Preoperative Identification of Sleep Apnea Risk in Elective Surgical Patients, Using the Berlin Questionnaire
Frances Chung,* Barnaby Ward,* Joyce Ho,* Hongbo Yuan,* Leonid Kayumov,† and Colin Shapiro†
(J Clin Anesth, 19:130-134, 2007)
Departments of *Anesthesiology and †Psychiatry, Toronto, Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada.
Surgical patients with sleep apnea are at increased risk for difficult airway management and difficult intubation and are more than twice as likely as those without the disorder to experience serious respiratory or cardiac adverse events after orthopedic joint replacement. The Berlin questionnaire, the most widely used screening tool for detecting sleep apnea, was examined for its ability to identify elective surgical patients previously diagnosed with sleep apnea.
Patients were recruited during their preoperative assessment visit to the hospital. Physical data regarding blood pressure and body mass index (BMI) were recorded, and patients completed the Berlin questionnaire. High risk for sleep apnea is determined on the basis of responses to questions about (1) frequency of snoring, (2) wake time sleepiness and/or drowsy driving, and (3) a history of high blood pressure or a BMI greater than 30 kg/m2. Lower risk patients are those who respond positively to only 1 of the 3 symptom categories or whose symptoms are not persistent. The Berlin questionnaire identified 24% (73/305) of patients as being at high risk for sleep apnea. Patients so identified included the 9 who were previously diagnosed with the disorder. Six of the remaining patients were referred for polysomnography testing, and 4 of these received a diagnosis of severe or mild sleep apnea. Thus, 13 patients had confirmed sleep apnea, yielding a frequency of 4.2% of surgical patients. Compared with those whose responses placed them in the low-risk category, patients identified as high risk by the Berlin questionnaire were older and had a higher BMI and a higher frequency of hypertension.
Because only a small number of patients whose responses indicated sleep apnea risk underwent polysomnography, it was not possible to calculate sensitivity, specificity, or positive/negative predictive values for the questionnaire. The 24% rate, however, was in keeping with detection rates in some previous studies. Identification of sleep apnea risk before surgery allows risks to be minimized and an appropriate anesthetic selected.