Acceleration of Recovery From General Anesthesia - Efficacy of Isocapnic Hyperpnoea in Obese Patients Undergoing Isoflurane Anesthesia

University Health Network, Toronto

Status: Completed

Conditions: Recovery Time From Isoflurane Anesthesia in Obese Patients

Treatments: Other: Isocapnic Hyperpnoea

Study type: Interventional

Funder types: Other

Identifiers

NCT00752492

UHNREB08-0019B

Details and patient eligibility

About

Faster recovery from anesthesia is important for obese patients because they are at high risk of respiratory complications following tracheal extubation. Isoflurane has several properties that make it a preferable agent for anesthesia in obese patients. Its main limitation is a longer recovery time due to slower elimination in comparison to other agents. Elimination of isoflurane from the lungs can be accelerated by increasing in patient's minute ventilation, which decreases the level of CO2 in blood (hypocapnia).Isocapnic Hyperpnoea (IH) is a method allowing increased ventilation and therefore enhancement of the elimination of inhalation agents while maintaining a normal blood CO2 level. The investigators will compare recovery time from isoflurane anesthesia in obese patients during standard anesthesia management protocol (control) to a group treated with IH.

Enrollment: 44 estimated patients

Sex: All

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

Elective gynecological or urological procedure,

• BMI > 35 kg/m²,
• ASA I-III,
• Signed informed consent.

Exclusion criteria

• Lack of informed consent,
• ASA IV-V,
• Contra-indications to isoflurane anesthesia or other anesthetics included in the protocol,
• History of cardiac or respiratory disease,
• Alcohol or drug abuse,
• Psychiatric illness and/or medications.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Single Group Assignment

Masking: Single Blind

---

44 participants in 1 patient group

Study intervention

Active Comparator group

Description:

Patient will be disconnected from the anesthetic circuit and connected to the resuscitation bag attached to the IH system. Ventilation will be assisted to maintain tidal volume of 8-10 mL/kg and respiratory rate of 20-25 breaths per minute to achieve minute ventilation of 15-20 L/min. Isocapnia manifold will maintain end-tidal PCO2 in range of 40-50 mm Hg.

Treatment:

Other: Isocapnic Hyperpnoea