View clinical trials related to Periodic Breathing.
Filter by:This is a prospective crossover study to compare the within-subject effect of the two target ranges of arterial oxygen saturation (SpO2), both within the clinically recommended range of 90- 95%. The specific objective of this study to evaluate the impact of targeting SpO2 within 93-95% compared to the 90-92% range on ventilatory stability in premature infants of 23-29 weeks gestational age (GA).
Central sleep apnoea (CSA) is common in patients with chronic systolic heart failure (HFrEF). Various trials have shown a prevalence of 21 - 37% in this group of people. Up to 66% of patients with CSA and HFrEF present with periodic breathing (PB), which is considered being a marker of HF severity and poor prognosis. Brack et al. summarized data from cohorts, longitudinal studies and retrospective analyses showing an independently increased risk of death in HF patients with PB (HR 2.1-5.7 in five of seven studies). Furthermore, PB in HF patients is known to reduce quality of life and exercise performance and to increase sympathetic nerve activity as well as the probability of malignant cardiac arrhythmias. The pathogenesis of PB is characterized by an instability of ventilatory drive. The level of carbon dioxide (CO2) in blood and cerebrospinal fluid correlates linearly with minute ventilation. A high level of CO2 increases ventilation while hypocapnia dampens it. This control theory is based on the loop gain (LG), which represents the sensitivity and reactivity of the ventilatory system and comprises three components: The plant gain defines the capacity of the system to change PaCO2 in response to a change in ventilation (metabolic response). It is influenced by the lung volume as well as the anatomy of the thorax and the upper airways. The feedback gain is defined by the chemoreceptor responsiveness in reaction to blood gas changes. The controller gain is represented by the respiratory control center in the brain stem and defines the capacity of the system to change ventilation in response to a change in PaCO2 (ventilatory response). Sands et al. proposed and validated a mathematical model based on the ventilatory cycle pattern that quantifies the feedback loop. The ratio of ventilatory and cycle duration within the PB pattern is defined as the duty ratio (DR), which is the basis to calculate the LG. Any temporary breathing disturbance causing a PB pattern with a LG < 1 stabilizes within a few breathing cycles. A LG > 1 represents an unstable ventilatory response and slight changes of CO2 are accompanied by overshooting and undershooting of the ventilation. In that case, the polysomnography shows the typical pattern of waxing and waning of the tidal volume and effort. HF patients typically present with an increased LG due to an impaired left ventricular function and a hyperstimulation of pulmonary vagal receptors. Furthermore, Khoo showed an increased chemosensitivity (controller gain) as well as a decreased ventilatory capacity (plant gain) in this group of people. Sands and colleagues characterized PB considering the mean LG derived from several ventilatory cycles during non-REM sleep. This retrospective study of PB in HFrEF patients addresses the following questions: 1. Is a single LG value appropriate to characterize the individual PB? 2. Does the LG depend on sleep stage and body position? 3. Does the intraindividual LG variability allow for the discrimination of different PB phenotypes and, if so, do these phenotypes differ in further characteristics?
This study will determine if modified adaptive servoventilation (ASV) is as effective as the conventional ASV in treating periodic breathing. The study will determine if the modified ASV reacts appropriately to reduce apneas and hypopneas and provides suitable levels of positive airway pressure compared to conventional ASV.
The purpose of this study is to determine the chronic safety and efficacy of phrenic nerve stimulation on central sleep apnea (CSA). Clinically, CSA events translate into sleep fragmentation, excessive daytime sleepiness, reduced exercise capacity, and possibly ventricular arrhythmias. The study is chronic in nature, such that subjects will undergo the implantation of an implantable pulse generator and stimulation lead. A sensing lead may also be placed during the initial implant procedure. Subjects will be followed for up to six-months on therapy to assess respiratory and heart failure outcomes. Following the six-month therapy visit, subjects will enter into a long-term follow-up phase until the completion of the study. It is anticipated that data obtained in this study will show that the proposed intervention can modify respiration with a low incidence of adverse effects. The results of this trial are intended to be used to develop a subsequent protocol for pivotal study.
We aim to test our method for measuring chemosensitivity (the ventilatory response to a change in carbon dioxide), which uses sinusoidal carbon dioxide stimuli. Hypotheses: - Carbon dioxide sensitivity is dependent on the cycle time over which we administer the gas (frequency). - Chemoreflex gain decreases as deadspace increases.
To evaluate whether cardiac output manipulation via a cardiac pacemaker can stabilise ventilation.
The objective of this study is to compare the modified adaptive servoventilation control algorithm of the with the standardised algorithms of routinely-used servoventilation processes (AutoSet CS2) in terms of the effect on obstructive and central events. The aim is to normalise breathing during sleep and hence eliminate the sleep-related breathing disorder, resulting in even more effective treatment of nocturnal breathing disorders in patients with cardiovascular diseases and sleep apnoea, to ensure optimum therapy success.