Clinical experience of high-flow nasal cannula oxygen therapy in severe corona virus disease 2019 (COVID-19) patients / 浙江大学学报·医学版

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19) induced by severe acute respiratory syndrome coronavirus 2 infection. Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial flow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.

Clinical experience of high-flow nasal cannula oxygen therapy in severe COVID-19 patients / 浙江大学学报·医学版

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19). Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical ill COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial ow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.

Efficacy analysis of sequential nasal high flow oxygen after extubation in patients with acute respiratory failure / 中华急诊医学杂志

Objective To investigate the clinical efficacy of sequential nasal flow ventilation after extubation in patients with acute respiratory failure (referred to as respiratory failure).First of all,before and after extubation in HFNCO group,the respiratory parameters (PaO2,PaCO2,pH,lactic acid value,oxygenation index,HR,RR and LVEF) were compared with each other.The circulatory parameters (PaO2,PaCO2,pH,lactate,oxygenation index,HR,RR),clinical outcomes at the end of treatment / comorbidities (delirium,diarrhea,reintubation,ICU stay after extubation).Methods PaO2,PaCO2,pH value,lactate value at 1 h,6 h,12 h and 24 h after extubation in HFNCO group were not significantly different from those before extubation (all P＞ 0.05) (P ＜0.05).The LVEF of patients after extubation was slightly higher than that before extubation (0.59 ± 0.09 vs.0.60 ± 0.09),and the difference was not statistically significant Significance (P＞ 0.05).PaO2,PaCO2,pH and lactate value in HFNCO group and NIV group at 1 h,6 h,12 h and 24 h after extubation showed no significant difference (all P＞ 0.05).The effect of HFNCO on improving the oxygenation index after extubation was better than that of NPV group (P ＜0.05).HR and RR before extubation were higher or higher in HFNCO group than those in NPV group lower HR,RR better (P ＜0.05).The incidence of diarrhea (33.33％ vs.38.89％) and reintubation rate (6.1％ vs 13.9％) in HFNCO group were lower than those in NIV group (38.89％),but the difference was not statistically significant (all P＞ 0.05).The incidence of delirium in HFNCO group (18.18％ vs.41.67％) and ICU stay time after extubation (2.00 to 3.50) were statistically significant (all P ＜0.05).Results There were no significant differences in the arterial blood gas analysis (PaO2,PaCO2,pH,lactate value),PaO2,PaCO2,pH value,lactate value and LVEF at 1 h,6 h,12 h and 24 h before and after extubation in HFNCO group (all P＞ 0.05) Slightly higher than before extubation (0.59 ± 0.09 vs.0.60 ± 0.09),the difference was not statistically significant (P＞ 0.05).PaO2,PaCO2,pH and lactate value in HFNCO group and NIV group at 1 h,6 h,12 h and 24 h after extubation showed no significant difference (all P＞ 0.05).The incidence of diarrhea (33.33％ vs.38.89％) and reintubation rate (6.1％ vs.13.9％) in HFNCO group were lower than those in NIV group (38.89％),but the difference was not statistically significant (all P＞ 0.05).The incidence of delirium (18.18％ vs.41.67％),and ICU stay time (2.00 to 3.50) in HFNCO group were significantly lower than those in NIV group (all P＜0.05).Conclusions For acute respiratory failure patients after mechanical ventilation extubation,sequential administration of HFNCO and NIV can provide stable and effective oxygen therapy support;relative to the NIV,HFNCO can effectively improve patients oxygenation index,improve patient comfort and reduce the incidence of delirium And ICU stay time.

Clinical Comparative Study of Adaptive Support Ventilation and Pressure-controlled Assist/Control Ventilation on Respiratory Failure / 医学研究杂志

Objective To compare adaptive support ventilation (ASV) and pressure-controlled assist/control ventilation (PCMV) and evaluate the clinical effects of ASV. Methods 12 cases of acute respiratory failure patients induced by all causes were selected in the study. All patients with breathing independently underwent endotracheal intubation. The patterns of mechanical ventilation was PCMV-ASV-PCMV. the two settings of PCMV were uniformity. With ASV mode mechanical ventilation,we adjusted the percentage of minute ventilation (MV%) and ideal body weight (IBW) of patients,so as to reach the same minute ventilation volume of PCMV. We compared the blood gas,respiratory mechanics,work of breathing(WOB),airway occlusion pressure (P0.05). Compared with the first of PCMV,various indicators and blood gas of ASV had no significant difference,work of breathing (WOB),airway occlusion pressure (P=0.1) and inspiratory pressure time product (PTP) were significantly lower (P0.05). Conclusion ASV can get similar goals with conventional ventilation,and reduce patient′s effort and the central respiratory drive.