Clinical review                         Downloaded from bmj.com on 1 October 2006 
                  ABCofintensive care
                  Organisation of intensive care
                  David Bennett,Julian Bion
                  Intensive care dates from the polio epidemic in Copenhagen in
                  1952.Doctors reduced the 90% mortality in patients receiving
                  respiratory support with the cuirass ventilator to 40% by a
                  combination of manual positive pressure ventilation provided
                  through a tracheostomy by medical students and by caring for
                  patients in a specific area of the hospital instead of across
                  different wards. Having an attendant continuously at the
                  bedside improved the quality of care but increased the costs
                  and,in some cases,death was merely delayed.
                      These findings are still relevant to intensive care today, even
                  though it has expanded enormously so that almost every
                  hospital will have some form of intensive care unit. Many
                  questions still remain unanswered regarding the relation
                  between costs and quality of intensive care, the size and location
                  of intensive care units, the number of nursing and medical staff
                  andintensive care beds required, and how to direct scarce          The origins of intensive care can be traced to the 1952 polio epidemic in
                  resources towards those most likely to benefit.                    Copenhagen
                  Patients
                  Intensive care beds are occupied by patients with a wide range of
                  clinical conditions but all have dysfunction or failure of one or
                  moreorgans,particularly respiratory and cardiovascular systems.
                  Patients usually require intensive monitoring,and most need
                  someformofmechanicalorpharmacologicalsupportsuchas
                  mechanicalventilation,renal replacement therapy,or vasoactive
                  drugs.Aspatients are admitted from every department in the
                  hospital, staff in intensive care need to have a broad range of
                  clinical experience and a holistic approach to patient care.
                      Thelengthofpatient stay varies widely. Most patients are
                  discharged within 1­2 days, commonly after postoperative
                  respiratory and cardiovascular support and monitoring. Some
                  patients, however, may require support for several weeks or
                  months.These patients often have multiple organ dysfunction.
                  Overall mortality in intensive care is 20­30%, with a further 10%
                  dying on the ward after discharge from intensive care.             “Experimental” intensive care ward, St George’s Hospital, 1967
                  Provision
                  Intensive care comprises 1­2% of total bed numbers in the
                  United Kingdom;this compares with proportions as high as
                  20%intheUnitedStates.Patients admitted in Britain therefore
                  tend be more severely ill than those in America. The average
                  intensive care unit in Britain has four to six beds, although units
                  in larger hospitals, especially those receiving tertiary referrals,
                  are bigger. Few units have more than 15 beds. Throughput
                  varies from below 200 to over 1500 patients a year. In addition
                  to general intensive care units, specialty beds are provided for
                  cardiothoracic, neurosurgical, paediatric, and neonatal patients
                  in regional centres.
                      Thefrequent shortages of intensive care beds and recent
                  expansion of high dependency units have led to renewed efforts
                  to define criteria for admission and discharge and standards of
                  service provision. Strict categorisation is difficult; an agitated,
                  confused but otherwise stable patient often requires at least as   Modern intensive care usually includes comprehensive monitoring and
                  muchattention as a sedated,mechanically ventilated patient.        organ support. Pressure on resources is high
                  Furthermore,underresourced hospitals may have to refuse
                  admission to those who would otherwise be admitted.A recent
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                                                            Downloaded from bmj.com on 1 October 2006                                 Clinical review
                   study sponsored by the Department of Health suggested that
                   patients refused intensive care have a higher mortality than
                   similar patients who do get admitted.
                       Transfer to another hospital is generally reserved for those
                   patients requiring mechanical ventilation, renal support, or
                   specialist treatment not available in the referring hospital.
                   Transfer of such critically ill patients is not undertaken lightly. It
                   is labour intensive and should be performed by experienced
                   staff with specialised equipment. In addition, such transfers
                   removestaff from the referring hospital, often at times when
                   they are in short supply.
                   Staffing
                   Medical
                   Eachintensive care unit has several consultants (ranging from        Mechanical ventilator, 1969
                   twotoseven)withresponsibility for clinical care,one of whom
                   will be the clinical director. There are few full time intensivists in
                   the United Kingdom.Mostconsultants will have anaesthetic or
                   medical sessions in addition to their intensive care commitments.
                   Theconsultants provide 24 hour non­resident cover.
                       In general, junior doctor staffing levels are lower in Britain
                   than elsewhere in Europe.Most junior doctors are either
                   anaesthetic senior house officers or specialist registrars, who
                   mayprovidededicated cover to the intensive care unit or have
                   duties in other clinical areas such as obstetrics and emergency
                   theatre. Increasingly, posts are being incorporated into medical
                   or surgical rotations. Larger units often also have a more senior
                   registrar on a longer attachment. These are training posts for
                   those intending to become fully accredited intensivists. Such
                   training schemes are a relatively recent innovation in Britain.
                       Themedicalstaff will typically perform a morning ward
                   roundandalessformalroundintheafternoon.Theoncall
                   teamdoesafurtherroundintheevening.
                   Nursing
                   Thegeneral policy in the United Kingdom is to allocate one
                   nurse to each intensive care patient at all times with two or
                   three shifts a day. One nurse may care for two less sick patients,
                   andoccasionally a particularly sick patient may require two          Mechanical ventilator, 1999
                   nurses. This nurse:patient ratio requires up to seven established
                   nursing posts for each bed and an average of 30­50 nurses per
                   unit. Elsewhere in Europe the nurse:patient ratio is usually 1:2
                   or 1:3, although the units are larger and have a higher              Roleofotherhealthcareprofessionals in intensive care
                   proportion of low risk patients. Many intensive care nurses will     Professional        Role
                   have completed a specialist training programme and have
                   extensive experience and expertise. Not surprisingly, nursing        Physiotherapists    Prevent and treat chest problems, assist
                   salaries comprise the largest component of the intensive care                            mobilisation, and prevent contractures in
                   budget.However,a shortage exists of appropriately qualified                              immobilised patients
                   staff, which leads to refused admissions, cancellation of major      Pharmacists         Advise on potential drug interactions and side
                                                                                                            effects, and drug dosing in patients with liver or
                   elective operations, and a heavy and stressful workload for the                          renal dysfunction
                   existing nurses. To ease this problem, healthcare assistants are     Dietitians          Advise on nutritional requirements and feeds
                   being increasingly used to undertake some of the more                Microbiologists     Advise on treatment and infection control
                   mundanetasks.                                                        Medical physics     Maintain equipment,including patient monitors,
                                                                                        technicians         ventilators, haemofiltration machines, and blood
                   Audit                                                                                    gas analysers
                   Intensive care audit is highly sophisticated and detailed.
                   Dedicated staff are often required to assist with data collection
                   which includes information on diagnoses,demographics,
                   severity, resource use, and outcome. Methods such as severity           Effective audit is essential for evaluating treatments in
                   scoring are being developed to adjust for case mix to enable            intensive care
                   comparisons within and between units.The establishment of
                   the Intensive Care National Audit Research Centre (ICNARC)
                   andScottish Intensive Care Society Audit Group has been an
                   BMJ VOLUME318 29MAY1999 www.bmj.com                                                                                              1469
                     Clinical review                             Downloaded from bmj.com on 1 October 2006 
                     important step in this respect. ICNARC has recently developed
                     a national case mix programme,to which many UK intensive
                     care units subscribe.
                     Cost
                     Intensive care is expensive. The cost per bed day is
                     £1000­£1800withsalaries accounting for over 60%,pharmacy
                     for 10%,and disposables for a further 10%. The current
                     contracting process has found it difficult to account for intensive
                     care, partly because it does not have multidisciplinary specialty
                     status and is therefore extremely difficult to isolate from the
                     structure of the “finished consultant episode.” This has been
                     partially resolved by the development of the augmented care
                     period (except in Scotland), defined by 12 data items which
                     include information about the duration and intensity of care. It
                     is intended that this will become part of hospital administration
                     systems and improve the process of contracting for intensive
                     care services. This is essential for budgetary health and the
                     development of intensive care as an independent
                     multidisciplinary specialty. In the United Kingdom, in parallel
                     with many other countries, specialty status is in the process of
                     being officially accorded.
                         Theintensive care budget often falls within a directorate
                     such as anaesthesia or theatres, although large units may have a
                     separate budget. Units now have a business manager, who may
                     be employed specifically for this role or, more commonly, be a
                     senior nurse. This is a daunting task. Severe constraints are
                     often rigorously applied by the hospital management leading to
                     bedclosures and an inability to replace ageing equipment.
                                                                                               Blood gas analysers, 1964 and 1999: technological developments have
                     Caring for relatives and patients                                         improved patient care but added to the cost
                     Theintensive care environment can be extremely distressing for
                     both relatives and conscious patients. The high mortality and
                     morbidity of patients requires considerable psychological and             Keypoints
                     emotional support.This is provided by the medical and nursing             x Organisation of intensive care units in the United Kingdom varies
                     staff often in conjunction with chaplains and professional and               widely
                     lay counsellors. Such support is difficult and time consuming             x Clinical managements strategies are determined by local need,
                     andrequires the involvement of senior staff.                                 facilities, and staff
                         Manyrelatives and close friends wish to be close to critically        x Lack of large scale studies has hampered consensus on treatment
                     ill patients at all times. Visiting times are usually flexible and        x Underprovision of intensive care is likely to dominate policy
                     manyunitshaveadedicatedvisitors’sitting room with basic                      decisions in near future
                     amenities such as a kitchenette, television, and toilet facilities.
                     Onsite overnight accommodation can often be provided.
                     Summary
                     Fewlarge scale studies exist of intensive care. This is partly
                     because the patient population is heterogeneous and difficult to
                     investigate. Although clinical management varies according to
                     local need and facilities and the views of medical and nursing            David Bennett is professor of intensive care medicine, St George’s
                     staff, similar philosophies are generally adopted.                        Hospital Medical School,London and Julian Bion is reader in
                         Underprovision of intensive care is likely to dominate policy         intensive care medicine, Queen Elizabeth Medical Centre,
                     decisions in the near future. Intensive care will probably have an        Birmingham
                     increasingly important role as the general population ages and
                     the expectation for health care and the complexity of surgery             TheABCofintensivecareisedited by Mervyn Singer,reader in
                     increases.                                                                intensive care medicine, Bloomsbury Institute of Intensive Care
                                                                                               Medicine,University College London and Ian Grant,director of
                     Thepicture of the patient with polio was provided by Danske               intensive care, Western General Hospital, Edinburgh. The series was
                     Fysioterpeuter (Danish journal of physiotherapy). We thank                conceived and planned by the Intensive Care Society’s council and
                     Radiometer UKandStGeorge’sHospitalarchivist for help.                     research subcommittee.
                     BMJ1999;318:1468­70
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                     Clinical review                               Downloaded from bmj.com on 1 October 2006 
                     ABCofintensive care
                     Criteria for admission
                     GarySmith,MickNielsen
                     Intensive care has been defined as “a service for patients with
                     potentially recoverable conditions who can benefit from more
                     detailed observation and invasive treatment than can safely be
                     provided in general wards or high dependency areas.” It is
                     usually reserved for patients with potential or established organ
                     failure. The most commonly supported organ is the lung,but
                     facilities should also exist for the diagnosis, prevention, and
                     treatment of other organ dysfunction.
                     Whotoadmit
                     Intensive care is appropriate for patients requiring or likely to
                     require advanced respiratory support, patients requiring
                     support of two or more organ systems,and patients with
                     chronic impairment of one or more organ systems who also
                     require support for an acute reversible failure of another organ.
                     Early referral is particularly important. If referral is delayed
                     until the patient’s life is clearly at risk, the chances of full              Ward observation chart showing serious physiological
                     recovery are jeopardised.                                                     deterioration
                     Categories of organ system monitoring and support
                     (Adapted from Guidelines on admission to and discharge from intensive care and high dependency units.London: Department of Health, 1996.)
                     Advancedrespiratory support                                                  Circulatory support
                     x Mechanical ventilatory support (excluding mask continuous positive         x Needforvasoactive drugs to support arterial pressure or cardiac
                        airway pressure (CPAP) or non­invasive (eg, mask) ventilation)              output
                     x Possibility of a sudden, precipitous deterioration in respiratory          x Support for circulatory instability due to hypovolaemia from any
                        function requiring immediate endotracheal intubation and                    cause which is unresponsive to modest volume replacement
                        mechanical ventilation                                                      (including post­surgical or gastrointestinal haemorrhage or
                     Basic respiratory monitoring and support                                       haemorrhagerelated to a coagulopathy)
                     x Needformorethan50%oxygen                                                   x Patients resuscitated after cardiac arrest where intensive or high
                     x Possibility of progressive deterioration to needing advanced                 dependencycare is considered clinically appropriate
                        respiratory support                                                       x Intra­aortic balloon pumping
                     x Needforphysiotherapy to clear secretions at least two hourly               Neurological monitoring and support
                     x Patients recently extubated after prolonged intubation and                 x Central nervous system depression,from whatever cause,sufficient
                        mechanical ventilation                                                      to prejudice the airway and protective reflexes
                     x Needformaskcontinuouspositive airway pressure or non­invasive              x Invasive neurological monitoring
                        ventilation                                                               Renalsupport
                     x Patients who are intubated to protect the airway but require no            x Needforacuterenal replacement therapy (haemodialysis,
                        ventilatory support and who are otherwise stable                            haemofiltration, or haemodiafiltration)
                          Aswithanyothertreatment,the decision to admit a patient
                     to an intensive care unit should be based on the concept of
                     potential benefit. Patients who are too well to benefit or those
                     with no hope of recovering to an acceptable quality of life
                     should not be admitted. Age by itself should not be a barrier to              Factors to be considered when assessing suitability for
                     admission to intensive care, but doctors should recognise that                admission to intensive care
                     increasing age is associated with diminishing physiological                   x Diagnosis
                     reserve and an increasing chance of serious coexisting disease.               x Severity of illness
                     It is important to respect patient autonomy, and patients should              x Age
                     not be admitted to intensive care if they have a stated or written            x Coexisting disease
                                                                                                   x Physiological reserve
                                                             —for example,in an
                     desire not to receive intensive care                                          x Prognosis
                     advanced directive.                                                           x Availability of suitable treatment
                          Severity of illness scoring systems such as the acute                    x Response to treatment to date
                     physiology and chronic health evaluation (APACHE) and                         x Recent cardiopulmonary arrest
                     simplified acute physiology score (SAPS) estimate hospital                    x Anticipated quality of life
                     mortality for groups of patients. They cannot be used to predict              x Thepatient’s wishes
                     which patients will benefit from intensive care as they are not
                     sufficiently accurate and have not been validated for use before
                     admission.
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