Increasing Duration of Apnea Without Desaturation at Induction of Anesthesia in Morbidly Obese Patients Using "Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE)"
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Medical University of Vienna
- Enrollment
- 40
- Locations
- 2
- Primary Endpoint
- Duration of safe apnea
Study Overview
Brief Summary
This project will investigate the duration of apnea without desaturation when using transnasal humidified rapid insufflation ventilatory exchange (THRIVE) vs. low flow nasal oxygen at anesthesia induction in obese patients.
Detailed Description
Background Providing safe anesthesia for surgery in obese patients requires specific consideration of the pathophysiological changes and respiratory complications are frequent. Anesthesia induction needs special attention in this patient population. A decrease in functional residual capacity (FRC) after induction of anesthesia dramatically shortens the duration of apnea without desaturation (DAWD) during which the airway can be secured.
Several measures such as positioning in a semi sitting position, preoxygenation with PEEP and passive insufflation of oxygen during laryngoscopy have been shown to prolong the DAWD. None of these measures is able to produce positive endexpiratory pressure (PEEP) during laryngoscopy which would counteract the loss of FRC and therefore prolong the DAWD further.
Transnasal humidified rapid insufflation ventilator exchange (THRIVE, also knowns as "high flow nasal oxygen therapy" and "heated and humidified nasal oxygen") devices have been used for several years in intensive care and are available from numerous vendors. With THRIVE, heated and humidified oxygen is insufflated via nasal prongs at a rate up to 120 l/minute and it has been shown that this creates levels of PEEP, proportional to the amount of gas flow. Using THRIVE during the apneic phase of anesthesia induction in obese patients might be superior compared to low flow oxygen techniques as THRIVE generates PEEP during laryngoscopy, which might counteract the loss of FRC and consequently might prolong the DAWD.
Aim of the project This project will investigate the DAWD when using THRIVE vs. low flow nasal oxygen at anesthesia induction in obese patients.
Hypothesis The duration of apnea without desaturation is longer in the "THRIVE" group compared to the "low flow oxygen" group.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Single (Investigator)
Masking Description
The monitor measuring the main outcome parameter will be in a separate room
Eligibility Criteria
- Ages
- 19 Years to 65 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Adult patients
- •American Society of Anesthesiologists physical status classification class 2-3
- •BMI > 40
- •elective surgery under general anesthesia
Exclusion Criteria
- •expected difficult airway (El Ganzouri Risk Index > 6)
- •oxygen saturation of less than 98% despite adequate preoxygenation,
- •nasal obstruction
- •smoker, more than 10 cigarettes per day
- •chronic respiratory disease
- •FEV1 (forced expiratory volume in one second) < 70%
- •elevated intracranial pressure
- •unable to give informed consent
- •Pregnant or breast feeding
Outcomes
Primary Outcomes
Duration of safe apnea
Time Frame: duration from the application of rocuronium until the oxygen saturation drops to 95% during laryngoscopy or a maximum of 15 minutes if the oxygen saturation does not drop to this level.
The duration until oxygen saturation drops to 95% during laryngoscopy
Secondary Outcomes
- blood gas analysis(every 2 minutes after rocuronium was given until 2 minutes after intubation)
Investigators
Thomas Hamp
Principal Investigator
Medical University of Vienna