An observational study in Apnea (Central and Obstructive), sponsored by Nanjing Medical University. Completed at 1 site in China. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2019-02-12.
Sponsored by Nanjing Medical University · Observational
Fluid retention in the legs due to chronic heart failure (CHF) during the daytime may redistribute to neck when with supine positioning at night. A portion of the shifted fluid accumulates in the neck, and narrows the upper airway, predisposing the patient to obstructive sleep apnea (OSA) and central sleep apnea (CSA). However, the mechanism of overnight fluid shift on OSA and CSA remains unclear. The investigators pre-experiment demonstrated there may be a different mechanism of overnight fluid shift on OSA and CSA. The accumulation of water content in neck soft tissue increases neck circumference and leads to pharyngeal resistance, upper airway collapse and causes OSA. The effect of nocturnal fluid shift on CSA may be because of increasing of chemosensitivity (fluctuation of PaCO2), circulation delay and hemodynamic disordered. This study is aimed to explore the different mechanism of overnight fluid shift on OSA and CSA by comparing the changes of upper airway (inside diameter, water content, and pharyngeal resistance), PaCO2, circulation delay (lung-to-finger circulation time) and hemodynamic (loop gain).
Methods:
Between June 2015 and December 2017, 180 patients with chronic heart failure caused by rheumatic heart disease, cardiomyopathy and coronary heart disease (in Cardiology Department and Cardiothoracic Surgery Department of the First Affiliated Hospital of Nanjing Medical University), were screened for sleep apnea by polysomnography (PSG). Of them, 20 obstructive sleep apnea (OSA) and 20 central sleep apnea (CSA) were enrolled. Clinical evaluations including NYHA class, electrocardiographic, echocardiographic, arterial blood gas analysis findings, baseline medication, and 6-minute walk test (6MWT) were recorded.
The fluid index, head and neck CT and pharyngeal resistance were tested at 20:00. Then a full night PSG and percutaneous PaCO2 were performed. The fluid index, head and neck CT and pharyngeal resistance were repeated at 6:00 after PSG.
The volume of fluid shift from legs to head and neck,inside diameter of the upper airway, and water content of neck soft tissue were calculated. The lung-to-finger circulation time and loop gain were measured.
Mechanism of overnight fluid shift on OSA:
Fluid shift volume from legs to head and neck,inside diameter of upper airway, water content of neck soft tissue, percutaneous PaCO2, severity of sleep apnea, minimum SP02, lung-to-finger calculation time and loop gain were measured at 22:00 and repeated at 6:00 next morning in patients with OSA.Correlations between changes of fluid shift volume and changes in diameter of upper airway, water content of neck soft tissue, PaCO2, minimum SP02, lung-to-finger calculation time and loop gain were analyzed.
Fluid shift volume from legs to head and neck,inside diameter of upper airway, water content of neck soft tissue, percutaneous PaCO2, severity of sleep apnea, minimum SP02, lung-to-finger calculation time and loop gain were measured at 22:00 and repeated at 6:00 next morning in patients with CSA.Correlations between changes of fluid shift volume and changes in diameter of upper airway, water content of neck soft tissue, PaCO2, minimum SP02, lung-to-finger calculation time and loop gain were analyzed.
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This study's enrollment of 36 is below the median of 106 across 386 observational studies indexed under Apnea.
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patients with chronic heart failure caused by rheumatic heart disease, cardiomyopathy and coronary heart disease.
Exclusion Criteria:
Of the 180 heart failure patients,20 OSA were enrolled. Clinical evaluations including NYHA class, electrocardiographic, echocardiographic, arterial blood gas analysis findings, baseline medication, and 6-minute walk test (6MWT) were recorded. The fluid index, head and neck CT and pharyngeal resistance were tested at 20:00. Then a full night PSG and percutaneous PaCO2 were performed. The fluid index, head and neck CT and pharyngeal resistance were repeated at 6:00 after PSG. The volume of fluid shift from legs to head and neck,inside diameter of the upper airway, and water content of neck soft tissue were calculated. The lung-to-finger circulation time and loop gain were measured.
Other: no interventions
Of the 180 heart failure patients,20 CSA were enrolled. Clinical evaluations including NYHA class, electrocardiographic, echocardiographic, arterial blood gas analysis findings, baseline medication, and 6-minute walk test (6MWT) were recorded. The fluid index, head and neck CT and pharyngeal resistance were tested at 20:00. Then a full night PSG and percutaneous PaCO2 were performed. The fluid index, head and neck CT and pharyngeal resistance were repeated at 6:00 after PSG. The volume of fluid shift from legs to head and neck,inside diameter of the upper airway, and water content of neck soft tissue were calculated. The lung-to-finger circulation time and loop gain were measured.
Other: no interventions
This is an observational study and no intervention applied.
nocturnal fluid shift, as determined by change in leg fluid volume
Nocturnal fluid shift was measured for 40 enrolled participants.
Time frame: up to 24 months
pharyngeal resistance,as the change from baseline in pharyngeal air-flow resistance
Pharyngeal resistance was measured for 40 enrolled participants.
Time frame: up to 24 months
Lung to Finger Circulation Time
Lung to Finger Circulation Time was measured for 40 enrolled participants.
Time frame: up to 24 months
Loop Gain
Loop Gain was measured for 40 enrolled participants
Time frame: up to 24 months
apnea-hypopnea index, as the severity of sleep apnea.
Apnea-hypopnea index was measured for 40 enrolled participants.
Time frame: up to 24 months
This study is completed, as verified in Feb 2019. You cannot join it, but the record below documents what was studied.
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Nanjing Medical University