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October 22, 2017
43030.416667 - 43030.479167
Room 51
Prevention of Post Operative Arterial Oxygen Desaturation in the Post Anesthesia Care Unit Using Pulse Oximetry With Automated Verbal Prompts
Joseph Lagrew, M.D., Drew Gonsalves, B.S., Anthony Destephens, B.S., Andrew Gifford, B.S., Judith Wishin, B.S.N., Amy Gunnett, B.S.N., Nikolaus Gravenstein, M.D., Samsun Lampotang, Ph.D.
University of Florida College of Medicine, Gainesville, Florida, United States
Disclosures: J. Lagrew: None. D. Gonsalves: None. A. Destephens: None. A. Gifford: None. J. Wishin: None. A. Gunnett: None. N. Gravenstein: None. S. Lampotang: None.

Arterial oxygen desaturation is a direct adverse effect of many anesthetics and analgesics. It frequently leads to post-operative arterial oxygen desaturation in the post anesthesia recovery unit (PACU). Continuous pulse oximetry monitoring1,2 can guide provider intervention at the bedside and greatly improved care of post-operative arterial oxygen desaturation.3 Although pulse oximetry-generated alarms have benefited PACU patients significantly, they have negative effects as well. Some studies have suggested the presence of alarms can affect patient recovery from surgery.4,5 Further they can lead to alarm overload/ fatigue6 and may present occupational hazards to health care workers or affect other patients’ care.4,7,8 Despite continuous pulse oximetry monitoring, arterial oxygen desaturation is still a relatively prevalent event requiring health care provider intervention in the PACU which can also additionally impact the patient’s perceived quality of recovery.9

Verbal automated prompted pulse oximetry utilizes oxygen saturation (SpO2) measurements to prompt patient breathing when values dip below a specified preset value that is higher than the low SpO2 alarm setting. Prompts mimic the initial provider intervention to patients who desaturate but do so without the requirement of provider time and effort and are set to enunciate prior to the alarm threshold, preventing an audible alarm in those patients who comply with verbal prompts. This prospective study evaluated the effect of verbal automated pulse oximetry on the number of alarms, oxygen use, time needed to treat hypoxia and quality of provider and patient experience in the post anesthesia care unit (PACU).


One hundred fifty (150) consenting PACU patients will be recruited and randomized to treatment with standard care (control) or standard care plus prophylactic automated verbal pulse oximetry associated with pulse oximetry saturation values less than or equal to 93% (intervention). Automation utilizes DDS middleware (Harvard MD PnP group) to access real time physiologic data from a monitor (IntelliVue MP50, Philips) through a serial RS232 connection to an embedded Linux system (Beaglebone Black). Patients and providers are monitored during the immediate post operative course for desaturation events, alarms and any interventions required and are given a follow up survey of their immediate post operative experience.

Demographics are analyzed using Student’s t-test for continuous variables and Fisher’s exact test for categorical variables. Desaturation episodes, supplemental oxygen utilizations, provider intervention data, and patient and provider quality survey information are analyzed using 2-way repeated measures analysis of variance (ANOVA) with multiple comparisons. This study was IRB approved.

Preliminary Results: In 27 patients (14 intervention, 13 control) studied to date there is a trend towards significance of decreased alarms in the study group (1.73 vs. 4.77 in the control group); decreased provider interventions at bedside for hypoxic events (1.11 vs. 2 in control group); and time spent on patient care for hypoxia (0.124 vs. 1.5 minutes in the control group). There was also a trend towards perceived decrease in alarms, overall noise and time addressing hypoxia among nurses treating patients in the intervention group compared to the control group. There were no trends towards decreased supplemental oxygen usage or increased patient satisfaction when comparing the control and intervention groups.

Conclusion: Preliminary results indicate that prompted verbal automated pulse oximetry use in the PACU decreased the number of audible SpO2 alarms per patient and decreased time required to treat desaturation.

Copyright © 2017 American Society of Anesthesiologists