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Would you explain what the level 3 or level 2/3 ICU is? What is the difference between ICU and HDU?

BMJ 2005; 330 doi: (Published 07 May 2005) Cite this as: BMJ 2005;330:s184
  1. Peter Shirley, intensive care consultant
  1. Royal London Hospital


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The Department of Health (UK) produced a document in 2001 called Comprehensive Critical Care in which the levels of care are summarised:

  • Level 1—Ward based care where the patient does not require organ support (for example, they may need an IV, or oxygen by face mask)

  • Level 2—High dependency unit (HDU). Patients needing single organ support (excluding mechanical ventilation) such as renal haemofiltration or ionotropes and invasive BP monitoring. They are staffed with one nurse to two patients

  • Level 3—Intensive care. Patients requiring two or more organ support (or needing mechanical ventilation alone). Staffed with one nurse per patient and usually with a doctor present in the unit 24 hours per day.



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