Isocapnic Hyperventilation - an Alternative Method

Oropharyngeal Neoplasms Clinical Trial

Official title:

Isocapnic Hyperventilation for Enhancing Recovery After Inhalation Anaesthesia - an Alternative Method

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03074110
• Other study ID #: GLS-588681
• Status: Completed
• Phase: N/A
• First received: March 3, 2017
• Last updated: December 29, 2017
• Start date: November 11, 2016
• Est. completion date: August 15, 2017

Study information

• Verified date: December 2017
• Source: Sahlgrenska University Hospital, Sweden
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Description:

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 IHV method was evaluated in a pilot study in humans, based on the results of our two previous experimental studies. To finalize the project the investigators now conduct a prospective randomized trial to evaluate the efficacy of the method, compared to a standard weaning procedure, after long-term sevoflurane anaesthesia.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 31
• Est. completion date: August 15, 2017
• Est. primary completion date: August 15, 2017
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Adult patients scheduled for major elective ear-nose-throat (ENT) surgery after informed consent was obtained during the pre-operative evaluation.

Exclusion Criteria:

• Patients with severe pulmonary or circulatory disease

Related Conditions & MeSH terms

• Hyperventilation
• Oropharyngeal Neoplasms

Intervention

Device:
• Isocapnic hyperventilation
Mechanical hyperventilation to enhance elimination of inahalation anesthetics. Administration of a precalculated flow of CO2 according to gender and weight into the inspiratory limb of the breathing circuit in order to avoid hypocapnia.

Locations

Country	Name	City	State
Sweden	Sahlgrenska University Hospital	Gothenburg

Sponsors (1)

Lead Sponsor	Collaborator
Sahlgrenska University Hospital, Sweden

Country where clinical trial is conducted

Sweden, 

References & Publications (2)

Hallén K, Stenqvist O, Ricksten SE, Lindgren S. A simple method for isocapnic hyperventilation evaluated in a lung model. Acta Anaesthesiol Scand. 2016 May;60(5):597-606. doi: 10.1111/aas.12674. Epub 2015 Dec 21. — View Citation

Hallén K, Stenqvist O, Ricksten SE, Lindgren S. Isocapnic hyperventilation shortens washout time for sevoflurane - an experimental in vivo study. Acta Anaesthesiol Scand. 2016 Oct;60(9):1261-9. doi: 10.1111/aas.12761. Epub 2016 Jul 10. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Time to extubation		5-20 minutes
Primary	Time to eye-opening		10-25 minutes
Primary	Time to discharge from OR		15-40 minutes
Secondary	Postoperative recovery	Postoperative quality of recovery (PQRS) scale	60 minutes
Secondary	Time to eligible for discharge from post-anaesthesia care unit (PACU)		1-6 hours