Titration Pressures in Sleep Apnea Patients Using ThermoSmart® Versus Conventional Humidification

Patients who have Obstructive Sleep Apnea (OSA) may have different Continuous Positive Airway Pressure (CPAP)when titrated with different levels of humidification. It is hypothesised that patients with ThermoSmart® technology (heated breathing tube technology) will have lower titrated pressures than those who are titrated using conventional humidification (non heated breathing tube).

Debate is present concerning the optimal level of humidification for obstructive sleep apnea (OSA) patients who need continuous positive airway pressure (CPAP) therapy. Recent evidence has shown that using a heated breathing tube to increase the amount of humidification that can be delivered has decreased patient side effects, increased subjective sleep quality and decreased subjective symptom scores. Anecdotal evidence exists, in the form of clinical observation, when ThermoSmart® technology is utilized during CPAP titration, patients laboratory titrated pressure may in fact prove to be lower. The possibility exists, on a titration night, patients potentially may experience an adverse response to the positive airway pressure which manifests as increased airway resistance and inflammation necessitating higher CPAP pressures to overcome upper airway resistance and flow limitation. Therefore, we hypothesize the delivery of higher levels of humidity might reduce the nasal airway resistance during the titration night, reducing the overall positive airway pressure requirements. The goal is to investigate this phenomenon to find if a reduction in pressure is necessary and if so to what degree. Patients who are titrated on Continuous Positive Airway Pressure devices with ThermoSmart® technology will have lower titrated pressures than those who are titrated using conventional humidification.

Each night, the participant underwent a CPAP titration to determine their therapeutic pressure. During a titration, a sleep technician manually adjusts the participants pressure to determine which pressure is best for that individual in reducing their Apnea Hypopnea Index (AHI) which is the measure of Obstructive Sleep Apnea (OSA) severity. Titration pressures for each group were compared to see if there was any impact of having a heated breathing tube versus a non heated breathing tube on titration pressure.

Relationship Between the Intervention (Heated Breathing Tube vs Non Heated Breathing Tube) and Total Sleep Time

A correlation table was computed to explore the relationship between the intervention (heated breathing tube vs no heated breathing tube) and total sleep time. This relationship was calculated for each arm and reported by a Correlation Coefficient (r score). The r score represents the strength and direction of a relationship between two variables. The value of r is always between -1 and +1. Therefore, an r score of -1 indicates a perfect negative relationship between the intervention and total sleep time. An r score of -.50 indicates a moderate negative relationship between the intervention and total sleep time. An r score of 0 indicates no relationship between the intervention and total sleep time. An r score of +.50 indicates a moderate positive relationship between the intervention and total sleep time. An r score of +1 indicates a perfect positive relationship between the intervention and total sleep time.

Inclusion Criteria: Male and Female patients over the age of 18 Apnea Hypopnea Index (AHI) ≥15 Patients must have at least 5 hours sleep time on each titration night Stable medications for 2 weeks prior to entry to the study and for study inclusion duration including sleep aids Exclusion Criteria: Receiving or requiring bi-level ventilation Use of a full face interface or chin strap Previous UPPP surgery or palatal reconstruction Recent angina symptoms within 2 weeks of entry CHF with EF < 40% Obesity Hypoventilation Syndrome Cheyne Stokes respiration > 50% Central apneas recorded on diagnostic polysomnogram Supplemental oxygen use Use of narcotic pain medication Hypoxemia as determined by room air pulse oxymetry of less than 89% on room air at rest awake Inability to tolerate positive pressure therapy Split Night Evaluations