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Is Near-Patient Monitoring with Haemoglobinometer as accurate as Spectrophotometry in determining Intra-Operative Haemoglobin Estimation and the need for Blood Transfusion during Surgery?
Abstract
Background: Accurate intra-operative estimation of blood loss and haemoglobin (Hb) is crucial in determining if and when to transfuse patients during surgery. In the surgical patient, intravascular volume and haemoglobin may change rapidly and frequent rapid assessment of patient status is indicated. We investigated whether near-patient monitoring using a haemoglobinometer was as accurate as a laboratory spectrophotometry in determining haemoglobin concentration.
Patients and Methods: All patients in which the decision to transfuse had been made by the attending anaesthetist
were studied. Haemoglobin concentration was measured immediately before transfusion using the haemoglobinometer
HumanMeter Hb Plus (HUMAN GmbH, Wiesbaden, Germany). A sample was collected in an EDTA bottle and analysed
in the laboratory by spectrophotometry using yanomethaemoglobin method. Demographic data, volume and type of fluids administered before transfusion were documented.
Results: Fifty patients were studied with a mean age of 37.28± 19.04 years (range 4 – 90 years). Mean pre-operative PCV was 30.21 ± 4.30% (range 20 – 44%). The mean pre-transfusion Hb level by haemoglobinometer was 7.88 ± 1.84 g/dl (range 3.11 to 11.15 g/dl) which was similar to that estimated by laboratory spectrophotometry of 7.94 ± 1.84 g/dl (range 2.90 to 11.0 g/dl) (p=0.387, t = -0.873, df = 49, correlation = 0.965). The mean difference between the results was 0.05 ± 0.48g/dl (range -0.7 to 1.0). The limit of agreement between the two methods was -0.91 to +1.01. Twenty-one patients (42%) were inappropriately transfused.
Conclusion: Near-patient monitoring with the haemoglobinometer provided a sufficiently accurate and reliable
estimation of haemoglobin comparable with laboratory spectrophotometry. The routine use of near-patient monitoring
could minimise unnecessary intra-operative blood transfusion.
Key words: intraoperative haemoglobin; laboratory spectrophotometry, haemoglobinometer
Patients and Methods: All patients in which the decision to transfuse had been made by the attending anaesthetist
were studied. Haemoglobin concentration was measured immediately before transfusion using the haemoglobinometer
HumanMeter Hb Plus (HUMAN GmbH, Wiesbaden, Germany). A sample was collected in an EDTA bottle and analysed
in the laboratory by spectrophotometry using yanomethaemoglobin method. Demographic data, volume and type of fluids administered before transfusion were documented.
Results: Fifty patients were studied with a mean age of 37.28± 19.04 years (range 4 – 90 years). Mean pre-operative PCV was 30.21 ± 4.30% (range 20 – 44%). The mean pre-transfusion Hb level by haemoglobinometer was 7.88 ± 1.84 g/dl (range 3.11 to 11.15 g/dl) which was similar to that estimated by laboratory spectrophotometry of 7.94 ± 1.84 g/dl (range 2.90 to 11.0 g/dl) (p=0.387, t = -0.873, df = 49, correlation = 0.965). The mean difference between the results was 0.05 ± 0.48g/dl (range -0.7 to 1.0). The limit of agreement between the two methods was -0.91 to +1.01. Twenty-one patients (42%) were inappropriately transfused.
Conclusion: Near-patient monitoring with the haemoglobinometer provided a sufficiently accurate and reliable
estimation of haemoglobin comparable with laboratory spectrophotometry. The routine use of near-patient monitoring
could minimise unnecessary intra-operative blood transfusion.
Key words: intraoperative haemoglobin; laboratory spectrophotometry, haemoglobinometer
