[1] Natl Univ Hlth Syst, Alexandra Hosp, Dept Anaesthesia, 378 Alexandra Rd, Singapore 159964, Singapore
[2] Natl Univ Hlth Syst, Natl Univ Hosp, Dept Anaesthesia, Singapore, Singapore
[3] Natl Univ Heart Ctr, Dept Cardiol, Singapore, Singapore
[4] Natl Univ Hlth Syst, Univ Med Cluster, Div Resp & Crit Care Med, Singapore, Singapore
[5] Natl Univ Hlth Syst, Alexandra Hosp, Fast Programme, Singapore, Singapore
[6] Natl Univ Hlth Syst, Alexandra Hosp, Chron Programme, Singapore, Singapore