Applicability of Techniques of Lung Expansion

Study Overview
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Brief Summary
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The survival of patients with lesions in the central nervous system is usually accompanied by physical and mental sequelae. These impairments favor the prolonged restriction to the bed, which may contribute with changes in respiratory function. In this context, lung re-expansion techniques are used to prevent or treat the various respiratory complications.

Detailed Description
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The survival of patients with lesions in the Central Nervous System is usually accompanied by physical and mental permanents sequelae. This impairment of cognitive status associated with motor injury favors prolonged restriction of these patients to the bed, which may contribute to the emergence of other health damages. In the clinical practice, lung expansion techniques has been used as a prophylaxis and treatment of respiratory conditions that involve volumetric reductions. However, the deficit of awareness and cooperation difficult the use of several therapeutic resources. There are few interventions that could be proposed due to no need the collaboration to be performed, such as Breath Stacking technique (BS) and Expiratory Positive Airway Pressure (EPAP). The BS is characterized by execution of inspiratory cycles through a one way valve, which allows stacked volume of gas during each inspiration, until it reaches values approximate to maximum inspiratory capacity. While in the EPAP, alveolar pressure is elevated to breath against a expiratory flow resistance generated by a spring load valve. The effects on lung volume promoted BS and EPAP can be safely measured using an electrical impedance tomography (EIT). This recent imaging modality offers information about lung air volumes distribution and have a strong linear correlation with regional ventilation within the thorax. The effects on lung volume promoted BS and EPAP can be safely measured using an EIT monitor. This recent imaging modality offers information about lung air volumes distribution and have a strong linear correlation with regional ventilation within the thorax. Until this moment, there is not description about the effect of lung expansion techniques on regional lung parameters.

Official Title
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Immediate Effect of Expiratory Positive Airway Pressure and Breath Stacking in Non-cooperative Patients Detected by Electrical Impedance Tomography

Conditions
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Stroke

Intervention / Treatment
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* Other: EPAP
* Other: Breath Stacking


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Patients undergoing neurosurgery restricted to bed for more than 14 days; Aged between 18 and 65 years; Glasgow Coma Scale < 10 points; Breathing spontaneously through the tracheostomy tube; No respiratory infection; Chest circumference between 88 and 98 centimeters; Exclusion criteria: Presence of chronic lung diseases; Chest deformity; Rib fracture; Asymmetrical chest expansion; Abdomen distension; Spasticity in any hemisphere with Ashworth Scale score more than 2 points for upper limbs; Uncoordinated movements of the limbs; Cardiorespiratory instability (heart rate < 60 or > 120 bpm; respiratory rate > 35 ipm; mean arterial pressure < 60 mmHg or > 120 mmHg; oxygen saturation < 90%).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: EPAP Group<br>The EPAP devices increase the alveolar pressure. This effect is obtained through valves that generate a resistance to airflow during expiration. | Other: EPAP<br>* The EPAP will be applied with a Spring Load Valve Resistor (Vital Signs, Totowa, NJ, USA), adjusted with a pressure of 10 cmH2O. The Spring Load Valve Resistor will be connected to the expiratory branch of the T-tube. Duration of intervention: 5 minutes.<br>* Other names: Expiratory Positive Airway Pressure;|
| Experimental: Breath Stacking Group<br>The Breath Stacking consists on the implementation of subsequent inspiratory efforts through a one way valve, which allows stacked volume of gas during each inspiration, until it reaches a maximum lung volume. | Other: Breath Stacking<br>* The BS will be performed by a T-tube with a one-way inspiratory valve and the expiratory branch occluded. The expiratory occlusion is maintain until observed the presence of a plateau in the impedance plethysmogram by EIT, which corresponds to the absence of inspired air displacement or when a maximum time of 40 seconds was attained. Durantion of intervention:Three BS interventions will be performed at one minute intervals between them.<br>* Other names: Air Stacking;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regional Lung Aeration | Change in Regional Lung Aeration (difference between the End-Expiratory Lung Impedance before and post-intervention). Each image along the time represent the relative change in impedance distribution within the transverse section of the chest, from the first scan (before intervention) to current scan. The pixel values are express as percentage changes of local impedance. | Before and 1, 5, 10, 15, 30, 60, 90, 120 minutes post-intervention. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regional Lung Ventilation | Change in Regional Lung Ventilation (difference between end-inspiratory and end-expiratory lung impedance before and post-intervention). | Before and 1, 5, 10, 15, 30, 60, 90, 120 minutes post-intervention. | 
| Heart Rate | Change in Heart Rate (beats per minute). | Before and 1, 5, 10, 15, 30, 60, 90, 120 minutes post-intervention. | 
| Mean Arterial Pressure | Change in Mean Arterial Pressure (mmHg) | Before and 1, 5, 10, 15, 30, 60, 90, 120 minutes post-intervention. | 
| Respiratory Rate | Change in Respiratory Rate (breath per minute) | Before and 1, 5, 10, 15, 30, 60, 90, 120 minutes post-intervention. | 
| Periferic Saturation of Oxygen | Change in Periferic Saturation of Oxygen (fraction of oxygen-saturated hemoglobin relative to total hemoglobin). | Before and 1, 5, 10, 15, 30, 60, 90, 120 minutes post-intervention. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Noncooperative patients