SctO2 Evaluated by NIRS Between Apneic Oxygenation With High-flow Oxygen Therapy and Tracheal Intubation During Laryngeal Microsurgery: a Prospective Non-inferiority RCT
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Enrollment
- 30
- Locations
- 2
- Primary Endpoint
- NIRS
Study Overview
Brief Summary
Over time, the accumulation of carbon dioxide reduces the pressure gradient for the alveolar transfer of oxygen, limiting the successful duration of apneic oxygenation. NIRS (Near-Infrared Spectroscopy) technology is able to provide an estimate of the regional balance between demand and supply of brain oxygen.
The primary hypothesis of this study is that although high-flow oxygen therapy may be associated with transiently higher PaCO2 values than those found in patients undergoing tracheal intubation and traditional mechanical ventilation, due to the brevity of this phenomenon the variations in the average values of frontal cerebral tissue oxygen saturation are expected to be of similar magnitude between the two groups.
Secondary objectives will be the comparison of the success rate of high-flow oxygen therapy compared to traditional airway management by mechanical ventilation.
The success rate will be defined as blood pressure of carbon dioxide (PaCO2) <= 65 mmHg and/or peripheral oxygen saturation (SpO2) >= 94% throughout the procedure, in the absence of adverse events (haemodynamic alteration, dyspnea, discomfort).
The data will be analyzed according to an intention-to-treat principle. Continuous variables with repeated measurements will be compared with a mixed-effect linear regression model. Normality of distribution will be verified with the Shapiro-Wilk test. Continuous variables will be compared with Student t- or Mann-Whitney test; categorical variables with the Chi-square test.
Detailed Description
Apneic oxygenation is a physiological phenomenon in which, provided that patency exists between the lungs and the external environment, the pulmonary flow of oxygen is maintained by a negative pressure gradient generated by the difference between the rate of alveolar extraction of oxygen and the excretion of carbon dioxide.
Over time, the accumulation of carbon dioxide reduces the pressure gradient for the alveolar transfer of oxygen, limiting, because of a condition of acidosis, the successful duration of apneic oxygenation.
The effects of hypercapnia on the mechanisms of cerebral blood flow autoregulation are well known and NIRS (Near-Infrared Spectroscopy) technology, through the non-invasive analysis of the relative absorbance of oxy- and deoxyhemoglobin in the frontal cerebral tissue microcirculation, is able to provide an estimate of the regional balance between demand and supply of brain oxygen.
High-Flow Nasal Cannula Oxygenation (HFNCO) is an open-loop oxygenation system that uses flows of up to 70 l/min of 100% oxygen through the Optiflow THRIVETM apparatus (Fisher and Paykel Healthcare Ltd, Auckland, New Zealand), increasingly used as an alternative to tracheal intubation in patients undergoing short-term general anesthesia.
Heating and humidification of the flows facilitate their tolerability by the patient; HFNCO produces a linear, flow-dependent effect of continuous positive airway pressure about 1 cmH20 for every 10 l/min increase in oxygen flows, reduces dead space and allows elimination of carbon dioxide, with the potential to increase alveolar volume and improve gas exchanges.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Other
- Masking
- Single (Participant)
Eligibility Criteria
- Ages
- 18 Years to 69 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •ASA I and II. Scheduled for Microlaryngeal surgery
Exclusion Criteria
- •age < 18 years;
- •pregnancy status;
- •NYHA class > III;
- •pre-existing cardiac arrhythmias;
- •high risk of inhalation;
- •neuromuscular diseases or metabolite accumulation;
- •refusal of informed consent or impossibility to express it.
Outcomes
Primary Outcomes
NIRS
Time Frame: each five minutes from anesthesia induction up to the end of surgery
Average values of frontal cerebral tissue oxygen saturation
Secondary Outcomes
- The success rate of high-flow oxygen therapy compared to traditional airway management by mechanical ventilation.(each five minutes from anesthesia induction up to the end of surgery)