Influence of Different PEEP Levels and Tidal Volumes on Regional Lung Function

Not Applicable

• Conditions: Pulmonary Ventilation; Newborn, Abnormal
• Interventions: Procedure: constant tidal volume - low PEEP; Procedure: Constant PEEP - high tidal volume; Procedure: Constant PEEP - low tidal volume; Procedure: constant tidal volume - high PEEP

• Registration Number: NCT03326414
• Lead Sponsor: Universitätsklinikum Hamburg-Eppendorf

Brief Summary

Mechanical ventilation is indispensable for most of surgical interventions but can induce lung injury even in pulmonary healthy patients. This can lead to postoperative pulmonary complications. These adverse effects could be prevented by a better monitoring of intraoperative lung function. Electrical impedance tomography is able to visualize aeration within the lung in real time.

The planned study investigates the influence of different levels of positive endexspiratory pressure and different tidal volumes on the aeration.

Detailed Description

Available perioperative parameters to set mechanical ventilation parameters represent only global lung function. But to reduce postoperative pulmonary complications induced by mechanical ventilation a better monitoring of intraoperative lung function seems to be crucial, that provides more regional information of lung collapse or over distention.

By application of small currents via electrodes around the thorax and measuring of the resultant resistance the electrical impedance tomography (EIT) can determine the level of aeration of the lung in a cross sectional plane. The EIT device used in this study calculates the percentage of the investigated lung area that can be defined as over distended or collapsed respectively. In these sections the change of resistance within a respiration cycle is reduced compared to well ventilated areas are therefore called silent spaces. Silent spaces located ventral are termed non-dependent (NSS) and silent spaces located dorsal are termed dependent (DSS). Based on this information the clinician is able to set the respirator in a more lung protective manor.

To better understand the influence of positive endexspiratory pressure (PEEP) and tidal volume (Vt) on reginal lung function we are going to carry out the presented study.

40 patients undergoing robot assisted prostatectomy should be enrolled in a study that consists of two phases. In the first phase 20 patients are ventilated with constant PEEP (10mbar) and in ten patients each the Vt is set to 5 or 12ml/kg ideal body weight. In the second phase in further 20 patients the Vt is set to 8ml/ kg ideal bodyweight and the PEEP is 3 or 12mbar in one half of the patients. Under the different ventilation settings the NSS and DSS, the oxygenation index and lung compliance will be investigated.

Study Timeline

• Study First Submitted: 2017-08-28
• Status Verified: 2017-10
• Study First Submitted QC: 2017-10-25
• Last Update Submitted: 2017-10-25
• Study First Posted: 2017-10-31
• Last Update Posted: 2017-10-31
• Study Start: 2018-01
• Primary Completion: 2018-04
• Study Completion: 2018-06

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: Male
• Target Recruitment: 40

Inclusion Criteria

• over 18 years of age
• scheduled for robot assisted prostate ectomy

Exclusion Criteria

• body mass index >35 kg/m²
• chronic obstructive lung disease (GOLD III or IV)
• obstructive sleep apnoe syndrome
• planned or unplanned admission to intensive care unit for prolonged ventilation
• mechanical ventialtion within the last 30 days
• lung operation in the past
• other lung disease that impairs activity

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
constant tidal volume - low PEEP	constant tidal volume - low PEEP	tidal volume is 8ml/kg IBW, PEEP is set to 3mbar
Constant PEEP - high tidal volume	Constant PEEP - high tidal volume	PEEP is 10mbar, tidal volume is set to 8-10ml/kg IBW
Constant PEEP - low tidal volume	Constant PEEP - low tidal volume	PEEP is 10mbar, tidal volume is set to 4-5ml/kg IBW
constant tidal volume - high PEEP	constant tidal volume - high PEEP	tidal volume is 8ml/kg IBW, PEEP is set to 12mbar

Primary Outcome Measures

Name	Time	Method
Change of "dependent silent spaces" (DSS) and "non-dependent silent spaces" (NSS)	measurement of DSS and NSS are carried out prior to induction of anesthesia, 10 minutes after induction, 30 minutes after after installation of capnoperitoneum, 10 minutes after skin closure, 15 minutes after arrival at the PACU	The change of silent spaces under different ventilator settings during surgery is investigated.

Secondary Outcome Measures

Name	Time	Method
Oxygenation index	prior to induction of anesthesia, 10 minutes after induction, 30 minutes after installation of capnoperitoneum, 10 minutes after skin closure, 15 minutes after arrival at the PACU	The partial pressure of oxygen is determined at every point of measurement and the value is devided by inspiratory oxygen fraction
complinace of the respiratory system	10 minutes after induction, 30 minutes after capnoperitoneum applied, 10 minutes after skin closure	The compliance of the respiratory system (ml/mbar) is mesured by the respirator during mechanical ventilation

Trial Locations

Locations (1)

Department of Anaesthesiology Center of Anaesthesiology and Intensive Care Medicine University Medical Center Hamburg-Eppendorf University of Hamburg; 🇩🇪 Hamburg, Germany