Critical Care Unit admission criteria

The Critical Care Unit should be seen as the hub of critical care provision throughout the hospital. In the UK, critical illness is now defined according to patient dependency levels (see table opposite), ranging from those suitable for ward care through to true intensive care requirement. Thus, admission to the Critical Care Unit is not necessary for all of those with a critical illness, particularly where a well-functioning outreach team can support care in the general ward environment. While dependency levels do not necessarily define the need for admission to a Critical Care Unit, it is generally those requiring level 2 or 3 care who are considered for admission.

Admission criteria may be set on a priority basis related to patient dependency levels, their specific diagnosis, physiological or biochemical abnormalities, or investigational findings.

Local policies for critical care admission should:

• Identify who has day-to-day responsibility to make admission decisions.

• Include a mechanism for reviewing difficult cases and difficult ethical decisions.

• Identify those who are too well or too sick to benefit from critical care admission (in the context of other facilities available locally).

• Identify priorities for admission during times of high utilisation of beds, e.g. level 3 patients admitted as a higher priority than level 2. Identify when, who, and how to transfer patients to other units.

• Identify categories of patients who should or should not be admitted to Critical Care Units, including conditions where admission is mandatory.

•Identify any age criteria below which admission is precluded.

• Clarify the links with local incident management policies, contingency plans, and triggers for the implementation of these plans.

A critical care consultant should consider the nature and severity of the patient’s illness, the potential reversibility of their condition, the long- and short-term probability of survival, and the wishes of the patient when deciding on Critical Care Unit admission.

Although patients with ‘do not attempt resuscitation’ orders or terminal illness for palliative care may fi t the criteria for level 2 or 3 care, a clear assessment needs to be made on how they would benefit from admission. Admission may be justified if there is benefit to the patient in terms of avoiding cardiac arrest or better provision of palliation. However, many such patients will clearly not benefit from admission to the Critical Care Unit or from continuation of treatment once admitted. Management of such patients can be difficult. Local guidance needs to ensure decisions are reviewed regularly. Mechanisms to share decision-making between several senior members of the team (sometimes with senior staff uninvolved with the patient’s care) should be in place given the potential of legal challenge of clinical decisions.

Critical care levels of dependency

Level 0

Patients are appropriately cared for in ordinary hospital wards such as are available in all acute hospitals and all general departments of surgery and medicine. Patients may need administration of medication, patientcontrolled analgesia, intravenous maintenance fl uids, blood transfusion, and other simple treatments. Observations would usually be required less frequently than every four hours.

Level 1

Patients are at risk of their condition deteriorating, e.g. recently relocated from higher levels of care, requiring additional monitoring or input from staff with specifi c expertise. In addition to level 0 requirements, patients may need administration of intravenous fl uids at rates in excess of 3,000mL/d, and regular but infrequent tracheal suction via a tracheostomy. Observations would be required at least every four hours.

Level 2

Patients require single-organ monitoring and support, e.g. inotropic support for the cardiovascular system, renal replacement therapy or non-invasive ventilatory support, patients with major uncorrected physiological abnormalities, patients classifi ed as American Society of Anaesthesiologists’ 3 or 4 following minor or major surgery, patients requiring preoperative optimisation but not requiring post-operative ventilation. In addition to level 1 requirements, patients may need frequent tracheal suction via a tracheostomy tube or rapid blood transfusion (perhaps up to six units in 24h).

Level 3

Patients require advanced respiratory monitoring or support, or monitoring and support for two or more organ systems (or one organ system with chronic impairment of at least one other).