Goh KJ, Wong J, Tien JC, Ng SY, Duu Wen S, Phua GC, Leong CK
We commend Xi et al. for their resilience and innovation in managing the ventilator shortage in their institution and agree with many of the points made. The COVID-19 pandemic has made it necessary for many physicians to implement unconventional strategies to increase access to intensive care, including the use of a single ventilator to ventilate multiple patients .
Indeed, there are many challenges associated with the use of anesthetic machines as ventilators. The problems with the circle circuit, side-stream gas analyzer, and need for more frequent changes of the heat and moisture exchanger filters are unique to anesthetic machines. The manpower requirement for a dedicated anesthesiologist to run the machine was mitigated by the reduction in elective surgical workload during the pandemic.
Fortunately, many anesthetic machines are also able to deliver more advanced modes of ventilation, including volume assist-control ventilation, pressure-regulated volume control, and synchronized intermittent mandatory ventilation, reducing the risk of dyssynchrony and barotrauma. The use of an anesthetic machine also facilitates the use of inhalationals, which confers the advantage of a reduction in dependence on intravenous infusions of sedatives during a supply chain disruption .
Apart from ventilation, other challenges exist when converting post-anesthetic care units into intensive care units. Central monitoring may not be possible, and a larger number of nursing or medical staff will therefore be required to watch for any clinical changes or observe for alarms. Due to existing infrastructural limitations, restrictions may exist with other modes of organ support. For instance, absence of taps and drainage may preclude the use of intermittent haemodialysis. Intensive care physicians may have to triage patients carefully and assign an appropriate intensive care unit according to the level of organ support that can be safely delivered .
Finally, infection prevention measures may be compromised when the patients are cohorted in the post-anesthetic care unit rather than cared for in single rooms. This is an important consideration especially if emergency surgery still needs to take place within the same operating theater complex .
Unique challenges exist at each institution depending on its clinical needs and available resources. The best and safest strategy is the one tailored to the individual hospital and current situation.