RESPONSE TIMES FOR ACUTE NON-INVASIVE VENTILATION SET-UPS

Dear Editor,

NIVis a lifesaving treatment in chronic obstructive pulmonary disease (COPD). Prompt NIV treatment in hypercapnic COPD exacerbations allows for improved physiological outcomes, reduced intubation rates and shortened hospital stay in (1, 2). Therefore, consensus expert opinion is that prompt application of acute NIV substantially reduces the risk of death and should be started without delay in appropriately selected patients with acute hypercapnic respiratory failure (AHRF).The ‘door-to-mask’ time (hospital arrival to NIV commencement: target ≤120 minutes) has been widely used to measure the quality of acute NIV services as per the 2018 BTS Quality Standards (3, 4). In setting a 120 min target from arrival to mask application, this statement intends to establish that recognition and treatment of AHRF are time-critical events for patients admitted acutely. We previously reported a median ‘door-to-mask’ time at the emergency department at Heartlands Hospital in 2014 of 115 min, meeting the 2018 BTS quality standard of ≤120 minutes(5). As part of an important quality improvement initiative, we have subsequently developed internal guidelines and monthly NIV training sessions to try to improve acute NIV service quality. We aimed to look at response times within the door-to-mask time using standards derived from the British Thoracic Society/Intensive Care Society Guideline for the ventilatory management of acute hypercapnic respiratory failure and 2019 BTS NIV Audit Report to generate insights for future quality improvement (6) (Figure 1).

Data on metrics were recorded for all acute NIV recipients in the Emergency Department (ED) at Heart of England Foundation NHS Trust and stored in our acute NIV quality database for subsequent extraction and calculation of median (interquartile ranges (IQR)). Between 27/03/19 and 26/09/19, 89 patients received NIV with 46 starting on acute NIV in ED, 38 developed acidosis later and 5 had incomplete data(7). The total door to mask time in ED was 163 (197) mins. Within this, the door-to-first-ABG time was 29 (55) minutes, the first-ABG-to-Decision making/call time was 72 (77)minutes and decision making-to-mask time was 40 (20) minutes. We saw an increase in door-to-mask time from 2014 to 2019, likely reflecting the national increase in ED wait times. However, the decision-making to mask time was 40 min which has decreased from 55 since 2014, reflecting the improved response times of physiotherapists potentially due to feedback on performance and monthly NIV training sessions for allied health professionals, as well as internal guideline development (8). This audit is part of a continual quality improvement project and will serve as a foundation to monitor specific response times and quality with iterative interventions. With the ongoing COVID-19 pandemic and stringent infection control measures around aerosol generating procedures, it is now essential to determine the impact this has had on NIV service quality and excess deaths with a view for continual quality improvement.