There are 225 AMUs in the UK. The term acute medical unit (AMU) is defined in an RCP report as ‘a dedicated facility within a hospital that acts as the focus for acute medical care for patients that have presented as medical emergencies to hospitals or who have developed an acute medical illness while in hospital’. The report provides a detailed description of the rationale and requirements for AMUs. The structure of an AMU is schematically represented in Fig 2. Ideally the AMU should be co-located with other acute and emergency services on an emergency floor (Fig 3).
Strong clinical and operational leadership is necessary for an AMU to function successfully. Medical leadership should come from a consultant physician specialising in acute internal medicine. Nursing leadership is equally important, especially the day-to-day operational role of the nurse coordinator as described by the Society for Acute Medicine (SAM).
Fig 2: Acute medical unit: example configuration and interactions with the transfer of care (TOC) out of hospital for a majority of acute medical patients, either direct from the AMU or short stay unit. Those requiring longer hospital stays being transferred into specialist beds. Specialist in-reach supports the AMU and AMU outreach provides urgent and emergency acute care for the hospital, in collaboration with the critical care team.
Fig 3: Emergency floor of large acute hospitals. This schematic illustrates some of the components required for an emergency floor in a major acute hospital. It would be scaled and configured to meet local needs. This model fosters closer working and more efficient clinical assessment and treatment by the right person, first time.
*Therapy teams include physiotherapy, occupational therapy, mental health and specialist multidisciplinary teams.
(Both figures reproduced from: Royal College of Physicians. Acute medical care. The right person, in the right setting – first time. Report of the Acute Medicine Task Force. London: RCP, 2007. Fig 2, page 19. Fig 3, page 29.)
Care is delivered by a multidisciplinary team that includes:
- occupational therapists
- social workers
- speech and language therapists
- patient-related administrative staff
- advanced nurse practitioners (ANP) either dedicated to AIM or specialty in-reach.
- support to doctors is also provided by the recent development of physician associates.
The extent to which consultants commit to the acute care of medical patients varies and comprises:
- Consultant acute physicians specialising solely in AIM. These consultants are responsible for the initial assessment and treatment of acutely unwell patients, traditionally called the ‘medical take’, and the ongoing care of patients in the AMU. Consultant acute physicians are responsible for the operation, governance and development of the service.
- Consultants supporting the medical take. There are a significant number of consultants trained in GIM and a specialty who support the traditional medical take. To run sustainable on-call consultant rotas, including a 7-day service, the ongoing support of these consultants to the medical take is essential and their contribution is greatly valued.
- Hybrid roles. There are many examples of consultants who work a hybrid job plan between these two polarised positions.
A career in acute medicine has been possible since 2003 via training on a previous GIM curriculum. In 2005, the GIM curriculum was expanded to include the then subspecialty of AIM. In 2007, the GIM/AIM curriculum was further expanded with clearly defined competencies. Since 2009 physicians have been able to train in AIM, usually with dual certification in GIM. Prior to specialty AIM training, many consultants trained in GIM and a specialty before joining AIM. There are a small number of consultants in AIM who trained in GIM alone, an option which no longer exists.
All physicians participating in the acute medical intake should have the skills to manage any patient presenting with an acute medical problem for up to 72 hours, whether they practise AIM as their sole specialty or GIM with another specialty.
Scope of care
Patients are assessed with a history and examination, termed ‘clerking’, by a competent clinical decision maker, to formulate a working diagnosis and guide initial investigations. If necessary, the normal assessment process can be delayed whilst resuscitative care is delivered. The initial assessment is reviewed by a senior clinical decision maker. The expected timeframe for patients to be assessed is laid out in the clinical quality indicators for AMU.
First line treatments are commenced.
Further care planning
Decisions about second line investigations and specialty referrals are made. Discharge planning should commence at the time of admission or a specialty bed should be requested. Complex ethical decisions are usually made in the AMU such as cardiopulmonary resuscitation status or deprivation of liberty orders.
A number of investigations and therapeutic procedures are provided in the AMU. Invasive procedures should be undertaken in a dedicated procedures room when available. Investigations such as lumbar puncture should be available in every AMU. The provision for other procedures is currently variable, such as echocardiography and ultrasound.
Delivery of high profile care initiatives
There are a number of conditions where poor care is recognised in contributing to adverse patient outcomes. The highest profile examples are sepsis and acute kidney injury. Both of these conditions are seen on a daily basis in an AMU, and one is currently covered in the RCP toolkit Acute care toolkit 12: Acute kidney injury and intravenous fluid therapy.
Units should provide cardiac telemetry.
Higher level care
An AMU cannot provide the care of a Level 2 high-dependency unit (HDU). However, the provision of Level 1 care in an enhanced care area within an AMU was recommended by the RCP in Acute medical care: the right person, in the right setting – ﬁrst time. Such facilities enable the provision of enhanced modes of care, for example non-invasive ventilation.
On admission to hospital a number of compulsory generic aspects of care are required, such as assessment and treatment for the prevention of thromboembolism. The AMU is frequently the starting point for the care described in local CQUINs (Commissioning for Quality and Innovation Payments).
Access to diagnostic services
Every AMU must be supported by a full range of diagnostic investigations 24 hours a day, 7 days a week.
Access to higher level care
Every AMU must be supported by a high-dependency unit, intensive care unit and coronary care unit.
High-quality nursing leadership is vital. Appropriate staffing ratios and skill mix are essential to provide the best care in an area of high patient turnover and acuity. The Society for Acute Medicine (SAM) provides important information, including The coordinator role in acute medicine (opens PDF, 305KB) and Workforce planning considerations for acute medical units (opens PDF, 55KB).
Access to allied health professionals and pharmacists
SAM has issued quality standards for AMUs (opens PDF, 833KB) that detail the following (see p 11 and 13). Each AMU should have daily access to physiotherapy, occupational health therapy, speech therapy and dietetics, with varying recommended times spent on the unit.
SAM also recommends the following pharmacy services:
- Access to pharmacy advice (24/7)
- Immediate supply of commonly used medications
- Supply of other medications (24/7)
- Daily (7/7) attendance on the unit by a pharmacist with General Level Framework (GLF) competencies who is working towards or has achieved Advanced Level Framework (ALF) competencies.
Specialty in-reach to AMU
For an AIM service to function well it needs to maintain strong links with all hospital specialties. Staff who in-reach to AMU include doctors and specialist nurses. In-reach services can occur routinely or when required. Examples of specialties that are expected to provide routine input to AMU include cardiology, respiratory medicine and neurology. Specialties that input to AMU when asked include dermatology and rheumatology. Specialist services led by nurses include palliative care, alcohol liaison, COPD and diabetes.
As well as medical specialties, AIM needs to work closely with other disciplines, for example surgical specialties, obstetrics and gynaecology, intensive care medicine and psychiatry. The availability of specialties that can in-reach to AMU will depend on the local service provision. It is important that every AMU has clear mechanisms to access all of the available specialties within its own hospital and develops robust links and relationships with services that are off site.
In a complex social model such as an AMU, assessing benefits through traditional research methods, such as a randomised controlled trial, is problematic. However, observational data has shown that AMUs reduce inpatient mortality, length of stay and emergency department access block without increasing readmission rates, whilst improving patient and staff satisfaction.