What blood conservation practices are effective at reducing blood sampling volumes and other clinical sequelae in intensive care? A systematic review

School of Nursing and Centre for Healthcare Transformation, Queensland University of Technology, Brisbane, Qld, Australia; Centre for Nursing and Midwifery Research and Intensive Care Services, Royal Brisbane and Women's Hospital, Brisbane, Qld, Australia; Alliance for Vascular Access Teaching and Research (AVATAR), School of Nursing and Midwifery, Griffith University, Brisbane, Qld, Australia. Electronic address: s2.keogh@qut.edu.au. Poche Centre for Indigenous Health, The University of the Queensland, Brisbane, Qld, Australia. Centre for Nursing and Midwifery Research and Intensive Care Services, Royal Brisbane and Women's Hospital, Brisbane, Qld, Australia; Alliance for Vascular Access Teaching and Research (AVATAR), School of Nursing and Midwifery, Griffith University, Brisbane, Qld, Australia; School of Nursing, Midwifery and Social Work, The University of Queensland, Brisbane, Qld, Australia; Queensland Children's Hospital, Children's Health Queensland Hospital and Health Service, Brisbane, Qld, Australia. Centre for Nursing and Midwifery Research and Intensive Care Services, Royal Brisbane and Women's Hospital, Brisbane, Qld, Australia; Alliance for Vascular Access Teaching and Research (AVATAR), School of Nursing and Midwifery, Griffith University, Brisbane, Qld, Australia; School of Nursing, Midwifery and Social Work, The University of Queensland, Brisbane, Qld, Australia. School of Nursing and Centre for Healthcare Transformation, Queensland University of Technology, Brisbane, Qld, Australia; Centre for Nursing and Midwifery Research and Intensive Care Services, Royal Brisbane and Women's Hospital, Brisbane, Qld, Australia.

Australian critical care : official journal of the Confederation of Australian Critical Care Nurses. 2023
PICO Summary

Population

Patients (adults, neonates and paediatrics) admitted to an intensive care unit (8 randomised controlled trials, n= 1,027).

Intervention

Different blood sampling strategies and systems, including the standard open arterial blood sampling system.

Comparison

Various comparators, including the closed-loop arterial blood sampling system, and adding small-volume tubes to the closed-loop system.

Outcome

Seven studies evaluated a closed loop blood sampling system, and one studied a conservative phlebotomy protocol. Studies were of low to moderate quality. Meta-analysis was not possible for interventions targeting blood sample volumes or haemoglobin. Decreased blood sample volumes reported in four studies were attributable to a closed loop system or conservative phlebotomy. No study reported a significant change in haemoglobin. Meta-analysis demonstrated that use of a closed system (compared to open system) reduced the proportion of patients receiving transfusion (Risk Ratio (RR) 0.65, 95% CI: 0.46-0.92; 287 patients) and reduced intraluminal fluid colonisation (RR 0.25, 95% CI: 0.07-0.58; 500 patients).
Abstract
OBJECTIVES The objective of this study was to critically appraise and synthesise evidence for blood conservation strategies in intensive care. Blood sampling is a critical aspect of intensive care to guide clinical decision-making. Repeated blood sampling can result in blood waste and contamination, leading to iatrogenic anaemia and systemic infection. REVIEW METHOD USED Cochrane systematic review methods were used including meta-analysis, and independent reviewers. DATA SOURCES A systematic search was conducted in Medline, CINAHL, PUBMED and EMBASE databases. The search was limited to randomised controlled trials (RCTs) and cluster RCTs, published in English between 2000 and 2021. REVIEW METHODS Paired authors independently assessed database search results and identified eligible studies. Trials comparing any blood conservation practice or product in intensive care were included. Primary outcomes were blood sample volumes and haemoglobin change. Secondary outcomes included proportion of patients receiving transfusions and infection outcomes. Quality appraisal employed the Cochrane Risk of Bias tool. Meta-analysis using random effects approach and narrative synthesis summarised findings. RESULTS Eight studies (n = 1027 patients), all RCTs were eligible. Six studies included adults, one studied paediatrics and one studied preterm infants. Seven studies evaluated a closed loop blood sampling system, and one studied a conservative phlebotomy protocol. Studies were of low to moderate quality. Meta-analysis was not possible for interventions targeting blood sample volumes or haemoglobin. Decreased blood sample volumes reported in four studies were attributable to a closed loop system or conservative phlebotomy. No study reported a significant change in haemoglobin. Meta-analysis demonstrated that use of a closed system (compared to open system) reduced the proportion of patients receiving transfusion [Risk Ratio (RR) 0.65, 95% CI 0.46-0.92; 287 patients] and reduced intraluminal fluid colonisation [RR 0.25, 95% CI 0.07-0.58; 500 patients]. CONCLUSIONS Limited evidence demonstrates closed loop blood sampling systems reduced transfusion use and fluid colonisation. Simultaneous effectiveness-implementation evaluation of these systems and blood conservation strategies is urgently required. PROSPERO PROTOCOL REGISTRATION REFERENCE CRD42019137227.
Study details
Study Design : Systematic Review
Language : eng
Credits : Bibliographic data from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine