End-tidal carbon dioxide concentration monitoring in obstructive sleep apnea patients.

PURPOSE: The objective of this study was to investigate the end-tidal carbon dioxide concentration (ETco(2)) monitoring in obstructive sleep apnea (OSA) patients during sleep and to explore whether the ETco(2) value may explain a significant portion of the relationship between ETco(2) value and apnea/hypopnea index (AHI) and nocturnal oxygenation indices. MATERIALS AND METHODS: Thirty-eight consecutive patients underwent overnight polysomnography and were synchronously monitored for ETco(2) using an microstream capnometer. Mean and maximum values during wake time and different sleep stages were recorded. We grouped 38 OSA patients into 2 subgroups on the basis of their difference of mean total sleep time and wake time ETco(2) [(T - W) ETco(2)]; one group, 20 patients with (T - W) ETco(2) less than 0, and the other group,18 patients with (T - W) ETco(2) greater than 0. RESULTS: Group with (T - W) ETco(2) less than 0 patients exhibited higher AHI (mean ± SD, 68.58 ± 22.78 vs. 27.61 ± 19.44 events/h) and lower nocturnal oxygenation indices (minimum Sao(2), 67.85 ± 10.08 vs. 82.61% ± 6.07%; mean Sao(2), 91.29 ± 3.31 vs. 95.15% ± 1.88%) compared with the other group. CONCLUSIONS: In summary, the study provides preliminary data showing that ETco(2) potentially can be used in continuous monitoring of OSA patients. And, (T - W) ETco(2) can indicate the severity of OSA.

Relationship of body position, upper airway morphology, and severity of obstructive sleep apnea/hypopnea syndrome among Chinese patients.

CONCLUSIONS: This study has shown that the body mass index (BMI), neck circumference, and modified Mallanpati grade (MMP) are predictive of severity of obstructive sleep apnea/hypopnea syndrome (OSAHS). The neck circumference and MMP were revealed to be important morphological features in the responders whose apnea/hyoponea index (AHI) was substantially decreased by positioning during sleep. OBJECTIVE: The aim of this study was to assess the predictive power of routine physical examination of the upper airway by an otorhinolaryngologist to identify OSAHS in Chinese patients, and to clarify the interaction of lateral and supine sleeping positions with upper airway morphology in patients with OSAHS. METHODS: In all, 103 consecutive patients with OSAHS (48 men and 65 women) underwent polysomnography and upper airway morphological examination. Upper airway morphology and anthropometric variables were evaluated to determine different severity of OSAHS in the responders and nonresponders. RESULTS: The neck circumference, BMI, and MMP showed statistical correlations with AHI and decreased AHI for changed sleeping position. Multiple logistic regression analysis showed that the neck circumference and MMP were significant predictors for the responders (p = 0.023, odds ratio = 1.180 and p = 0.006, odds ratio = 1.922, respectively).

Characteristics in the secretion of liver TNF-? induced by infusion of LPS into veins in goats / 中国病理生理杂志

AIM: To study the role of liver in immune regulation in experimental endotoxemia. METHODS: 17 castrated male goats were subjected to simultaneously installing catheters in jugular, hepatic and portal veins by surgery. Four days later, lipopolysaccharide (LPS) was infused in term of three groups as followings: In group ①, LPS of 20 EU (endotoxin unit, EU)?kg -1 was infused into portal vein; In group ②, LPS of 20 EU?kg -1 was infused into jugular vein and LPS of 1 500 EU?kg -1 infused into jugular vein in group ③. Before and after infusion, blood samples were collected from the three veins through the catheters for 8 h. The plasma levels of TNF-? were measured by RIA. RESULTS: In group ①, the plasma TNF-? levels of hepatic and portal vein rose to peak value at 5 h, but that of the jugular vein did not changed. In group ②, the plasma TNF-? levels in hepatic vein rose to peak value at 3 h. The TNF-? levels of jugular vein rose to peak value at 1 h and the one in portal vein enhanced continuously between 0-8 h. In group ③, the plasma TNF-? levels in jugular, hepatic and portal vein rose to significant peaks at 1 h simultaneously. CONCLUSION: During experimental endotoxemia,liver showed different dynamic characteristics in TNF-? secretion according to the pathway and doses of LPS delivery. [