Predictor of respiratory disturbances during gastric endoscopic submucosal dissection under deep sedation.

BACKGROUND: Sedation is commonly performed for the endoscopic submucosal dissection (ESD) of early gastric cancer. Severe hypoxemia occasionally occurs due to the respiratory depression during sedation. AIM: To establish predictive models for respiratory depression during sedation for ESD. METHODS: Thirty-five adult patients undergoing sedation using propofol and pentazocine for gastric ESDs participated in this prospective observational study. Preoperatively, a portable sleep monitor and STOP questionnaires, which are the established screening tools for sleep apnea syndrome, were utilized. Respiration during sedation was assessed by a standard polysomnography technique including the pulse oximeter, nasal pressure sensor, nasal thermistor sensor, and chest and abdominal respiratory motion sensors. The apnea-hypopnea index (AHI) was obtained using a preoperative portable sleep monitor and polysomnography during ESD. A predictive model for the AHI during sedation was developed using either the preoperative AHI or STOP questionnaire score. RESULTS: All ESDs were completed successfully and without complications. Seventeen patients (49%) had a preoperative AHI greater than 5/h. The intraoperative AHI was significantly greater than the preoperative AHI (12.8 ± 7.6 events/h vs 9.35 ± 11.0 events/h, P = 0.049). Among the potential predictive variables, age, body mass index, STOP questionnaire score, and preoperative AHI were significantly correlated with AHI during sedation. Multiple linear regression analysis determined either STOP questionnaire score or preoperative AHI as independent predictors for intraoperative AHI ≥ 30/h (area under the curve [AUC]: 0.707 and 0.833, respectively) and AHI between 15 and 30/h (AUC: 0.761 and 0.778, respectively). CONCLUSION: The cost-effective STOP questionnaire shows performance for predicting abnormal breathing during sedation for ESD that was equivalent to that of preoperative portable sleep monitoring.

Occurrence of Cortical Arousal at Recovery from Respiratory Disturbances during Deep Propofol Sedation.

Abstract: Recent evidences suggest that non-arousal mechanisms can restore and stabilize breathing in sleeping patients with obstructive sleep apnea. This possibility can be examined under deep sedation which increases the cortical arousal threshold. We examined incidences of cortical arousal at termination of apneas and hypopneas in elderly patients receiving propofol sedation which increases the cortical arousal threshold. Ten elderly patients undergoing advanced endoscopic procedures under propofol-sedation were recruited. Standard polysomnographic measurements were performed to assess nature of breathing, consciousness, and occurrence of arousal at recovery from apneas and hypopneas. A total of 245 periodic apneas and hypopneas were identified during propofol-induced sleep state. Cortical arousal only occurred in 55 apneas and hypopneas (22.5%), and apneas and hypopneas without arousal and desaturation were most commonly observed (65.7%) regardless of the types of disordered breathing. Chi-square test indicated that incidence of no cortical arousal was significantly associated with occurrence of no desaturation. Higher dose of propofol was associated with a higher apnea hypopnea index (r = 0.673, p = 0.033). In conclusion, even under deep propofol sedation, apneas and hypopneas can be terminated without cortical arousal. However, extensive suppression of the arousal threshold can lead to critical hypoxemia suggesting careful respiratory monitoring.

Polysomnographic assessment of respiratory disturbance during deep propofol sedation for endoscopic submucosal dissection of gastric tumors.

AIM: To investigate that polysomnographic monitoring can accurately evaluate respiratory disturbance incidence during sedation for gastrointestinal endoscopy compare to pulse oximetry alone. METHODS: This prospective observational study included 10 elderly patients with early gastric cancer undergoing endoscopic submucosal dissection (ESD) under propofol sedation. Apart from routine cardiorespiratory monitoring, polysomnography measurements were acquired. The primary hypothesis was tested by comparing the apnea hypopnea index (AHI), defined as the number of apnea and hypopnea instances per hour during sedation, with and without hypoxemia; hypoxemia was defined as the reduction in oxygen saturation by ≥ 3% from baseline. RESULTS: Polysomnography (PSG) detected 207 respiratory disturbances in the 10 patients. PSG yielded a significantly greater AHI (10.44 ± 5.68/h) compared with pulse oximetry (1.54 ± 1.81/h, P < 0.001), thus supporting our hypothesis. Obstructive AHI (9.26 ± 5.44/h) was significantly greater than central AHI (1.19 ± 0.90/h, P < 0.001). Compared with pulse oximetry, PSG detected the 25 instances of respiratory disturbances with hypoxemia 107.4 s earlier on average. CONCLUSION: Compared with pulse oximetry, PSG can better detect respiratory irregularities and thus provide superior AHI values, leading to avoidance of fatal respiratory complications during ESD under propofol-induced sedation.

Obstructive Sleep Apnea in a Severely Obese Child With Combined Central Sleep Apnea and Sleep-Related Hypoventilation Disorder Caused by a Medullary Tumor.

ABSTRACT: A medullary tumor is a relatively rare disease that causes severe and complicated respiratory disorders, including sleep-related breathing disorders, due to dysregulation of respiratory control. A severely obese 12-year-old male was admitted to our hospital for worsening dyspnea and received a diagnosis of type II respiratory failure. Although obstructive sleep apnea (OSA) and/or obesity hypoventilation syndrome were suspected, a polysomnogram obtained during a nap (nap study) revealed central sleep apnea (CSA) and sleep-related hypoventilation disorder (SRHD) in addition to OSA. Brain magnetic resonance imaging showed a mass in the medulla oblongata. The patient received a diagnosis of CSA/SRHD caused by a medullary tumor, and with OSA. A partial brainstem tumor resection was performed. Noninvasive positive airway pressure therapy was initiated, and was continued after surgery. However, the patient died unexpectedly, 20 months after surgery. When children with sleep problems caused by OSA present with atypical symptoms of OSA, a neurological examination and polysomnography should be conducted to detect CSA and SRHD.

The accuracy and uncertainty of a sheet-type portable monitor as a screening device to identify obstructive sleep apnea-hypopnea syndrome.

OBJECTIVE: Laboratory-based polysomnography (PSG) is the gold standard for diagnosing obstructive sleep apnea-hypopnea syndrome (OSAHS), but it is expensive and requires overnight hospitalization. Recently, a sheet-shaped breath detection monitor, the SD-101, has been developed, and several reports have so far demonstrated the screening accuracy of this device. The aim of this study was to assess the accuracy and the uncertainty of this device. METHODS: A total of 101 suspected OSAHS patients underwent simultaneous examinations with PSG and the SD-101. RESULTS: There was a statistically significant relationship between the respiratory disturbance index (RDI) by the SD-101 and the apnea-hypopnea index (AHI) by PSG. At an RDI cutoff of 14 episodes per hour, the sensitivity and specificity to detect an AHI ≥20 episodes per hour were 90.2% and 90.0%, respectively. To reduce the influence of sleep efficiency, the time in bed (TIB) obtained from PSG, instead of the total seep time (TST), was used to calculate the AHI from the PSG data. There was also a statistically significant relationship between the RDI and AHI for the TIB. Moreover, it was suggested that arousal index and TIB were likely associated with false-negative and/or false-positive results. CONCLUSION: Although the present study demonstrated a close relationship between the RDI and the AHI, use of the SD-101 to examine symptomatic OSAHS patients should be performed with a full understanding of its incapability to detect the sleep state, including arousal reaction and the existence of false respiratory events caused by body movements.