ABSTRACT
BACKGROUND: There is limited research into the utility of average volume- assured pressure support (AVAPS), a volume-assured pressure-controlled mode, especially in patients with hypercapnic respiratory failure. AIMS: This study aimed at a randomized comparison of AVAPS and bilevel positive airway pressure spontaneous/timed (BPAP S/T) modes in non-invasive mechanical ventilation application with hypercapnic respiratory failure patients in the emergency department. STUDY DESIGN: Randomized controlled study. METHODS: Eighty of 140 patients admitted to the emergency department with hypercapnic respiratory failure requiring non-invasive mechanical ventilation were randomly assigned to the AVAPS or S/T groups (33 patients in the S/T group, 47 patients in the AVAPS group) using the sealed envelope method. Data of arterial blood gas, vital parameters, Glasgow Coma Score, additional treatment needs, and clinical outcomes were evaluated, and the treatment success rates of both groups were compared. RESULTS: A total of 80 patients, 33 in the S/T and 47 in the AVAPS group, were analyzed in the study. The pH values improved in the AVAPS group compared to the baseline (0.07 [0.04-0.10] vs 0.03 [0.00-0.11]). PaCO2 (partial pressure of carbon dioxide) excretion was faster in the AVAPS group than in the S/T group in the first hour (10.20 mmHg [6.20-19.20] vs. 4.75 ([-] 0.83-16.88)). The comparison of blood gas measurements showed no significant differences between the groups regarding the changes in PaCO2 and pH values over time (P = .141 and P = .271, respectively). During the emergency department follow-up, 3 (6.4%) patients in the AVAPS group and 5 (15.2%) patients in the S/T group needed intubation [Relative risk: 0.42 (95% CI: 0.11 to 1.64), P = .21]. CONCLUSION: The AVAPS mode is as effective and safe as BPAP S/T in treating patients with hypercapnic respiratory failure in the emergency department.
Subject(s)
Continuous Positive Airway Pressure , Hypercapnia/therapy , Noninvasive Ventilation/methods , Positive-Pressure Respiration/methods , Respiratory Insufficiency/therapy , Aged , Aged, 80 and over , Blood Gas Analysis/methods , Critical Care/methods , Emergency Service, Hospital , Female , Humans , Male , Middle Aged , Prospective Studies , Treatment OutcomeABSTRACT
BACKGROUND: High-flow nasal cannula (HFNC) oxygen is becoming an integral part of respiratory failure management. Effects of HFNC on arterial blood gas (ABG) parameters especially partial carbon dioxide (PaCO2) require further investigation to provide insight into the efficacy and safety of the treatment. METHODS: Acute respiratory failure patients with sequential ABG parameters before and after initiating HFNC between June 2015 and June 2017 were analyzed in a tertiary academic center. Patients' baseline characteristics were evaluated and sequential ABG changes were compared and subgrouped as chronic obstructive pulmonary disease (COPD), respiratory acidosis, hypercapnia, and high lactate. RESULTS: A total of 120 patients were enrolled in the study. There was a significant difference between the mean partial pressure of oxygen in arterial blood (PaO2), lactate, and peripheral oxygen saturation (SpO2) values between sequential ABGs after HFNC (P <0.001). In the COPD group (n=32), there was a significant difference between initial ABG means of PaO2, lactate, and SpO2 values and sequential ABG means (p<0.001). Hypercapnic patients PaCO2 levels were significantly lower after HFNC (p<0.001), while in the COPD group there was no significant change in PaCO2 values (p=0.068). CONCLUSIONS: Treatment with HFNC produced improvement of blood gas parameters in subjects with acute respiratory failure in the emergency department (ED). These results suggest that HFNC can be used in hypercapnic patients as well as hypoxemic patients. Further randomized controlled studies required to establish the impact of HFNC in the ED.
