Systematic Review and Meta-Analysis of Effects of Transfusion on Hemodynamic and Oxygenation Variables
Cavalcante Dos Santos E, Orbegozo D, Mongkolpun W, Galfo V, Nan W, Gouvea Bogossian E, Taccone FS, Vallet B, Creteur J, Vincent JL
Critical care medicine. 2020;48(2):241-248
OBJECTIVES RBC transfusions can increase oxygen availability to the tissues, but studies have provided conflicting results. The objectives of this study were, therefore, to evaluate, using systematic review and meta-analysis, the effects of transfusion on hemodynamic/oxygenation variables in patients without acute bleeding. DATA SOURCES PubMed, Scopus, Cochrane Database of Systematic Reviews, and Embase from inception until June 30, 2019. STUDY SELECTION All articles that reported values of prespecified hemodynamic or oxygenation variables before and after RBC transfusion. DATA EXTRACTION Publication year, number of patients, number of transfusions and the type of population studied, hemodynamic and oxygenation data (heart rate, cardiac index, mixed venous oxygen saturation or central venous oxygen saturation, oxygen delivery index, oxygen consumption index, oxygen extraction ratio, arteriovenous oxygen difference and arterial blood lactate) before and after transfusion. We performed a meta-analysis for each variable for which there were sufficient data to estimate mean differences. We also performed subgroup analyses comparing septic with nonseptic patients. DATA SYNTHESIS We retrieved 6,420 studies; 33 met the inclusion criteria, 14 of which were in patients with sepsis. In the meta-analysis, the estimated mean differences and 95% CIs comparing the periods before and after transfusion were -0.0 L/min/m (-0.1 to 0.1 L/min/m) (p = 0.86) for cardiac index; -1.8 beats/min (-3.7 to 0.1 beats/min) (p = 0.06) for heart rate; 96.8 mL/min/m (71.1-122.5 mL/min/m) (p < 0.01) for oxygen delivery index; 2.9% (2.2-3.5%) (p < 0.01) for mixed venous oxygen saturation or central venous oxygen saturation; -3.7% (-4.4% to -3.0%) (p < 0.01) for oxygen extraction ratio; and 4.9 mL/min/m (0.9-9.0 mL/min/m) (p = 0.02) for oxygen consumption index. The estimated mean difference for oxygen consumption index in the patients with sepsis was 8.4 mL/min/m (2.3-14.5 mL/min/m; p = 0.01). CONCLUSIONS Transfusion was not associated with a decrease in mean cardiac output or mean heart rate. The increase in mean oxygen delivery following transfusion was associated with an increase in mean oxygen consumption after transfusion, especially in patients with sepsis.
High-dose tranexamic acid reduces blood loss in postpartum haemorrhage
Ducloy-Bouthors AS, Jude B, Duhamel A, Broisin F, Huissoud C, Keita-Meyer H, Mandelbrot L, Tillouche N, Fontaine S, Goueff F, et al
Critical Care (London, England). 2011;15((2):):R117.
INTRODUCTION Our purpose in conducting this study was to determine whether administration of high-dose tranexamic acid (TA) at the time of diagnosis of postpartum haemorrhage (PPH) could reduce blood loss. METHODS This was a randomised, controlled, multicentred, open-label trial. Women with PPH >800 mL following vaginal delivery were randomly assigned to receive TA (loading dose 4 g over 1 hour, then infusion of 1 g/hour over 6 hours) or not. In both groups, packed red blood cells (PRBCs) and colloids could be used according to French guidelines. The use of additional procoagulant treatments was permitted only in cases involving intractable bleeding. The primary objective was to assess the efficacy of TA in the reduction of blood loss in women with PPH, and the secondary objectives were the effect of TA on PPH duration, anaemia, transfusion and the need for invasive procedures. RESULTS A total of 144 women fully completed the protocol (72 in each group). Blood loss between enrolment and 6 hours later was significantly lower in the TA group than in the control group (median, 173 mL; first to third quartiles, 59 to 377) than in controls (221 mL; first to third quartiles 105 to 564) (P = 0.041). In the TA group, bleeding duration was shorter and progression to severe PPH and PRBC transfusion was less frequent than in controls (P < 0.03). Invasive procedures were performed in four women in the TA group and in seven controls (P = NS). PPH stopped after only uterotonics and PRBC transfusion in 93% of women in the TA group versus 79% of controls (P = 0.016). Mild, transient adverse manifestations occurred more often in the TA group than in the control group (P = 0.03). CONCLUSIONS This study is the first to demonstrate that high-dose TA can reduce blood loss and maternal morbidity in women with PPH. Although the study was not adequately powered to address safety issues, the observed side effects were mild and transient. A larger international study is needed to investigate whether TA can decrease the need for invasive procedures and reduce maternal morbidity in women with PPH. TRIAL REGISTRATION Controlled Trials ISRCTN09968140.