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Service Delivery Innovation Profile

24-Hour Inpatient Pulse Oximetry Monitoring Reduces Rescue Events and Intensive Care Unit Transfers

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Most inpatient units at Dartmouth-Hitchcock Medical Center use round-the-clock monitoring via a pulse oximetry system that recognizes the early signs of deterioration in patients. Tracking blood oxygen saturation levels and heart rate, the system automatically alerts the nurse via pager when preset thresholds are violated. To reduce "alarm fatigue"—the tendency for medical staff to become desensitized to frequent alarms—preset thresholds are set to identify situations that truly require intervention based on patient need, and the pager notification is activated only after the threshold has been met for more than 30 seconds (to avoid false alarms triggered by patient movements or actions). All nurses receive training on proper use of the system. The program has significantly reduced rescue events and transfers to the intensive care unit without causing adverse events and has been well accepted by patients.

Evidence Rating (What is this?)

Moderate: The evidence consists primarily of pre- and post-implementation comparisons of rescue events and intensive care unit transfers on an orthopedic unit that implemented the program, along with comparisons with two other surgical units that had not implemented it.
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Developing Organizations

Dartmouth-Hitchcock Medical Center
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Date First Implemented


Problem Addressed

A small but significant percentage of patients deteriorate during their hospital stay and subsequently die, with postoperative patients being at high risk. These deaths can often be avoided if signs of deterioration are identified and addressed in a timely manner. Medical devices that proactively alert nurses when physiological changes suggest deterioration can help, but to be effective they must minimize false alarms and associated alarm fatigue and be acceptable to patients.
  • Many postoperative deaths: A 2009 study of 186 hospitals found that death rates after inpatient surgery ranged from 3.5 to 6.9 percent.1 Many of these deaths occur as a result of hospital staff not noticing signs of patient deterioration. At Dartmouth-Hitchcock Medical Center, for example, unrecognized patient deterioration represented a major concern prior to implementation of this program. At that time, 3.4 out of every 1,000 patients on the hospital's orthopedic unit required a rescue event, with some patients dying from respiratory depression caused by use of opioids for pain control.
  • Challenges in identifying deteriorating patients: Identifying patients at risk for deterioration can be quite challenging, since some patients without easily identifiable risk factors (such as sleep apnea or a need for supplemental oxygen) nevertheless deteriorate.2 At most hospitals, nurses check on postoperative patients every 4 to 6 hours in general care units, but patients may experience a decline in health status between these checks.
  • Unrealized potential of well-constructed monitoring system: Before a patient destabilizes, there are often physiological changes that can be detected by monitoring systems, such as changes in heart rate, blood pressure, respiration rate, skin temperature, and blood oxygen saturation.3 Continuous monitoring systems can detect these changes, but such systems must be reliable, avoid frequent false alarms that inhibit nurses from responding, and be comfortable for patients to wear. Many monitoring systems do not meet these criteria.4

What They Did

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Description of the Innovative Activity

Most units at Dartmouth-Hitchcock Medical Center use round-the-clock monitoring of hospitalized patients via a pulse oximetry system that recognizes the early signs of deterioration. Tracking blood oxygen saturation levels and heart rate, the system automatically alerts the nurse via pager when preset thresholds are violated. To reduce alarm fatigue, these thresholds are set to identify situations that truly require intervention based on patient need, and the pager notification is activated only after the threshold has been met for more than 30 seconds. A detailed description follows:
  • Round-the-clock monitoring in most units: Monitoring occurs on most units of the hospital, including three postsurgical units (orthopedic, cardiothoracic, and general surgery), three adult medical units, and the pediatric unit. (Only the emergency department and the obstetric unit do not use the system.) On these units, patients wear a pulse oximetry monitor (usually on a finger) plugged into the wall with a 6-foot cord. The monitor connects to a central server and radio transmitter that can communicate with nurses via pager. Patients are encouraged to keep the monitor on at all times, unless they are being directly observed by clinicians.
  • Carefully selected thresholds and built-in delay to avoid alarm fatigue: As detailed below, program leaders designed the system to minimize false alarms and associated alarm fatigue.
    • Thresholds that emphasize clinically actionable alarms: Preset thresholds for physiological factors determine when an alarm will be sounded. Based on a month-long trial on the orthopedic unit, program leaders decided to set the threshold for blood oxygen level below 80 percent and for heart rate below 50 or above 140 beats per minute. These thresholds can be adjusted for patients with abnormal baseline physiology (such as chronically low-oxygen saturation due to chronic obstructive pulmonary disease) that can lead to nonactionable alerts. In these cases, nursing staff can adjust the thresholds by up to 10 percent, and physicians may adapt thresholds to patients' individual physiology. (More information on the process used to set the thresholds can be found in the Planning and Development Process section.)
    • Notification delay to avoid false alarms: To minimize false alarms due to temporary, incorrect readings (which are often caused by patient movements such as clenching a fist, lifting a cup, or holding a toothbrush), the system incorporates a 15-second audio alarm delay at the bedside and an additional 15-second delay before paging the nurse. In other words, when a reading that would normally trigger an alarm occurs, the nurse is not notified by pager if the reading returns to normal within 30 seconds. The 30-second delay serves to eliminate most false alarms without jeopardizing the patient's health in a genuine crisis.
  • Immediate staff response to alarms: After receiving a page, the unit-based nurse (who has received training on the system) responds immediately, taking needed actions to stabilize the patient. If necessary, the nurse calls for the appropriate rapid response team (typically the hospital's general team, with a separate code blue team available for patients in cardiopulmonary arrest and a STAT airway team available for patients requiring urgent intubation). (More information about nurse training can be found in the Planning and Development Process section.)

Context of the Innovation

An academic medical center located in Lebanon, NH, Dartmouth-Hitchcock Medical Center includes Mary Hitchcock Memorial Hospital (a 353-bed teaching hospital), the Dartmouth-Hitchcock Clinic (a network of more than 1,200 primary care physicians and specialists), and the Geisel School of Medicine at Dartmouth. The orthopedic unit that first used the monitoring system has 36 beds that primarily serve patients after joint replacement surgery. Each nurse on the unit handles five patients, many of whom are elderly and obese and require opioids for pain.

Hospital leaders began focusing on improving patient surveillance following a series of adverse events in the mid-2000s involving postoperative patients receiving opioids via patient-controlled analgesia pumps. In 2006, the hospital formed a multidisciplinary team to investigate these events and identify potential strategies for avoiding them. The team included patient safety experts, researchers, physicians, nurses, biomedical and human factors engineers, and information technology experts.

Did It Work?

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The program has significantly reduced rescue events and transfers to the intensive care unit (ICU) without leading to an increase in adverse events and has been well accepted by patients.
  • Fewer rescue events: On the orthopedic unit, the number of rescue events (defined as situations requiring activation of a rapid response team) fell in the 11 months before implementation from 3.4 to 1.2 per 1,000 patient days in the 10 months afterward. Over this same time period, a general surgical unit that did not implement the program experienced a smaller decline (from 2.0 to 1.3 rescue events per 1,000 patient days), while a specialty unit caring for patients after urologic, gynecologic, and vascular procedures experienced an increase in rescue events (from 2.7 to 3.4 per 1,000 patient days).
  • Fewer ICU transfers: The number of transfers to the ICU among patients on the orthopedic unit fell from 5.6 before implementation to 2.9 per 1,000 patient days afterward. This decline translates into roughly 150 fewer days spent in ICU beds. Less significant declines occurred in the two comparison units that did not implement the program—from 5.7 to 5.2 ICU transfers per 1,000 patient days on the general surgical unit and from 15.0 to 12.7 ICU transfers per 1,000 patient days on the specialty unit.
  • Elimination of adverse events: Between December 2007 and the end of 2013, no patient on the orthopedic unit suffered irreversible severe brain damage or died from respiratory cause.
  • Similar improvements on other units: Additional surgical and inpatient units that implemented the surveillance system following the trial period have also experienced reductions in rescue events and ICU transfers, with greater reductions seen on wards with high-risk patients who require significant amounts of opioid pain medication.
  • Well accepted by patients: During the study period on the orthopedic unit, 98.2 percent of patients wore the finger probes throughout their stays. This percentage has remained relatively consistent over time and with the expansion of the monitoring system.

Evidence Rating (What is this?)

Moderate: The evidence consists primarily of pre- and post-implementation comparisons of rescue events and intensive care unit transfers on an orthopedic unit that implemented the program, along with comparisons with two other surgical units that had not implemented it.

How They Did It

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Planning and Development Process

Key steps included the following:
  • Investigating adverse occurrences: In 2006, the multidisciplinary team conducted an investigation of adverse occurrences at the hospital that involved opioid administration, finding them to be textbook cases of "failure to rescue" (defined as hospital deaths after a complication of an underlying illness or medical care). Based on this investigation, the hospital implemented several measures to improve treatment of patients at increased risk of adverse occurrences due to known comorbidities, including double-checking opioid administration and using "smart" patient-controlled analgesia pumps with software that can alert users to potential errors. When these measures failed to significantly reduce adverse occurrences, team members decided to focus on early identification of deterioration in all patients, not just those with known risk factors. Accordingly, the team began looking for a monitoring system that would be reliable, relatively easy for staff to use, and comfortable for patients.
  • Deciding on pulse oximetry: Before deciding on pulse oximetry, the team researched and tested several options, including a respiratory rate monitor (which requires a strap around the chest) and an end-tidal carbon dioxide monitor (which requires tubing to be placed in the patient's nose). The team also looked at nursing workflow and human factors issues with the intention to implement the system in a way that it would be a tool to support nursing tasks, instead of being a replacement or a burden. Systemic integration of the system into existing tasks was an important consideration. After deciding on pulse oximetry, the team chose to track two variables: oxygen saturation and heart rate. Oxygen saturation is an especially effective marker because it tends to drop quickly when a patient begins to deteriorate (regardless of the underlying disease process).
  • Selecting suitable technology: Based on their research and discussions, the team began looking for a pulse oximetry system that allowed alarm thresholds to be modified for specific patients, that could incorporate alarm delays, and that connected to the hospital's existing server. (These requirements prevented the hospital from using its existing pulse oximeters.) This process led to a contract with an outside vendor (Masimo Corporation) to install the system (known as Patient SafetyNet) and train staff to use it. Prior to installation, the networking infrastructure was enhanced and the hospital installed additional power outlets at the appropriate height in each room to accommodate the new monitors.
  • Setting alarm thresholds and delays: As alluded to earlier, the team spent a month closely observing selected postoperative patients in the orthopedic unit who had volunteered to use the new pulse oximeters. For oxygen saturation, the alarm threshold was initially set low and gradually increased. The team chose this approach to minimize the likelihood that nurses would be overwhelmed by alarms and dislike the new system. The observations ultimately led the team to choose a standard alarm threshold of 80 percent, which they felt reached a balance between actionable and false-positive alarms. (By contrast, the threshold for patients in operating rooms or under sedation is typically set at 93 percent). Similarly, the alarm thresholds chosen for heart rate (less than 50 and more than 140 beats per minute) tend to be somewhat outside the limits that would set off an alarm in the operating room. The team's observations and tests also led to the decision to use two 15-second delays before nurses would be notified.
  • Training nurses: Before implementing the system in the orthopedic unit, the team developed a comprehensive training program for the unit's 40 nurses and 20 licensed nurse assistants. Training began with a classroom session that included a motivational discussion led by a physician about the problem of unrecognized patient deterioration, a description of the alarm threshold policy, and instructions from a vendor representative on using the monitors. This session proved critical to gaining nurses' initial buy-in for the new system, as a nurse manager on the team answered nurses' questions, explained the potential benefits in terms of improved patient care and outcomes, and addressed concerns that the new system would make their jobs too demanding. When the system went live in December 2007, team members led daily clinical rounds for 2 weeks to help nurses become comfortable with the system. These rounds continued on a less frequent basis for several weeks.
  • Gradually expanding to other units: Based on the positive results from the orthopedic unit, the hospital implemented the surveillance system on two other surgical units (general surgery and cardiothoracic surgery) in 2009, three adult medical units in 2010, and the pediatric and adolescent unit in 2012. As part of this rollout, nurses on these units received extensive training on how to use the monitoring system. Training began with an online slide presentation that explains the rationale for monitoring and describes how to use the system as a problem-solving tool. Nurses then took a competency exam on this content. After passing this exam, the nurses received hands-on training on the various types of equipment, including pagers (which tend to be unfamiliar to younger nurses), the different types of patient probes, the room monitors, and the central monitor. All newly hired nurses on these units go through a similar training process.

Resources Used and Skills Needed

  • Staffing: The program did not require the hiring of additional staff.
  • Costs: Major costs include the initial purchase of the surveillance system, ongoing purchase of sensors used in the pulse oximeters (some of which can be used with multiple patients and some of which can be used by only one patient), installation of additional power outlets in patient rooms, and staff time spent researching and implementing the system and training nurses to use it. Program leaders believe that in units with a high proportion of at-risk patients (such as an orthopedic unit), these costs are more than offset by the savings generated through reductions in ICU transfers, rescue events, and length of stay. On medical units with lower-risk patients, program leaders believe the system is either cost neutral or entails some increase in costs.
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Funding Sources

Dartmouth-Hitchcock Medical Center
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Tools and Other Resources

Additional information on the technology used by the surveillance system is available at:

Adoption Considerations

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Getting Started with This Innovation

  • Create multidisciplinary team: To ensure that clinical and technological issues are identified and addressed, the team implementing the system should include physicians, nurses, and information technology staff.
  • Select thresholds carefully: As noted, alarm triggers should be set to strike a balance between actionable and false-positive alarms, reducing the potential for alarm fatigue. Project leaders encourage others who implement similar monitoring systems to consider using the thresholds they have adopted.
  • Emphasize education: From the outset, project leaders understood the need for nurses to support the monitoring system. As a result, they included nurse managers on the project team and devoted significant time to explaining the system's potential benefits to and addressing the concerns of frontline nurses. As noted, nurses received extensive classroom and hands-on training to ensure they felt comfortable using the system. These efforts convinced many nurses to become strong supporters of the system, encouraging their peers on other units to lobby for its implementation.
  • Start small and expand: Project leaders recommend beginning the program on a single unit with a high percentage of patients who are at significant risk for deterioration. This targeted approach allows a small group of staff to become comfortable using the system and maximizes the likelihood the program will have a significant, positive impact on patient care. The program can be expanded to other units once it has proven itself and elicited strong support from staff.

Sustaining This Innovation

  • Keep existing safeguards: Patient monitoring via pulse oximetry should be considered an additional mechanism to promote patient safety, not a replacement for existing safeguards. For example, staff should continue to frequently interact with patients to assess their mental status and take vital signs, and hospitals should not reassign nurses to different tasks or reduce nurse-to-patient ratios.
  • Share data on program success: Nurse supervisors should routinely share data demonstrating the positive impact of the program (e.g., trends in patient rescues) with nursing staff and emphasize that these improvements are the direct result of their work.
  • Maintain focus on education: Because of high turnover rates, comprehensive training on the system should be made part of the standard orientation program for all newly hired nurses.

Spreading This Innovation

Following the publication of several studies and articles highlighting the positive results achieved in the orthopedic unit, clinicians and administrators at hospitals in several States (including Vermont, Florida, New York, and Tennessee) contacted program leaders at Dartmouth-Hitchcock and visited the medical center to observe the system in use. Many of those who visited subsequently implemented similar or identical systems.

More Information

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Contact the Innovator

Andreas H. Taenzer, MD, FAAP
Department of Anesthesiology
Dartmouth-Hitchcock Medical Center
Dartmouth Medical School
One Medical Center Drive
Lebanon, NH 03756
(603) 650-6823

Innovator Disclosures

Dr. Taenzer reported having no financial interests or business/professional affiliations relevant to the work described in the profile.


Members of the team that implemented the pulse oximetry surveillance system won the 2011 AAMI Foundation/Institute for Technology in Health Care Clinical Application Award (since renamed the Clinical Solution Award). Given annually, this award recognizes individuals who apply innovative clinical engineering practices or principles to solve significant patient care problems. More information about the award is available at:

In recognition of this program, the Dartmouth-Hitchcock Medical Center won the 2009 ECRI Institute Health Devices Achievement Award for excellence in health technology management. More information about the award is available at:

References/Related Articles

Healthcare Technology Safety Institute. Safeguarding patients with surveillance monitoring: the Dartmouth-Hitchcock Medical Center experience. 2013. Available at: (If you don't have the software to open this PDF, download free Adobe Acrobat ReaderĀ® software External Web Site Policy.).

Taenzer AH, Blike GT. Postoperative monitoring: the Dartmouth experience. Anesthesia Patient Safety Foundation Newsletter. Spring-Summer 2012. Available at:

Taenzer AH, Pyke JB, McGrath SP, et al. Impact of pulse oximetry surveillance on rescue events and intensive care unit transfers: a before-and-after concurrence study. Anesthesiology. 2010;112(2):282-7. [PubMed]

Taenzer AH, Pyke JB, McGrath SP. A review of current and emerging approaches to address failure-to-rescue. Anesthesiology. 2011;115(2):421-31. [PubMed]


1 Ghaferi AA, Birkmeyer JD, Dimick JB. Variation in hospital mortality associated with inpatient surgery. N Engl J Med. 2009;361(14):1368-75. [PubMed]
2 Galhotra S, DeVita MA, Simmons RL, et al. Mature rapid response system and potentially avoidable cardiopulmonary arrests in hospital. Qual Saf Health Care. 2007;16(4):260-5. [PubMed]
3 Buist M, Bernard S, Nguyen TV, et al. Association between clinically abnormal observations and subsequent in-hospital mortality: a prospective study. Resuscitation. 2004;62(2):137-41. [PubMed]
4 Taenzer AH, Pyke JB, McGrath SP. A review of current and emerging approaches to address failure-to-rescue. Anesthesiology. 2011;115(2):421-31. [PubMed]
Comment on this Innovation

Disclaimer: The inclusion of an innovation in the Innovations Exchange does not constitute or imply an endorsement by the U.S. Department of Health and Human Services, the Agency for Healthcare Research and Quality, or Westat of the innovation or of the submitter or developer of the innovation. Read more.

Original publication: June 18, 2014.
Original publication indicates the date the profile was first posted to the Innovations Exchange.

Last updated: June 18, 2014.
Last updated indicates the date the most recent changes to the profile were posted to the Innovations Exchange.

Andreas H. Taenzer, MD, FAAP
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