[Preliminary evaluation of sequential therapy by high flow nasal cannula oxygen therapy following endotracheal tube extubation in mechanically ventilated patients].

OBJECTIVE To evaluate the feasibility and effect of sequential treatment by the heated humidified high flow nasal cannula oxygen therapy (HFNC) in mechanically ventilated patients following endotracheal tube extubation. METHODS A prospective randomized controlled trial was conducted. Forty-nine patients with the sequential treatment after tracheal intubation extraction admitted to Department of Critical Care Medicine of Shanghai Tenth People's Hospital from January 1st to December 31st 2016 were enrolled. The patients were randomly divided into HFNC group (n = 25) and non-invasive positive pressure ventilation (NPPV) group (n = 24) in accordance with the random number table. During the study, arterial blood gas and the sputum viscosity were assessed at 12, 24, and 48 hours after NPPV or HFNC treatment, and the nasal and facial pressure ulcers within 1 week was also recorded. Receiver operating characteristic curve (ROC) was plotted, and the effect of NPPV or HFNC on oxygenation was analyzed. RESULTS Among the 25 patients in the HFNC group, 1 patient who was re-intubated and 2 patients who were changed to NPPV were excluded, and a total of 22 patients with complete data were enrolled in HFNC group. Among the 24 patients in the NPPV group, 1 patient who gave up the treatment and 1 patient who was re-intubated were excluded, and a total of 22 patients with complete data were enrolled in NPPV group. After the sequential treatment, most patients in NPPV group showed moderate viscous sputum (12, 12 and 10 cases at 12, 24 and 48 hours, respectively), whereas the patients in HFNC group showed thin sputum (15, 16 and 15 cases at 12, 24 and 48 hours, respectively). Sputum viscosity of patients in HFNC group at each time point was significantly lower than that in NPPV group (all P < 0.01). Arterial oxygen saturation (SaO2) and arterial partial pressure of oxygen (PaO2) at 12, 24 and 48 hours in the HFNC group were significantly higher than those in the NPPV group [SaO2: 0.978±0.009 vs. 0.906±0.139 at 12 hours, 0.976±0.019 vs. 0.924±0.103 at 24 hours, 0.973±0.019 vs. 0.935±0.079 at 48 hours; PaO2 (mmHg, 1 mmHg = 0.133 kPa): 97.85±22.99 vs. 79.24±25.86 at 12 hours, 108.10±43.87 vs. 84.44±29.24 at 24 hours, 102.31±39.02 vs. 79.04±27.46 at 48 hours, all P < 0.05], however, the difference in arterial partial pressure of carbon dioxide (PaCO2) at all of the time points between the two groups was not significant. In NPPV group, 4 patients with nasal and facial pressure ulcers was found, and all with I phase of pressure ulcers, and no nasal and facial pressure ulcers was found in HFNC group, which was significantly decreased as compared with NPPV group (χ 2 = 4.400, P = 0.036). A good effect of oxygen therapy was defined as PaO2 at 48 hours after the sequential treatment was increased by 20% as compared with that before the treatment. ROC curve analysis showed that the area under the ROC curve (AUC) of HFNC on improving oxygenation was higher than that of NPPV (0.917 vs. 0.830); when PaO2 at 48 hours after HFNC treatment was 76.25 mmHg, the sensitivity was 100%, and the specificity was 75.0%. CONCLUSIONS Compared with NPPV, adoption of HFNC as sequential treatment is a feasible manner in dealing with the mechanically ventilated patients after endotracheal tube extubation, which can improve the oxygenation as well as reducing the degree of sputum viscosity and incidence of nasal and facial pressure ulcers. HFNC is a promising therapy, which may be worthy to recommend broadly in such a clinical situation.