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

Abstract

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.

Keywords: CPAP; Obstructive sleep apnea; STOP-Bang; adherence; compliance; continuous positive airway pressure; perioperative.

Figure 1. Flow diagram of patients in the study that were referred to the sleep laboratory

Figure 2. Prevalence of moderate or severe OSA across all STOP-Bang scores in 211 patients who underwent in-laboratory polysomnogram

Figure 3. Box plots showing the distribution of and differences in 3% oxygen desaturation index (ODI 3%) and percent of total sleep time below oxygen saturation of 90% (T90) across the two STOP-Bang categories

Lower and upper boundaries of the box indicate 25th and 75th percentages. A solid line within the box marks the median, and vertical lines indicate the 10th and 90th percentages. Circles are outliers. ODI 3% and T90 were significantly higher in patients with STOP-Bang scores of 5-8 (p = 0.001 and p = 0.003, respectively).