Dysfunctional breathing treated with continuous positive airway pressure in newly diagnosed obstructive sleep apnoea: a prospective cohort study

A prospective cohort study investigating patients with obstructive sleep apnoea (OSA) was conducted to determine the prevalence of dysfunctional breathing and if continuous positive airway pressure (CPAP) therapy improves associated symptoms. Almost half of newly diagnosed patients with OSA had dysfunctional breathing and CPAP was not an effective treatment. Dysfunctional breathing is common in patients with OSA.     

The lowest VE/VCO2 ratio best identifies chronic thromboembolic pulmonary hypertension

Introduction

The natural history of acute pulmonary embolism (PE) under treatment is about a gradual resolution of the thrombi, and uncommonly, the development of chronic thromboembolic pulmonary hypertension (CTEPH). We hypothesized that ventilatory efficiency parameters during cardiopulmonary exercise testing (CPET) may be able to monitor the process and predict CTEPH.

Methods

15 patients rehabilitated from acute PE (total resolution of thrombi), 44 patients with chronic PE (with residual thrombi), 66 patients with CTEPH, and 36 sedentary healthy controls performed incremental CPET.

Results

The lowest VE/VCO₂ was higher in CTEPH patients than that in chronic PE and rehabilitated patients (43.4 L/min vs 29.9 L/min vs 27.1 L/min, p < 0.005). The VE/VCO₂ slope (48.4 L/min/L/min vs 29.9 L/min/L/min vs 28.0 L/min/L/min, p < 0.005) and oxygen uptake efficiency plateau (OUEP) (37.1 L/min vs 27.0 L/min vs 25.2 L/min, p < 0.005) had the similar changes. In logistic regression analysis, the lowest VE/VCO₂ ≥ 34.35 L/min was the best predictor of CTEPH (OR 159.0, 95% CI 36.0-702.3, p < 0.001). The lowest VE/VCO₂ was higher in chronic PE patients compared with the controls (29.9 L/min vs 26.5 L/min, p < 0.05), but there was no difference between the rehabilitated patients and the controls. In multiple linear regression analysis, the percentage of vascular obstruction by ventilation-perfusion lung scanning (PVO) was the most significant independent predictor for indices of ventilatory efficiency in chronic PE and rehabilitated patients.

Conclusions

CTEPH is associated with weakened ventilatory efficiency. The lowest VE/VCO2 ratio has the best capability to predict CTEPH. Ventilatory inefficiency improves along with recovery of acute PE.     

The neuroscience of human relationships: Attachment and the developing social brain

This article explores the background of Elsa Gindler, in the early part of the twentieth century in Berlin, and whom she influenced in the 1930s and later, both in body psychotherapy and in other disciplines. It particularly explores the connection with Wilhelm Reich and Gindler's indirect influence on the development of his Vegetotherapy.     

Sleep-disordered breathing and oxidative stress in preclinical chronic mountain sickness (excessive erythrocytosis)

Chronic mountain sickness (CMS) is considered to be a loss of ventilatory acclimatization to high altitude (>2500 m) resulting in marked arterial hypoxemia and polycythemia. This case–control study explores the possibility that sleep-disordered breathing (SDB) and associated oxidative stress contribute to the etiology of CMS. Nocturnal respiratory and Sa_O2${\text{Sa}}_{{\text{O}}_2}$ patterns were measured using standard polysomnography techniques and compared between male high-altitude residents (aged 18–25) with preclinical CMS (excessive erythrocytosis (EE), n = 20) and controls (n = 19). Measures of oxidative stress and antioxidant status included isoprostanes (8-iso-PGF2_alpha), superoxide dismutase and ascorbic acid. EE cases had a greater apnea–hypopnea index, a higher frequency of apneas (central and obstructive) and hypopneas during REM sleep, and lower nocturnal Sa_O2${\text{Sa}}_{{\text{O}}_2}$ compared to controls. 8-iso-PGF2_alpha was greater in EE than controls, negatively associated with nocturnal Sa_O2${\text{Sa}}_{{\text{O}}_2}$, and positively associated with hemoglobin concentration. Mild sleep-disordered breathing and oxidative stress are evident in preclinical CMS, suggesting that the resolution of nocturnal hypoxemia or antioxidant treatment may prevent disease progression.     

Chronic hyperoxia and the development of the carotid body

Preterm infants often experience hyperoxia while receiving supplemental oxygen. Prolonged exposure to hyperoxia during development is associated with pathologies such as bronchopulmonary dysplasia and retinopathy of prematurity. Over the last 25 years, however, experiments with animal models have revealed that moderate exposures to hyperoxia (e.g., 30–60% O₂ for days to weeks) can also have profound effects on the developing respiratory control system that may lead to hypoventilation and diminished responses to acute hypoxia. This plasticity, which is generally inducible only during critical periods of development, has a complex time course that includes both transient and permanent respiratory deficits. Although the molecular mechanisms of hyperoxia-induced plasticity are only beginning to be elucidated, it is clear that many of the respiratory effects are linked to abnormal morphological and functional development of the carotid body, the principal site of arterial O₂ chemoreception for respiratory control. Specifically, developmental hyperoxia reduces carotid body size, decreases the number of chemoafferent neurons, and (at least transiently) diminishes the O₂ sensitivity of individual carotid body glomus cells. Recent evidence suggests that hyperoxia may also directly or indirectly impact development of the central neural control of breathing. Collectively, these findings emphasize the vulnerability of the developing respiratory control system to environmental perturbations.     

BiPAP无创呼吸机治疗治疗慢阻肺合并Ⅱ型呼吸衰竭临床观察

目的 探讨慢性阻塞性肺疾病合并Ⅱ型呼吸衰竭患者使用BiPAP呼吸机通气的疗效.方法 将42例患者随机分为两组,在相同的常规治疗下,治疗组22例加用BiPAP呼吸机通气治疗,对照组20例加用呼吸兴奋剂治疗,观察治疗前后两组血气分析结果的pH值、PaCO2及PaO2的变化.结果 治疗组与对照组治疗后pH值,PO2,PCO2比较均有显著性差异(P＜0.05),疗效明显优于对照组.结论 BiPAP呼吸机无创正压通气治疗能显著降低COPD合并Ⅱ型呼吸衰竭患者的二氧化碳分压,改善缺氧,疗效确切.     

OSAHS患者咽部解剖与呼吸驱动的关系研究

目的 探讨OSAHS患者咽腔形态与呼吸驱动(p0.1)的关系.方法 随机选取OSAHS患者35例,进行仰卧位睡眠状态下呼吸驱动测定及螺旋CT扫描,针对轻度(AHI ＜20)、中重度(AHI＞ 20)两组患者进行研究.结果 睡眠状态下,①中重度组软腭长度,软腭厚度,颏舌肌宽度及舌体面积明显增加(P＜0.05),软腭后区最小气道面积明显减小(P＜0.05);②中重度组P0.1的下降更为明显(P＜0.05).③中重度组颏舌肌宽度与P0.1有明显负相关性(r=-0.574,P＜0.05).结论 睡眠状态下,咽腔狭窄程度与OSAHS病情相关,随着OSAHS患者病情加重,颏舌肌的代偿作用增加,当代偿到一定程度时出现呼吸驱动的降低.     

改良运动处方对慢性阻塞性肺疾病稳定期患者的康复疗效

目的 以联合缩唇-腹式呼吸法和六字诀训练为改良的运动处方,探讨其对慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)稳定期患者的康复疗效.方法 将100例患者随机分为四组:对照组、缩唇-腹式呼吸组、六字诀组、运动处方组,每组25例,各组分别于锻炼前和坚持锻炼半年后测定肺功能、6分钟步行距离(6MWD)和动脉血气分析.结果 运动处方组较对照组、缩唇-腹式呼吸组、六字诀组的肺功能指标FEV1、FEV1占预计值百分比和6MWD及血气分析等有明显改善,差异有统计学意义.结论 改良运动处方能有效改善COPD稳定期患者的肺功能、提高运动耐力、提高动脉血氧分压(PaO2)及降低动脉二氧化碳分压(PaCO2),且在改善肺功能、提高运动耐力及降低PaCO2等方面的疗效明显优于单独的缩唇-腹式呼吸操和六字诀训练.