Dyspnoea relief as an inherent benefit of high flow nasal cannula therapy: A laboratory randomized trial in healthy humans.

BACKGROUND AND OBJECTIVE: Persistent dyspnoea is a public health issue for which the therapeutic arsenal is limited. This study tested high-flow nasal cannula therapy (HFNT) as a means to alleviate experimental dyspnoea. METHODS: Thirty-two healthy subjects underwent an experimental dyspnoea induced by thoracoabdominal elastic loading. HFNT was administered with alternately FiO2 of 100% (HFNT100) or 21% (HFNT21). The sensory (S-VAS) and affective (A-VAS) components of dyspnoea, transcutaneous CO2 pressure (PtcCO2 ), pulse-oximetry oxygen saturation (SpO2 ), heart rate, respiratory rate and skin galvanometry were monitored continuously. Three experimental sessions of 8 min were conducted: the first session consisted in familiarization with the experimental dyspnoea and the next two sessions tested the effects of HFNT100 and HFNT21 alternatively in a randomized order. RESULTS: HFNT21 and HFNT100 significantly reduced dyspnoea, respectively of ∆A-VAS = 0.80 cm [-0.02-1.5]; p = 0.007 and ∆A-VAS = 1.00 cm [0.08-1.75]; p < 0.0001; ∆S-VAS = 0.70 cm [-0.15-1.98]), p < 0.0001 and ∆S-VAS = 0.70 cm [0.08-1.95]), p = 0.0002) with no significant difference between HFNT21 and HFNT100. HFNT did not significantly alter the respiratory rate or the heart rate, reduced PtcCO2 only on room air and GSR under both experimental conditions. CONCLUSION: HFNT was associated with a statistically significant reduction in the intensity of the sensory and affective components of dyspnoea, independent of oxygen addition. This relief of laboratory dyspnoea could result from a reduction of afferent-reafferent mismatch.

Latency to N3 interruption in arousal disorders.

STUDY OBJECTIVES: To help expert witnesses in criminal cases using the "sleepwalking defense," we studied the time of first and last interruptions from stage N3 in patients with arousal disorders, including sexsomnia, as well as their determinants. METHODS: The epochs of lights off, sleep onset, first N3 interruption (with and without behaviors), and last N3 interruption were determined by videopolysomnography on two consecutive nights in 163 adults with disorders of arousal, including 46 with and 117 without sexsomnia. RESULTS: The first N3 interruption (independently of concomitant behavior) occurred as early as 8 minutes after sleep onset and within 100 minutes of falling asleep in 95% of cases. The first motor arousal from N3 occurred as early as 25 minutes after lights off time, a timing more variable between participants (between 30 and 60 minutes after lights off time in 25% of participants and within 60 minutes of falling asleep in 50%). These latencies did not differ between the groups with and without sexsomnia. No correlation was found between these latencies and the young age, sex, or clinical severity. The latency of motor arousals was shorter when they were associated with a fast-wave EEG profile and were not preceded by another type of N3 arousal. CONCLUSIONS: The first motor arousal may occur early in the night in patients with arousal disorders, with or without sexsomnia, suggesting that abnormal behaviors occurring as early as 25 minutes after lights off time in clinical and criminal cases can be a parasomnia manifestation.

ERS International Congress 2023: highlights from the Respiratory Intensive Care Assembly.

Early career members of Assembly 2 (Respiratory Intensive Care) attended the 2023 European Respiratory Society International Congress in Milan, Italy. The conference covered acute and chronic respiratory failure. Sessions of interest to our assembly members and to those interested in respiratory critical care are summarised in this article and include the latest updates in respiratory intensive care, in particular acute respiratory distress syndrome and mechanical ventilation.