Sleep apnea is prevalent among patients scheduled for surgery of colorectal cancer

Background: Age and obesity are risk factors for both colorectal cancer and sleep apnea, but the prevalence of sleep apnea is unknown in patients with colorectal cancer. Aim: To investigate the prevalence of sleep apnea among patients scheduled for surgery of colorectal cancer. Methods: 68 patients with colorectal cancer mean age 70 ± 11 years, 22 women, BMI 26 ± 4 were investigated with polysomnography (Embla) including continuous recordings of respiration, breathing movements, oxygen saturation, EEG, EOG, chin EMG, ECG and body position sensor at hospital during the night before surgery. They were also investigated with STOP-BANG, Epworth sleepiness scale, height, weight and Mallampati score. Results: Eight-one percent had sleep apnea with 5 or more apneas and hypopneas per hour of sleep i.e. AHI >5, 38% had mild sleep apnea with AHI 5-15 sleep, 28% had moderate sleep apnea and 15% severe sleep apnea with AHI >30. Patients slept on average 43% of the time in the supine position. In the supine position, they had an AHI of 28 ± 24 versus 8 ± 9 in the lateral position. Mallampati score and age were related to sleep apnea, while gender, body mass index, Epworth sleepiness scale, STOP-BANG and a history of snoring was not. Conclusions: Sleep apnea is prevalent among patients who undergo surgery for colorectal cancer. Age, sleeping in the supine position and a high tongue according to Mallampati score were risk factors for sleep apnea.