RESUMO
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 Of the former, 80.8% had no limitation of LST, 13.0% had LST withheld, and 6.2% had LST withdrawn.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.
RESUMO
PURPOSE: Education in airway management is a fundamental component of anesthesiology training programs. There has been a shift towards the use of simulation models of higher fidelity for education in airway management. The goal of this study was to create a novel cadaveric model of a simulated parapharyngeal abscess with features of a difficult airway such as distorted anatomy and narrow airway passages presenting as stridor. The model was further assessed for its suitability for enhanced experiential learning in the management of difficult airways. METHODS: Cadaver heads were modified surgically to simulate parapharyngeal abscess. Airtight torso of the cadaver was connected to an Oxylog ventilator to simulate respiratory movements-the opening and closing of air channels with breaths in a patient with parapharyngeal abscess. Advanced airway workshop facilitators conducted directed one-to-one learning, and provided feedback to participants. A paper-based feedback was obtained from 72 participants on their confidence level, and the realism, attractiveness, beneficial, and difficulty levels of the simulated cadaveric models. RESULTS: The modified cadavers were reliable in simulating difficult airways. The majority of participants (91%) reported an increase in confidence level for management of the difficult airway after the experience with the modified cadavers and found the models realistic (93%), attractive (92%), beneficial (93%), and difficult (85%). CONCLUSIONS: Surgical modifications of cadavers to simulate difficult airways such as parapharyngeal abscess with edema and stridor can be incorporated into advanced airway management courses to enhance experiential learning in airway management by awake fibreoptic intubation, and promote patient safety.
