CPAP therapy prevents increase in blood pressure after upper airway surgery for obstructive sleep apnoea.

OBJECTIVE: The aim of this study was to investigate the efficacy of continuous positive airway pressure (CPAP) therapy following uvulopalatopharyngoplasty (UPPP) to prevent blood pressure (BP) elevation during sleep. METHODS: Sixteen normotensive patients with OSA were subjected to UPPP with or without septoplasty. These patients were instrumented for 24 h of ambulatory BP recording, polysomnography, nocturnal urinary catecholamine and pain evaluation using a visual analogue scale in the day prior to surgery (D-1), following the surgery (D+1) and 30 days later (D+30). For the D+1, the patients were divided into two groups: the without CPAP therapy group and the with CPAP therapy group. RESULTS: The apnoea-hypopnoea index (AHI) significantly increased in the patients without CPAP therapy compared with the D-1 (74 ± 23 vs. 35 ± 6 times/h, p < 0.05), and in the CPAP group, there was a significant reduction in the average AHI value to 14 ± 6 times/h, p < 0.01. During D+1, we observed an increase in the nocturnal systolic BP (10 %), diastolic BP (12 %) and heart rate (14 %) in the group without CPAP. These metrics were re-established in the CPAP group to values that were similar to those that were observed on the D-1. The absence of nocturnal dipping in the group without CPAP was followed by a significant increase in nocturnal norepinephrine (42 ± 12 µg/l/12 h) and epinephrine (8 ± 2 µg/l/12 h) levels compared with the D-1 (norepinephrine 17 ± 3; epinephrine 2 ± 0.3 µg/l/12 h, p < 0.001). In the patients who used the CPAP treatment, the nocturnal catecholamine levels were similar to D-1. The effectiveness of intravenous analgesic therapy was verified by a significant decrease in the pain scores in patients both with and without CPAP therapy. CONCLUSION: These data confirm an increase in the AHI on the night following UPPP with or without septoplasty. This increase promotes an absence of nocturnal dipping and a significant increase in urinary catecholamine levels. CPAP therapy was effective to prevent the transitory increase in BP.