2007 OPEN FORUM Abstracts
CONTINUOUS NON-INVASIVE MEASUREMENT OF HEMOGLOBIN VIA PULSE CO-OXIMETRY DURING MAJOR SURGERY
M. R. Macknet1, P. Kimball-Jones1, R. L. Applegate1, R. D. Martin1, M. W. Allard1
New advances in pulse oximetry technology have led to the development of a prototype multi-wavelength pulse CO-Oximeter designed to continuously and non-invasively measure hemoglobin concentration (SpHb). These case reports examine this device's ability to measure continuous SpHb perioperatively and evaluates the accuracy compared with hemoglobin concentration (Hb) measured by a laboratory CO-oximeter.
After IRB approval and informed consent, both patients were monitored with three prototype SpHb sensors, optically isolated from each other, attached to a data collection system (Masimo Inc., Irvine, CA). Routine anesthetic care of this patient was not altered and no treatment decisions were made based on the SpHb numbers. Data was collected throughout the course of the surgery. Per routine blood samples were gathered a minimum of every hour and more frequently if clinically indicated. Arterial blood samples were analyzed by laboratory CO-Oximeter (Radiometer ABL735), and the resulting Hb measurements were compared with the data collected from the corresponding SpHb readings.
Case 1 A 65 year old female undergoing liver and kidney transplantation was monitored for a total of 16.6 hours. During that time 17 Hb/SpHb data pairs were collected. The Hb concentration ranged from 5.8 to 10.3 gm/dl and the bias of the SpHb sensors was 0.146 and precision was 0.740.
Case 2 A 29 year old female undergoing mitral value replacement was monitored. During this procedure 7 Hb/SpHb pairs were obtained. The Hb concentration ranged from 8.1 to 15.4 gm/dl and the bias of the SpHb sensors was 0.35 and the precision was 1.17.
SpHb correlated well with CO-Oximeter determined Hb during these complicated procedures. Measurements showed good correlation during times of rapidly changing Hb concentration related to surgical blood loss and transfusion. Continuous and non-invasive hemoglobin monitoring would be an extremely useful tool in many clinical scenarios. This technology has the potential to greatly improve patient care and safety during surgical procedures.