Historically, patients on extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome have received ventilatory "lung rest" with conventional or high-frequency oscillating ...ventilators. We present a series of adults treated with high-frequency percussive ventilation (HFPV) to enhance recovery and recruitment during ECMO. Adult respiratory patients, treated between January 2009 and December 2012 were cared for with a combination of standard ECMO practices and a protocol of recruitment strategies, including HFPV. Data are reported as mean ± standard error of the mean, percentage, or median. Comparisons are made by χ for categorical variables and by t-test and Mann-Whitney test for continuous variables. Significance is noted at the 95% confidence level (p < 0.05). There were 39 HFPV patients. They were 39.9 ± 2.2 years of age and had 3.0 ± 0.37 days of mechanical ventilation before the initiation of ECMO. Their pre-ECMO PaO2 to FiO2 ratio (PF ratio) was 52.3 ± 3.0 and their pCO2 was 50.22 ± 2.4. HFPV patients required a mean of 143.1 ± 17.6 hours and a median of 106 hours (range 45.75-350.25) of ECMO support and had a 62% survival to discharge. The post-ECMO PF ratio in the HFPV cohort was 301.8 ± 16.7. A protocolized practice of active recruitment that includes HFPV is associated with reduced duration of ECMO support in adults with respiratory failure.
During preservation, donated liquid red blood cells (RBCs) experience multiple functional and structural changes known as the storage lesion. Increased RBC age is associated with increased infection ...rates, organ failure, and mortality.
This prospective, randomized, double-blinded pilot study enrolled stable trauma patients who required RBC transfusion. Patients were randomly assigned to receive standard or cryopreserved RBCs. Continuous tissue oxygenation (StO2) monitoring was performed during the peritransfusion period. Hematocrit and thrombelastography before and after transfusion were evaluated. Patients were monitored for transfusion reactions and clinical outcomes.
Fifty-seven patients were randomized, and groups were well matched for demographics and Injury Severity Score (ISS). No statistically significant differences were noted in hematocrit change, thrombelastography parameters, transfusion reactions, or clinical outcomes. StO2 was found to be higher in the cryopreserved group.
Cryopreserved RBCs are equally safe and efficacious to refrigerated RBCs. This storage technique extends the life span of RBCs to 10 years, potentially preserving a precious resource and preventing the storage lesion. StO2 was superior in patients receiving cryopreserved RBCs. This finding has the potential to drive a paradigm shift in transfusion practices.
Therapeutic study, level II.
Liquid preserved packed red blood cell (LPRBC) transfusions are used to treat anemia and increase end-organ perfusion. Throughout their storage duration, LPRBCs undergo biochemical and structural ...changes collectively known as the storage lesion. These changes adversely affect perfusion and oxygen off-loading. Cryopreserved RBCs (CPRBC) can be stored for up to 10 years and potentially minimize the associated storage lesion. We hypothesized that CPRBCs maintain a superior biochemical profile compared with LPRBCs.
This was a prospective, randomized, double-blinded study. Adult trauma patients with an Injury Severity Score (ISS) greater than 4 and an anticipated 1-U to 2-U transfusion of PRBCs were eligible. Enrolled patients were randomized to receive either CPRBCs or LPRBCs. Serum proteins (haptoglobin, serum amyloid P, and C-reactive protein), proinflammatory and anti-inflammatory cytokines, d-dimer, nitric oxide, and 2,3-DPG concentrations were analyzed. Mann-Whitney U-test and Wilcoxon rank sum test were used to assess significance (p < 0.05).
Fifty-seven patients were enrolled (CPRBC, n = 22; LPRBC, n = 35). The LPRBC group's final interleukin 8, tumor necrosis factor α, and d-dimer concentrations were elevated compared with their pretransfusion values (p < 0.05). After the second transfused units, 2,3-DPG was higher in the patients receiving CPRBCs (p < 0.05); this difference persisted throughout the study. Finally, serum protein concentrations were decreased in the transfused CPRBC units compared with LPRBC (p < 0.01).
CPRBC transfusions have a superior biochemical profile: an absent inflammatory response, attenuated fibrinolytic state, and increased 2,3-DPG. A blood banking system using both storage techniques will offer the highest-quality products to critically injured patients virtually independent of periodic changes in donor availability and transfusion needs.
Therapeutic study, level II.
To determine the safety and efficacy of cryopreserved packed red blood cell (CPRBC) transfusion in trauma patients.
Liquid packed red blood cells (LPRBCs) have an abbreviated shelf-life and worsening ...storage lesion with age. CPRBCs are frozen 2 to 6 days after donation, stored up to 10 years, and are available for 14 days after thawing and washing. CPRBCs can be utilized in diverse settings, but the effect on clinical outcomes is unknown.
We performed a prospective, randomized, double-blind study at 5 level 1 trauma centers. Stable trauma patients requiring transfusion were randomized to young LPRBCs (≤14 storage days), old LPRBCs (>14 storage days), or CPRBCs. Tissue oxygenation (StO2), biochemical and inflammatory mediators were measured, and clinical outcomes were determined.
Two hundred fifty-six patients with well-matched injury severity and demographics (P > 0.2) were randomized (84 young, 86 old, and 86 CPRBCs). Pretransfusion and final hematocrits were similar (P > 0.68). Patients in all groups received the same number of units postrandomization (2 1-4; P > 0.05). There was no difference in the change in tissue oxygenation between groups. CPRBCs contained less α2-macrogobulin, haptoglobin, C-reactive protein, and serum amyloid P (P < 0.001). Organ failure, infection rate, and mortality did not differ between groups (P > 0.2).
Transfusion of CPRBCs is as safe and effective as transfusion of young and old LPRBCs and provides a mechanism to deliver PRBCs in a wide variety of settings.
We performed this study to optimize reconstituted lyophilized plasma (LP) into a minimal volume fluid that provides effective hemostatic resuscitation for trauma while minimizing logistical ...limitations.
We performed a prospective, blinded animal study. Plasma was lyophilized following whole blood collection from anesthetized swine. The minimal volume needed for reconstitution was determined, and this solution was evaluated for safe infusion into the swine. Reconstituted LP was analyzed for electrolyte content, osmolarity, and coagulation factor activity. Twenty swine were anesthetized and subjected to a validated model of polytrauma and hemorrhagic shock (including a Grade V liver injury), then randomized to resuscitation with LP reconstituted to either 100% of the original plasma volume (100%LP) or the minimal volume LP fluid. Physiologic data were monitored, and blood loss and hematocrit were measured. Coagulation status was evaluated using thrombelastography.
The minimal volume of reconstituted LP safe for infusion in swine was 50% of the original plasma volume (50%LP). The 50%LP had higher electrolyte concentrations, osmolarity, and increased coagulation factor activity levels by volume compared with 100%LP (p < 0.05). Blood loss, hematocrit, mean arterial pressure, and heart rate did not differ between animals receiving 100%LP (n = 10) or 50%LP (n = 10) at any time point (p > 0.05). International normalized ratio and thrombelastography parameters were not different between groups (R time, α angle, or maximal amplitude, p > 0.05).
Resuscitation with 50%LP fluid was well tolerated and equally effective compared with 100%LP, with respect to physiologic and hemostatic properties. The smaller volume of fluid necessary to reconstitute hypertonic LP makes it logistically superior to 100%LP for first responders and may reduce adverse effects of large-volume resuscitation.
Erroneous patient birthdates are common in health databases. Detection of these errors usually involves manual verification, which can be resource intensive and impractical. By identifying a frequent ...manifestation of birthdate errors, this paper presents a principled and statistically driven procedure to identify erroneous patient birthdates.
Generalized additive models (GAM) enabled explicit incorporation of known demographic trends and birth patterns. With false positive rates controlled, the method identified birthdate contamination with high accuracy. In the health data set used, of the 58 actual incorrect birthdates manually identified by the domain expert, the GAM-based method identified 51, with 8 false positives (resulting in a positive predictive value of 86.0% (51/59) and a false negative rate of 12.0% (7/58)). These results outperformed linear time-series models.
The GAM-based method is an effective approach to identify systemic birthdate errors, a common data quality issue in both clinical and administrative databases, with high accuracy.
With few exceptions, research in the addictive sciences has relied on linear statistics and methodologies. Addiction involves a complex array of nonlinear behaviors. This study applies two machine ...learning techniques, Bayesian and decision tree classifiers, in the assessment of outcome of an alcohol dependence treatment program. These nonlinear approaches are compared to a standard linear analysis. Seventy-three alcohol-dependent subjects undertaking a 12-week cognitive-behavioral therapy (CBT) program and 66 subjects undertaking an identical program but also prescribed the relapse prevention agent Acamprosate were employed in this study. Demographic, alcohol use, dependence severity, craving, health-related quality of life, and psychological measures at baseline were used to predict abstinence at 12 weeks. Decision trees had a 77% predictive accuracy across both data sets, Bayesian networks 73%, and discriminant analysis 42%. Combined with clinical experience, machine learning approaches offer promise in understanding the complex relationships that underlie treatment outcome for abstinence-based alcohol treatment programs.
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