Abstract
Aim Determination of hemoglobin (Hb) concentration by standard methods is time consuming,
invasive, and intermittent. Noninvasive (NI) methods of Hb estimation are less time
consuming, and reduce the risk of infection, number of required working personnel,
and long-term costs. In this study, we aimed to find the accuracy of Hb values at
various time points using noninvasive (NI) Hb monitoring and standard invasive techniques
such as laboratory (LabHb) and arterial blood gas (ABG).
Methods All American Society of Anesthesiologists (ASA) physical grade I and II adult patients
between 18 and 65 years of either gender undergoing pituitary surgery under general
anesthesia were included over a period of 1 year. Samples were collected for Hb estimation
from the arterial line (aHb) using ABG analyzer machine and LabHb using automated
Hb analyzer. Simultaneously, Hb reading from the NI Hb monitor was recorded using
Masimo Spot Hemoglobin Check Device. Bland–Altman plot was used to find out agreement
between Hb values drawn from three different techniques. A p-value < 0.05 was considered significant.
Results A total of 30 patients participated in the study. The male to female ratio was 13:17.
Statistical analysis showed poor correlation between the invasive and NI methods of
Hb estimation.
Conclusion NI method of Hb estimation may be successfully used in clinical practice, replacing
estimation from ABG analysis or laboratory tests. However, NI method cannot replace
the invasive methods of Hb estimation.
Keywords
noninvasive hemoglobin monitor - invasive hemoglobin monitor - blood loss - arterial
blood gas - laboratory test
