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CC BY 4.0 · J Neuroanaesth Crit Care
DOI: 10.1055/s-0045-1810607
Case Report

Exploratory Modeling of Intraoperative Co-oximetry Data for Predicting Hemodynamic Trends in a Thalassemic Patient: A Pilot Case

Kunal K. Sharma 
1   Department of Neuroanesthesia Super-speciality Cell, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
,
Kotipi Rajagopal M. Reddy
2   Department of Neuroanesthesia and Neurocritical Care, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
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Abstract

Background

Thalassemia minor presents unique challenges in intraoperative hemodynamic management due to chronically low hemoglobin and altered oxygen-carrying capacity. While pleth variability index (PVi) is an established surrogate of volume responsiveness, its behavior in hemoglobinopathies remains underexplored. This pilot case investigates the relationship between PVi and co-oximetry-derived parameters to assess perfusion trends when plethysmographic signals may be unreliable.

Methods

A 36-year-old female with thalassemia minor undergoing parasagittal craniotomy was monitored using Masimo Radical-7 co-oximeter (spectral hemoglobin [SpHb], perfusion index [Pi], spectrophotometric oxygen content [SpOC], PVi) and GE Centricity hemodynamic records. Data were time-synchronized using POSIX conversion and down-sampled to 1-minute intervals. Multivariate regression and LOESS (locally estimated scatterplot smoothing) curve fitting were used to explore relationships among SpHb, SpOC, Pi, and PVi.

Results

Regression modeling yielded:

PVi = 0.45 × SpHb + 0.15 × SpOC + 1.57 × Pi − 1.04,

with an adjusted R2 of 0.92. Pi emerged as the strongest predictor of PVi. LOESS plots revealed nonlinear associations, especially between PVi and Pi. SpHb showed minimal early-phase variability, consistent with limited responsiveness to acute blood loss.

Conclusion

This exploratory model highlights physiologically grounded inter-variable behavior of co-oximetry parameters in thalassemia. It provides a foundation for redundant trend monitoring and decision support during neurosurgery in patients with hematologic disorders.

Keywords

thalassemia - co-oximetry - hemodynamic - predictive modeling - monitoring - intraoperative


Publication History

Article published online:
21 August 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/)

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