Red Blood Cell Transfusion in Patients With Placenta Accreta Spectrum: A Systematic Review and Meta-analysis.

OBJECTIVE: To evaluate red blood cell use during delivery in patients with placenta accreta spectrum. DATA SOURCES: We searched MEDLINE, EMBASE, CINAHL, Cochrane Central, ClinicalTrials.gov, and Scopus for clinical trials and observational studies published between 2000 and 2021 in countries with developed economies. METHODS OF STUDY SELECTION: Abstracts (n=4,275) and full-text studies (n=599) were identified and reviewed by two independent reviewers. Data on transfused red blood cells were included from studies reporting means and SDs, medians with interquartile ranges, or individual patient data. The primary outcome was the weighted mean number of units of red blood cells transfused per patient. Between-study heterogeneity was assessed with an I2 statistic. Secondary analyses included red blood cell usage by placenta accreta subtype. TABULATION, INTEGRATION, AND RESULTS: Of the 599 full-text studies identified, 20 met criteria for inclusion in the systematic review, comprising 1,091 cases of placenta accreta spectrum. The number of units of red blood cells transfused was inconsistently described across studies, with five studies (25.0%) reporting means, 11 (55.0%) reporting medians, and four (20.0%) reporting individual patient data. The weighted mean number of units transfused was 5.19 (95% CI 4.12-6.26) per patient. Heterogeneity was high across studies (I2=91%). In a sensitivity analysis of five studies reporting mean data, the mean number of units transfused was 6.61 (95% CI 4.73-8.48; n=220 patients). Further quantification of units transfused by placenta accreta subtype was limited due to methodologic inconsistencies between studies and small cohort sizes. CONCLUSION: Based on the upper limit of the CI in our main analysis and the high study heterogeneity, we recommend that a minimum of 6 units of red blood cells be available before delivery for patients with placenta accreta spectrum. These findings may inform future guidelines for predelivery blood ordering and transfusion support. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42021240993.

Effectiveness and safety of tranexamic acid in pediatric trauma: A systematic review and meta-analysis.

OBJECTIVE: Trauma is the leading cause of childhood death in the United States. Our goal was to determine the effectiveness of tranexamic acid (TXA) in improving survival in pediatric trauma. METHODS: MEDLINE (OVID), Embase (OVID), Cochrane Central Register databases, CINAHL (EBSCO), Web of Science (Clarivate Analytics), and grey literature sources were searched for publications reporting survival and safety outcomes in children receiving TXA in acute trauma, with no language restrictions, published until February 11, 2021. Two independent researchers assessed studies for eligibility, bias, and quality. Data on the study setting, injury type, participants, design, interventions, TXA dosing and outcomes were extracted. The primary outcome was survival in children who received TXA following trauma. Forest plots of effect estimates were constructed for each study. Heterogeneity was assessed and data were pooled by meta-analysis using a random-effects model. RESULTS: Fourteen articles met inclusion criteria - six single-institution and eight multicentre retrospective cohort studies. Overall, TXA use was not associated with increased survival in pediatric trauma (adjusted odds ratio [aOR]: 0.61, 95% CI: 0.30-1.22) after adjustment for patient-level variables, such as injury severity. Increased survival was documented in the subset of children experiencing trauma in combat settings (aOR for mortality: 0.31, 95% CI: 0.14-0.68). There were no differences in the odds of thromboembolic events (OR 1.15, 95% CI: 0.46-2.87) in children who received TXA versus not. CONCLUSIONS: The utility of TXA in children with trauma is unclear. Guidelines supporting TXA use in pediatric trauma may not be based on the available evidence of its use in this context. Rigorous trials measuring survival and other meaningful outcomes and exploring optimal TXA dosing are urgently needed. Study Registration (PROSPERO): CRD42020157683.