2000 OPEN FORUM Abstracts
IMPROVED PULSE OXIMETER TECHNOLOGY CHANGES CAREGIVER PRACTICE PATTERNS: MASIMO SET® VS. CONVENTIONAL PULSE OXIMETRY
Charles G. Durbin, Jr., MD, FCCM, Stephanie K. Rostow, RRT; University of Virginia Health System, Charlottesville, VA
INTRODUCTION- Monitors provide data upon which decisions about patient care are based. ICU practice patterns have been based largely upon the technology incorporated in monitoring systems. Recent advances have produced pulse oximeters with increased sensitivity and decreased interference from artifact. The Masimo SET® pulse oximeter (Masimo Corporation, Irvine, CA) (MSO) uses a novel signal processing technology to identify arterial saturation, which is resistant to movement artifacts and low flow states. Using the Masimo SET pulse oximeter (MSO), we sought to test the hypothesis that improved technology would change clinician's practice patterns. Specifically, we examined the time to wean to an FiO2 of 0.4, the time to extubation, the number of ventilator changes and the number of arterial blood gases (ABGs) obtained during this weaning process.
METHODS- We prospectively evaluated the effects on caregiver practice patterns of two pulse oximetry technologies. We compared the MSO technology to a conventional pulse oximeter (CPO), the Ohmeda 3740 (Datex-Ohmeda, Louisville CO). After obtaining Human Use Committee approval, 68 adult cardiac surgery patients with good preoperative ventricular function, following CABG surgery, were enrolled. On arrival in the ICU, both a CPO and a MSO were attached to the same hand of each patient. The output from both monitors was continuously recorded to a computer system until 4 hours following extubation or for a maximum of 24 hours postoperatively. The digits to which the monitors were attached were randomly chosen by the bedside clinician. Patients were randomly assigned to have the display of either the CPO or MSO available to the caregivers with the other device "blinded". No other routine clinical management was altered during the study. We determined the time until weaning to FiO2 = 0.4, time until extubation, and the number of ABGs obtained during weaning. Differences were analyzed using Student's t test. Significance was determined at p<0.05.
RESULTS- There was no difference in time to extubation [647 ± 335 (MSO) vs. 705 ± 338 (CPO) minutes] or the number of ventilator changes [2.6 (MSO) vs. 2.5 (CPO)] in weaning to FiO2 = 0.4. However, there was a significant difference in the time required to wean oxygen to FiO2 = 0.4, the MSO group in 168 ± 99 minutes vs. 324 ± 263 minutes for the CPO group, p=0.02. There were significantly fewer ABGs performed when the MSO oximeter was used, 2.2±0.9 vs. 3.8±1.8 for the CPO group, p<0.01.
DISCUSSION- Our data supports the hypothesis, that clinician's practice patterns will change when provided with improved pulse oximetry technology as with the Masimo SET pulse oximeter. Although extubation time was not different, the number of ABGs obtained and the time to wean to a low FiO2 was nearly half. This change in practice reduces the costs of oxygen supply and delivery and the associated risk of morbidity from excessive oxygen exposure. Clinicians achieved these efficiencies while decreasing the number of blood gases obtained. This change in practice could result in a savings of over 1200 ABGs in our cardiac intensive care annually. While accuracy of monitored data is often reported in studies of monitors, impact on caregiver behavior is a more relevant method of monitor evaluation.
Some technical support and equipment was provided by the Masimo Corporation, Irvine, CA