Incidence of Sleep-disordered Breathing and Upper Airway Collapsibility in Postpartum Patients and Its Intervention

Study Overview
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Brief Summary
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The investigators hypothesized that sleeping in a 45 degrees elevated body position decreases the likelihood of upper airway vulnerability to collapse early after delivery. Furthermore, the investigators want to elucidate the anatomical and physiological risk factors that contribute in the upper airway obstruction in post-partum patients.

Detailed Description
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After obtaining study consent, each patient underwent measurements of upper airway cross-sectional area (CSA) during daytime within 48 h after delivery. The minimum upper airway CSA was measured using acoustic pharyngometry (Eccovision Acoustic Pharyngometry; Sleep Group Solutions, Inc) in sitting, 45° elevated, and nonelevated upper body position. This method has been previously used and validated in pregnant women. In the patients who further gave consent for the sleep study, polysomnography (PSG) was performed throughout the entire study night. Within a crossover design, patients were randomly assigned to receive first either nonelevated or 45° elevated upper body position. Position was changed after 3.5 h by a member of the team.

Official Title
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Incidence of Sleep-disordered Breathing and Upper Airway Collapsibility in Postpartum Patients and Its Intervention

Conditions
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Sleep Disordered Breathing, Upper Airway Collapsibility, Upper Airway Obstruction

Intervention / Treatment
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* Procedure: elevated body position
* Procedure: supine body position


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Postpartum mothers within 48 hours of delivery in a major academic teaching hospital. Age over 18 years. Admitted to the Massachusetts General Hospital OB service for the delivery. Interventions will be randomly assigned to the patients enrolled in this study Exclusion Criteria: Age under 18 years. History of pre-existing pulmonary and cardiac diseases, including bronchial asthma, cystic fibrosis, chronic obstructive lung disease, neck and chest tumors (thyroid, mediastinal, etc.), irradiation to the neck and/or chest, and congenital airway deformities, other critically-ill conditions.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Elevated body position<br>We collect data about the apnea- hypopnea index, obstructive and central apneas, as well as oxygen, by comparing supine to 45 degrees elevated body position. | Procedure: elevated body position<br>* 45 degrees elevated upper body position<br>|
| Active Comparator: supine body position<br>We collect data about the apnea- hypopnea index, obstructive and central apneas, as well as oxygen, by comparing supine to 45 degrees elevated body position. | Procedure: supine body position<br>* non-elevated upper body position<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Apnea-hypopnea Index (AHI), Defined as the Number of Apneas and Hypopneas Per Hour of Sleep | We conduct polysomnography in non-elevated and 45 degrees elevated body position, to show the effect of body position in context of sleep disordered breathing.We collect data of the apnea-hypopnea-index, central apneas, obstructive apneas and oxygen. | 48 hours after delivery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Minimum Upper Airway Cross-sectional Area: to Elucidate the Anatomical and Physiological Risk Factors That Contribute to the Upper Airway Obstruction in Post-partum Patients | Each patient underwent measurements of upper airway CSA during daytime within 48 h after delivery. The minimum upper airway CSA was measured using acoustic pharyngometry (Eccovision Acoustic Pharyngometry; Sleep Group Solutions, Inc) in sitting, 45° elevated, and nonelevated upper body position. | 48 hours after delivery |