1 Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital, Faculty of Health Sciences, University of Cape Town, Cape Town 7935, South Africa. Electronic address: bruce.biccard@uct.ac.za.
2 Kamuzu Central Hospital, Lilongwe, Malawi.
3 School of Medicine and Allied Health Sciences, University of The Gambia, Banjul, The Gambia.