Factors which influence intensive care admission

Whether or not one offers Intensive Care admission to any given patient is a fairly important question for those responsible for curating access to these unique resources, at least in the rules-based order of closed intensive care models. In is therefore surprising that this daily question is absent from the CICM syllabus document, and has not appeared in the CICM exams until Question 10 from the first paper of 2025, where a mildly hypotensive cellulitis was used as a vehicle to open a discussion of admission decisions. The "softness" of an ICU admission, and how it is softened or hardened by system factors, seems like something all trainees should be able to discuss with the benefit of their considerable personal experience; and the following chapter only aims to give some shape and structure to something already familiar and well developed.

Patient factors:

• Fraily and baseline function.
• Comorbidities and the risk of remaining in the ward vs. the burden and imposition of ICU admission on the patient
• Likelihood of survival and good functional outcome, treatment limitations
• Patient preferences, family preferences, the collaborative model of decisionmaking which is often referred to by the nauseating term "consumer partnership"

Disease factors:

• Support requirements: some things (eg. mechanical ventilation, vasopressors) cannot be carried on in any other setting, making the decision easy
• Intervention requirements: the patient may not be unwell enough to require ICU, but they may soon require something invasive that will imperil their airway, or bring their haemodynamics into disarray. 
• Urgency, disease trajectory ("this will get worse before it gets better", eg. a septic bone marrow transplant patient who has not yet engrafted)
• En route convenience: there may be something else that could be done on the way to ICU (eg. a CT brain for the mysterious unconscious dude).

Referrer factors:

• Present tenure: where the patient currently resides is a major factor for the decision, or for a decision to delay. The relative safety of another ICU or the understaffed emergency department of a small regional hospital have different safety profiles.
• Referring staff: whether the assessment can be trusted and whether instructions regardiung intervantions can be executed remotely depends on the seniority of the staff at the referring site. A patient referred from the ward where the nursing ratio is 1:1000 is not going to get hourly BSL measurements and urine output monitoring.
• Access block: The duration of time this patient has spent waiting for ICU-level care should factor in to the decision

System factors:

• ICU bed status. A full ICU gives rise to an almost involuntary reflex to reject admissions. Kim et al (2016) discovered that an ICU close to full capacity (>90% bed occupancy) has a tendency to reject a further 9% more patients who would otherwise have been eligible for admission, to their overall detriment.
• Availablity of service at the destination: if the patient needs Invasive  Transfacial Horrendoplasty (ITFH), is the specialist who provices this service available, or will they be available when the patient arrives? If not, there may be an argument for waiting until their theatre schedule is better organised.
• Workforce: the ICU may have beds, and maybe even nurses, but the one junior medical officer who is keeping it together overnight is not confident to intubate independently, and no senior help is available within a half-hour drive. The immediate destination for the patient requiring intibation would therefore have to be somewhere else, where an airway technician is available, and then to ICU.

Cultural factors:

• Equity and cultural safety: considerations regarding maintaining equitable ICU access to remote and indigenous communities needs to play a role.
• Australian / NZ slant on decisionmaking: the culture of local intensive care places much of the responsibility for the decisionmaking on the intensivist.