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Admission to critical care 

Admission to critical care
Admission to critical care

Heather Baid

, Fiona Creed

, and Jessica Hargreaves

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date: 09 May 2021

Changes to the delivery of critical care

The changing face of acute nursing

The face of acute care and critical care has changed substantially over the last two decades. This change has been influenced by a number of factors, but perhaps most significantly by the increasing number of acutely ill patients within the hospital environment. A number of factors have influenced patient acuity, including:

  • an ageing population with increased levels of comorbidity

  • use of advanced treatment modalities and technologies

  • increased complexity of patient needs.

The changes in acuity levels have meant that healthcare providers have been faced with challenges related to caring for an increasing number of acutely and critically ill patients.

Over 15 years ago the National Audit Office1 identified a lack of provision of critical care beds, and reported that demand for critical care beds often exceeded the number of such beds available. This necessitated an urgent review of critical care provision.

The publication of Comprehensive Critical Care: a review of adult critical care services by the Department of Health2 a year later helped to redevelop the provision of acute and critical care services in the UK. This document marked the end of traditional boundaries associated with critical care, and emphasized the need for a hospital-wide approach to caring for acutely and critically ill patients.

The vision of comprehensive critical care was that hospitals should meet the needs of all critically ill patients, not just those in designated critical care beds, and gave rise to the concept of ‘critical care without walls.’ It highlighted both the need to radically change critical care provision, and the need for the following characteristics of a modern critical care service:

  • integration of services beyond the boundaries of critical care units to allow provision of acute and critical care and the optimization of resources

  • the development of critical care networks to share standards and protocols and to develop future care provision

  • workforce development to ensure that all staff caring for acutely and critically ill patients have sufficient knowledge and training.

Recognition of deterioration

Alongside the redevelopment of critical care services, problems with the recognition of deterioration in the patient’s condition were being highlighted.

A seminal study by McQuillan and colleagues3 first introduced the now well-recognized concept of suboptimal care for acutely ill adults. Suboptimal care relates to multifactorial issues that contribute to misdiagnosis, mismanagement, and lack of timely intervention for acutely ill deteriorating patients. Delays in treating acutely ill patients were linked to unexpected deaths and unplanned and perhaps preventable admissions to critical care units.

McQuillan and colleagues’3 study identified that over 50% of patients encountered suboptimal management prior to admission to critical care units. Unfortunately, similar statistics are still evident despite ongoing interventions to improve the situation. The current literature often uses the term ‘failure to rescue’ to refer to suboptimal care.

Factors related to suboptimal care—or, more recently, ‘failure to rescue’—include:

  • lack of knowledge and lack of experience in dealing with acutely ill patients

  • failure to appreciate the urgency of the need to treat the patient’s condition

  • failure to seek senior or expert advice about the patient’s condition

  • lack of senior medical staff involvement

  • organizational failings that prevent adequate assessment and management of the deteriorating patient.

A number of initiatives have been developed to improve recognition and management of the deteriorating patient. Analysis of the literature suggests that the number of preventable deaths and unplanned critical care admissions could be reduced if deteriorating patients were identified earlier and managed in a timely manner.


1 National Audit Office. Critical to Success: the place of efficient and effective critical care services within the acute hospital. Audit Commission: London, 1999.Find this resource:

2 Department of Health. Comprehensive Critical Care: a review of adult critical care services. Department of Health: London, 2000.Find this resource:

3 McQuillan P et al. Confidential inquiry into quality of care before admission to intensive care. British Medical Journal 1998; 316: 1853–8.Find this resource:

Preventing admissions to critical care

A number of initiatives have been implemented to help to prevent the admission of acutely ill patients into critical care units. These initiatives include:

  • development of critical care outreach teams

  • development of early warning scores

  • utilization of medical emergency teams

  • education initiatives.

Critical care outreach

The widespread development of critical care outreach services followed the publication of Comprehensive Critical Care: a review of adult critical care services.4 Indeed, the National Institute for Health and Care Excellence (NICE)5 identified the need to establish outreach services in all acute hospitals 24 hours a day, 7 days a week.

Outreach teams were initially established with the following key aims:

  • to avert admission to critical care units

  • to support staff in ward areas

  • to provide education programmes for ward-based staff

  • to support critical care patients following transfer from critical care, in order to avert readmissions

  • to provide follow-up services on discharge from hospital, to determine the impact of critical care on the patient.

The implementation of outreach has not been consistent across acute trusts, and various teams have been developed. These include:

  • critical care outreach teams

  • patient at-risk teams

  • rapid response teams.

Although differences exist between various configurations of critical care outreach teams, these teams are generally nurse led and have been introduced to support and help to educate ward nurses when they are caring for deteriorating and acutely ill patients. Unfortunately there is little substantive research to support the effectiveness of outreach in improving patient outcomes. Therefore more research is needed to review the effectiveness of the role of outreach.6

Early warning scores

These were introduced to try to help ward staff to recognize and respond to deteriorating patients on general wards. The systems use routine physiological measurements, and each measurement is given a numerical value depending on the variation from normal parameters. The individual parameter scores are added together and an aggregate score is then obtained that highlights the need for patient review. Put simply, the higher the score, the more ill the patient is. The early warning scores are linked to an escalation process.

Most recently the Royal College of Physicians has been instrumental in developing a National Early Warning Score (NEWS)7 that is in the process of being implemented throughout the UK.

This tool has been developed to provide standardization of assessment and escalation processes throughout NHS trusts. The NEWS system provides values for each observation recorded (see Table 1.1). The aggregate NEWS score is then linked to a national escalation policy (see Table 1.2). It is anticipated that implementation of this system will enable consistency in detecting and responding to acutely ill patients, and help to avoid admissions to critical care by identifying deteriorating patients earlier.

Table 1.1 NEWS abnormal observation values







Respiratory rate (breaths/min)

≤ 8



≥ 25

Heart rate (beats/min)

≤ 40




≥ 131

Systolic blood pressure (mmHg)

≤ 90




Temperature (°C)

≤ 35



≥ 39.1

Oxygen saturation (%)

≤ 91



Supplemental oxygen


Level of consciousness

V, P, or U

Table 1.2 NEWS escalation tool

NEWS score

Frequency of monitoring

Clinical response


Minimum of 12-hourly

Continue routine NEWS monitoring

Total: 1–4

Minimum of 4- to 6-hourly

Inform registered nurse

Total: 5 or moreor3 in one parameter

Hourly observations

  • Inform medical team urgently

  • Urgent assessment by clinician with core competencies

  • Monitoring required

Total: 7 or more

Continuous observations

  • Immediately inform specialist registrar

  • Emergency assessment by staff with critical care competencies

  • Consider move to higher level of care

Medical emergency teams and emergency response teams

Medical emergency teams have been developed in many NHS trusts to respond immediately to a medical emergency. It is thought that a rapid response to a deteriorating patient may provide the opportunity to intervene and quickly treat symptoms. This may help to avert cardiac arrests, further deterioration, and subsequent admission to critical care units.

Medical emergency teams normally consist of doctors and nurses who possess advanced life support skills. The aim of the team is to respond early to patient deterioration and provide an immediate coordinated response for the acutely ill deteriorating patient. Calls to the team may be in response to a trigger from an early warning score (see Table 1.2), or may be based on a nurse’s or doctor’s concern about the patient.

Although there is no significant research to support these teams yet, there is compelling evidence that the medical emergency teams may improve quality of care for seriously ill patients who are nursed outside critical care areas.

Education initiatives

Other educational initiatives have also been developed to help to provide a multidisciplinary approach to assessment and management of the acutely ill patient .The rationale of these programmes is to provide an understanding of systematic patient assessment tools (see Chapter 2) and initial management of the deteriorating patient.

Courses are either multidisciplinary or medically focused, and use a range of low- to high-fidelity simulation scenarios to teach assessment and management of the deteriorating patient. These programmes include:

  • acute NHS trust in-house training days

  • the Acute Life-threatening Events Recognition and Treatment (ALERT©) programme

  • the Acute Illness Management (AIM) course

  • Care of the Critically Ill Surgical Patient (CCrISP®)

  • Ill Medical Patients Acute Care and Treatment (IMPACT).


4 Department of Health. Comprehensive Critical Care: a review of adult critical care services. Department of Health: London, 2000.Find this resource:

5 National Institute for Health and Care Excellence (NICE). Acutely Ill Patients in Hospital: recognition of and response to acute illness in adults in hospital. CG50. NICE: London, 2007. Admission to critical care this resource:

6 Rowan K et al. Evaluation of Outreach Services in Critical Care. National Intensive Care Research and Audit Committee: London, 2009.Find this resource:

7 Royal College of Physicians. National Early Warning Score (NEWS): standardising the assessment of acute-illness severity in the NHS. Report of a working party. Royal College of Physicians: London, 2012.Find this resource:

Levels of care

These were first devised in 2000 by the Department of Health8 to help to replace traditional boundaries that labelled patients as critical care patients or ward patients. Linked to the concept of ‘critical care without walls’, these levels help to clarify the dependency levels of patients and assist in informing decision making about the management of patient care.

The initial levels were highlighted by the Department of Health (see Table 1.3.). These levels were too simplistic, and were soon superseded by levels published by the Intensive Care Society,9 which gave further guidance about what might be appropriate patient management at each level. The Intensive Care Society levels provide specific examples (see Table 1.4). Further details of specific examples can be found on the Intensive Care Society website (Admission to critical care

Table 1.3 Levels of care8




Patients whose needs can be met in a ward environment


Patients at risk of deterioration who can be managed in a ward area with additional advice and support ( this includes patients recently relocated from higher levels of care)


Patients who require detailed observation and support of a single failing system, or complex post-operative care (again this includes patients recently relocated from higher levels of care)


Patients who require advanced respiratory support or basic respiratory support together with support of at least two organ systems (also includes patients with multi-organ failure)

Table 1.4 Additional guidance, adapted from Intensive Care Society levels of care9

Level criteria

Selected specific examples*

Level 1

  • Patients recently discharged from higher level of care

  • Patients in need of additional monitoring

  • Patients requiring critical care support

  • Requiring a minimum of 4-hourly observations

  • Continuous oxygen, epidurals, patient-controlled analgesia (PCA), tracheostomy in situ

  • Risk of clinical deterioration, or patient has abnormal observations

Level 2

  • Patients requiring pre-operative optimization

  • Patients requiring extended post-operative care

  • Patients stepping down from a higher level of care

  • Patients requiring:

    • single organ support

    • basic respiratory or CVS support

    • advanced CVS support

    • renal support

    • neurological support

    • dermatological support

  • CVS, respiratory, or renal optimization

  • Major or emergency surgery, and risk of complications

  • Needing hourly observation and at risk of deterioration

  • Non-invasive ventilation; intubated to protect airway

  • Insertion of CVP or arterial line Single vasoactive drug or cardiac output monitoring

  • Renal replacement therapy

  • CNS depression, ICP monitoring, EVD

  • Major skin rashes, exfoliation, burns, or complex dressings

Level 3

  • Patients receiving advanced respiratory support alone

  • Patients receiving support for a minimum of two organs

  • Invasive mechanical ventilation or extracorporeal support

  • Ventilation plus support of at least one other failing system

*Complete list is available on ICS website (Admission to critical care


8 Department of Health. Comprehensive Critical Care: a review of adult critical care services. Department of Health: London, 2000.Find this resource:

9 Intensive Care Society. Levels of Critical Care for Adult Patients. Intensive Care Society: London, 2009.Find this resource:

Admission criteria

Although the number of critical care beds has increased steadily over the past decade, there are still situations in which provision of critical care beds does not meet demand for critical care admission. Recent statistical evidence from NHS England10 has identified a critical care bed occupancy rate of 87.8%, suggesting a service that is near to full capacity. Shortages of critical care beds may have far-reaching implications in practice, including:

  • reduced access to critical care beds

  • enforced transfer of critically ill patients

  • cancelled urgent and elective procedures.

As critical care is a limited resource, it needs to target those patients who are most likely to benefit from admission to critical care units. Although decisions relating to admission are complex and multifactorial, and it is difficult to provide clear guidance on admission criteria, it is clear that decisions relating to admission (or, more importantly, non-admission) should be based on objective, ethical, and transparent decision-making processes.11

The General Medical Council (GMC) provides guidance on ethical and legal aspects of decision making, but it is sometimes difficult to apply these to critical care patients for whom the level of complexity of needs and the disease trajectory are not always clear.

A number of guiding principles may be used to assist the decision-making process, and it is important to remember that admission to a critical care unit may not be an appropriate decision for all patients. It is recommended that admission criteria should be available in all critical care units. It is therefore imperative that any local admissions policies and guidelines are utilized in conjunction with the critical care admission team. The critical care consultant’s decision about admission would always take precedence over the decision of other medical staff.

Guiding principles for admission

Fullerton and Perkins11 suggest that it is useful to:

  • review the patient, and establish ongoing comorbidities and responses to current treatment

  • formulate a prognosis

  • discuss the risks and associated burdens of treatment with the patient and their carers

  • reach a consensus on the treatment plan, and agree any ceilings to treatment in advance.

In general, critical care admission is appropriate if:

  • the patient’s condition is potentially reversible

  • the patient can reasonably be expected to survive the critical care admission

  • there is reasonable doubt about the likely outcome for the patient.

Factors that may preclude admission to critical care include the following:

  • the patient’s condition is likely to be fatal and will not be amenable to recovery, or has progressed beyond any reasonable likelihood of recovery

  • the patient’s pre-existing comorbidities make the prospect of recovery very unlikely

  • the patient has mental capacity and refuses to be admitted on the basis of either an advance directive or discussion with the critical care team.


10 NHS England. Critical Care Bed Capacity and Urgent Operations Cancelled 2013–14 Data. Admission to critical care

11 Fullerton JN and Perkins GD. Who to admit to intensive care? Clinical Medicine 2011; 11: 601–4.Find this resource:

Organizing admission to critical care

Nursing responsibilities

It is important that the critical care nurse possesses the appropriate skills, knowledge, and attitudes to safely admit patients to the critical care unit. The Critical Care Networks-National Nurse Leads (CC3N) have recently published competencies relating to critical care nursing.12 One of the Step 1 Competencies relates to admissions to critical care. The key responsibilities for an effective admission to critical care include:

  • safe preparation of the bed area

  • safe staffing levels within the intensive care area

  • initial assessment and monitoring of the critically ill patient

  • communication with the patient and their family or carers.

Safe preparation of the bed area

It is likely that each individual critical care unit will have an admission protocol describing in detail how to prepare adequately for admission of a patient to critical care. If such a protocol is available it should be followed. There are several guiding principles for preparing the bed area:

  • Follow local guidance relating to appropriate cleaning of the area to prevent cross-contamination from the previous patient in that bed area. Personal protective equipment should be readily available at each bed area.

  • Prepare any equipment that will be required for care of the patient. This should be ready to use and safety checks completed according to local protocols. Equipment that is likely to be needed for most patients includes an appropriate ventilator, intubation equipment, safety equipment, syringe drivers, infusion pumps, and trolleys for cannulation and arterial line insertion.

  • Monitoring systems should be ready to use, and additional disposable equipment such as ECG electrodes should be prepared in advance. Pressure bags and transducers should be prepared and labelled according to local guidelines.

  • Computerized documentation systems for patients should be ready to use. Smaller units may still utilize paper documentation, and if so this should be prepared in advance.

  • The patient details should provide an indication of the severity of the patient’s condition, especially in the case of an unplanned or emergency admission. It is likely that additional staff may be required to assist with admission of an unstable critically ill patient, and this should be organized prior to admission of the patient.

  • Consideration should be given to providing same-sex accommodation wherever possible.13 In situations where this is not feasible, consideration should be given to maintaining the dignity and privacy of the patient in mixed-sex accommodation.

Safe staffing levels within the intensive care area

With regard to staffing levels, the British Association of Critical Care Nurses (BACCN)14 and the Royal College of Nursing (RCN)15 have provided guiding principles. Many factors may affect staffing levels, and it is difficult to provide an exact guide to what represents a safe number of staff. Local policies based on the BACCN and RCN guidelines may be used to determine safe staff numbers, as staffing is affected by a number of locally determined factors, including the following:

  • The acuity levels of these patients (i.e. the number of level 2 and level 3 patients). Very critically ill patients may require two nurses for periods of care.

  • The design of the unit. Units where the environment and design of the unit limit the ability to overview other patients may need increased staffing ratios.

  • Flexibility should be built in to allow for unplanned events such as intra-hospital transfers or sudden deterioration.

The BACCN guidelines emphasize that it is essential for all patients to have immediate access to a registered nurse with a post-registration qualification. They suggest that level 3 patients should be nursed with a ratio of 1:1, and that the ratio for care of level 2 patients should not exceed 1:2. Problems with staffing ratios should be reported and acted upon by the nurse in charge of the unit, in order to maintain patient safety.

Initial assessment of the patient

The patient’s condition will need to be assessed on admission and then reassessed frequently until it has stabilized. In the case of emergency and unplanned admissions it is likely that initial patient assessment will involve several members of the critical care team so that any life-threatening problems can be quickly identified and appropriate management provided. At the very minimum the patient should be assessed by the receiving nurse and a member of medical staff from the critical care team.

The initial assessment should be thorough and systematic. Use of the ABCDE system (see Chapter 2) ensures that life-threatening problems are assessed and managed first, before other assessments are undertaken. It also ensures that a quick and robust assessment of the patient is performed.

In addition, the initial assessment should include a full physical assessment and documentation of any areas of concern (e.g. previous pressure damage, bruising or injury prior to admission). It is important that consideration is also given to assessment of mental health status, mental capacity, and any advance directives.

Assessment for previous resistant infections should be undertaken, and local protocols followed with regard to isolation of patients transferred from other areas within the hospital, and for referrals from another hospital.

Alongside these assessments you may also be required to assess other areas that will have an impact on nursing. This will be determined by local policy, but may include:

  • venous thromboembolism risk

  • pressure damage risk

  • nutritional assessment

  • falls risk

  • data collection for audit purposes

  • acuity and patient scoring systems information (e.g. APACHE II, SAPS II/III, MODS, and SOFA scores). Some of these data may be obtained from electronic patient record systems.

All of the information that is obtained during the initial assessment should be either documented electronically on computerized systems or recorded on paper. This will ensure ongoing effective documented assessment and identification of the patient’s needs. All of the information that is obtained at the initial assessment can then be utilized to plan effective care for the patient. Assessment findings should be communicated effectively to other members of the multidisciplinary teams, as this has been shown to improve patient safety by ensuring continuity of appropriate care.

Communication with the patient and their family or carers

Admission to the critical care environment can be a frightening experience for the patient and their family or carers, and it is vital that effective communication and psychological support are provided for all of these individuals.

It is universally accepted that communication with the patient is vital irrespective of whether they are conscious or unconscious on admission to the critical care unit. If the patient is conscious and has mental capacity, it is important that they are communicated with effectively and actively involved in decision making about their treatment and ongoing care. Family members may be able to provide insight into the patient’s wishes if the patient lacks mental capacity or is unconscious.

Most critical care units provide printed booklets containing information for patients and relatives. Such information is also available from the Intensive Care Society16 and ICUSteps17.

Effective communication with families and carers is important, especially in the early stages of admission, as it is unlikely that they will be able to see the patient during the initial stages of assessment and treatment, or until the patient’s condition has been stabilized. Effective communication about the need to stabilize and assess the patient first is vital for helping to establish trusting relationships with families and carers. The provision of honest, realistic information in a form that can be easily understood is essential both during the initial period of care and subsequently.


12 Critical Care Networks-National Nurse Leads (CC3N). National Competency Framework for Adult Critical Care Nurses. CC3N, 2013. Admission to critical care

13 Department of Health. Impact Assessment of Delivering Same Sex Accommodation. Department of Health: London, 2009.Find this resource:

14 Bray K et al. Standards for Nurse Staffing in Critical Care. British Association of Critical Care Nurses (BACCN), Critical Care Networks-National Nurse Leads, and Royal College of Nursing Critical Care Forum: Newcastle upon Tyne, 2010.Find this resource:

15 Galley K and O’Riordan B. Guidance for Nurse Staffing in Critical Care. Royal College of Nursing: London, 2007. Admission to critical care this resource:

16 Intensive Care Society. Patient Information Booklets. Intensive Care Society: London. Admission to critical care

17 ICUSteps. Intensive care: a guide for patients and families. ICUSteps: Milton-Keynes, 2010. Admission to critical care

Further reading

British Association of Critical Care Nurses (BACCN). Admission to critical care

Faculty of Intensive Care Medicine. Admission to critical care

Gibson V and Hill K. Admitting a critically ill patient. In: Mallett J, Albarran JW, and Richardson A (eds) Critical Care Manual of Clinical Procedures and Competencies. John Wiley & Sons, Ltd.: Chichester, 2013. pp. 59–62.Find this resource:

Intensive Care Society. Admission to critical care

Royal College of Physicians. Admission to critical care