Prediction of hospital mortality among critically ill patients in a single centre in Asia: comparison of artificial neural networks and logistic regression-based model.

INTRODUCTION: This study compared the performance of the artificial neural network (ANN) model with the Acute Physiologic and Chronic Health Evaluation (APACHE) II and IV models for predicting hospital mortality among critically ill patients in Hong Kong. METHODS: This retrospective analysis included all patients admitted to the intensive care unit of Pamela Youde Nethersole Eastern Hospital from January 2010 to December 2019. The ANN model was constructed using parameters identical to the APACHE IV model. Discrimination performance was assessed using area under the receiver operating characteristic curve (AUROC); calibration performance was evaluated using the Brier score and Hosmer-Lemeshow statistic. RESULTS: In total, 14 503 patients were included, with 10% in the validation set and 90% in the ANN model development set. The ANN model (AUROC=0.88, 95% confidence interval [CI]=0.86-0.90, Brier score=0.10; P in Hosmer-Lemeshow test=0.37) outperformed the APACHE II model (AUROC=0.85, 95% CI=0.80-0.85, Brier score=0.14; P<0.001 for both comparisons of AUROCs and Brier scores) but showed performance similar to the APACHE IV model (AUROC=0.87, 95% CI=0.85-0.89, Brier score=0.11; P=0.34 for comparison of AUROCs, and P=0.05 for comparison of Brier scores). The ANN model demonstrated better calibration than the APACHE II and APACHE IV models. CONCLUSION: Our ANN model outperformed the APACHE II model but was similar to the APACHE IV model in terms of predicting hospital mortality in Hong Kong. Artificial neural networks are valuable tools that can enhance real-time prognostic prediction.

Ten-year territory-wide trends in the utilisation and clinical outcomes of extracorporeal membrane oxygenation in Hong Kong.

INTRODUCTION: The utilisation of extracorporeal membrane oxygenation (ECMO) has been rapidly increasing in Hong Kong. This study examined 10-year trends in the utilisation and clinical outcomes of ECMO in Hong Kong. METHODS: We retrospectively reviewed the records of all adult patients receiving ECMO who were admitted to the intensive care units (ICUs) of public hospitals in Hong Kong between 2010 and 2019. Temporal trends across years were assessed using the Mann-Kendall test. Observed hospital mortality was compared with the Acute Physiology and Chronic Health Evaluation (APACHE) IV-predicted mortality. RESULTS: The annual number of patients receiving ECMO increased from 18 to 171 over 10 years. In total, 911 patients received ECMO during the study period: 297 (32.6%) received veno-arterial ECMO, 450 (49.4%) received veno-venous ECMO, and 164 (18.0%) received extracorporeal cardiopulmonary resuscitation. The annual number of patients aged ≥65 years increased from 0 to 47 (27.5%) [P for trend=0.001]. The median (interquartile range) Charlson Comorbidity Index increased from 1 (0-1) to 2 (1-3) [P for trend<0.001] while the median (interquartile range) APACHE IV score increased from 90 (57-112) to 105 (77-137) [P for trend=0.003]. The overall standardised mortality ratio comparing hospital mortality with APACHE IV-predicted mortality was 1.11 (95% confidence interval=1.01-1.22). Hospital and ICU length of stay both significantly decreased (P for trend=0.011 and <0.001, respectively). CONCLUSION: As ECMO utilisation increased in Hong Kong, patients put on ECMO were older, more critically ill, and had more co-morbidities. It is important to combine service expansion with adequate resource allocation and training to maintain quality of care.

Hong Kong's experience on the use of extracorporeal membrane oxygenation for the treatment of influenza A (H1N1).

OBJECTIVE: To report Hong Kong's experience on the use of extracorporeal membrane oxygenation for the treatment of acute respiratory distress syndrome caused by influenza A (H1N1). DESIGN: Multi-centred, retrospective observational study. SETTING: Intensive care units in Hong Kong. PATIENTS: Recipients of extracorporeal membrane oxygenation for confirmed influenza A (H1N1) infection from 1 May 2009 to 28 February 2010. MAIN OUTCOME MEASURE: Hospital mortality. RESULTS: During the study period, 120 patients were mechanically ventilated in intensive care units, among whom seven received veno-venous extracorporeal membrane oxygenation. The median (interquartile range) age of the latter patients was 42 (39-50) years, four had various chronic illnesses and one had a body mass index of greater than 30 kg/m². The median (interquartile range) time from symptom onset to hospital admission was 5 (4-7) days. Corresponding values for the duration of extracorporeal membrane oxygenation, mechanical ventilation, intensive care unit stay, and hospital stay were 6 (6-10), 19 (11-25), 19 (18-30), and 31 (25-55) days, respectively. One patient died (hospital mortality, 14%) and six made full recoveries. All seven patients received oseltamivir; in addition three received intravenous zanamivir, four received convalescent plasma, and one received hyperimmune immunoglobulin. Nosocomial infection was the commonest complication. There was no life- or limb-threatening complication directly attributable to extracorporeal membrane oxygenation. CONCLUSION: In response to the pandemic of influenza A (H1N1), some intensive care units in Hong Kong were able to offer extracorporeal membrane oxygenation to selected cases. In this small series, patient outcomes were similar to those reported in other observational studies, indicating that intensive care units in Hong Kong are capable of successfully introducing this technology. However, the cost-effectiveness and optimal delivery of this strategy remain uncertain.

Clinical characteristics and outcomes of obstetric patients admitted to the Intensive Care Unit: a 10-year retrospective review.

OBJECTIVE: To review the characteristics and health-related quality-of-life outcomes of obstetric patients admitted to the Intensive Care Unit. DESIGN: Retrospective cohort study. SETTING: A regional hospital in Hong Kong. PATIENTS: Consecutive obstetric patients admitted to the Intensive Care Unit of Pamela Youde Nethersole Eastern Hospital from January 1998 to December 2007. RESULTS: Fifty obstetric patients (mean [standard deviation] age, 31 [6] years; mean gestational age, 34 [9] weeks) were analysed. The most common obstetric cause of admission was postpartum haemorrhage (n=19, 38%), followed by pregnancy-associated hypertension (n=7, 14%). The commonest non-obstetric cause of admission was sepsis (n=7, 14%). The commonest intervention was arterial line insertion (n=33, 66%) and mechanical ventilation (n=29, 58%). Maternal mortality was 6% (n=3), while the perinatal mortality rate was 8% (n=4). The average Short Form-36 Health Survey scores of our patients were lower than the norm for the Hong Kong population of the same age and gender. CONCLUSION: Postpartum haemorrhage and pregnancy-associated hypertension were the most common causes of admission to our Intensive Care Unit. Overall mortality was low. Long-term health-related quality of life in discharged patients was lower than the norm of the Hong Kong population. Appropriate antenatal care is important in preventing obstetric complications. Continued psychosocial follow-up of discharged patients has to be implemented.