Predictors and outcomes of withholding and withdrawal of life-sustaining treatments in intensive care units in Singapore: a multicentre observational study

BACKGROUND

Clinical practice guidelines on limitation of life-sustaining treatments (LST) in the intensive care unit (ICU), in the form of withholding or withdrawal of LST, state that there is no ethical difference between the two. Such statements are not uniformly accepted worldwide, and there are few studies on LST limitation in Asia. This study aimed to evaluate the predictors and outcomes of withholding and withdrawal of LST in Singapore, focusing on the similarities and differences between the two approaches.

METHODS

This was a multicentre observational study of patients admitted to 21 adult ICUs across 9 public hospitals in Singapore over an average of three months per year from 2014 to 2019. The primary outcome measures were withholding and withdrawal of LST (cardiopulmonary resuscitation, invasive mechanical ventilation, and vasopressors/inotropes). The secondary outcome measure was hospital mortality. Multivariable generalised mixed model analysis was used to identify independent predictors for withdrawal and withholding of LST and if LST limitation predicts hospital mortality.

RESULTS

There were 8907 patients and 9723 admissions. Of the former, 80.8% had no limitation of LST, 13.0% had LST withheld, and 6.2% had LST withdrawn. Common independent predictors for withholding and withdrawal were increasing age, absence of chronic kidney dialysis, greater dependence in activities of daily living, cardiopulmonary resuscitation before ICU admission, higher Acute Physiology and Chronic Health Evaluation (APACHE) II score, and higher level of care in the first 24 h of ICU admission. Additional predictors for withholding included being of Chinese race, the religions of Hinduism and Islam, malignancy, and chronic liver failure. The additional predictor for withdrawal was lower hospital paying class (with greater government subsidy for hospital bills). Hospital mortality in patients without LST limitation, with LST withholding, and with LST withdrawal was 10.6%, 82.1%, and 91.8%, respectively (p < 0.001). Withholding (odds ratio 13.822, 95% confidence interval 9.987-19.132) and withdrawal (odds ratio 38.319, 95% confidence interval 24.351-60.298) were both found to be independent predictors of hospital mortality on multivariable analysis.

CONCLUSIONS

Differences in the independent predictors of withholding and withdrawal of LST exist. Even after accounting for baseline characteristics, both withholding and withdrawal of LST independently predict hospital mortality. Later mortality in patients who had LST withdrawn compared to withholding suggests that the decision to withdraw may be at the point when medical futility is recognised.

Impact of Guideline-Based Asthma Treatment on Health Services Use in Singapore Before and During COVID-19 Outbreak

Introduction

To date, the role of standard asthma care in reducing asthma-related health services use (HSU) during the COVID-19 pandemic remains unclear. This study examined the impact of guideline-based asthma treatment on the use of asthma-related emergency department (ED) visits, polyclinic visits (total visits and urgent visits characterized by nebuliser use) before and during the pandemic.

Methods

Data from April 2017 to October 2020 was obtained from the National University Health System, one of the three healthcare clusters in Singapore. Using generalized linear models, we estimated the joint effects of the ratio of preventer to reliever dispensations (PRR) and COVID-19 on asthma-related ED visits per hospital per month, total asthma-related polyclinic visits and asthma-related urgent polyclinic visits per clinic per month.

Results

Findings show that before the onset of COVID-19, for every 0.5 unit increase in PRR, the number of asthma-related ED visits and urgent polyclinic visits decreased by 12.9% (95% CI: -13.0% to -12.9%) and 6.8% (95% CI: -6.9% to -6.7%), respectively, whereas total asthma-related polyclinic visits increased by 1.0% (95% CI: 0.9% to 1.0%). During the pandemic, a 0.5 unit increase of PRR decreased the number of asthma-related ED visits, urgent and total polyclinic visits by 16.9% (95% CI: -17.0% to - 16.9%), 9.3% (95% CI: -9.5% to -9.2%) and 0.7% (95% CI: -0.8% to -0.7%), respectively.

Discussion

These findings suggest that regardless of the COVID-19 pandemic, an increase in PRR consistently reduced the frequency of asthma-related urgent and emergent care, although it barely influenced routine asthma follow-up visits.

Dominant negative TRAF3 variant with recurrent Mycobacterium abscessus infection and bronchiectasis

Host factors leading to pulmonary NTM (PNTM) disease is poorly understood compared to disseminated NTM disease which is linked to IL12-IFNγ signaling pathway. We elucidated TNF receptor–associated factor 3 (TRAF3) R338W variant in patient with recurrent PNTM infection: demonstrating TRAF3-and TNF-α deficient phenotype, via ex-vivo immune and cloning-transfection cellular studies.

Eosinophilic endotype of chronic obstructive pulmonary disease: similarities and differences from asthma

Approximately 25% to 40% of patients with chronic obstructive pulmonary disease (COPD) have the eosinophilic endotype. It is important to identify this group accurately because they are more symptomatic and are at increased risk for exacerbations and accelerated decline in forced expiratory volume in the 1st second. Importantly, this endotype is a marker of treat ment responsiveness to inhaled corticosteroid (ICS), resulting in decreased mortality risk. In this review, we highlight differences in the biology of eosinophils in COPD compared to asthma and the different definitions of the COPD eosinophilic endotype based on sputum and blood eosinophil count (BEC) with the corresponding limitations. Although BEC is useful as a biomarker for eosinophilic COPD endotype, optimal BEC cut-offs can be combined with clinical characteristics to improve its sensitivity and specificity. A targeted approach comprising airway eosinophilia and appropriate clinical and physiological features may improve identification of subgroups of patients who would benefit from biologic therapy or early use of ICS for disease modification.

Association between lung compliance phenotypes and mortality in COVID-19 patients with acute respiratory distress syndrome

ABSTRACT Introduction: Acute respiratory distress syndrome (ARDS) in COVID-19 is associated with a high mortality rate, though outcomes of the different lung compliance phenotypes are unclear. We aimed to measure lung compliance and examine other factors associated with mortality in COVID-19 patients with ARDS. Methods: Adult patients with COVID-19 ARDS who required invasive mechanical ventilation at 8 hospitals in Singapore were prospectively enrolled. Factors associated with both mortality and differences between high (<40mL/cm H2O) and low (<40mL/cm H2O) compliance were analysed. Results: A total of 102 patients with COVID-19 who required invasive mechanical ventilation were analysed; 15 (14.7%) did not survive. Non-survivors were older (median 70 years, interquartile range [IQR] 67–75 versus median 61 years, IQR 52–66; P<0.01), and required a longer duration of ventilation (26 days, IQR 12–27 vs 8 days, IQR 5–15; P<0.01) and intensive care unit support (26 days, IQR 11–30 vs 11.5 days, IQR 7–17.3; P=0.01), with a higher incidence of acute kidney injury (15 patients [100%] vs 40 patients [46%]; P<0.01). There were 67 patients who had lung compliance data; 24 (35.8%) were classified as having high compliance and 43 (64.2%) as having low compliance. Mortality was higher in patients with high compliance (33.3% vs 11.6%; P=0.03), and was associated with a drop in compliance at day 7 (-9.3mL/cm H2O (IQR -4.5 to -15.4) vs 0.2mL/cm H2O (4.7 to -5.2) P=0.04). Conclusion: COVID-19 ARDS patients with higher compliance on the day of intubation and a longitudinal decrease over time had a higher risk of death. Keywords: ARDS, COVID-19-associated respiratory failure, high-flow nasal cannula therapy, HFNC, post-intubation, ventilation strategies

Improving Influenza Vaccination Coverage Among Patients With COPD: A Pilot Project

Background and objective

Guidelines for chronic obstructive pulmonary disease (COPD) advocate regular influenza vaccination, which has been shown to reduce exacerbations. However, influenza vaccination rates remain low. This quality improvement project was initiated to help improve influenza vaccination rates in a tertiary hospital.

Methods

All patients with COPD in the airway program (TAP) in the National University Hospital at the end of 2013 were recruited. The interventions were implemented in 2014; thus, population was stratified into the pre-intervention group and post-intervention group. Those who died in 2014 were excluded. They were (1) patient education posters in the clinics on the need for regular influenza vaccination, (2) direct interventions by physicians, and (3) intervention by the nurses when vaccinations were neglected. Physicians were made aware of previous vaccination rates, vaccination card reminders were placed in the clinics, and a new electronic healthcare record system (EHR) was implemented. The patients were followed up till the end of 2015 or until death. When an influenza vaccination was administered, the patients were asked which of the interventions led to the vaccination. A questionnaire was delivered to the physicians to determine the interventions that led to any change in vaccination prescription practices.

Results

The pre-intervention influenza vaccination rate was low at 47.7%. The post-intervention influenza vaccination rate improved to 80.7% with the multi-pronged approach. Physicians initiated the majority of vaccinations (87.9%), while nurses helped intervene in a further 12.1%. Physicians’ vaccination prescription practices changed as a result of self-awareness of low vaccination rates, vaccination card reminders, and the new EHR. Patient education made minimal impact.

Conclusion

This project demonstrates that with regular audits to track progress and several easy-to-implement interventions, improving influenza vaccination rates is an achievable goal.