Wilson, Gregory

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 .

BackgroundIdentifying antibodies to HLA (anti‐HLA) by solid‐phase assays is used to screen blood donors to mitigate transfusion‐related acute lung injury risk. Various cutoffs for detection assays have been proposed in the literature; however, these do not take into consideration lot‐to‐lot variability of commercially available assays.Study Design and MethodsSamples from 93 nontransfused males were tested using five different lots of a multiplex bead‐based anti‐HLA detection kit. A subset of 17 samples was tested on 5 days using a single lot. An additional 96 samples from donations with varied anti‐HLA levels were tested using kits from two different lots. Results were reported as a normalized background (NBG) ratio.ResultsFor the 93 nontransfused donors, NBG values generated using the reference lot were significantly higher than those obtained with three of the four comparator lots. However, for the 96 samples with low‐, moderate‐, and higher‐level anti‐HLA, Class I (CL‐I) values were 1.4 times lower and Class II (CL‐II) values were 1.2 times lower using the reference versus comparator lot. For CL‐I antibodies the between‐lot standard deviation (SD) was 1.36 (95% confidence interval [CI], 1.19‐1.60), while the between‐day SD was 1.27 (95% CI, 1.08‐1.52). Similarly, for CL‐II antibodies the between‐lot SD was 0.81 (95% CI, 0.70‐0.95), while the between‐day SD was 0.50 (95% CI, 0.43‐0.60).ConclusionsThere is interlot variability in the tested HLA detection assay as well as significant bias between lots. It may be reasonable to develop a new cutoff when a new lot is obtained.

BACKGROUND: Optimal titration of inspired oxygen is important to prevent hyperoxia in mechanically ventilated patients in ICUs. There is mounting evidence of the deleterious effects of hyperoxia; however, there is a paucity of data about F IO 2 practice and oxygen exposure among patients in ICUs. We therefore sought to assess excessive F IO 2 exposure in mechanically ventilated patients with acute lung injury and to evaluate the effect on pulmonary outcomes. METHODS: From a database of ICU patients with acute lung injury identified by prospective electronic medical record screening, we identified those who underwent invasive mechanical ventilation for > 48 hours from January 1 to December 31, 2008. Ventilator settings, including F IO 2 and corresponding S pO 2 , were collected from the electronic medical record at 15-min intervals for the first 48 hours. Excessive F IO 2 was defined as F IO 2 > 0.5 despite S pO 2 > 92%. The association between the duration of excessive exposure and pulmonary outcomes was assessed by change in oxygenation index from baseline to 48 hours and was analyzed by univariate and multivariate linear regression analysis. RESULTS: Of 210 patients who met the inclusion criteria, 155 (74%) were exposed to excessive F IO 2 for a median duration of 17 hours (interquartile range 7.5–33 h). Prolonged exposure to excessive F IO 2 correlated with worse oxygenation index at 48 hours in a dose-response manner ( P < .001.). Both exposure to higher F IO 2 and longer duration of exposure were associated with worsening oxygenation index at 48 hours ( P < .001), more days on mechanical ventilation, longer ICU stay, and longer hospital stay ( P = .004). No mortality difference was noted. CONCLUSIONS: Excessive oxygen supplementation is common in mechanically ventilated patients with ALI and may be associated with worsening lung function.

Abstract Rationale Transfusion-related pulmonary complications are leading causes of morbidity and mortality attributed to transfusion. Observational studies suggest an important role for red blood cell (RBC) storage duration in these adverse outcomes. Objectives To evaluate the impact of RBC storage duration on short-term pulmonary function as well as immunologic and coagulation status in mechanically ventilated patients receiving RBC transfusion. Methods This is a double-blind, randomized, clinical trial comparing fresh (≤5 d of storage) versus standard issue single-unit RBC transfusion in adult intubated and mechanically ventilated patients. The primary outcome is the change in pulmonary gas exchange as assessed by the partial pressure of arterial oxygen to fraction of inspired oxygen concentration ratio (ΔPaO2/FiO2). Secondary outcomes include changes in immune and coagulation status. Measurements and Main Results Fifty patients were randomized to receive fresh RBCs and an additional 50 patients to standard issue RBCs. Median storage age was 4.0 days (interquartile range, 3.0–5.0) and 26.5 days (interquartile range, 21.0–36.0) in the fresh RBC group and standard issue RBC group, respectively. No differences were noted in the primary outcome of ΔPaO2/FiO2 (difference between the mean ΔPaO2/FiO2 in the standard issue RBC group vs. the fresh RBC group, –11.5; 95% confidence interval, −35.3 to 12.3; P = 0.22). Similarly, no significant differences were noted in markers of immunologic or coagulation status. Conclusions In this randomized clinical trial, no differences were noted in early measures of pulmonary function or in immunologic or coagulation status when comparing fresh versus standard issue single-unit RBC transfusion. Clinical trial registered with ClinicalTrials.gov (NCT00751322).

AbstractTransfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. To determine TRALI incidence by prospective, active surveillance and to identify risk factors by a case-control study, 2 academic medical centers enrolled 89 cases and 164 transfused controls. Recipient risk factors identified by multivariate analysis were higher IL-8 levels, liver surgery, chronic alcohol abuse, shock, higher peak airway pressure while being mechanically ventilated, current smoking, and positive fluid balance. Transfusion risk factors were receipt of plasma or whole blood from female donors (odds ratio = 4.5, 95% confidence interval [CI], 1.85-11.2, P = .001), volume of HLA class II antibody with normalized background ratio more than 27.5 (OR = 1.92/100 mL, 95% CI, 1.08-3.4, P = .03), and volume of anti–human neutrophil antigen positive by granulocyte immunofluoresence test (OR = 1.71/100 mL, 95% CI, 1.18-2.5, P = .004). Little or no risk was associated with older red blood cell units, noncognate or weak cognate class II antibody, or class I antibody. Reduced transfusion of plasma from female donors was concurrent with reduced TRALI incidence: 2.57 (95% CI, 1.72-3.86) in 2006 versus 0.81 (95% CI, 0.44-1.49) in 2009 per 10 000 transfused units (P = .002). The identified risk factors provide potential targets for reducing residual TRALI.