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NCT Number: NCT02644005

Automated Control of Mechanical Ventilation During General Anaesthesia

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

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Key information

Conditions

Anesthesia

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

University Hospital St. Pölten, Department of Anesthesiology and Intensive Care Medicine, Sankt Pölten, Austria

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About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Smart Vent Control

Device

Smart Vent Control (SVC) was designed to automatically control the following ventilator settings: mechanical breathing frequency, inspiratory pressure, pressure support, inspiratory time, trigger sensitivity. SVC adjusts the ventilator settings with the aim to keep a patient stable in a target zone (TZ). Numerous predefined TZs exist that can be set according to the current therapeutic situation. All TZs are adoptable by the user for each individual patient and consist of upper and lower limits for tidal volume and for the partial pressure of end-tidal carbon dioxide (PetCO2). Based on these limits, the system classifies the current quality of ventilation, called Classification of Ventilation, and derives new ventilator settings accordingly. SVC is available as a software option on Zeus Infinity Empowered anesthesia machines (Drägerwerk AG & Co. KGAa, Lübeck, Germany) and is approved as a medical product according to 93/42/European Economic Community.

Primary outcomes

  1. Frequency of adverse events.

    Time frame: During artificial ventilation with SVC (up to 8 hours).

    • 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.

Secondary outcomes

  1. Frequency of normoventilated, hypoventilated and hyperventilated patients.

    Time frame: During artificial ventilation with SVC (up to 8 hours).

    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

  2. Time period between switch from controlled ventilation to augmented ventilation and achievement of stable assisted ventilation of the patient.

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  3. Proportion of time within the target zones for tidal volume and PetCO2 as individually set up for each patient by the user.

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  4. Frequency of alarms.

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  5. Frequency distribution of tidal volume (ml/kg predicted body weight).

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  6. Frequency distribution of inspiratory pressure (mbar).

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  7. Frequency distribution of inspiration time (s).

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  8. Frequency distribution of expiration time (s).

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  9. Frequency distribution of PetCO2 (mmHg).

    Time frame: During artificial ventilation with SVC (up to 8 hours).

  10. Number of re-intubations.

    Time frame: During artificial ventilation with SVC (up to 8 hours).

Sponsors and collaborators

Lead sponsor

University Hospital Schleswig-Holstein

Other

Collaborators

  • Drägerwerk AG & Co. KGaA

Registry information

Official study title

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

Acronym: AVAS

Important dates

Study start
2017
Primary completion
2019
Study completion
2019
First posted
Dec 31, 2015
Registry last updated
Apr 18, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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