Khaya-warmer: blood warming in a resource-constrained setting

Authors

Keywords:

resource-constrained setting, blood warming, blood transfusion, inline gravitational flow blood transfusion, outflow temperature

Abstract

Background: Blood warming poses a challenge for healthcare workers in a resource-constrained setting due to financial limitations. Various blood-warming methods have been studied, but to our knowledge, none have investigated inline gravitational blood warming using a preheated water bath. We aimed to test the efficiency of an improvised blood warmer (named the Khaya-warmer) to warm cold packed red blood cells (PRBC) to a mean temperature of 35°C, utilising consumables readily available in a resource-constrained setting. The primary outcome was the outflow temperature–time profile; secondary outcomes included flow rates and cost comparisons with standard methods.

Methods: This was a laboratory-based, experimental, proof-of-concept study. We ran 20 cold PRBC units through extended blood transfusion lines, each immersed in a 1 000 ml water bath preheated to 46°C. Using a 4-probe electronic thermometer, we measured the following temperatures: ambient, PRBC bag, water bath and outflow.

Results: Mean outflow temperature was 35.2°C (95% CI 35.1–35.4); mean emptying time 9.0 minutes (95% CI 8.7–10.2) with a mean flow rate of 25.4 ml.min-1 (95% CI 24.1–26.6).

Conclusion: The Khaya-warmer proved to be effective in safely warming cold PRBC units to a mean temperature of 35.2°C using a cost-effective method. Future studies include investigating various flow rates using a pressure bag or a flow regulating device, and to replace the preheated water bath with a thermally insulated flask.

Author Biographies

A Kenny, Stellenbosch University

Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa

T Lotz, Stellenbosch University

Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa

JF Coetzee, Stellenbosch University

Department of Anaesthesiology and Critical Care, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa

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Published

2023-10-19

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Section

Original Research