A Comparative Study On The Effects Of Different Temperatures And Flow Rates Of Humidified High Flow Nasal Cannula Oxygen Therapy On ICU Patients After Extubation

Research Purpose:In this study,patients with sequential nasal high-flow humidified oxygen therapy after ICU extubation were used as the research object.Using a factorial design approach,the influence of oxygen therapy comfort and curative effect of two important factors?temperature and flow rate?for 2×3 factorial design combination.By finding the best temperature and flow rate settings,it will not affect the patient's oxygen therapy effect,but also can reduce the patient's mouth and nose dryness and throat pain score,thereby further improving the patient's compliance and tolerance to oxygen therapy and promoting the patient physical and mental comfort.Research Methods:?1?In this study,168 patients with sequential nasal high-flow humidification oxygen therapy after extubation from ICU in a third-grade a hospital in Zhejiang Province from January 2019 to December 2019 were selected as research objects.Using a factorial design approach,Factor 1:Temperature setting,three levels are 31?,34?,37?respectively.Factor 2:Flow rate setting,two levels are 40L/min and 50L/min respectively.The patients were randomly divided into groups A1,A2,A3,B1,B2 and B3,6 groups in total,with 28 patients in each group.Group A1:31?-40L/min;Group A2:34?-40L/min;Group A3:37?-40L/min;Group B1:31?-50L/min;Group B2:34?-50L/min;Group B3:37?-50L/min.Before the application of HHFNC oxygen therapy,baseline evaluation?including:gender,age,BMI,mechanical ventilation time,APACHE II score,etc.?was conducted,and the comfort score,vital signs,blood gas index and adverse reactions of patients were collected 30 minutes after HHFNC oxygen therapy intervention,so as to find the best combination scheme of temperature and flow rate.?2?In this study,Excel was used for data entry,and SPSS 22.0 software was used for data statistical analysis and processing.For counting data,relative number and frequency were used to express,and Chi-square test or Fisher exact probability method were used for comparison among multiple groups.The measurement data first to determine whether they meet the normal distribution,to satisfy the normal distribution?or mild skewness?and homogeneity of variance data,it was expressed as the mean±standard deviation?`x±s?,compared to One-way ANOVA among multiple groups or completely random design analysis of variance.If the P value<0.05,the difference was statistically significant,Bonferroni method was required to make a pairwise comparison.For the data that do not meet the normality test?or obvious skewness?,the median?M?and interquartile range?Q?were expressed,and the comparison among multiple groups was performed using Kruskal-Wallis H nonparametric test.The effects of different temperatures,different flow rates,and combinations of temperature and flow rates were compared using a 2×3factorial design analysis of variance,and the results were statistically significant with P<0.05.Research Results:?1?In terms of comfort of oxygen therapy:1 Score of oral and nasal dryness:Different temperature and flow rate settings had significant main effect on the score of oral and nasal dryness?P<0.001?,and had significant interaction effect on reducing the score of oral and nasal dryness in patients?P<0.05?.when the fixed flow velocity,the temperature of 31?,34?,respectively,compared with 37?,the results showed that different temperature settings when performing pairwise comparisons had statistical difference?P<0.05?,but compared to 31?,34?in reducing the score of dry mouth and nose on there was no statistical difference?P>0.05?,and 31?was the most significant in reducing the score of dry mouth and nose.Comparison of different flow rate settings of 40L/min and 50L/min,the results show that the former can significantly reduce the patient's mouth and nasal dryness score?P<0.05?.2 Throat pain score:The main effect of different temperature settings on reducing the throat pain score was significant?P<0.001?,and the main effect of different flow rate settings on reducing the throat pain score was also significant?P<0.001?,but there was no significant interaction effect of different temperature and flow rate settings on reducing the throat pain score?P>0.05?.The Bonferroni method was used to compare different temperature settings,and the results showed that,when compared with 37°C,the difference of 31°C and 34°C was statistically significant in reducing the throat pain score of patients?P=0.002<0.05,P=0.014<0.05?,but there was no statistical difference between 31°C and 34°C?P=1.000>0.05?.Comparing different flow settings at 40L/min and 50L/min,the results show that the former can significantly reduce the patient's throat pain score,and the difference was statistically significant?P=0.000<0.05?.?2?In terms of vital signs:Different temperature and flow rate settings had no interaction effect on the patient's HR,RR,and MAP?P>0.05?,and different temperature settings had a major effect on the patient's HR?P=0.046<0.05?,but the major effect on patient RR and MAP was not significant?P>0.05?,and different flow rate settings had no main effect on the indicators of patient HR,RR and MAP?P>0.05?.?3?In terms of blood gas indicators:Different temperatures and flow rates were set in patients'blood oxygen indicators,such as PaO₂,PaCO₂,PaO₂/FiO₂,pH and Lac indicators,with no interaction effect?P>0.05?.There was no major effect at different temperatures on patients'PaO₂,PaCO₂,PaO₂/FiO₂,pH and Lac indicators?P>0.05?,and there was no statistically significant effect at different flow rates on patients'PaO₂,PaCO₂,PaO₂/FiO₂,pH and Lac indicators?P>0.05?.?4?In terms of the incidence of adverse reactions related to oxygen therapy:There was no significant difference in the incidence of respiratory burning,neck and chest discomfort and abdominal distention between the six groups?P>0.05?.Research Conclusion:?1?Different temperature settings had significant main effects on the scores of dry mouth,nasal cavity and throat pain in the patients.The scores of dry mouth,nasal cavity and throat pain in the groups of 31?and 34?were significantly lower than those of the 37?group,while there was no significant difference between the 31?group and the 34?group.Different flow rate settings had significant main effects on the scores of oral and nasal dryness and laryngopharyngeal pain in patients,and the scores of oral and nasal dryness and laryngopharyngeal pain in the group with flow rate of 40L/min were significantly lower than those in the group with flow rate of50L/min.Therefore,this study suggested that the parameter setting of HHFNC oxygen therapy at31?-40L/min could significantly improve the patient's oxygen therapy comfort,thus improving the patient's oxygen compliance and tolerance.?2?Different temperature and flow rate settings had no interaction effect on patients'vital signs and blood gas indicators.Except that the temperature setting had a certain main effect on patient HR,there was no statistical difference in other indicators,which suggested that the setting of HHFNC oxygen treatment parameters would not cause significant changes in patients'vital signs and blood gas indicators in a short time.?3?There was no significant difference in the incidence of respiratory burns,neck and chest discomfort and abdominal distension among the six groups,suggesting that the setting of HHFNC oxygen treatment parameters at 31°C-40L/min did not increase the occurrence of related adverse reactions.?4?Without affecting the effect of oxygen therapy,it is suggested that the setting of early temperature and flow rate should start from 31?-40L/min for patients with sequential HHFNC oxygen therapy after ICU extubation.