Anesthesia, General, Lung Function, Ventilation
Conditions
Keywords
Flow-controlled ventilation, High frequency jet ventilation, Lung protection, Laryngotracheal surgery
Brief summary
Laryngotracheal surgery often requires a small diameter endotracheal tube to oxygenate patients under general anesthesia. Oxygenation is often only possible with high-frequency jet ventilators due to the use of small diameter and high resistance airway cannulas. Flow controlled ventilation is a new ventilation modality capable for ventilation through a small diameter endotracheal tube (Tritube) with an active expiratory phase and the possibility of controlled carbon dioxide elimination during mechanical ventilation. The aim of the present trial is to characterize perioperative changes in lung volume, ventilation inhomogeneity and respiratory mechanics in patients undergo upper airway surgery under general anesthesia with either flow controlled or high-frequency jet ventilation.
Detailed description
This study is a randomized, controlled, assessor blind, monocentric study. A new ventilation mode, called Flow Controlled Ventilation (FCV), has been suggested to minimize the amount of dissipated energy in the lungs and potentially could be protective during mechanical ventilation. FCV is unique in creating a stable gas flow into and also out of the patient's lungs to generate inspiration and expiration respectively. The FCV ventilation mode by its design allows the use of an ultrathin endotracheal tube with an inflatable cuff to secure the airways for ventilation. Therefore FCV offers several new surgical options for the treatment during laryngeal and tracheal surgery where the standard approach is usually the use of high-frequency jet ventilation (HFJV). The limitations of HFJV are however the lack of airway protection, limited monitoring of the respiratory variables and potential carbon dioxide (CO2) accumulation. Participants for this study will be recruited at the University Hospitals of Geneva, scheduled for laryngotracheal surgery under general anesthesia. A total of 50 patients will be enrolled and randomly assigned into 2 groups: Group FCV (Flow controlled ventilation) and Group HFJV (high-frequency jet ventilation). Measurements of functional residual capacity (FRC) and lung clearance index (LCI) will be performed in patients with a nitrogen multiple breath washout method, before and approximately 1 hour after surgery. Similarly, respiratory system resistance (R) and respiratory reactance (X) will be measured at the same time by using the Forced Oscillation Technique. Relevance: There are no studies that addressed the value of flow controlled ventilation in terms of lung function parameters (FRC and LCI) and lung mechanics (R, X) in comparison to high-frequency jet ventilation in patients undergoing upper airway surgery.
Interventions
OTHERGeneral anesthesia for laryngotracheal surgery
Patients undergoing general anesthesia and mechanical ventilation.
OTHERMechanical ventilation by FCV
Mechanical ventilation is assured by Flow-controlled ventilation mode.
OTHERMechanical ventilation by HFJV
Mechanical ventilation is assured by High frequency jet ventilation mode.
Sponsors
University Hospital, Geneva
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
Inclusion criteria
* Informed Consent signed by the subject * General anesthesia for laryngotracheal surgery * Adult patients, female and male, over 18 years of age * Elective surgery
Exclusion criteria
* Documented severe heart conditions (New York Heart Association Class 4, severe pulmonary hypertension) * Documented severe respiratory disease (uncontrolled asthma, severe pulmonary fibrosis, chronic obstructive pulmonary disease GOLD 4) * Documented severe Neurological diseases (Acute ischemic and hemorrhagic stroke within the preceding 3 months, uncontrolled seizures) * Surgery that requires tracheotomy * Obesity (Body Mass Index ≥ 30 kg/m2) * Inability to follow the procedures of the study (mental condition or language barrier e.g. incomprehension of French language) * Previous enrolment into the current study or other study that involves unknown medication in the past 12 months * Allergy or contraindication to Propofol and/or Remifentanil and/or Rocuronium
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Alterations in the functional residual capacity (FRC) | Right before general anesthesia and approximately 1 hour after general anesthesia or before discharge from post anesthesia care unit | FRC measured by the nitrogen multiple breath washout technique that will be applied before and after general anesthesia |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Alterations in the Lung clearance index (LCI) | Right before general anesthesia and approximately 1 hour after general anesthesia or before discharge from post anesthesia care unit | LCI measured by the nitrogen multiple breath washout technique that will be applied before and after general anesthesia |
| Alterations in the respiratory resistance assessed by the forced oscillation technique (FOT) | Right before general anesthesia and approximately 1 hour after general anesthesia or before discharge from post anesthesia care unit | Respiratory mechanics will be measured by the forced oscillation technique (FOT) to evaluate respiratory resistance (R). |
| Alterations in the respiratory reactance assessed by the forced oscillation technique (FOT) | Right before general anesthesia and approximately 1 hour after general anesthesia or before discharge from post anesthesia care unit | Respiratory mechanics will be measured by the forced oscillation technique (FOT) to evaluate respiratory reactance (X). |
Other
| Measure | Time frame | Description |
|---|---|---|
| Changes in mean blood pressure | Intraoperative period with specific time points: before anesthesia induction, at the beginning of the surgery, at the end of surgery, right after extubation | mean blood pressure (mmHg) |
| Changes in heart rate | Intraoperative period with specific time points: before anesthesia induction, at the beginning of the surgery, at the end of surgery, right after extubation | heart rate (beat per minute) |
| Changes in oxygen saturation | Intraoperative period with specific time points: before anesthesia induction, at the beginning of the surgery, at the end of surgery, right after extubation | Oxygen saturation will be measured by pulse oximetry (%) |
| Changes in transcutaneous carbon dioxide | Intraoperative period with specific time points: before anesthesia induction, at the beginning of the surgery, at the end of surgery, right after extubation | Transcutaneous carbon dioxide will be measured |
Countries
Switzerland
Contacts
Primary ContactGergely Albu, MD, PhD
Outcome results
None listed