Regional Distribution of Ventilation at Different Respiratory Rates

Study Overview
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Brief Summary
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This study will investigate the distribution of gas during mechanical ventilation in patients undergoing robot assisted laparoscopic prostatectomy. The gas distribution of ventilation are monitored and data extracted using electric impedance tomography in different respiratory rates.

Detailed Description
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Mechanical ventilation during anaesthesia and intensive care often results in an uneven gas distribution of ventilation. Patients anaesthetized for laparoscopic surgery and patients positioned i a Trendelenburg position is particularly at risk. A less harmful mode of ventilation could possible lead to a more optimal ventilation with avoidance of ventilator induced lung injuries. Our project will investigate if volume controlled ventilation with a higher respiratory frequency can be used in this purpose. We intend to investigate patients, without previously known lung disease, undergoing robot-assisted laparoscopic prostatectomy. After the patients have given informed consent, they will be included in our project. The distribution of ventilation will be monitored with electric impedance tomography (EIT). Once the patients have been anaesthetized, positioned with the head down and the surgical procedure have been started with insufflation of carbon dioxide we will start our test. We will perform three episodes of standardized ventilation with the respiratory rate (RR) of 20, 40 and 60. With a higher RR the tidal volume will be reduced tom maintain a constant inhaled minute volume. Data will be collected from the EIT-equipment, the anaesthesia machine and the monitoring system.

Official Title
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Regional Distribution of Ventilation in Different Respiratory Rates: A Study of Mechanically Ventilated Patients Undergoing Robot-assisted Laparoscopic Prostatectomy

Conditions
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Mechanical Ventilation, Atelectasis, Distribution of Ventilation

Intervention / Treatment
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* Device: Ventilation 20-40-60
* Device: Ventilation 60-40-20
* Device: Ventilation 40-60-20


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients planned for robot-assisted laparoscopic prostatectomy > 18 years Consent to take part in the study Exclusion Criteria: Impaired cognitive function Previously known lung disease Insufficient skills in Swedish language to understand information about the study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Male

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: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 20-40-60<br> | Device: Ventilation 20-40-60<br>* The respiratory rate during mechanical ventilation will be altered from 20 to 40 and finally to 60 breaths per minute.<br>|
| Experimental: 60-40-20<br> | Device: Ventilation 60-40-20<br>* The respiratory rate during mechanical ventilation will be altered from 60 to 40 and finally to 20 breaths per minute.<br>|
| Experimental: 40-60-20<br> | Device: Ventilation 40-60-20<br>* The respiratory rate during mechanical ventilation will be altered from 40 to 60 and finally to 20 breaths per minute.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distribution of ventilation | Gas distribution of ventilation between different regions of interest monitored with electrical impedance tomography. | During the prostatectomy procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Distribution of ventilation | Gas distribution of ventilation measured as center of ventilation monitored with electrical impedance tomography. | During the prostatectomy procedure |