Nov 01, 2011
By Mary Kjorven, RN, BSN, MSN , Denise Dunton, RN, MSN, MHSA , Richard Milo, RRT , Lynn Gerein, RN, BScN

Bedside capnography: Better management of surgical patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) is a disorder characterized by complete or partial upper airway obstruction occurring at intervals during sleep. Untreated OSA is associated with oxygen desaturation, increased levels of carbon dioxide and cardiac complications, any of which may lead to cardiac arrest and death.

Hospitals across the country are faced with the challenge of providing safe and appropriate perioperative and postoperative management of these patients in a health-care environment where critical care access is limited and surgical wait lists are increasing to unprecedented levels. Most facilities meet the requirements for monitoring these patients through pulse oximetry, administering continuous positive airway pressure (CPAP) and/or providing one-to-one care. However, these approaches have drawbacks:

  • The results of pulse oximetry may be deceptive, especially when the patient is receiving supplemental oxygen, because it may detect an adequate level of arterial oxygen even when the patient’s respirations are depressed. Pulse oximetry does not detect changes in respiration rate, pauses in breathing or exhaled carbon dioxide levels, which are important early indicators of respiratory depression. In addition, declining ventilation in patients on supplemental oxygen may not be recognized until bradypnea progresses to apnea, which can lead to harm or even death.

  • Although many patients with OSA are effectively treated at home with established CPAP, CPAP alone is not sufficient to manage patients postoperatively. The addition of general anaesthetic and opioid therapy places the patient at higher risk. Knowing the patient is receiving CPAP may also give care providers a false sense of security.

  • Providing one-to-one care is costly, and cohorting of postoperative OSA patients does not always allow for care by providers who have the specific knowledge and competencies required for individual patients.

Kelowna General Hospital (KGH), a 345-bed tertiary hospital in the B.C. interior, was the first facility in Canada to implement continuous bedside capnography monitoring for postoperative patients with a history of OSA who are discharged from the recovery room to patient care wards. Capnography measures the concentration of carbon dioxide in the respiratory gases, apneic events and respiratory rate. In the past, capnography was used mainly intraoperatively as well as postoperatively in critical care. Today’s monitors are portable and practical for use on inpatient units, with the ability to measure end tidal C02 while delivering up to five litres/minute of supplemental oxygen.

Bedside capnography was an addition to the existing OSA monitoring approach at KGH, which was based on American Society of An esthesiologists guidelines for perioperative management of patients with OSA. The guideline that called for continuous monitoring of respiratory status had proven problematic.

Before bedside capnography was initiated, all surgical patients with a history of OSA were monitored via capnography in critical care settings or by respiratory therapists or licensed practical nurses, under the direction of RNs, on a designated surgical unit. A shortage of critical care beds and the need for one-to-one monitoring meant that a limit of two postoperative patients with OSA could be managed per day without a significant increase in staff overtime. The one-to-one assignments on this unit were unfunded positions, which further negatively impacted the budget. Hospital administrators agreed that this system of care delivery was not sustainable and turned to the KGH respiratory manager, respiratory clinical supervisor and a surgical manager to come up with solutions. These three individuals became the first members of the OSA management (OSAM) team; the respiratory clinical supervisor subsequently became the lead.

The respiratory clinical supervisor had just come back from an American Association for Respiratory Care conference, where he was introduced to bedside capnography. U.S. hospitals were beginning to incorporate it as a standard of care for postoperative OSA patients, owing to litigation and patient safety issues. He began to conduct extensive research on the subject. Next, he contacted suppliers, set up on-site presentations and arranged for a two-week trial of the equipment on one of our surgical patient care units. One model was selected, and six units were purchased. The initial funding for the purchase of six monitors would come from KGH’s minor capital budget. The cost of patient-specific equipment would be covered by individual department budgets. At this point, health-service administrators, surgeons, anesthesiologists, educators and front-line nurses and respiratory therapists had been invited and agreed to join what soon became a multidisciplinary team. Each of the authors of this article was a member.

The development and implementation phases took approximately six months. The respiratory and nursing education departments jointly provided training for all surgical nursing and respiratory therapy staff. The team met daily during the early weeks of implementation to discuss concerns identified by front-line care providers. The team leader met each morning with them to get their feedback and address questions. The monitor’s alarm system was one of their major concerns early on. The alarm was too sensitive and this caused a number of nuisance alarms. Monitors had to be adjusted to patient-specific indicators.

On the staff’s recommendation, the team revised the OR booking form and the presurgical screening questionnaire to include OSAM care requirements. The team also developed an OSA assessment flow sheet to record capnography data.


This program improved patient care and made better use of resources, because the right staff were now caring for the patient in the right place at the right time. Surgical access and patient flow through the system improved significantly. Surgery postponements as a result of inability to provide adequate monitoring became a rarity. Patients receive postoperative care from staff who have the specific knowledge and required competencies.

In the first 18 months after implementation, KGH managed 400 postoperative patients with OSA, an average of seven cases per week. Program costs incurred for this period, including purchase of six additional monitors. A review of the program after one year showed a 70 per cent reduction in operating costs on the surgical unit in which these patients had previously been cared for, because one-to-one monitoring was no longer required.

Changes in assessment and documentation procedures resulted in early identification of OSA patients. Nursing staff gained a heightened awareness of the dangers of OSA in postoperative patients and had access to a new tool that assists them in recognizing patients with deteriorating OSA postoperatively and alerts them to intervene appropriately.


Staff from various areas had the opportunity to join the team and to provide feedback during implementation. We learned that early engagement of all members of the surgical health-care team and consistent and ongoing communication are essential for successful implementation of this type of program.

This experience taught team members that changing practice and engaging in a quality improvement process take leadership, commitment, time and resources. We encountered some specific challenges: determining which health-care professional had responsibility for certain tasks, such as ordering pain management and discontinuing capnography monitoring, and ensuring we had support from administrators so that the team’s recommendations for maximum ward capacity levels would be followed.

Because bedside capnography represented a change in the provision of care, the nursing staff initially expressed concerns about increased workloads and compromised patient safety. With access to ongoing education and support, most nurses have accepted the practice change.


Although we have not had the resources to allow us to conduct a formal evaluation of the program, informal evaluation is ongoing, and members of the team continue to meet regularly to look for ways to improve the process of identifying patients at risk, scheduling surgery and coordinating care. In the works are standardized postoperative orders and an OSAM clinical pathway. The health region’s Anesthesia Working Group has endorsed the principles of the program and will be working to provide standardized care for all patients with OSA. Meanwhile, other hospitals in Interior Health have begun to implement the program

Mary Kjorven, RN, BSN, MSN, is a Clinical Nurse Specialist, Interior Health, Kelowna, B.C.

Denise Dunton, RN, MSN, MHSA, is the Surgical Services Clinical Leader, Interior Health Medical Affairs and Clinical Networks, Kelowna, B.C.

Richard Milo, RRT, is the Professional Practice Leader, Central Okanagan Respiratory Services, Interior Health, Kelowna General Hospital, Kelowna, B.C.

Lynn Gerein, RN, BScN, is the Network Director, Emergency & Trauma Services, Interior Health Medical Affairs and Clinical Networks, Kelowna, B.C.
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