Early identification of undiagnosed obstructive sleep apnea improves patient safety

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder in the world, affecting up to 936 million people globally. 

Introduction

The highest prevalence of OSA has been reported in China, followed by the US, Brazil, and India. Sleep apnea represents an ever-increasing challenge for anaesthesia providers because it is both common and grossly underdiagnosed. Approximately 70% of adult patients with OSA are obese, placing them at risk of arthritis of the hip and knee joints, which potentially requires total joint arthroplasty. With better surgical techniques, these surgeries are increasingly performed on an outpatient basis. However, this puts patients at risk of complications in an unmonitored environment once they are discharged home.

Background

Despite the high prevalence of OSA, up to 90% of individuals with moderate to severe OSA may remain undiagnosed, even in highly resourced countries. OSA increases morbidity and mortality in the general population, and is estimated to increase all-cause mortality by three to six times compared to surgical patients without OSA. Post-operative complications associated with airway management, cardiovascular status, and delirium also increase health care costs and inpatient length of stay. However, many studies using continuous positive airway pressure (CPAP) with OSA patients in a variety of surgical settings have demonstrated significant reductions in the Apnea-Hypopnea Index, hospital length of stay, and cardiopulmonary complications.

The use of validated tools, such as the STOP-Bang Questionnaire, has shown high levels of sensitivity (83.6%) and specificity (56.3%) in identifying patients with previously undiagnosed OSA prior to surgery. This tool is easy to use, highly sensitive, and can aid the anaesthesia and surgical team in identifying patients at risk of OSA prior to surgery so that they can be referred for evaluation and treatment with CPAP on the day of surgery.

The problem

During general anaesthesia, dose-dependent depression of ventilation occurs when volatile gases or intravenous anaesthetics are administered to patients. Depending on the severity of the obstructive airway disease, many patients with OSA are at an increased risk of developing peri-operative complications, such as prolonged intubation requiring ICU admission, emergency reintubation following extubation at the end of surgery, pneumonia, aspiration, arrhythmias, and cardiac arrest. Since patients frequently present for surgery without the proper screening and treatment for OSA, a protocol for early screening, detection, and referral was needed to reduce patient risk of post-operative pulmonary complications when presenting for outpatient total joint surgery.

Implementing evidence

The Society of Anaesthesia and Sleep Medicine recommends routine screening of peri-operative patients using the validated STOP-Bang tool. These recommendations are echoed in a 2021 JBI Evidence Summary (updated in 2023),10 which outlines the following best practices:

Patients at risk of OSA should be identified prior to surgery using a reliable screening tool such as the STOP-Bang, P-SAP, Berlin Questionnaire, or ASA Checklist. (Grade A)

Sleep study results and recommended PAP settings of patients diagnosed with OSA should be obtained prior to surgery. (Grade B)

Patients diagnosed with OSA should continue to wear their CPAP device pre-operatively. (Grade A)

Based on these recommendations, we implemented an evidence-based practice project following the seven steps of the JBI Evidence Implementation Framework. The project was conducted in a midwestern community hospital in the US, with a collaborative team of quality improvement leaders, DNP nurse anaesthesiology students, and nurse “navigators” (who help patients navigate the complicated peri-operative period). Through the project, the existing protocol used in the hospital was reviewed and revised to align with the best available evidence.

A baseline audit was conducted on 30 patients undergoing joint surgery between June and December 2020. The aim of this audit was to measure current practices against best practices. The audit found that several patients were not being screened properly using the STOP-Bang tool. Direct teaching using sample patients and a slide presentation was conducted to ensure accurate assessment by the nursing staff. In addition, the DNP team met with IT specialists to make this important assessment more visible on the surgical dashboard of the electronic medical record (EMR). Clinical decision information was also added to aid nurses conducting the assessment.

Establishing the need for the project and obtaining buy-in was achieved through several educational in-service sessions held with various nursing and physician staff over the course of several weeks. In addition, the surgical leadership sent emails to all clinical staff outlining the evidence on referral for sleep study prior to surgery, when indicated.

A protocol was instituted for the direct referral of patients for polysomnography, or sleep study, if they were found to have at least moderate OSA. Patients were instructed to complete the sleep study, obtain a CPAP machine if indicated, and bring it with them on the day of surgery for use in the peri-operative period. The DNP students created a branded educational brochure that was distributed to patients prior to their surgery which explained the risk factors for OSA and the necessity of a sleep study to improve their experience on the day of surgery and beyond.

Demonstrating impact with evidence

A follow-up audit of an additional 30 patients was conducted between July and December 2021. The aim of this audit was to measure the impact of the improvement strategies. Prior to implementation, only 5 of 30 patients (17%) were assessed using the STOP-Bang tool, and four of them were scored incorrectly, resulting in an overall accurate assessment rate of only 3%. After implementation, 17 of 30 patients (57%) had a documented STOP-Bang score, while the accuracy of scoring increased to 29%, yielding an overall accuracy rate of 17%. Additionally, five patients had been referred for sleep study (20%), a promising increase from zero referrals before the project. Peri-operative CPAP compliance data remained unchanged from the initial audit; however, this was likely due to the compressed implementation timeline. Patient assessment using the STOP-Bang tool increased by 70.6%, while accuracy in recorded STOP-Bang scores improved five-fold compared with the baseline audit. The improvements in assessment and referral reflected the positive impact of the project.

Challenges and lessons learned

Leadership support is critical for the success of any implementation project. It can be difficult for students to be agents of change without the support of managers and quality improvement administrators. Constant communication with leadership, regular updates regarding progress, and transparency in the change process were effective steps to overcome the limited authority of the primary project team members.

When considering updates to the EMR, this may take several months to enact. Early engagement with the technology team is therefore recommended, especially when that step is foundational to the rest of the project.

Implementation of this important project occurred in the midst of the COVID-19 pandemic. Resources that otherwise may have gone toward improving peri-operative OSA management may have been directed toward COVID-related priorities. Since the pandemic, many hospitals have transitioned typical inpatient surgeries to the outpatient setting as a result of minimally invasive surgical techniques and effective pain management through regional anaesthesia. However, management of OSA in the outpatient setting is an ongoing safety concern.

Sustainability and next steps

We presented the implementation project to the hospital system via Grand Rounds. This meeting served to alert high-level administrators about the need for broad adoption of this protocol based on the evidence. Quality improvement staff and the evidence-based practice council would be in a position to continue such work.

Yearly education for the surgical and nursing staff is needed to ensure compliance as new evidence emerges and new staff come on board due to turnover or additional hiring.

Conclusion

The use of a validated assessment tool is an important means of identifying patients at risk of OSA and potential complications after surgery. Working with an interprofessional group of collaborators, and conducting frequent and targeted education are useful strategies when implementing appropriate use of these tools and the peri-operative management of OSA among patients undergoing total joint arthroplasty. The methods and findings of this implementation project can be used in any type of outpatient surgical population to ensure a safe transition to the home setting. 

Key takeaways

Using an academic–clinical partnership model, the DNP project offers a means for robust, evidence-based practice projects to be undertaken in the clinical setting with students who are trained in evidence implementation. Close collaboration between the academic and clinical entities is imperative to conduct meaningful and feasible projects that benefit the clinical site and allow for timely completion by the DNP student.

References

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Kindgen-Milles D, Muller E, Buhl R, Bohner H, Ritter D, Sandman W, et al. Nasal-continuous positive airway pressure reduces pulmonary morbidity and length of hospital stay following thoracoabdominal aortic surgery. Chest. 2005;128:821-8.

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Links to additional resources

Read more about OSA in the surgical population and how to use the STOP-Bang tool

Author

Jennifer Greenwood^1,2

1. Rosalind Franklin University of Medicine and Science

2. RFU Center for Interprofessional Evidence Based Practice, a JBI Center of Excellence
JBI, University of Adelaide, Australia