Non-invasive ventilation for acute hypoxaemic respiratory failure: a propensity-matched cohort study.

BACKGROUND: Non-invasive ventilation (NIV), although effective in treating hypercapnic respiratory failure, has not demonstrated the same efficacy in treating acute hypoxaemic respiratory failure. We aimed to examine the effect of NIV use on ventilator-free days in patients with acute hypoxaemic respiratory failure admitted to the intensive care unit (ICU). METHODS: We conducted a retrospective study of patients admitted to the ICU with acute hypoxaemic respiratory failure at Waikato Hospital, New Zealand, from 1 January 2009 to 31 December 2018. Patients treated with NIV as the initial oxygenation strategy were compared with controls treated with early intubation. The two groups were matched using a propensity score based on baseline characteristics. The primary outcome was the number of ventilator-free days at day 28. The secondary outcomes were ICU and hospital length of stay and in-hospital mortality. RESULTS: Out of 175 eligible patients, 79 each out of the NIV and early intubation groups were matched using a propensity score. Early NIV was associated with significantly higher median ventilator-free days than early intubation (17 days vs 23 days, p=0.013). There was no significant difference in median ICU length of stay (112.5 hours vs 117.7 hours), hospital length of stay (14 days vs 14 days) or in-hospital mortality (31.6% vs 37.9%) between the NIV and the early intubation group. CONCLUSION: Compared with early intubation, NIV use was associated with more ventilator-free days in patients with hypoxaemic respiratory failure. However, this did not translate into a shorter length of stay or reduced mortality based on our single-centre experience.

Impact of COVID-19 pandemic restrictions on the cardio-respiratory health of New Zealanders.

BACKGROUND AND OBJECTIVE: The COVID-19 pandemic has caused disruption to health, social interaction, travel and economies worldwide. In New Zealand, the government closed the border to non-residents and required all arrivals to quarantine for 14 days. They also implemented a strict contact-restriction system to eliminate COVID-19 from the community. These measures also reduced the circulation of other respiratory viruses such as influenza and respiratory syncytial virus. We assessed the impact of these measures on hospital admissions for respiratory and cardiac diseases. METHODS: National data on hospital admissions for each week of 2020 were compared to admissions for the previous 5 years. Analyses were curtailed after week 33, when a COVID-19 outbreak in Auckland led to different levels of pandemic restrictions making national data difficult to interpret. RESULTS: The numbers of acute infectious respiratory admissions were similar to previous years before the introduction of COVID-19 restrictions, but then fell lower and remained low after the pandemic restrictions were eased. The usual winter peak in respiratory admissions was not seen in 2020. Other than small reductions during the period of the strictest contact restrictions, non-infectious respiratory and cardiac admissions were similar to previous years and the usual winter peak in heart failure admissions was observed. CONCLUSION: The observed patterns of hospital admissions in 2020 are compatible with the hypothesis that circulating respiratory viruses drive the normal seasonal trends in respiratory admissions. By contrast, these findings suggest that respiratory viruses do not drive the winter peak in heart failure.

Cardiac biomarkers and long-term outcomes of exacerbations of COPD: a long-term follow-up of two cohorts.

BACKGROUND: COPD patients often have cardiac comorbidities. Cardiac involvement at the time of a COPD exacerbation is associated with a high short-term mortality, but whether this influences long-term outcomes is unknown. We explored whether biomarkers of cardiac dysfunction at the time of a COPD exacerbation predict long-term outcomes. METHODS: Two prospective cohorts of patients admitted to Waikato Hospital for exacerbations of COPD were recruited during 2006-2007 and 2012-2013. N-terminal pro-B-type natriuretic peptide (NT-proBNP) and troponin T were measured on admission and were used to indicate cardiac stretch and myocardial injury, respectively. 5-year survival after discharge and subsequent admissions for cardiac disease and COPD exacerbations were analysed using Kaplan-Meier and Cox proportional hazards tests. RESULTS: The overall 5-year mortality was 61%. Patients with high NT-proBNP on admission had higher mortality than those with normal cardiac biomarkers (adjusted hazard ratio (aHR) 1.76, 95% CI 1.18-2.62). High NT-proBNP was also associated with a higher risk of future cardiac admissions (aHR 1.75, 95% CI 1.2-2.55). Troponin T levels were not associated with long-term survival (aHR 0.86, 95% CI 0.40-1.83) or future cardiac admissions (aHR 0.74, 95% CI 0.34-1.57). Neither biomarker predicted future COPD exacerbations. CONCLUSION: The long-term prognosis following a hospitalisation for an exacerbation of COPD is poor with less than half of patients surviving for 5 years. Elevated NT-proBNP at the time of a COPD exacerbation is associated with higher long-term mortality and a greater likelihood of future cardiac admissions, but not future COPD exacerbations.