Intended for healthcare professionals

Clinical Review ABC of intensive care

Other supportive care

BMJ 1999; 319 doi: (Published 17 July 1999) Cite this as: BMJ 1999;319:175
  1. Sheila Adam,
  2. Sally Forrest

    As well as specific organ support techniques such as mechanical ventilation and renal replacement therapy, patients in intensive care require other interventions to maintain organ function and prevent further damage. These include nutritional support, preserving skin integrity, psychological support, and mobilisation. These interventions enable patients to recover their previous level of health, prevent intercurrent problems such as nosocomial infection and lung atelectasis, and support psychological and physical wellbeing.


    Intensive care is not just about organ support

    Chest physiotherapy

    Patients who are intubated or mechanically ventilated require chest physiotherapy to remove excess bronchial secretions, re-expand atelectatic areas, improve ventilation, decrease ventilation-perfusion mismatch, and mobilise the thoracic cage.

    Respiratory complications associated with tracheal intubation and mechanical ventilation

    • Inability to clear secretions

    • Trauma related to high inflation pressures, large tidal volumes, and shear stresses

    • Microatelectasis and consolidation

    • Alterations in ventilation-perfusion matching

    Bronchial secretions increase in intubated patients as the tracheal mucous membrane is irritated. These secretions may become tenacious as the patients' natural humidification has been bypassed. Expectoration may also be reduced by an ineffective cough, decreased ciliary action, and loss of sigh breaths.

    Secretion tenacity can be reduced by adequate humidification and systemic hydration. Clearance of secretions is achieved by chest physiotherapy, suctioning, and occasionally bronchial lavage.


    Manual hyperinflation improves lung compliance and arterial oxygenation

    Disadvantages of immobility

    • Venous stasis

    • Increased risk of venous thrombosis and pulmonary embolism

    • Decrease in functional residual capacity (when supine)

    • Decreased lung compliance

    • Retained secretions

    • Atelectasis

    • Increased excretion of nitrogen, calcium, potassium, magnesium, and phosphorus

    • Osteoporosis

    • Kidney stones

    • Decrease in muscle bulk

    • Loss of bone density

    • Decreased range of joint movement

    • Pressure sores

    The primary aims of chest physiotherapy are to improve gas exchange and prevent atelectasis and consolidation, which occur as a result of mucus plugging or infection. Patients are assessed daily and will receive the following treatments as appropriate.

    Positioning—For postural drainage or to improve ventilation-perfusion matching.

    Manual hyperinflation—A 2 litre manual inflation bag is used to deliver up to 1.5 times the patient's tidal volume. An inspired breath is delivered at a slow rate and held for a short period before releasing rapidly. Normal saline can be instilled before the breath. This technique reinflates atelectatic areas of lung and loosens secretions by improving collateral ventilation. This improves arterial oxygenation and lung compliance.

    Manual techniques—Shaking and vibrations applied to the chest wall may loosen secretions in the airways.

    Suction— Secretions are removed by applying 25-30 kPa of negative pressure through a catheter passed down the endotracheal tube to the level of the carina.

    Some of these techniques may then be done by nursing staff to maintain the condition of the chest.


    The musculoskeletal system is designed to keep moving; it takes only seven days of bed rest to reduce muscle bulk by up to 30%. Immobility and muscle wasting in intensive care patients must be attended to after an initial assesment. Immobility may be caused by administration of sedative and neuromuscular blocking agents, neurological deficit, and general debilitation and weakness. Patients with cardiorespiratory instability may need to be immobilised for long periods. The use of restricting support technology—for example, haemofiltration or intra-aortic balloon counterpulsation—may also limit movement.

    Some patients develop critical illness polyneuropathy or myopathy after the acute phase of multiple organ dysfunction. This results in muscle wasting and often profound weakness. Affected patients exhibit flaccidity and a reduction or loss of deep tendon reflexes. Function is usually recovered, although it may take several months of rehabilitation.


    Tilt tables help early mobilisation

    Some patients may be able to undertake a partial active exercise regimen but most will require either active assisted or passive movements. These movements maintain full joint range, maintain full muscle length and extensibility, assist venous return, and maintain the sensation of normal movement.

    Shoulders, hands, hips, and ankles are at particular risk of contractures. Resting splints for the hands and feet can be made or bought to maintain and protect these joints in a neutral position.

    Early mobilisation out of bed is crucial even when the patient is intubated and ventilated. Hoists, tilt tables, and walking aids can be used to promote early physical rehabilitation.

    Factors increasing likelihood of developing pressure sores in critically ill patients

    • Inability to move

    • Emaciation and muscle wasting

    • Altered sensory function

    • Depressed cardiac function

    • Increased vasoconstriction

    • Reduced peripheral perfusion

    Pressure area problems

    Patients not moved regularly will develop pressure sores on dependent areas. The most vulnerable areas are the tissues over bony prominences. Several factors associated with critical illness increase the likelihood of pressure sores.

    Trauma and burns patients are at particular risk of pressure sores as are those with cardiovascular instability or diabetes. Preventive measures include regular turning and repositioning (usually every two to four hours). Special beds and mattresses should be used to relieve pressure over susceptible points and spread the pressure load in vulnerable patients. Regular inspection of the patient's skin integrity (especially high risk areas), early commencement of feeding, and prevention of contamination will all decrease the likelihood of problems.

    Severe pressure sores can usually be prevented by regular repositioning

    Severe pressure sores can usually be prevented by regular repositioning

    Eye and mouth care

    The mechanisms which normally protect mucosal and conjunctival surfaces exposed to the environment are lost to a greater or lesser degree in critically ill patients. Ventilated, sedated patients are often unable to blink or close their eyelids completely. There may be decreased tear production, a decreased resistance to infection, and a decrease in venous return with increased periorbital oedema due to rises in intrathoracic pressure associated with positive pressure ventilation.

    The two commonest eye problems are dry eye and exposure keratopathy. The most effective measures are preventive. The corneal surface is kept moist by regularly applying artificial teardrops and hydrogel pads or tape to close the eyelids. Conjunctival oedema can be avoided by optimising ventilator settings, raising the patient's head, and ensuring that tapes securing the endotracheal tube are not too tight.


    Good oral hygiene is important

    The incidence of buccal mucosal sores and infection is also increased because of a decreased or absent oral fluid intake, mucosal dehydration, decreased saliva production, the effects of drugs such as antibiotics, and the orotracheal tube hindering oral hygiene.

    Mucosal care is also mainly preventive with frequent moisturising, teeth brushing, and removal of debris, saliva, and sputum. Oral candidiasis is common and requires early recognition and treatment with nystatin mouthwashes. Gingivitis should be treated with chlorhexidine mouthwashes.

    Maintenance of nutritional intake

    Most patients in intensive care are too sick to sustain an adequate oral diet. They therefore require enteral or parenteral nutrition, or a combination. The potential complications of parenteral nutrition mean that enteral feeding is attempted in most patients.

    Typical contents of enteral feeds (1.5-2.5 l/day)

    Advantages and disadvantages of enteral and parenteral nutrition

    View this table:

    Unless there are specific reasons to the contrary, all patients likely to remain in intensive care for more than 48 hours should be started on enteral nutrition. Most patients can be enterally fed, sometimes with the use of prokinetic drugs.

    A feeding protocol is a useful means of closing the gap between the volume of feed prescribed and that actually delivered to the patient. If patients cannot tolerate enteral nutrition, mixed feeding with minimal enteral feed plus parenteral supplementation or parenteral nutrition alone may be used.

    Critically ill patients need about 0.7-1.0 g protein/kg/day, a minimum of 1 litre 10% fat emulsion weekly, and 83-146 kJ of non-protein energy/kg/day. Non-protein energy is usually given in a fat:carbohydrate ratio of 1:2.

    Typical composition of daily parenteral feed

    View this table:

    Advantages and disadvantages of enteral and parenteral nutrition

    Advantages and disadvantages of enteral and parenteral nutrition

    View this table:

    Absolute contraindications to enteral nutrition are gastrointestinal obstruction, prolonged paralytic ileus, and enterocutaneous fistulae. Relative contraindications include malabsorption and short bowel syndrome, inflammatory bowel disease, pancreatitis, and cholecystitis.

    Increased infection risks

    Patients in intensive care are five times more likely to develop a nosocomial infection than those on a general ward. Common sites of nosocomial infection are the lung, catheter puncture sites, urinary tract, and wounds. Three patterns of infection are seen:

    Primary endogenous infection—the patient's own flora are the infecting organisms (for example, Haemophilus influenzae, Streptococcus pneumoniae, Escherichia coli).

    Secondary (distant) endogenous infection—Caused by organisms from the throat or gastrointestinal tract (for example, Acinetobacter spp, Serratia spp, Klebsiella).

    Exogenous infection—Direct transfer of organisms from the intensive care environment to the patient without passage through the throat or gut (such as Staphylococcus spp).

    Causes of increased risk of nosocomial infection

    • Multiple vascular access sites

    • Endotracheal tube bypassing mucous membranes and ciliary defences

    • Sedation, mechanical ventilation, and immobility leading to pneumonia

    • Indwelling urinary catheter

    • Compromised immune function from critical illness, poor nutrition, underlying disease

    • High numbers of critically ill patients in one area

    • High use of antibiotics leading to bacterial resistance and fungal overgrowth

    Mechanisms of infection include contamination of inspired air (through respiratory equipment), spread from neighbouring tissue, blood borne spread from a distant focus, and oropharyngeal-gastric colonisation followed by transfer to the trachea.

    The most important preventive measure against the spread of infection is hand washing. As many as 40% of infections are transmitted on the hands of hospital staff.

    Cross infection rates can be reduced by a vigorous infection control policy covering antibiotic use, timing and reasons for changing central venous catheters, isolation techniques, and use of disposable components (such as ventilator tubing and filters). Regular staff education and audit help to reinforce good practice.

    Preventing stress ulcers

    The incidence of serious bleeding from stress ulcers in critically ill patients has fallen greatly in the past two decades. This is due to better overall patient management and greater attention to maintaining adequate organ perfusion and nutrition rather than to any specific treatment. A recent multicentre study suggested that ranitidine was superior to sucralfate with no increased risk of nosocomial pneumonia. Enteral feeding has been shown to be equally protective.

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    Psychological effects

    Psychological disturbances associated with intensive care include sensory imbalance and disorientation. Patients may be confused, distracted, disoriented, restless, incoherent, agitated, or have hallucinations. There may be frank delirium, “intensive care unit psychosis,” or acute anxiety disorders. There are numerous frightening or unpleasant stimuli such as pain, the presence of the endotracheal tube, disconnection from the ventilator, and sounding of ventilator, syringe pump, and monitor alarms. Patients may find the environment noisy, mechanistic, lacking in privacy, confined, and isolated. They may find it difficult to distinguish the passage of time, and dreams and hallucinations often have depersonalisation or torture themes.

    Causes of psychological disturbance

    • Patients' illness—for example, head injury, sepsis, and hypotension

    • Secondary complications such as nosocomial infection and electrolyte disorders

    • Drugs and drug withdrawal— for example, sedatives, recreational drugs, alcohol

    • Alien environment

    • Loss of normal circadian rhythms and sleep patterns

    Management is aimed at prevention of these problems. Staff should emphasise a clear difference between night and day by changing the ambient light. Natural light and windows at the patient's eye level are important design features. Clock faces should be large and easily visible, and patients should be surrounded by familiar objects, music, and family photos. Patients need repeated simple explanations about what is happening to them. Family participation in care and conversation is encouraged. Touch and human contact by both carers and family are also comforting and reassuring. As the patient's condition stabilises, lengthy periods of uninterrupted sleep are sought by clustering interventions; ensuring comfort by positioning, warmth, and analgesia; and reducing ambient noise and light. As the patient improves, control over the environment and independence should be encouraged.

    If patients become disturbed, correctable causes such as catheter related infection should be sought. Patients can often be calmed verbally or with gentle yet firm touch. Sedatives or strong tranquillisers may be necessary to prevent the patient from self harm. Although agitation is obviously distressing, family and friends can be reassured that it is self limiting. It usually settles within a few days, and the patient often does not remember this acute confusional state.

    Support of the family is also crucial and requires both skill and time. Relatives and friends are often traumatised by the patient's admission to intensive care and require comfort, information, and consideration in order to cope. Although they often feel frustrated and helpless during the acute phase of critical illness, they have a vital role in aiding recovery once the patient stabilises and regains awareness.

    Up to two thirds of patients will have little or no recollection of their stay in intensive care. However, a small number will have clear memories and some will develop long term psychological disturbances. A post-traumatic stress disorder may occur, resulting in depression, sleep disturbances, and often vivid nightmares. Follow up clinics and psychological counselling for both patient and family are being introduced to help patients cope with the sequelae of their critical illness.


    • Sheila Adam is clinical nurse specialist, Intensive Care Unit, and Sally Forrest is a superintendent physiotherapist, University College London Hospitals, London.

      The ABC of intensive care is edited by Mervyn Singer, reader in intensive care medicine, Bloomsbury Institute of Intensive Care Medicine, University College London and Ian Grant, director of intensive care, Western General Hospital, Edinburgh. The series was conceived and planned by the Intensive Care Society's council and research subcommittee.

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