According to the STOP-Bang screening tool, which of the following variables is MOST likely a risk factor for obstructive sleep apnea (OSA)?

  • (A) Female sex
  • (B) Body mass index of 38 kg/m2
  • (C) Neck circumference of 35 cm (about 14 inches)

Obstructive sleep apnea (OSA) is the most common type of sleep-disordered breathing. Males are more frequently affected (24% of males vs. 9% of females). OSA is characterized by loud snoring, observed periods of apnea, excessive daytime sleepiness, and abrupt awakenings accompanied by gasping or choking. It may also be associated with difficulty concentrating, irritability, and hypertension. OSA is associated with recurrent upper airway collapse during sleep that leads to reduced or complete cessation of airflow despite ongoing respiratory efforts.

Patients with OSA present a unique set of intraoperative concerns, including an elevated risk of perioperative airway obstruction, atelectasis, hypoxemia, pneumonia, cardiovascular complications, and prolonged hospitalizations. Patients with OSA also tend to be more sensitive to the respiratory depressant effects of opioids. Techniques to manage the airway, such as mask ventilation, direct laryngoscopy, and endotracheal intubations, tend to be more challenging in the presence of OSA. If left unchecked, severe OSA may eventually lead to chronic hypoxemia, hypertension, polycythemia, pulmonary hypertension, and right-sided heart failure. Because of the prevalence of OSA, many patients will present for surgery with undiagnosed OSA. The STOP-Bang screening tool (Table) is useful to identify those at higher risk.

Table: STOP-Bang scoring model. Increased risk of OSA: answering yes to three or more items. The first four questions are asked of the patient, while the last four are objective assessments by medical personnel. Modified with permission, from Chung F, Yegneswaran B, Liao P, et al. STOP questionnaire: a tool to screen patients for obstructive sleep apnea (Anesthesiology 2008;108:812-21).

Table: STOP-Bang scoring model. Increased risk of OSA: answering yes to three or more items. The first four questions are asked of the patient, while the last four are objective assessments by medical personnel. Modified with permission, from Chung F, Yegneswaran B, Liao P, et al. STOP questionnaire: a tool to screen patients for obstructive sleep apnea (Anesthesiology 2008;108:812-21).

Each “yes” answer on the screening tool adds 1 point to the STOP-Bang score, for a maximum score of 8. Patients with a STOP-Bang score of 0 to 2 can be classified as low risk for moderate-to-severe OSA, whereas those with a score of 5 to 8 can be classified as high risk for moderate-to-severe OSA. In patients with midrange scores (3 or 4), further criteria are required for classification.

Additional consideration must be given for patients with OSA who are cared for in ambulatory settings. The potential for challenging airway management should be anticipated and opioids should be used judiciously. Those patients with OSA who are undergoing more invasive surgeries or those who may have an increased requirement for postoperative opioids may be less suitable for surgery in an ambulatory setting.

ANSWER B