Hypercapnic Spontaneous Hyperpnoea and Recovery From Sevoflurane Anesthesia

University Health Network, Toronto

Status: Completed

Conditions: Surgery; Anesthesia

Treatments: Device: Hypercarbic Spontaneous Hyperpnoea; Other: Standard Anesthesia management for post surgical patients

Study type: Interventional

Funder types: Other

Identifiers

NCT01151267

UHN REB 08-0017-B

Details and patient eligibility

About

The rate of elimination of inhalation agent is directly proportional to the degree of alveolar ventilation. Using Isocapnic Hyperpnoea (IH) device, it is possible to maintain constant end-tidal CO2 with increased minute ventilation. This is achieved by passively adding a flow of CO2 to the inspirate in proportion to increases in ventilation above the baseline. In animal and human studies IH shortens the time of awakening from isoflurane and sevoflurane anesthesia when manual positive pressure ventilation is applied. IH device could be used for spontaneous hyperpnoea as well. The investigators want to compare recovery times from sevoflurane anesthesia in patients with application of hypercapnic spontaneous hyperpnoea (HSH) versus the standard anesthesia protocol (controls). 44 patients ill be randomized to either HSH facilitated recovery, or conventional recovery (controls).The time intervals from the end of anesthesia (turning off the vaporizer) until recovery milestones will be recorded.

Enrollment: 44 patients

Sex: Female

Ages: 18 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• elective gynecological surgery
• age 18-80
• ASA I-III
• informed consent

Exclusion criteria

• ASA IV-V,
• contra-indications to sevoflurane anesthesia or other anesthetics included in the protocol
• history of cardiac or respiratory disease
• intracranial pathology
• alcohol or drug abuse
• psychiatric illness and/or medications

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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44 participants in 2 patient groups

Control Arm

Other group

Description:

The O2 flow on the anesthetic machine will be set at 15 L/min. Ventilatory assistance will be performed to maintain O2 saturation \>97% and end tidal CO2 at 35-45mmHg.

Treatment:

Other: Standard Anesthesia management for post surgical patients

HSH Group

Active Comparator group

Description:

Patient will be disconnected from the anesthetic circuit and connected to the resuscitation bag attached to the IH system. With O2 flow of 2 L/min patient will be gently ventilated until recovery of the spontaneous ventilation. After starting spontaneous ventilation basal O2 flow will be adjusted to keep ETCO2 in range of 50-60 mm Hg or minute ventilation of 15-17 L/min, whichever occurs first.

Treatment:

Device: Hypercarbic Spontaneous Hyperpnoea