Automated Control of Mechanical Ventilation During General Anaesthesia (AVAS)

Automated Control of Mechanical Ventilation During General Anaesthesia - A Bicentric Prospective Observational Trial

Prospective, bicentric observational study to assess a novel system for automated control of mechanical ventilation (Smart Vent Control, SVC) during general anesthesia.

Study Overview

• Status: Completed
• Conditions: Anesthesia
• Intervention / Treatment: Device: Smart Vent Control

Detailed Description

The "Automated control of mechanical ventilation during general anesthesia study (AVAS study) is an international investigator-initiated bicentric observational study investigating the application of Smart Vent Control (SVC) during general anesthesia. The main objective of this study is to describe the application of SVC and to assess its safety and efficacy.

• Study Type: Observational
• Enrollment (Actual): 100

Contacts and Locations

Study Locations

• Austria
  • St. Pölten, Austria, A-3100
    • University Hospital St. Pölten, Department of Anesthesiology and Intensive Care Medicine
• Germany
  • Kiel, Germany, 24105
    • University Medical Center Schleswig-Holstein, Campus Kiel, Department of Anesthesiology and Intensive Care Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Adult patients scheduled for elective surgery in general anesthesia.

Description

Inclusion Criteria:

• Planned elective surgery of the upper limb, lower limb or peripheral vascular surgery in general anesthesia
• Patient is classified as American Society of Anesthesiologists physical status (ASA) I, II or III
• Age ≥ 18 years
• Written consent of the patient for study participation

Exclusion Criteria:

• Mild, moderate or severe acute respiratory distress syndrome (ARDS)[10]
• Known chronic obstructive pulmonary disease Gold stage III or higher

• Two or more of the following organ failures

  • Mild, moderate or severe ARDS
  • Hemodynamic instability: systolic blood pressure < 90 mm Hg, mean arterial pressure < 70 mm Hg or administration of any vasoactive drugs.
  • Acute renal failure: oliguria (urine output < 0.5 ml/kg/h for at least 2 hours despite of adequate management or creatinine increase > 0.5 mg/dl
  • Cerebral failure: loose of consciousness or encephalopathy
• Patient is pregnant.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency of adverse events.	Severe hypoventilation defined as minute volume lower than 40 ml/kg predicted body weight for longer than 5 minutes; Apnea for longer than 90 seconds; Hyperventilation defined as PetCO2 lower than 5 mm Hg of the lower target setting for SVC for longer than 5 minutes; Hypoventilation defined as PetCO2 higher than 5 mm Hg of the upper target setting for the SVC for longer than 5 minutes; Respiratory rate > 35 breaths per minute for longer than 5 minutes; Any override or stop of the automated controlled ventilation settings by the anesthesiologist in charge if the settings are clinically not acceptable. Reasons for overriding or stopping the system will be noted.	During artificial ventilation with SVC (up to 8 hours).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency of normoventilated, hypoventilated and hyperventilated patients.	The responsible anesthesiologist defines a target range for the arterial partial pressure of carbon dioxide (PaCO2_target) before the induction of the general anesthesia and sets up the corresponding endtidal CO2-range in the automated ventilation system. 15 minutes after the begin of the surgical procedure an arterial blood gas analysis will be performed and the PaCO2 will be measured. Then patients will be classified as follows: hypoventilated patient: PaCO2 > (PaCO2_target+5); hyperventilated patient: PaCO2 < (PaCO2_target-5); normoventilated patient: (PaCO2_target-5) ≤ PaCO2 ≤ PaCO2_target+5	During artificial ventilation with SVC (up to 8 hours).
Time period between switch from controlled ventilation to augmented ventilation and achievement of stable assisted ventilation of the patient.		During artificial ventilation with SVC (up to 8 hours).
Proportion of time within the target zones for tidal volume and PetCO2 as individually set up for each patient by the user.		During artificial ventilation with SVC (up to 8 hours).
Frequency of alarms.		During artificial ventilation with SVC (up to 8 hours).
Frequency distribution of tidal volume (ml/kg predicted body weight).		During artificial ventilation with SVC (up to 8 hours).
Frequency distribution of inspiratory pressure (mbar).		During artificial ventilation with SVC (up to 8 hours).
Frequency distribution of inspiration time (s).		During artificial ventilation with SVC (up to 8 hours).
Frequency distribution of expiration time (s).		During artificial ventilation with SVC (up to 8 hours).
Frequency distribution of PetCO2 (mmHg).		During artificial ventilation with SVC (up to 8 hours).
Number of re-intubations.		During artificial ventilation with SVC (up to 8 hours).

Collaborators and Investigators

• Sponsor: University Hospital Schleswig-Holstein
• Collaborators: Drägerwerk AG & Co. KGaA
• Investigators: Principal Investigator: Norbert Weiler, M.D., University Medical Center Schleswig-Holstein, Campus Kiel, Germany, Department of Anesthesiology and Intensive Care Medicine; Principal Investigator: Christoph Hörmann, M.D., University Hospital St. Pölten, Austria, Department of Anesthesiology and Intensive Care Medicine

Publications and helpful links

General Publications

• Schadler D, Miestinger G, Becher T, Frerichs I, Weiler N, Hormann C. Automated control of mechanical ventilation during general anaesthesia: study protocol of a bicentric observational study (AVAS). BMJ Open. 2017 May 10;7(5):e014742. doi: 10.1136/bmjopen-2016-014742.

Study record dates

Study Major Dates

• Study Start (Actual): July 7, 2017
• Primary Completion (Actual): March 7, 2019
• Study Completion (Actual): March 7, 2019

Study Registration Dates

• First Submitted: December 11, 2015
• First Submitted That Met QC Criteria: December 30, 2015
• First Posted (Estimate): December 31, 2015

Study Record Updates

• Last Update Posted (Actual): April 18, 2019
• Last Update Submitted That Met QC Criteria: April 17, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: AVAS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No