Humidification via high-flow nasal cannula oxygen therapy does not generate aerosols

Effect of high-flow nasal cannula oxygen therapy in combination with non-invasive ventilation on critically ill patients with acute respiratory failure: a retrospective study

Background

Acute respiratory failure (ARF) is a respiratory disease in which ventilation dysfunction of the lungs occurs at rest due to various factors, resulting in oxygen deprivation and carbon dioxide (CO2) retention. In recent years, high-flow nasal cannula (HFNC), as a new type of oxygen therapy, has attracted increasing attention. Compared with traditional oxygen therapy, HFNC adopts nasal catheter to make it more in line with the physiological and respiratory characteristics of the human body, and thus can provide a higher and more constant inhalation of oxygen. This retrospective study was conducted to explore the clinical effect of HFNC combined with non-invasive ventilation (NIV) in the treatment of critically ill patients with ARF.

Methods

A total of 532 critically ill patients with ARF treated in our hospital from January 2019 to December 2020 were screened for the suitability for being included in the study. Of these, 261 patients in this study received NIV. In total, 151 patients were included after applying the inclusion and exclusion criteria. NIV was generally given intermittently, and the daily duration of application was determined according to the patient's condition. The NIV-treated patients were assigned into two groups according to the oxygen inhalation mode during intermittent NIV: (I) standard group: normal oxygen inhalation was applied at the NIV interval; and (II) research group: patients treated with HFNC at the NIV interval. The respective basic data and outcome observation indices were collected.

Results

In terms of the clinical outcome, the number of NIV treatment days in the research group was lower (P<0.05). At 30 min, 1 h, and 24 h after treatment, the partial pressure of arterial oxygen (PaO2), arterial oxygen saturation (SaO2), oxygenation index (P/F) indices in the research group were higher, while the CO2 partial pressure (PaCO2) was lower (P<0.05). Finally, the 28- and 90-day survival rates were compared between the groups and the results indicated no significant difference in the 28-day survival rates, but the 90-day survival rates of the research group were considerably higher (P<0.05).

Conclusions

The use of HFNC combined with NIV to treat ARF in critically ill patients can effectively improve the ARF-related respiratory indicators in critically ill patients.

Comparison of preoxygenation efficiency measured by the oxygen reserve index between high-flow nasal oxygenation and facemask ventilation: a randomised controlled trial

BACKGROUND

High-flow nasal oxygenation and the oxygen reserve index (ORI), which is a non-invasive and innovative modality that reflects the arterial oxygen content, are used in general anaesthesia. This study compares the preoxygenation efficiency (measured by the ORI) of high-flow nasal oxygenation and facemask ventilation during the induction process.

METHODS

This single-centre, two-group, randomised controlled trial included 197 patients aged ≥ 20 years who underwent orotracheal intubation for general anaesthesia for elective surgery. The patients were randomly allocated to receive preoxygenation via facemask ventilation or high-flow nasal oxygenation. The ORI was measured and compared between both groups.

RESULTS

The ORI increased during preoxygenation in all patients. At 1 min of preoxygenation, the ORI was significantly higher in the high-flow nasal oxygenation group (0.34 ± 0.33) than in the facemask ventilation group (0.21 ± 0.28; P = 0.003). The highest ORI was not significantly different between the two groups (0.68 ± 0.25 in the high-flow nasal oxygenation group vs. 0.70 ± 0.28 in the facemask ventilation group; P = 0.505).

CONCLUSIONS

High-flow nasal oxygenation results in an oxygenation status similar to that provided by facemask ventilation during the induction process of general anaesthesia; therefore, high-flow nasal oxygenation is a feasible preoxygenation method.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT04291339).