Nasal High Flow Therapy in Surgical Patients with Unrecognized Obstructive Sleep Apnea

University Health Network, Toronto22 enrolled

Overview

In this study the investigators will determine whether using high flow oxygen in moderate-to-severe Obstructive Sleep Apnea patients following a major non cardiac surgery is more efficacious than usual care in preventing decrease in oxygen level in blood.

The POSA-II trial is a culmination of the investigator's program of research to prevent postoperative adverse outcomes in surgical patients with untreated Obstructive Sleep Apnea (OSA). It is a multi center open label, randomized clinical trial of nasal high-flow vs. usual care in patients with untreated moderate-to-severe OSA undergoing major non cardiac surgery. It is a proof of concept trial to show that nasal high-flow reduces severe desaturation, the causal mechanism for OSA-related adverse events, and to collect key feasibility data for a large international multi center trial with enough power to detect effects on the clinical outcomes. Eligible patients undergoing major non cardiac surgery with high-risk OSA will have a home sleep study. One hundred and ninety patients with moderate-to-severe Sleep Apnea will be randomized into either nasal high-flow or usual care group. Sleep studies, oximetry, electrocardiogram (ECG), and Troponin will be done preoperatively. Postoperatively, ECG and Troponin will be determined daily for the 1st three days, and nocturnal oximetry for the 1st 3 nights. Patients will be followed during their hospitalization and for 30 days postoperatively to ascertain any adverse outcomes. A blinded clinical events committee will adjudicate all components of the composite outcome.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Enrollment

Conditions

Obstructive Sleep Apnea Sleep Disordered Breathing

Interventions

Nasal High FlowOTHER

Delivery of oxygen via OptiflowTM system (AirvoTM, Fisher \& Paykel Inc.) with airflow of 20 to 50 Litre/minute

Usual CareOTHER

Delivery of oxygen at 2-4 Litre/minute via nasal cannula or 6 Litre/minute via face mask

Eligibility

Sex: ALLMin age: 45 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Adult, age ≥45 years, undergoing major elective non cardiac surgery under general and/or regional anesthesia with anticipated overnight stay or longer in hospital * Patients with untreated moderate-to-severe Obstructive Sleep Apnea. * STOP-Bang score 5 or higher Exclusion Criteria: * Predetermined need for postoperative CPAP therapy or ventilation, * Cheyne-Stokes respiration or Central Apnea, * Oxygen dependent due to moderate to severe chronic obstructive lung disease available Forced Expiratory Volume at 1 second of \< 50% predicted) or advanced interstitial lung disease, * Pre-existing chronic hypercapnia or obesity hypoventilation syndrome, Intracranial and otolaryngological procedures, and * Unable to use nasal high-flow (nasal/oral malformations, pre-existing tracheostomy, planned postoperative nasal packing).

Locations (8)

St. Michael's Hospital

Toronto, Ontario, Canada

Toronto General Hospital

Toronto, Ontario, Canada

Toronto Western Hopsital, Dept. of Anesthesia

Toronto, Ontario, Canada

Prince of Wales Hospital

Hong Kong, Hong Kong

Outcomes

Primary Outcomes

Oxygen Desaturation Index (ODI)

The investigators will measure Oxygen Desaturation Index(the number of desaturation events per hour) by using Pulsox 300i for maximum of three nights post-operatively at the hospital preventing the severe desaturation in surgical patients with untreated moderate-to-severe OSA undergoing major non cardiac surgery. Higher values of ODI are considered worst. If successful, it will provide feasibility data for the performance of a large randomized clinical trial focusing on clinical outcomes and the cost effectiveness of the therapy to the health care system.

Time frame: 72 hours

Secondary Outcomes

Time (minutes) spent below 90% and 80% SpO2 (T90, T80)

The investigators will measure the time spent in minutes with SpO2 between 0% to %79 (T80) and the time spent in minutes with SpO2 between 0% to 89% (T90). ODI, T90 and T80 will serve as surrogate outcomes of adverse events in the pilot study. In POSA study, an increase in time spent with SpO2 \<80% after surgery was associated with a higher risk of postoperative vascular events under usual care.

Time frame: 72 hours

Compliance to Nasal High-Flow

To determine the tolerability and adherence of patients with OSA to Nasal High-Flow in the wards using a 10-point numeric rating scale to grade general discomfort, in which points 0 to 3 means not comfortable, 4 to 6 means comfortable and 7 to 10 means the most comfortable.

Time frame: 72 hours

Titration protocol of nasal high-flow

The appropriate titration protocol of nasal high-flow will be measured; FiO2: flow rates.

Time frame: 72 hours

The rate of postoperative adverse events

The rate of postoperative cardiovascular events will be collected during hospitalization and following discharge from hospital, emergency department (if visited) and physician records, and patient by phone at day 30. Adjudicators who are blinded to the results of the ECG, Troponin, sleep study and oximetry will evaluate outcome events.

Data from ClinicalTrials.gov

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