Comparison of haemoglobin measurement methods in the operating theatre

Abstract

† This study compared the accuracy of four bedside methods for haemoglobin (Hb) assessment [non-invasive and continuous haemoglobin measurement with Pulse CO-Oximetry (SpHb), arterial blood measurement by satellite CO-Oximetry (HbSat), and HemoCue arterial (HcueArt) and capillary (HcueCap) blood] with a laboratory haematology analyser (LHA). † HcueArt is closest to LHA even when Hb concentrations change rapidly. † HbSat provided values in close agreement LHA but requires sample preparation and handling. † SpHb is less invasive, less accurate, but measures continuously. † When absolute accuracy is essential then invasive measurements are needed to confirm SpHb or HcueCap values before transfusion.Background. Various methods of haemoglobin (Hb) measurement are available to guide transfusion including several methods that allow for measurement at the bedside. This study directly compared their absolute and trend accuracy compared with values from the central lab (reference method).Methods. Adult patients undergoing surgery with expected blood loss wore a rainbow ReSposable sensor connected to a Radical-7 Pulse CO-Oximeter (SpHb). Arterial samples were analysed with a haematology analyser (HbLab), a satellite CO-Oximeter (HbSat), and a point-of-care haemoglobinometer (HemoCue; HcueArt). Concomitantly, ear capillary blood was tested using the same haemoglobinometer (HcueCap). Absolute accuracy and the clinical significance of error were assessed with Bland-Altman plots and three-zone error grids. Trend analysis was performed using a modified polar plot, testing both directionality and magnitude of Hb changes compared with the reference.Results. Two hundred and nineteen measurements from 53 patients with HbLab ranging between 6.8 and 16.3 g dl 21 (4.2 and 10.1 mmol litre 21 ) were recorded. Compared with the reference method, bias (precision) was 0.2 (0.2) g dl 21 [0.1 (0.1) mmol litre 21 ] for HcueArt, 0.8 (0.3) g dl 21 [0.5 (0.2) mmol litre 21 ] for HbSat, 0.5 (0.5) g dl 21 [0.3 (0.3) mmol litre 21 ] for HcueCap and 1.0 (1.2) g dl 21 [0.6 (0.7) mmol litre 21 ] for SpHb. None of the devices tested would have led to unnecessary or delayed transfusion according to 2006 ASA transfusion criteria. Trend accuracy was better for HcueArt and HbSat than for HcueCap and SpHb. Conclusion.Bedside Hb measurement methods differ in their agreement to a laboratory haematology analyser but none would have led to transfusion errors.

The Accuracy and Reliability of Non-Invasive Haemoglobin Measurements in the Emergency Room: a Small Prospective Observational Quality Control Study from a Swiss University Hospital ED

“…The accuracy and reliability of the portable Pronto-7 Pulse COOximeter was reported in numerous studies conducted in the operating room [10][11][12][13][14][15][16][17][18][19][20][21] and in the intensive care unit [4,5,[22][23][24][25] with predominantly satisfactory performance. In a study done in bleeding trauma patients the agreement was moderate [bias (LOA) of -0.6 (-3.0; +1.9)] g/dl [26], where the limit of agreement is defined as the mean difference + twice the standard deviation of the differences [27].…”

Hemorragia posparto tardía y utilidad de la determinación no invasiva de hemoglobina: comunicación de un caso

“…El valor de la Hb no es el único indicador de transfusión y es recomendable comprobar la correlación que existe entre el valor que muestra el cooxí-metro con el que obtenemos en el laboratorio de referencia del centro 10 , pero el análisis de la tendencia sí es de gran ayuda para valorar la necesidad de transfusión y la respuesta a los fluidos infundidos. La literatura recoge menor fiabilidad de este dispositivo en función de la versión del software del equipo, cuando los cambios hemodinámicos son muy agudos, en pacientes mal perfundidos, ante sangrados masivos o en valores extremos de Hb, ya que tiende a sobreestimar la lectura cuando el valor real es bajo y a infraestimarla en valores de Hb mayores 8,10,11 . Aunque no obtengamos la lectura en el 100% del tiempo monitorizado, es obvio que esta herramienta proporciona más datos que cualquier aná-lisis intermitente, como los que nos facilitan otras medidas invasivas.…”

The impact of anemia and body mass index (BMI) on neuromotor development of preschool children

“…This device was chosen due to its portability and capacity of proving fast results to determine anemia or blood loss in a non-invasive manner. 15,16 The purpose of hemoglobin measurement in children is to obtain a concrete feedback about their levels of anemia. In our study, the WHO hemoglobin cut-off values of anemia were taken as reference and, therefore, the lower limit for hemoglobin levels in children between the ages of 5 to 11 years was accepted as 11.5 g/dL.…”