Study On The Feasibility And Effectiveness Of Pulsed-dose Oxygen Delivery System Combined With Noninvasive Positive Pressure Ventilation

Objective:Studies have shown that approximately 30%of patients with noninvasive positive pressure ventilation?NPPV?need long-term oxygen therapy?LTOT?at the same time.When this part of the patient has the needs of going out,traveling and even on the plane,if the patient can be simultaneously treated with noninvasive positive pressure ventilation and oxygen therapy,it will improve the patient's treatment compliance and quality of life.Therefore,the Noninvasive ventilator was directly connected the Pulsed portable concentrator?POC?with a data line and then investigated the feasibility and effectiveness of pulsed-dose oxygen delivery system combined with noninvasive positive pressure ventilation.Method:In the bench study,we used Active simulated lung?ASL5000?as a test platform,which setting was same as a COPD patient and connected the Noninvasive ventilator and the POC to simulate oxygen delivery during NPPV.Respiratory rate was respectively set to 10 and 20.Oxygen injection points were:the mask?point A?,the mask near the end?point B?and ventilator outlet?point C?.The POC was set to deliver either a continuous flow of 1?3 and 5 L/min or a pulsed dose of 1?3 and 5 gear.After changing the test conditions for 3 minutes each time,observed variables for 10 consecutive respiratory cycles were recorded.In animal study,a crossover study,we induced ALI in 6dogs using an oleic acid model.The POC was set to deliver either a continuous flow of 1and 3 L/min or a pulsed dose of 1and 3 gear.Each oxygen delivery condition is 10minutes,the elution period is 5 minutes,then enters another oxygen delivery condition,and recorded the observed variables of each period.Results:In the bench study,1.At similar settings,the average ratio of Fi O₂ for the pulsed dose to Fi O₂ for the continuous flow was 0.85±0.14;2.No matter what kind of oxygen delivery system,Fi O₂ was the highest in the position A;3.In the pulsed dose delivery,Fi O₂ increased significantly with the increase of respiratory rate and setting gear?P<0.05?;in the continuous flow,Fi O₂ increased significantly with the decrease of respiratory rate and increase of flow rate?P<0.05?;4.The respiratory rate displayed by the ventilator,the frequency of the oxygen supply for pulse display by the oxygen generator,and the spontaneous breathing rate for the simulated lung settings were consistent;5.Both oxygen supply methods had no significant effect on the performance of non-invasive positive pressure ventilation?P>0.05?In animal study,1.In compare with the basic state,the pulsed dose and the continuous flow could supply higher PaO₂?P<0.05?.2.Respiratory rate and heat rate were significantly improvement in the pulsed dose and the continuous flow?P<0.05?,no significant effect on other indicators?E.g.systolic,diastolic??P>0.05?.3.There was no significant difference in vital signs,respiratory mechanics,and hemodynamic parameters between the continuous flow and the pulsed dose?P>0.05?.Conclusion:The pulse dosed could be combined with noninvasive positive pressure ventilation at the same time.The pulsed dose and the continuous flow were similar equivalent in oxygen supply,the two had no effect on noninvasive positive pressure ventilation.