Evaluation of the usefulness of non-invasive serum haemoglobin measurement in a perioperative setting in a prospective observational study

Abstract

Patient Blood Management (PBM) programmes seek to reduce the number of missed anaemic patients in the run-up to surgery. The aim of this study was to evaluate the usefulness of haemoglobin (Hb) measured non-invasively (SpHb) in preoperative screening for anaemia. We conducted a prospective observational study in a preoperative clinic. Adult patients undergoing examination for surgery who had their Hb measured by laboratory means also had their Hb measured non-invasively by a trained health care provider. 1216 patients were recruited. A total of 109 (9.3%) patients (53 men and 56 women) was found to be anaemic by standard laboratory Hb measurement. Sensitivity for SpHb to detect anaemic patients was 0.50 (95% CI 0.37–0.63) in women and 0.30 (95% CI 0.18–0.43) in men. Specificity was 0.97 (95% CI 0.95–0.98) in men and 0.93 (95% CI 0.84–1.0) in women. The rate of correctly classified patients was 84.7% for men and 89.4% for women. Positive predictive value for SpHb was 0.50 (95% CI 0.35–0.65) in men and 0.40 (95% CI 0.31–0.50) in women; negative predictive value was 0.93 (95% CI 0.92–0.94) in men and 0.95 (95% CI 0.94–0.96) in women. We conclude that due to low sensitivity, SpHb is poorly suitable for detecting preoperative anaemia in both sexes under standard of care conditions.

Comparing Non-Invasive Spectrophotometry to Hematology Analysis for Hemoglobin Measurements in Sickle Cell Disease Patients

“…The SpHb sensitivity varies between different studies. In Khalafallah et al's RCT study (2015) and Wittenmeier et al's prospective study (2021), both groups reported adequate SpHb and adequate sensitivity [10,12] in contrast with Honnef G et al's study (2022), an observational study, which reported lower SpHb sensitivity, similar to our findings [11].…”

“…Variations in accuracy between these devices are still the focus of debates [10][11][12][13][14][15], and there are a few recently published studies examining patients with SCD [8,16].…”

Can Non-Invasive Spectrophotometric Hemoglobin Replace Laboratory Hemoglobin Concentrations for Preoperative Anemia Screening? A Diagnostic Test Accuracy Study

“…Khalafallah et al, in their RCT (2015), reported an increase in the SpHb accuracy (sensitivity) at low Hb values for males compared to females. Honnef et al (2022), in an observational study, reported that the sensitivity of SpHb to identify anemia was low, in contrast to the prospective study by Wittenmeier et al (2021) [9][10][11]. This diversity between various researchers motivated our team to design this current research to study the Masimo Radical-7 performance as a non-invasive hemoglobin monitor.…”

Diffuse reflectance spectroscopy and RGB-imaging: a comparative study of non-invasive haemoglobin assessment

“…Early works on PPG demonstrated that detecting transmitted or re ected light from a ngertip allows to determine Hb level by analysing the oscillating component of diffuse re ection associated with blood pulsation [10]. However, although a number of studies reported results with an error of less than 10 g/l [7,8], independent prospective studies show that even the FDAcerti ed devices have a high measurement error exceeding 15-20 g/l and have a low sensitivity in detecting anaemia [3,11,12]. Namely, some works report sensitivity of detecting a low Hb level using PPG to be ~0.4-0.5 [3,11]; other studies report the detection of a low Hb level with a sensitivity of about 0.8 [13].…”

“…However, although a number of studies reported results with an error of less than 10 g/l [7,8], independent prospective studies show that even the FDAcerti ed devices have a high measurement error exceeding 15-20 g/l and have a low sensitivity in detecting anaemia [3,11,12]. Namely, some works report sensitivity of detecting a low Hb level using PPG to be ~0.4-0.5 [3,11]; other studies report the detection of a low Hb level with a sensitivity of about 0.8 [13]. Sensitivity of the prediction of low Hb level in newborns was reported to be in the 0.7-0.9 range [14], while the speci city of the PPG (in prediction of normal Hb level) is generally higher (0.8-0.9).…”