
Dr. Christian Poets, World Renowned Neonatologist, Presents Research on New Developments in Pulse Oximetry at the 44th Annual Japan Society for Premature and Newborn Medicine Meeting
Masimo SET Pulse Oximetry Credited for Overcoming Problems Previously Considered Inherent in Pulse Oximetry
Okayama, Japan, November 22, 1999 - Dr. Christian Poets, world-renowned neonatologist from the Hanover Medical School, presented research that he and his colleagues have done on pulse oximetry at the 44th Annual Japan Society for Premature and Newborn Medicine Meeting in Okayama. Dr. Poets was invited to this meeting to discuss the clinical implications of Masimo SET. Dr. Poets presented the pitfalls of conventional pulse oximetry as well as the new advancements from Masimo Corporation, which have been shown clinically, to dramatically improve the reliability of pulse oximetry.
Dr. Christian Poets is Professor of Pediatric Pulmonology and Neonatology and Director of the Neonatal Intensive Care Unit at the Hanover Medical School in Hanover, Germany. Dr. Poets is also the co-chair of the Annenberg Conference, the international group working to reduce the risk of sudden infant death syndrome (SIDS) with newborn babies. Dr. Poets is well known for his research in transcutaneous oxygen monitoring and pulse oximetry. His most recent research is focused on the issues surrounding unreliable conventional pulse oximeters which miss critical, life threatening events and have high false alarm rates. Many studies have proven that conventional pulse oximetry is highly unreliable under motion artifact and low perfusion conditions. Dr. Poets has been investigating new technologies from several pulse oximetry manufacturers, and presented his research results on these products which claim to have improved performance under these conditions.
The data Dr. Poets presented compared Masimo SET pulse oximetry to Mallinckrodt's (Nellcor) Oxismart pulse oximeter. Dr. Poets noted while both oximeters claim to reduce false alarms, these two technologies operate very differently. Oxismart, from Nellcor, uses alarm management to hold alarms, if artifact is detected, for up to one minute before the unit will zero out and sound an audible alarm. On the other hand, Masimo SET does not use alarm management, but rather uses Low Noise Optical Probe, adaptive filter and Discrete Saturation Transform technology to read through the motion artifacts and low signal to noise situations in real time.
Dr. Poets then reviewed his published clinical studies performed on these technologies. He first discussed his study comparing Masimo SET to conventional pulse oximetry on neonates to determine if the frequency of alarms could be reduced. The results showed that there were 93% fewer alarms with Masimo SET as compared to the conventional pulse oximetry. Dr. Poets explained that these results were impressive, but another question still needed to be answered. Is this reduction in false alarms achieved at the expense of delayed or missed true alarms? To address this question, he and his colleagues performed a second study, which focused on the reliability of Masimo SET in detecting true alarms. This study also included Nellcor’s Oxismart technology for comparison. The results of this study showed that even though Masimo SET reduced alarm rates in the NICU by 93%, the Masimo SET technology was more reliable in detecting true alarms (true events of hypoxemia and bradycardia) than conventional pulse oximetry. Dr. Poets stated, “The Masimo SET instrument investigated in this study missed only one out of 185 (0.5%) hypoxemic episodes. In contrast, the other low alarm rate instrument investigated, the Nellcor Oxismart, failed to alarm in 10 (5.4%) episodes where there was definite hypoxemia for a long duration. Although the N200 alarmed during all of these hypoxemic episodes, during 15 hypoxemic events, it only alarmed because it had lost the signal and alarmed due to it zeroing out, which does not help clinicians make a clinical decision. The pulse oximeter’s ability to identify bradycardia differed even more widely, with more than 67% of episodes missed by the Nellcor Oxismart and 33% by the N200. The Masimo SET pulse oximeter again performed significantly better, missing only four out of 54 (7%) bradycardias.”
Dr. Poets also shared with the audience his preliminary impression of his current study under way, comparing Masimo SET with Oxismart XL and HP Veridia M3. Dr. Poets stated, “The Masimo SET still appears superior to these two new products, although further research is needed before more specific statements can be made.” Dr. Poets stressed that alarm management based products such as the Oxismart and Oxismart XL do not help clinicians take care of their patients. Dr. Poets commented, “Although SatSeconds, Nellcor’s new alarm management technique, may be acceptable for the home setting, it is not ideal for the NICU setting because NICU physicians often want to know about their patients’ physiology rather than just reduce alarms. In the NICU, we need to know the physiology of the patients, and Nellcor’s SatSeconds Alarm Management is not an acceptable way of reducing alarms. Masimo SET is advantageous because even though it reduces alarms by 93%, it doesn’t do that by ignoring physiological changes. The Signal Extraction Technology from Masimo measures the patient’s physiology accurately by extracting the signal fraught with noise.”
Another area of concern discussed by Dr. Poets was the problem of misapplied or misalligned sensors. Dr. Poets showed clinical data indicating that reusable sensors are more likely to cause this problem. Dr. Poets stated, “These less conformable sensors have the tendency to open up and come off the patients. In one case the conventional pulse oximeter with a reusable multi-site sensor reported erroneously high oxygen saturation even though the patient’s true arterial oxygen saturation was much lower. This had occurred because the sensor had opened up because of the inflexible material typically used in reusable probes. We refuse to use reusable sensors on our patients because of this increased risk.” Dr. Poets explained that, up till now, adhesive sensors had the disadvantage that they were more expensive than reusable sensors, but that Masimo now offers their LNOP single patient adhesive sensors, which not only offer optimal performance, but have been designed with greater durability to last longer and cost less. Dr. Poets commented, “A recent study found that the average longevity of these disposable sensors was twice that of their main competitor (Nellcor).”
“In summary,” Dr. Poets stated, “it appears from the data available to date, that some of the problems previously considered inherent to pulse oximetry, and thus apparently unsolvable, namely erroneous readings causing false alarms during motion and/or being due to low pulse pressures, have been greatly overcome by Masimo Signal Extraction Technology. Masimo SET should help pulse oximetry become the true ’foul weather’ friend we all need in our neonatal intensive care units. Masimo SET pulse oximetry should also allow us to better monitor babies at risk of SIDS by finally measuring their arterial oxygen saturation reliably without all the false alarms.”
