Lung Ventilation During Cardiopulmonary Resuscitation

Study Overview
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Brief Summary
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The authors to measure passive tidal volumes generated during external chest compressions in order to determine whether chest compressions alone without any mechanical ventilatory support in cardiopulmonary resuscitation can provide adequate ventilation. The authors will study 25 volunteers who meet the following inclusion criteria: age 18-55 years, ASA I-II, candidates for surgical operation, who will receive general anesthesia. Patients who will be operated in the chest, who present musculoskeletal diseases, cardiopulmonary or vascular acute or chronic diseases, who had history of pneumothorax, of thromboembolism, osteoporosis, menopause, history of current rib or sternal or clavicle fractures, will be excluded. All eligible patients will enter the study and will receive general anesthesia and intubation according to treating doctors' decision. Patients will be ventilated mechanically for 5 minutes to establish stable conditions. A pneumotachograph will be then connected to the ventilatory circuit so that respiratory efforts (volume, airway pressure and flow) can be continuously monitored at real time. An esophageal catheter will be then inserted to monitor esophageal pressures and to provide data for lung mechanics calculation. Following the above procedures and before any surgical procedure, chest compressions will be performed to the patient by a senior anesthesiologist according to ERC guidelines of 2010 for 30 seconds. Following chest compressions, patients will be evaluated for possible complications and after the establishment of stable conditions surgical procedures will follow. After the end of the surgical operation clinical and chest ultrasound evaluation will be performed. Written inform consent will be obtained by all patients before procedures.

Conditions
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Ventilation During Cardiopulmonary Resuscitation

Intervention / Treatment
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* Other: Cardiopulmonary resuscitation chest compressions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age 18-55 years ASA I-II candidates for surgical operation who will receive general anesthesia Exclusion Criteria: surgical operation in the chest musculoskeletal diseases cardiopulmonary or vascular acute or chronic diseases history of pneumothorax thromboembolism osteoporosis menopause history of current rib or sternal or clavicle fractures

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

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Patients<br>Cardiopulmonary resuscitation with measurement of tidal volume, airway pressure and flow by a pneumotachograph and airway, oesophageal pressure sensors | Other: Cardiopulmonary resuscitation chest compressions<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tidal volume during cardiopulmonary resuscitation | Tidal volume will be assessed by a pneumotachograph (Hans Rudolf USA) | 30 seconds | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Esophageal pressures during cardiopulmonary resuscitation | esophageal pressures will be assessed with an esophageal balloon-catheter that will be introduced via the nares while the patients is still awake and will be positioned at 40 cm from the nares. Correct positioning will be confirmed by the demonstration of negative pressure swings against an occluded airway. | 30 seconds | 
| Lung compliance before and at the end of cardiopulmonary resuscitation | Lung compliance will be assessed as the ratio of tidal volume change over transpulmonary pressure changes (subtracting oesophageal pressures from airway pressures) during tidal breathing (average of 10 breaths); oesophageal will be used as a measure of pleural pressures. | 30 seconds |