was created to evaluate the association of each rescue strategy with hospital mortality. RESULTS: Among 1,032 subjects with severe hypoxemia, 239 subjects received some form of rescue strategy (59 received a combination of therapies, and 180 received individual therapies). Inhaled vasodilators were the most common, followed by HFOV. Rescue strategies were used in younger subjects with severe oxygenation deficits. Subjects receiving rescue strategies had higher mortality and longer ICU stays. None of the strategies individually or in combination showed a significant association with hospital mortality after adjusting covariates by propensity scoring. Adjusted Odds ratios and respective 95% CI were as follows: HFOV 0.67 (0.35–1.27), extracorporeal membrane oxygenation 0.63 (0.18–1.92), prone position 1.07 (0.49–2.28), and inhaled vasodilators 1.17 (0.78–1.77). CONCLUSIONS: In this retrospective comparative effectiveness study, there was no association of rescue strategies with hospital mortality in subjects with severe hypoxemia.
Ventilator-associated events (VAEs) are associated with increased risk of poor outcomes, including death. Bundle practices including thromboembolism prophylaxis, stress ulcer prophylaxis, oral care, and daily sedation breaks and spontaneous breathing trials aim to reduce rates of VAEs and are endorsed as quality metrics in the intensive care units. We sought to create electronic search algorithms (digital signatures) to evaluate compliance with ventilator bundle components as the first step in a larger project evaluating the ventilator bundle effect on VAE. We developed digital signatures of bundle compliance using a retrospective cohort of 542 ICU patients from 2010 for derivation and validation and testing of signature accuracy from a cohort of random 100 patients from 2012. Accuracy was evaluated against manual chart review. Overall, digital signatures performed well, with median sensitivity of 100% (range, 94.4%–100%) and median specificity of 100% (range, 100%–99.8%). Automated ascertainment from electronic medical records accurately assesses ventilator bundle compliance and can be used for quality reporting and research in VAE.
Cytokines and clinical predictors in distinguishing pulmonary transfusion reactions
BACKGROUND Pulmonary transfusion reactions are important complications of blood transfusion, yet differentiating these clinical syndromes is diagnostically challenging. We hypothesized that biologic markers of inflammation could be used in conjunction with clinical predictors to distinguish transfusion‐related acute lung injury (TRALI), transfusion‐associated circulatory overload (TACO), and possible TRALI. STUDY DESIGN AND METHODS In a nested case‐control study performed at the University of California at San Francisco and Mayo Clinic, Rochester, we evaluated clinical data and blood samples drawn before and after transfusion in patients with TRALI (n = 70), possible TRALI (n = 48), TACO (n = 29), and controls (n = 147). Cytokines measured included granulocyte‐macrophage–colony‐stimulating factor, interleukin (IL)‐6, IL‐8, IL‐10, and tumor necrosis factor‐α. Logistic regression and receiver operating characteristics curve analyses were used to determine the accuracy of clinical predictors and laboratory markers in differentiating TACO, TRALI, and possible TRALI. RESULTS Before and after transfusion, IL‐6 and IL‐8 were elevated in patients with TRALI and possible TRALI relative to controls, and IL‐10 was elevated in patients with TACO and possible TRALI relative to that of TRALI and controls. For all pulmonary transfusion reactions, the combination of clinical variables and cytokine measurements displayed optimal diagnostic performance, and the model comparing TACO and TRALI correctly classified 92% of cases relative to expert panel diagnoses. CONCLUSIONS Before transfusion, there is evidence of systemic inflammation in patients who develop TRALI and possible TRALI but not TACO. A predictive model incorporating readily available clinical and cytokine data effectively differentiated transfusion‐related respiratory complications such as TRALI and TACO.
Recipient clinical risk factors predominate in possible transfusion‐related acute lung injury
Background Possible transfusion‐related acute lung injury (p TRALI ) cases by definition have a clear temporal relationship to an alternative recipient risk factor for acute respiratory distress syndrome ( ARDS ). We questioned whether transfusion factors are important for the development of p TRALI . Study Design and Methods In this nested case‐control study, we prospectively identified 145 consecutive patients with p TRALI and randomly selected 163 transfused controls over a 4‐year period at the U niversity of C alifornia at S an F rancisco and the M ayo C linic ( R ochester, M innesota). Results For p TRALI , we found evidence against transfusion being important: receipt of plasma from female donors (odds ratio [ OR ], 0.82; 95% confidence interval [ CI ], 0.29‐2.3; p = 0.70), total number of units transfused ( OR , 0.99; 95% CI , 0.89‐1.10; p = 0.86), and number of red blood cell and whole blood units transfused ( OR , 0.78; 95% CI , 0.59‐1.03; p = 0.079). In contrast, we found that risk for p TRALI was associated with additional recipient factors: chronic alcohol abuse ( OR , 12.5; 95% CI , 2.8‐55; p < 0.001), current smoker ( OR , 4.2; 95% CI , 1.67‐10.8; p = 0.0024), shock before transfusion ( OR , 4.6; 95% CI , 2.0‐10.7; p < 0.001), and positive fluid balance before transfusion ( OR , 1.32/ L ; 95% CI , 1.20‐1.44; p < 0.001). Conclusion Recipient risk factors for ARDS rather than transfusion risk factors predominate in p TRALI .
Findings from the Implementation of a Validated Readmission Predictive Tool in the Discharge Workflow of a Medical Intensive Care Unit
Abstract Rationale Provider decisions about patients to be discharged from the intensive care unit (ICU) are often based on subjective intuition, sometimes leading to premature discharge and early readmission. The Stability and Work Load Index for Transfer (SWIFT) score, as a risk stratification tool, has moderate ability to predict patients at risk of ICU readmission. Objectives To describe findings following the incorporation of the SWIFT score into the discharge workflow of a medical ICU. Methods The study involved 5,293 consecutive patients discharged alive from the medical ICU of an academic medical center. The SWIFT score and associated percentage risk for readmission were incorporated into daily rounds for purpose of discharge decision-making. We measured readmission rates before and after implementation and observed changes in provider discharge decisions for individual patients after SWIFT discussions. Measurements and Main Results Baseline (n = 1,906) and implementation (n = 1,938) cohorts differed with respect to APACHE III scores (P = 0.03). In the implementation cohort, 26.2% of subjects had SWIFT scores greater than 15 and thus were predicted to have a higher risk of unplanned readmissions. In this high-risk group, 25% had SWIFT discussed in their discharge planning. There was modification of provider discharge decisions in 108 (30%) of cases in which the SWIFT was discussed. SWIFT score values above a prespecified cutoff of 15 were associated with physician tendency to prolong ICU stay or to discharge to a monitored setting (P < 0.001). There was no difference in 24-hour or 7-day readmission rates between the baseline and implementation cohorts (1.9 vs. 2.4%, P = 0.24; 6.5 vs. 7.4%, P = 0.26, respectively) even after adjustment for severity of illness. Conclusions Using the SWIFT score as an adjunct to clinical judgment, physicians modified their discharge decisions in one-third of subjects. Introducing such tools into the discharge workflow may present change management challenges that limit the evaluation of their impact on readmission rates and other relevant ICU outcomes.
SpO
2
/FiO
2
Ratio on Hospital Admission Is an Indicator of Early Acute Respiratory Distress Syndrome Development Among Patients at Risk
Purpose: Oxygen saturation to fraction of inspired oxygen ratio (SpO 2 /FiO 2 ) has been validated as a surrogate marker for partial pressure of oxygen to fraction of inspired oxygen ratio among mechanically ventilated patients with acute respiratory distress syndrome (ARDS). The validity of SpO 2 /FiO 2 measurements in predicting ARDS has not been studied. Recently, a Lung Injury Prediction Score (LIPS) has been developed to help identify patients at risk of developing ARDS. Methods: This was a secondary analysis of the LIPS-1 cohort. A multivariate logistic regression included all established variables for LIPS, Acute Physiology and Chronic Health Evaluation 2, age, and comorbid conditions that could affect SpO 2 /FiO 2 . The primary outcome was development of ARDS in the hospital. The secondary outcomes included hospital mortality, hospital day of ARDS development, and hospital day of death. Results: Of the 5584 patients, we evaluated all 4646 with recorded SpO 2 /FiO 2 values. Median SpO 2 /FiO 2 in those who did and did not develop ARDS was 254 (100, 438) and 452 (329, 467), respectively. There was a significant association between SpO 2 /FiO 2 and ARDS ( P ≤ .001). The SpO 2 /FiO 2 was found to be an independent predictor of ARDS in a “dose-dependent” manner; for SpO 2 /FiO 2 < 100—odds ratios (OR) 2.49 (1.69-3.64, P < .001), for SpO 2 /FiO 2 100 < 200—OR 1.75 (1.16-2.58, P = .007), and for SpO 2 /FiO 2 200 < 300—OR 1.62 (1.06-2.42, P = .025). The discriminatory characteristics of the multivariable model and SpO 2 /FiO 2 as a single variable demonstrated area under the curve (AUC) of 0.81 and AUC of 0.74, respectively. Conclusions: The SpO 2 /FiO 2 , measured within the first 6 hours after hospital admission, is an independent indicator of ARDS development among patients at risk.
Predictors of Disseminated Intravascular Coagulation in Patients with Septic Shock
Purpose. The goal of this study was to identify potential clinical predictors for the development of disseminated intravascular coagulation (DIC) in patients with septic shock. Material and Methods. We performed a retrospective analysis of a cohort of adult (>18 years of age) patients with septic shock admitted to a medical ICU in a tertiary care hospital from July 2005 until September 2007. A multivariate logistic regression model was used to determine the association of risk factors with overt DIC. Results. In this study, a total of 390 patients with septic shock were analyzed, of whom 66 (17%) developed overt DIC. Hospital mortality was significantly greater in patients who developed overt DIC (68% versus 38%, P<0.001). A delay in the timing of antibiotics was associated with an increased risk of the development of overt DIC (P<0.001). Patients on antiplatelet therapy prior to hospital admission and who that received adequate early goal-directed therapy (EGDT) were associated with a decreased risk of overt DIC (P<0.001). Conclusions. In our cohort of patients with septic shock, there was a risk reduction for overt DIC in patients on antiplatelet therapy and adequate EGDT, while there was an increased risk of DIC with antibiotic delay.
Emerging Pharmacological Therapies for Prevention and Early Treatment of Acute Lung Injury