Digital recording and analysis of esophageal pressure for patients with obstructive sleep apnea–hypopnea syndrome

Abstract

To evaluate sleep-related obstructive breathing events in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS), we developed a technique for digital recording and analysis of esophageal pressure (Pes) and elucidated the Pes parameters. Pes was recorded overnight with a microtip-type pressure transducer in 74 patients with OSAHS. Simultaneously, in all patients digital polysomnography was recorded. The mean nadir end-apneic Pes swing (Pes Nadir) ranged from -20.2 to -147.4 cmH(2)O, with a mean of -53.6+/-2.9 cmH(2)O. Correlation of the mean Pes Nadir indicated a linear relationship with the mean ratio of maximal Pes swing to apnea duration (r(2)=0.70) and the mean area of the Pes (Pes Area) (r(2)=0.82). Significant correlations were noted between the mean Pes Nadir and apnea-hypopnea index (AHI, ranging from 7.9 to 109.5 per hour; r(2)=0.66), minimum SpO(2) (r(2)=0.60), oxygen desaturation index (ODI) of more than 3 (r(2)=0.65), arousal index (r(2)=0.54), and between the mean Pes Area and AHI (r(2)=0.63), minimum percutaneous arterial oxygen saturation (SpO(2); r(2)=0.57), ODI (r(2)=0.69), and arousal index (r(2)=0.41). Pes parameters were found to be significant in the evaluation of the severity of the respiratory effort during the sleep-related obstructive breathing events for patients with OSAHS.

Loop Gain Predicts the Response to Upper Airway Surgery in Patients With Obstructive Sleep Apnea

“…In contrast to our LG findings, this may suggest that an elevated arousal threshold is an acquired feature of OSA. This is further supported by our finding that the arousal threshold remained higher in nonresponders post surgery and previous studies showing that (1) the severity of OSA has been strongly linked to the arousal threshold 19,[27][28][29] and (2) the arousal threshold increases following discontinuation of CPAP 30 and decreases immediately following institution of CPAP therapy, 31 a trend which continues up until at least 3 months. …”

Clinical Predictors of the Respiratory Arousal Threshold in Patients with Obstructive Sleep Apnea

“…Our work has the major advantage over previous investigations in that we included patients with a wide spectrum of OSA severity. Previous studies in predominantly severe patients with OSA have reported modest univariate correlations between the non-REM ArTH and the AHI (13,14,20) and other markers of OSA severity including the minimum Sp O 2 and ArI (13) and the ESS (21). Taken together, these findings suggest that the ArTH is strongly related to severity of disease, which is consistent with our physiologic understanding.…”

“…Instead, invasive procedures, such as an epiglottic or an esophageal pressure catheter, are required. Previous studies suggest that a high ArTH is associated with more severe OSA (higher apnea-hypopnea index [AHI]), lower nadir oxygen saturation, and a higher arousal index (ArI) (13,14). A major limitation of many of these studies, however, is that they either involved a small number of participants or were conducted in patients with homogenous disease severity (predominately severe OSA).…”

The impact of obstructive sleep apnoea on the aorta

“…In humans, the negative end-apnoeic pressures were quantified in one in vivo study (n=74), with a mean±SD of −53.6±2.9 cmH 2 O and peak pressure of −147.4 cmH 2 O [73]. Compared with physiological inspiration pressure of around −5 to −8 cmH 2 O in healthy subjects [74] or nocturnal systolic blood pressure of around 160 cmH 2 O (equal to 120 mmHg, which is considered the upper limit for normal nocturnal blood pressure [75]), apnoeic episodes in OSA can involve a substantial amount of energy.…”