Health effects of identifying patients with undiagnosed obstructive sleep apnea in the preoperative clinic: a follow-up study

Potential Use of SGLT-2 Inhibitors in Obstructive Sleep Apnea: A new treatment on the horizon

BACKGROUND

Obstructive sleep apnea (OSA) is characterized by hypoxic episodes due to collapse of the airway during sleep and is frequently associated with obesity, type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). There is currently no pharmacological agent approved for the treatment of OSA. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have the potential to both increase life expectancy and quality of life of these patients making them promising agents for this role. There are relatively few studies investigating this possible beneficial relationship between these drugs and OSA.

METHOD

We aimed to increase awareness on the potential benefits of SGLT2 inhibitors in OSA patients by describing the current evidence on the effectiveness of these inhibitors in both overall and cardiovascular morbidity and mortality. We performed a literature search for articles reporting on the use of SGLT2 inhibitors in patients with OSA and T2DM.

RESULTS

We identified 4 manuscripts studying the use of SGLT2 inhibitors in 475 OSA patients with T2DM. Among them, 332 patients were administered SGLT2 inhibitors, and 143 patients were in a control group. SGLT2 inhibitors have many potential positive impacts on OSA patients by targeting various mechanisms involved in OSA pathogenesis.

CONCLUSION

SGLT2 inhibitors are prime pharmacological candidates for the treatment of OSA, and additional studies are needed to better explore mechanisms and outcomes unique to this population. Additionally, patients with OSA often have multiple comorbidities that are clinical indications for SGLT2 inhibitor therapy. Physicians should recognize and encourage the use of these agents in such patients.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Machine learning-based prediction of adherence to continuous positive airway pressure (CPAP) in obstructive sleep apnea (OSA)

Continuous positive airway pressure (CPAP) is the "gold-standard" therapy for obstructive sleep apnea (OSA), but the main problem is the poor adherence. Therefore, we have searched for the causes of poor adherence to CPAP therapy by applying predictive machine learning (ML) methods. The study was conducted on OSAs in nighttime therapy with CPAP. An outpatient follow-up was planned at 3, 6, 12 months. We collected several parameters at the baseline visit and after dividing all patients into two groups (Adherent and Non-adherent) according to therapy adherence, we compared them. Statistical differences between the two groups were not found according to baseline characteristics, except gender (P< .01). Therefore, we applied ML to predict CPAP adherence, and these predictive models showed an accuracy and sensitivity of 68.6% and an AUC (area under the curve) of 72.9% through the SVM (support vector machine) classification method. The identification of factors predictive of long-term CPAP adherence is complex, but our proof of concept seems to demonstrate the utility of ML to identify subjects poorly adherent to therapy. Therefore, application of these models to larger samples could aid in the careful identification of these subjects and result in important savings in healthcare spending.

Modified Mallampati Score Improves Specificity of STOP-BANG Questionnaire for Obstructive Sleep Apnea

BACKGROUND

An accurate, clinical screening tool for obstructive sleep apnea (OSA) that identifies patients for further diagnostic testing would assist in the diagnosis of this comorbidity. One example, the STOP-BANG questionnaire (SBQ), has been validated as a screening tool with high sensitivity. However, its specificity may result in a high false-positive rate. The aim of this study to determine if addition of the Modified Mallampati score to the SBQ improves its specificity.

METHODS

The authors studied 162 patients referred to the Sleep Disorders Clinic at Yedikule Chest Disease Education and Research Hospital. All patients were prospectively screened for risk of OSA using the SBQ, their oral anatomy was assessed by Modified Mallampati scoring, and sleep quality characterized by polysomnography. Polysomnography results were reviewed when available and the predictive performance of the SBQ and the modified SBQ scoring models were compared.

RESULTS

In the authors' study an SBQ score ≥3 yielded sensitivities of 0.85, 0.86, and 0.91 for Apnea-Hypopnea Index (AHI) ≥5/h, AHI ≥15/h, and AHI ≥30/h, respectively, and specificities of 0.09, 0.10, and 0.18. The modified SBQ with a cutoff of ≥4 (>3) points for AHI levels of >5, >15, and >30 yielded respective sensitivities of 0.84, 0.86, and 0.91 and specificities of 0.25, 0.26, and 0.27.

CONCLUSIONS

The author's results from indicated the modified SBQ with a cutoff of >3 points in this study was more specific than the standard SBQ but no less sensitive, and may be used in identifying OSA patients for further diagnostic evaluation or avoiding unnecessary testing.

Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients With Obstructive Sleep Apnea

Supplemental Digital Content is available in the text.

The purpose of the Society of Anesthesia and Sleep Medicine guideline on preoperative screening and assessment of adult patients with obstructive sleep apnea (OSA) is to present recommendations based on the available clinical evidence on the topic where possible. As very few well-performed randomized studies in this field of perioperative care are available, most of the recommendations were developed by experts in the field through consensus processes involving utilization of evidence grading to indicate the level of evidence upon which recommendations were based. This guideline may not be appropriate for all clinical situations and all patients. The decision whether to follow these recommendations must be made by a responsible physician on an individual basis. Protocols should be developed by individual institutions taking into account the patients’ conditions, extent of interventions and available resources. This practice guideline is not intended to define standards of care or represent absolute requirements for patient care. The adherence to these guidelines cannot in any way guarantee successful outcomes and is rather meant to help individuals and institutions formulate plans to better deal with the challenges posed by perioperative patients with OSA. These recommendations reflect the current state of knowledge and its interpretation by a group of experts in the field at the time of publication. While these guidelines will be periodically updated, new information that becomes available between updates should be taken into account. Deviations in practice from guidelines may be justifiable and such deviations should not be interpreted as a basis for claims of negligence.

Outpatient Anesthetic Safety Considerations for Obstructive Sleep Apnea

Most patients with obstructive sleep apnea (OSA) are not diagnosed preoperatively. The STOP-Bang questionnaire may identify patients at risk of OSA, especially those with severe OSA. Patients with mild to moderate OSA, with optimized comorbidities, can usually safely undergo outpatient surgery. Patients with severe OSA, who are not optimized medically, should avoid outpatient surgery.

Pre-operative screening for obstructive sleep apnoea

Sleep disordered breathing, especially obstructive sleep apnoea (OSA), has a high and increasing prevalence. Depending on the apnoea and hypopnoea scoring criteria used, and depending on the sex and age of the subjects investigated, prevalence varies between 3% and 49% of the general population. These varying prevalences need to be reflected when considering screening for OSA. OSA is a cardiovascular risk factor and patients are at risk when undergoing medical interventions such as surgery. Screening for OSA before anaesthesia and surgical interventions is increasingly considered. Therefore, methods for screening and the rationale for screening for OSA are reviewed in this study.

CPAP in the Perioperative Setting: Evidence of Support

OSA is a commonly encountered comorbid condition in surgical patients. The risk of cardiopulmonary complications is increased by two to threefold with OSA. Among the different treatment options for OSA, CPAP is an efficacious modality. This review examines the evidence regarding the use of CPAP in the preoperative and postoperative periods in surgical patients with diagnosed and undiagnosed OSA.

Perioperative Assessment and Management for Sleep Apnea in the Ambulatory Surgical Patient

The overwhelming majority of surgical procedures performed in the United States are done on an outpatient basis. Patients with complicated medical problems are routinely scheduled for ambulatory procedures that have become progressively more complex. Appropriate patient selection is paramount to ensuring optimal perioperative outcomes, and the patient with known or suspected OSA presents unique challenges to the anesthesia care team regarding airway management, pain control, and postoperative monitoring requirements. Currently, a relative paucity of high-quality evidence exists on which to base guidelines or recommendations for the anesthetic care of these patients. It is generally agreed that early identification of those at risk for OSA allows for planning and implementation of strategies to help to reduce the risk of adverse perioperative events. Although various national societies have published consensus statements aimed at guiding the perioperative management of the patient at risk for OSA, more studies are needed to define the optimal approach to the perioperative care of this population.

Obstructive sleep apnea in adult patients: considerations for anesthesia and acute pain management

Obstructive sleep apnea (OSA) represents a challenge in the perioperative period for both physicians and the health care system alike. A number of studies have associated OSA with increased risk for postoperative complications. This is of particular concern in the face of this disease remaining vastly underdiagnosed. In this context, current guidelines and established concepts such as the use of continuous positive airway pressure or the level of postoperative monitoring, lack strong scientific evidence. Other interventions such as the use neuraxial/regional anesthesia may however offer added benefit. This review aims to address considerations for physicians in charge of OSA patients in the perioperative setting and to give an outlook for current and future research on this topic.

Alternative scoring models of STOP-bang questionnaire improve specificity to detect undiagnosed obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) is common among surgical patients. The STOP-Bang questionnaire is a validated screening tool with a high sensitivity. However, its moderate specificity may yield fairly high false positive rate. We hypothesized that the specific combinations of predicting factors in the STOP-Bang questionnaire would improve its specificity.

METHODS

After research ethics approval, consented patients were asked to complete the STOP-Bang questionnaire and then underwent sleep studies. The predictive performance of the STOP-Bang alternative scoring models was evaluated. Five hundred sixteen patients with complete data on the STOP-Bang questionnaire and polysomnography were reported.

RESULTS

When the STOP-Bang score was ≥ 3 (any 3 positive items), the sensitivity and specificity for identifying moderate-severe OSA was 87% and 31%, respectively. The specificity for any 2 positive items from the 4 STOP questions plus BMI > 35 kg/m(2), male gender, or neck circumference > 40 cm for identifying moderate-severe OSA was 85%, 77%, and 79%, respectively. Compared with STOP-Bang score ≥ 3, the predicted probability for severe OSA of the specific combinations of STOP score ≥ 2 + male and STOP score ≥ 2 + BMI increased by 36% and 42%, respectively. For severe OSA, the specific combination of STOP score ≥ 2 + BMI + male demonstrated a specificity of 97% and 86% increase in predicted probability versus any 4 positive items of STOP-Bang questionnaire.

CONCLUSIONS

The specific constellations of predictive factors improved the specificity of STOP-Bang questionnaire. For patients with STOP score ≥ 2, male gender, and BMI > 35 kg/m(2) were more predictive than age ≥ 50 and neck circumference > 40 cm.

Preanesthesia evaluation for ambulatory surgery: do we make a difference?

PURPOSE OF REVIEW

Ambulatory surgery is considered low risk; however, both surgery-related and patient-related factors combine to determine the overall risk of a procedure. The preanesthesia evaluation is useful to gather information and determine whether additional testing or medical optimization is necessary prior to surgery with the goal to prevent adverse events and improve outcomes.

RECENT FINDINGS

Recent literature focused on the preanesthesia evaluation provides guidelines for patient-centered testing. Routine, protocolized preoperative testing is expensive and has not shown to improve outcomes. The preanesthesia visit is useful for patient evaluation, not specifically testing, but for the synthesis of information, medical optimization, additional targeted testing if indicated, assessment of risk, and plan for perioperative management.

SUMMARY

Current literature supports a preanesthesia visit that focuses on individual patient evaluations and patient-directed effective interventions. This is in contrast to the previous routine, protocolized preoperative preparations. The challenge for anesthesiologists lies in understanding both surgery-specific and patient-specific risk factors, and targeting interventions to optimize the outcomes.

Factors Associated with Postoperative Exacerbation of Sleep-disordered Breathing

Introduction:

The knowledge on the mechanism of the postoperative exacerbation of sleep-disordered breathing may direct the perioperative management of patients with obstructive sleep apnea. The objective of this study is to investigate the factors associated with postoperative severity of sleep-disordered breathing.

Methods:

After obtaining approvals from Institutional Review Boards, consenting patients underwent portable polysomnography preoperatively, and on postoperative nights 1 and 3 in hospital or at home. The primary outcomes were polysomnography parameters measuring the sleep-disordered breathing. They were treated as repeated measurement variables and analyzed for associated factors by mixed models.

Results:

Three hundred seventy-six patients, 168 men and 208 women, completed polysomnography on preoperative and postoperative night 1. Age was 59 ± 12 yr (mean ± SD). Preoperative apnea–hypopnea index (AHI) was 12 (4, 26) (median [25th, 75th percentile]) events per hour. Thirty-five patients had minor surgeries, 292 intermediate surgeries, and 49 major surgeries, with 210 general anesthesia and 166 regional anesthesia. The 72-h opioid dose was 55 (14, 85) mg intravenous morphine-equivalent dose. Preoperative AHI, age, and 72-h opioid dose were associated with postoperative AHI. Preoperative central apnea index, male sex, and general anesthesia were associated with postoperative central apnea index. Slow wave sleep percentage was inversely associated with postoperative AHI and central apnea index.

Conclusions:

Patients with a higher preoperative AHI were predicted to have a higher postoperative AHI. Preoperative AHI, age, and 72-h opioid dose were positively associated with postoperative AHI. Preoperative central apnea, male sex, and general anesthesia were associated with postoperative central apnea index.

Perioperative Auto-titrated Continuous Positive Airway Pressure Treatment in Surgical Patients with Obstructive Sleep Apnea

Background:

Obstructive sleep apnea (OSA) may worsen postoperatively. The objective of this randomized open-label trial is to determine whether perioperative auto-titrated continuous positive airway pressure (APAP) treatment decreases postoperative apnea hypopnea index (AHI) and improves oxygenation in patients with moderate and severe OSA.

Methods:

The consented patients with AHI of more than 15 events/h on preoperative polysomnography were randomized into the APAP or control group (receiving routine care). The APAP patients received APAP for 2 or 3 preoperative, and 5 postoperative nights. All patients were monitored with oximetry for 7 to 8 nights (N) and underwent polysomnography on postoperative N3. The primary outcome was AHI on the postoperative N3.

Results:

One hundred seventy-seven OSA patients undergoing orthopedic and other surgeries were enrolled (APAP: 87 and control: 90). There was no difference between the two groups in baseline data. One hundred six patients (APAP: 40 and control: 66) did polysomnography on postoperative N3, and 100 patients (APAP: 39 and control: 61) completed the study. The compliance rate of APAP was 45%. The APAP usage was 2.4–4.6 h/night. In the APAP group, AHI decreased from preoperative baseline: 30.1 (22.1, 42.5) events/h (median [25th, 75th percentile]) to 3.0 (1.0, 12.5) events/h on postoperative N3 (P &lt; 0.001), whereas, in the control group, AHI increased from 30.4 (23.2, 41.9) events/h to 31.9 (13.5, 50.2) events/h, P = 0.302. No significant change occurred in the central apnea index.

Conclusions:

The trial showed the feasibility of perioperative APAP for OSA patients. Perioperative APAP treatment significantly reduced postoperative AHI and improved oxygen saturation in the patients with moderate and severe OSA.

Preoperative screening and perioperative care of the patient with sleep-disordered breathing

PURPOSE OF REVIEW

Emerging data are raising concerns that patients with known or suspected obstructive sleep apnea (OSA) are at increased risk for a myriad of perioperative complications. Strategies to identify patients preoperatively with OSA, or at risk for OSA, are being advocated. In addition, approaches to identify patients most at risk for OSA-related postoperative complications have been described. While lacking solid evidence, a number of perioperative management strategies have been proposed for the care of these patients.

RECENT FINDINGS

Recent studies utilizing different methodologies have provided additional evidence regarding the impact that OSA can have on postoperative outcomes, including increased risk of difficult intubations, adverse pulmonary outcomes, and delirium. Tools, such as the STOP-Bang questionnaire and limited channel monitoring, have been investigated with regards to their utility to identify not only patients at risk for OSA but also those at risk for more severe OSA. Consensus-based guidelines for the perioperative care of OSA patients have recently been published.

SUMMARY

OSA is quite common in patients presenting for elective surgery and has been linked to increased perioperative complications. Attempts to identify these patients preoperatively appear prudent. Protocols on how best to manage these patients are available, although validation of their effectiveness is needed.

CPAP adherence in patients with newly diagnosed obstructive sleep apnea prior to elective surgery

BACKGROUND

Obstructive sleep apnea (OSA) is prevalent in the surgical population, and it has been suggested that preoperative patients should be screened and treated for OSA. However, it remains unclear whether patients diagnosed with OSA in the preoperative period adhere to prescribed CPAP therapy.

OBJECTIVE

Our aim was to objectively quantify CPAP adherence, investigate predictors of poor CPAP adherence, and to establish an optimal CPAP setting in a cohort of presurgical patients diagnosed with OSA as part of the preoperative work-up.

METHODS

In a retrospective observational study, we collected data on all adult presurgical patients seen by the Anesthesia Perioperative Medicine Clinic (APMC) who screened positive for OSA on the STOP-Bang questionnaire and underwent an in-laboratory diagnostic polysomnogram (PSG) before surgery. CPAP was offered to patients with moderate or severe OSA. Objective CPAP adherence was recorded during the perioperative period. Factors associated with reduced CPAP adherence were delineated. Patient characteristics were compared between those with STOP-Bang scores of 3-4 and those with higher scores (STOP-Bang score ≥ 5).

RESULTS

During a 2-year period, 431 patients were referred and 211 patients completed a PSG. CPAP therapy was required in 65% of patients, and the optimal level was 9 ± 2 cm H(2)O. Objective CPAP adherence was available in 75% of patients who received CPAP therapy; median adherence was 2.5 h per night, without any significant difference between the STOP-Bang subgroups. African American race, male gender, and depressive symptomatology were independent predictors of reduced CPAP adherence. Severe OSA was significantly more prevalent in patients with a STOP-Bang score ≥ 5 than those whose score was 3-4 (55.1% versus 34.4%, p = 0.005). However, optimum CPAP pressure levels and adherence to therapy did not differ between the 2 STOP-Bang groups.

CONCLUSIONS

Adherence to prescribed CPAP therapy during the perioperative period was extremely low. African American race, male gender, and depressive symptoms were independently associated with reduced CPAP usage. Further research is needed to identify and overcome barriers to CPAP acceptance and adherence in the perioperative setting.