Principles of safe inter-hospital transfer of critically unwell adults

The nature of critical care means that adults admitted to such units will be critically unwell and experiencing organ dysfunction or other life-threatening conditions (Jackson and Cairns, 2021). Higher staffing ratios on critical care units, specialised equipment and advanced monitoring aim to reduce morbidity and mortality in people experiencing critical illness. On occasion, a patient will require care that is unavailable at the hospital and the decision to transfer a critically unwell adult to another care facility should be planned, risk assessed and appropriately resourced.

There are significant risks associated with the inter-hospital transfer of critically unwell adults (Dabija et al, 2021). Mueller et al (2019) suggested the practice of inter-hospital transfer varies and is non-standardised, which contributes to poor clinical outcomes, including longer hospitalisation and a higher risk of mortality.

Levels of critical illness

The Intensive Care Society (ICS) (2021) has outlined the levels of care a person requires, according to their condition:

• Ward-level care: this reflects the care of an acutely unwell person with needs that can be met through normal ward care in an acute hospital
• Level 1 care: this is defined as ‘enhanced care’, which includes people who require more detailed observation and interventions. Normally, level 1 critical care patients require interventions to prevent deterioration that cannot be met on a general ward
• Level 2 critical care: this is required by acutely unwell people necessitating two or more organ support interventions and patients needing extended periods of advanced respiratory support
• Level 3 critical care: this is for people who require advanced respiratory monitoring and interventions to support multiple organ failure. The level 3 classification includes people requiring haemodynamic support, renal replacement therapy or advanced neurological care.

Reasons for inter-hospital transfer

According to NHS England (2021), there is a daily requirement to move critically ill people within each region of the UK to specialist units and help balance critical care bed capacity. NHS England (2021) data reveal that between 20000 and 25000 inter-hospital transfers of critically unwell adults occurred during 20192020. The possible reasons for inter-hospital transfer are defined specifically by NHS England (2024). These include patients requiring specialist care that is not available in the referring hospital. Specialisms may include burns, cardiac, interventional radiology, major trauma, neurosurgery, severe acute respiratory failure, stroke and vascular. A small but important number of these patients are classified as time-critical transfers.

Types of inter-hospital transfer

The North of England Critical Care Network (2017) identified three main categories of inter-hospital transfer of critically ill people:

• A ‘clinical transfer’ is described as the upgrading of a critically ill person to a tertiary or specialist centre for further investigations and treatment
• A ‘capacity transfer’ occurs when there is no critical care resource at the host hospital, which necessitates transfer to another critical care unit with capacity to admit. Capacity transfers are often contentious and decisions to undertake this mode of transfer must be carefully considered to reduce risk
• A ‘repatriation transfer’ occurs when a critically ill person is transferred back to the referring hospital.

Prioritisation of inter-hospital transfer is discussed within the National Framework of Inter-Facility Transfer (IFT) (NHS England and Association of Ambulance Chief Executives, 2021). Essentially, emergency ambulance response times are divided into four levels. Levels 1 and 2 are concerned with critically unwell patients. Faculty of Intensive Care Medicine (FICM) and ICS (2021) guidance states that:

• IFT level 1 requires a mean target response time of 7 minutes (90% in 14 minutes) according to the Ambulance Response Programme (ARP). This is reserved for critically unwell people where there is imminent danger to life and who require urgent treatment at another care facility
• IFT level 2 demands a mean ARP time of 18 minutes (90% in 40 minutes) and is ringfenced ‘for situations where transfer is required for immediate (time critical) life, limb or sight saving intervention in another facility’ (FICM and ICS, 2021: 15).

Crucially, IFT levels 1 and 2 should be escalated by the referring duty consultant to the practitioner in charge of the ambulance control centre to ensure timely allocation of an emergency crew and vehicle.

Transfer teams

Dedicated and trained transfer teams enhance the clinical outcome of critically ill patients (Wiegersma et al, 2011; Singh et al, 2014). Importantly, ICS guidance clearly stipulates that every acute hospital trust and associated critical care network should have a nominated clinical lead for transfer, transfer policy/protocol and quality assurance processes (ICS, 2021). Usually a lead consultant provides strategic oversight for governance and training for a locally constructed critical care ‘transfer group’.

Nurses have an important role to ensure that relatives and, if conscious, the patient are kept updated during the proposed inter-hospital transfer process. As well as careful monitoring of the patient, nurses must ensure that all personal belongings, including routine medication, are assembled and with the patient before departure.

Planning the inter-hospital transfer

Following stabilisation and resuscitation from haemodynamic instability, some patients may require transfer to another hospital for continuation of specialised critical care and services. For example, haemodynamic instability normally arises from hypovolaemic, cardiogenic or septic shock, which causes a hypoperfused state to central organs, tissues and cells. Haemodynamic instability consists of hypotension (low blood pressure) with compensatory tachycardia (fast heart rate), which reduces the provision of oxygen and nutrients to cells.

The decision to transfer a critically unwell adult ultimately lies with the referring and receiving unit consultants. In addition, prior to the transfer of a critically ill patient, a risk assessment must be undertaken and documented by a senior clinician to determine the level of anticipated risk during transfer. The outcome of the risk assessment should be used to determine the competencies of the staff required to accompany the patient during transfer (ICS, 2021). Risks of the transfer fall into three broad categories:

• Technical (patient/equipment)
• Non-technical (crew resource issues and expertise)
• Organisational (governance).

The transfer process has specific stages as outlined by Bourn et al (2018) (Box 1).

Box 1.

Transfer process

Source: Bourn et al, 2018

It is vital that all patients are appropriately stabilised prior to transfer to reduce the physiological disturbance associated with movement and reduce the risk of deterioration during the transfer. Research by Dabija et al (2021) found that movement of critically ill patients with artificial airways is often complex and risky. Janz et al (2019) conducted a cohort study capturing 699 patients requiring inter-hospital transfer to a tertiary centre and examined changes in vital signs and clinical outcome. They concluded that strict adherence to transfer policy, protocol and guidance resulted in no significant difference in vital signs or increased mortality. However, there were limitations to this study because results derive from a study in the USA and are not readily translatable to UK inter-hospital transfers.

A retrospective cohort study by Mueller et al (2019) explored the clinical outcomes of 24352 patients who underwent inter-hospital transfer. They reported increased risk during night-time transfers compared to day-time transfers. Specifically, the cohort study found that ‘night transfers had increased 30-day mortality’ (Mueller et al, 2019). The workload of the admitting team also impacted upon 30-day mortality and clinical outcome. However, there are credible reasons for these findings, which include patients being transferred to tertiary surgical services, which could reflect a critical need to facilitate the transfer as an emergency at night and at weekends.

Inter-hospital transfer checklists and charts

Supportive checklists should be used to help to ensure that all necessary preparations have been completed, prior to each stage of the transfer. There are locally agreed transfer checklists but a good example is provided by Greater Manchester Critical Care and Major Trauma (2021).

A hermeneutical observational study by Karlsson et al (2019) exposed several significant challenges faced during inter-hospital transfer, including the intensity of the procedures and care required. They described the patient's situation during the inter-hospital transfer as ‘being in a constantly changing space’ (Karlsson et al, 2019). They stated that, as well as the confined space of the emergency vehicle and distorted view of the patient, the use of monitoring equipment and infusion pumps resulted in a ‘dwindling space’ in which to work. This could lead to the patient's body being used as a work surface or storage area for essential transfer equipment.

However, guidance from the ICS (2021) stipulates that minimum standards of monitoring must be applied in every case, despite the challenges outlined regarding a confined working space during transfer. Meticulous resuscitation and stabilisation of the patient before transport is the key to avoiding complications during the journey, although the time taken to achieve this must be balanced against the need for immediate transfer for specialist lifesaving interventions. For a level 3 critical care patient monitoring of respiration, heart rate, pulse oximetry, blood pressure, capnography and temperature are compulsory during transfer. Moreover, physiological monitoring should be continuous throughout the inter-hospital transfer. All equipment monitors, including ventilator displays and syringe drivers, should be visible to accompanying staff (ICS, 2021). Vital signs should be regularly monitored throughout the transfer and documented on a transfer chart. Each critical care network has agreed a transfer chart and checklists and it is vital to be familiar with locally agreed decisions on which documents should be used.

Structured assessment during the transfer

Kulshrestha and Singh (2016: 452) discussed the principles of safe inter-hospital transfer, which commences with ‘proper and meticulous preparation and stabilisation of [the] patient’. Use of the Resuscitation Council (UK) (2021) guidelines for the ABCDE approach should be employed and revisited at frequent points (Table 1). Crucially, the ABCDE assessment requires staff to identify problems with the patient's airway at the earliest opportunity and indicates when urgent intervention is required.

Patient monitoring and safety

Clinical observation and monitoring should be continuous during the inter-hospital transfer. This includes cardiac monitoring (ECG), respiration, heart rate, non-invasive/invasive blood pressure, end tidal carbon dioxide in intubated/ventilated patients, oxygen saturation and temperature. Kulshrestha and Singh (2016) advise that ventilated patients should be transferred using portable ventilators with the capability to display ‘tidal volume, airway pressure, inspiratory:expiratory ratio, inspired oxygen fraction and respiratory rate’. Central venous catheterisation is not essential but may be prudent in patients requiring intravascular fluid and vasopressors. All monitors and syringe pumps, including labels, should be visible to the accompanying team throughout the transfer. A record of clinical observations should be recorded on the locally agreed transfer chart.

The FICM and ICS (2021) guidance quotes Department for Transport (DfT) statistics that between 2008 and 2016, 2979 people were injured in accidents involving ambulances. The main issue during the transfer is the safety of staff, patient and other road users and pedestrians. The patient should be securely fastened to a dedicated 5-point harness transfer trolley. Care and reassurance should be provided to conscious patients as the securely fastened harness belts may cause distress. Timing the arrival of the transporting ambulance should be carefully planned so that patient pressure areas are not exposed to the transfer trolley for excessive periods. All invasive lines and infusions should be carefully assembled with free ports clearly visible for the administration of emergency drugs.

UK legislation states that transferring personnel should remain seated with seat belts fastened during the transfer. Section 2.1 of The Motor Vehicles (Wearing of Seat Belts) (Amendment) Regulations 2015 (DfT, 2015) exempts people riding in an ambulance from the requirement to wear a seat belt while that person is providing medical attention or treatment to a patient that cannot be delayed. However, if sudden medical emergencies arise that require an urgent medical intervention, it is essential that this is not attempted in a moving vehicle. The transferring medical team should be alerted, and the ambulance stopped in a safe place so that medical interventions can proceed. Furthermore, all transfer equipment should be safely stowed to prevent injury during the transfer.

Kulshrestha and Singh (2016) discuss the environment in the ambulance, which may affect the patient, including excessive noise and vibration from uneven roads and speed bumps, acceleration/deceleration forces and variations in ambient temperature. Motion sickness may be a problem. Potential difficulties during the transfer involve endotracheal tube dislodgment or displacement during transit, pneumothorax, cardiovascular complications (hypotension, hypertension, tachycardia, bradycardia and arrhythmias), and endocrine and metabolic disturbances (hypoglycaemia, hyperglycaemia, acid base derangement). Health professionals accompanying the patient should be appropriately trained and competent in inter-hospital transfer, preferably with advanced life support, advanced airway skills and critical care experience.

Communication and documentation

Poor quality communication and documentation at each stage of the inter-hospital transfer will compromise patient safety. Ong and Coiera (2011) performed a systematic review of 24 studies, and highlighted the need to enhance communication during the inter-hospital transfer to mitigate risk. The prospective cohort study by Szary et al (2010) emphasised the need to use recognised checklists and templates to improve communication and transfer of critical information between hospital facilities.

Mueller et al (2021) explored suboptimal communication during transfers and concluded that if transfer staff have no access to essential clinical information this creates uncertainty in clinical management. Results from this longitudinal survey by Mueller et al (2021) revealed that 12% of respondents reported a delay in ordering therapeutic tests or initiating other therapies due to uncertainty, driven by poor clinical communication. Therefore, poor communication during the inter-hospital transfer contributes directly to poor patient outcome and risk. Advanced notification – that is informing clinicians at the receiving hospital of the patient's condition, test results and so on, ahead of the transfer is an important communication strategy to enhance receiving clinicians’ clinical understanding in advance of the patient transfer (Mueller et al, 2020).

Literature by Singh (2014), Kulshrestha and Singh (2016), Janz et al (2019), Mueller et al (2019) and Dabija et al (2021) reveal consistent themes, suggesting that inter-hospital transfer is not without risk. Importantly, the evidence indicates that meticulous planning and risk assessment are important to ensure safe inter-hospital transfer of critically unwell adults.

Conclusion

The inter-hospital transfer of critically unwell adults is an essential stage of continuing healthcare provision. The decision to activate an inter-hospital transfer should be made and agreed with the referring and accepting consultants and, importantly, carefully planned. Transporting clinicians should be appropriately trained and skilled to deal with unforeseen medical problems and emergencies. Communication channels should be transparent to ensure the effective transition of critical medical information. The literature reveals that meticulous planning, active care of the patient before transfer and structured assessment using dedicated checklists are significant considerations to eliminate risk. An abundance of inter-hospital clinical guidelines is available to support health professionals with clinical decisions. BJN

Key Points

• Careful planning of the inter-hospital transfer is crucial to mitigate risk and enhance patient safety
• Use of recognised documentation charts and checklists protect the patient during the transfer
• The movement of critically unwell adults in ambulances creates physiological alterations that require clinical expertise and experience to manage successfully
• Monitoring of heart rate, blood pressure, respiration, oxygen saturations, temperature and end tidal carbon dioxide (for ventilated patients) should be mandatory and continuous during the inter-hospital transfer
• Robust communication at all stages of the inter-hospital transfer is essential to prevent patient harm

CPD reflective questions

• Do you know how to find clinical guidelines and policy documents aligned to the safe inter-hospital transfer of critically unwell adults?
• Can you identify the potential risks of an inter-hospital transfer?
• Can you identify how the ABCDE assessment can be applied during inter-hospital transfer? Reflect on why robust patient assessment is crucial