Clinical Trial: Isocapnic Hyperventilation - an Alternative Method
Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional
Official Title: Isocapnic Hyperventilation for Enhancing Recovery After Inhalation Anaesthesia - an Alternative Method
Brief Summary: Isocapnic hyperventilation (IHV) is a method that shortens time to extubation after inhalation anaesthesia by increasing airway carbon dioxide (CO2) during hyperventilation (HV). In two experimental studies (mechanical lung model and porcine model) and in a pilot study on patients undergoing sevoflurane anaesthesia for major ear-nose-throat (ENT) surgery, the investigators evaluated the feasibility of an alternative technique of IHV. By performing a prospective, randomised controlled study, the investigators want to further test this alternative method for IHV.
Detailed Summary:
Isocapnic hyperventilation (IHV) provides an alternative method for weaning from inhalation anaesthesia which decreases the time to eye-opening, extubation and time spent in the PACU. The method is well known since at least 40-50 years and involves the maintenance of a stable CO2 level during hyperventilation, which increases the elimination of anaesthetic gas without producing hypocapnia. Studies have declared that the reduction in time to eye-opening is 50-60 % compared to a standard weaning procedure after inhalation anaesthesia.
There are several principally different ways to maintain the CO2 level during hyperventilation, where a number of technical solutions that add dead-space to the anaesthesia circuit and thereby produce rebreathing of CO2 during hyperventilation are the most studied methods so far. However, the original method of directly adding CO2 to the breathing circuit during hyperventilation could be considered in need of a re-evaluation, as modern anaesthesia delivery units and monitoring equipment to a great extent can eliminate the risk of hypercapnia, that was described with this procedure in the 1980ies.
An alternative IHV method is to directly infuse CO2 to the inspiratory limb of the breathing circuit through a mixing box while using mechanical hyperventilation by a standardised protocol. This technique was recently evaluated by the investigators, in a bench test, and in an in vivo model. Based on these studies, the CO2 dosage needed to achieve isocapnia during HV at various levels of alveolar ventilation, CO2 production and dead space was estimated and a gender- and weight-based nomogram for CO2 delivery during IHV was constructed. Furthermore, the investigators could show, in vivo, that the washout time of sevoflurane anaesthesia was one-third compared to normal ventilation. The feasibility of this
Sponsor: Sahlgrenska University Hospital, Sweden
Current Primary Outcome:
- Time to extubation [ Time Frame: 5-20 minutes ]
- Time to eye-opening [ Time Frame: 10-25 minutes ]
- Time to discharge from OR [ Time Frame: 15-40 minutes ]
Original Primary Outcome: Same as current
Current Secondary Outcome:
- Postoperative recovery [ Time Frame: 60 minutes ]Postoperative quality of recovery (PQRS) scale
- Time to eligible for discharge from post-anaesthesia care unit (PACU) [ Time Frame: 1-6 hours ]
Original Secondary Outcome: Same as current
Information By: Sahlgrenska University Hospital, Sweden
Dates:
Date Received: March 3, 2017
Date Started: November 11, 2016
Date Completion: November 1, 2017
Last Updated: March 9, 2017
Last Verified: March 2017
