Open and closed models of intensive care units

The question of who is actually responsible for the decisionmaking in intensive care is an ongoing debate in critical care medicine. Traditionally in Australia the intensive care specialist takes responsibility for all decisionmaking for the patients under their care, and refers to the primary team only for consultation on specific questions, or for specialist services (eg. angiography, surgery, endoscopy etc). This model is supported by our robust (nightmarish, exhausting, arbeit macht frei) training program which produces world-class intensive care physicians. However, the primary team's desire to have active input into the care of their patients is a source of conflict, and it must be acknowledged that many ICUs in developed countries function reasonably well without intensivists.

Question 26 from the second paper of 2007 asked the candidates what they understood by "open" and "closed" ICUs, and what are the advantages/limitations of each. As the pass rate was around 60%, most candidates understood this fairly well. This bodes well for their future practice. Australian ICUs tend to be all "closed", with the exception of private hospitals where it seems the admitting surgical specialist can make (occasionally disastrous) decisions which countermand whatever the staff intensivist has recommended, making it a de facto open model. The reason for such openness is the imbalance of power in private institutions, where the surgeons are dominant revenue-bringers. As the chief money-makers, their influence over clinical decisions tends to be more supported by the executive staff whenever a dispute arises. It is economically more sensible to jettison the troublemaking intensivist then to risk losing the surgeon.

Anyway.  As far as useful resources go, there is some material out there:

Oh's manual has surprisingly little to say on this matter, presumably because in the opinion of the authors the matter is settled. A paragraph is devoted to the issue on page 6, where the Pronovost (2002) review is quoted in support of thew closed model.

Definition of "open" and "closed" ICU models

  • An "Open" ICU is one where specialty teams have full admitting rights and where an intensivist is merely "consulting".
  • A "Closed" ICU is one where the intensivist is the admitting medical officer and the specialty teams collaborate with ICU staff.
  • A "High intensity" staffing model is one which involves either a closed ICU, or a "mandatory consult" situation where the specialty teams might still have admitting privileges to the ICU but every patient must be seen by an intensivist (hence "mandatory"). An alternative is a model where some of the ICU beds are allocated as "closed" and others are "open" and cared for by the specialist teams.
  • Most ICUs worldwide are closed. The open vs. closed debate is largely an American thing. In America, half of ICUs don't have any intensivist coverage. In context, this means that even large units would not meet with the CICM accreditation criteria, and would be ineligible to accept trainees for the ICU training program.
  • The terms "open" and "closed" are probably misleading and inappropriate, as they imply exclusion and inclusion. Better terms might be "service" ICUs for the open model, and "specialist" ICUs for the closed model.

Advantages of a "closed" ICU

Advantages of an "open" ICU

  • There is no need for an interfering intensivist, which might be favoured by specialist teams
  • Primary physicians and surgeons have a better familiarity with their patients, whereas the intensivist has only met them for the first time in the context of their critical illness.
  • Primary specialists carry on care after ICU admission, promoting continuity of care
  • Much of the workload traditionally associated with ICU specialists in Australia can be outsourced to allied health staff (eg. respiratory care technicians manage ventilation in America because the primary physicians are unwilling or incapable of it; American nurses and physicians assistants can intubate the patients and insert central lines). This can be a cost-saving measure.
  • Each time a patient enters or leaves an ICU a hand-over must take place, which is an opportunity for information to be lost or misrepresented.
  • Continuity of care may result in improved patient and family satisfaction, as they end up dealing with the same familiar faces rather than having to discuss important issues with a relatively unfamiliar specialist

Evidence in support of the closed model

  • Carson et al (1996) found improved outcomes when a medical ICU converted from open to closed. Specdific improvements noted were improved ratios of actual to expected mortality (i.e a crude SMR) and increased nurse confidence with clinical decisionmaking.
  • Hackner et al (2009) found an improvement in mortality associated with the closed model in a medical ICU, but no difference in ICU length of stay.
  • Ghorra et al (1999) found a variety of improved outcome parameters when a 9-bed surgical ICU converted to a closed model, including improved mortality and a decreased use of dopamine (this study was from the era when low-dose "renal" dopamine was in vogue).
  • van der Sluis et al (2011) also found a mortality benefit when their surgical ICU converted to a closed model.

Evidence in support of the open model

  • A 2008 study by Levy et al as well as a subsequent meta-analysis by the same author discovered that ICU patients who had an intensivist involved had increased mortality. A more recent (2014) analysis of mortality in 69 centres also failed to detect an improvement in mortality associated with a closed model. How did this happen?
    • The studies was limited to the US
    • Many of the ICUs only involved an intensivist if the specialty team requested their opinion
    • The patients managed by an intensivist were on average far sicker and had more procedures
    • The closed units were probably run by an "internist", i.e. a general physician with no critical care expertise. Brilli et al (2001) found that 56% of American ICUs were run by a person not certified in critical care. Now, you put some FCICMs in there and see what happens.
  • Other American authors (Weissman and Halpern,  2016) has pointed out that the evidence for the superiority of a closed model is largely retrospective, and that " units that transitioned to intensivist-led models did not achieve improvements in risk-adjusted mortality in either medical or surgical units"

Some synthesis of the above

  • A "closed" ICU model is clearly superior in an environment where critical care training is as evolved as it is in Australia and New Zealand.
  • A collaborative approach with primary specialist teams is still essential to promote high quality patient care. In Worthley's words:

We don’t have‘his’ or ‘her’ patients, we have ‘our’ patients, and in the event that the home team feels that there may be aspects of our treatment that require explanation, we are only too happy to discuss this with them — civilly."


Pronovost, Peter J., et al. "Physician staffing patterns and clinical outcomes in critically ill patients: a systematic review." Jama 288.17 (2002): 2151-2162.

Levy, Mitchell M., et al. "Association between critical care physician management and patient mortality in the intensive care unit." Annals of internal medicine 148.11 (2008): 801-809.

Wilcox, M. Elizabeth, et al. "Do Intensivist Staffing Patterns Influence Hospital Mortality Following ICU Admission? A Systematic Review and Meta-Analyses*." Critical care medicine 41.10 (2013): 2253-2274.

Wallace, David J., et al. "Nighttime intensivist staffing and mortality among critically ill patients." New England Journal of Medicine 366.22 (2012): 2093-2101.

Checkley, William, et al. "Structure, process, and annual ICU mortality across 69 centers: United States critical illness and injury trials group critical illness outcomes study*." Critical care medicine 42.2 (2014): 344-356.

Capanni, Francesca, and William Checkley. "Differences in Hospital Mortality by ICU Staffing Models: You Cannot Always Get What You Want, but Sometimes You Get What You Need*." Critical care medicine 41.10 (2013): 2433-2434.

Carson, Shannon S., et al. "Effects of organizational change in the medical intensive care unit of a teaching hospital: a comparison of'open'and'closed'formats." Jama 276.4 (1996): 322-328.

Hackner, Dani, et al. "Do faculty intensivists have better outcomes when caring for patients directly in a closed ICU versus consulting in an open ICU?." Hospital practice 37.1 (2009): 40-50.

Ghorra, Salim, et al. "Analysis of the effect of conversion from open to closed surgical intensive care unit." Annals of surgery 229.2 (1999): 163.

Brilli, Richard J., et al. "Critical care delivery in the intensive care unit: defining clinical roles and the best practice model." Critical care medicine 29.10 (2001): 2007-2019.

Worthley, L. I. "The ideal intensive care unit: open, closed or somewhere between?." Critical Care and Resuscitation 9.2 (2007): 219.

van der Sluis, Frederik J., et al. "The impact of open versus closed format ICU admission practices on the outcome of high risk surgical patients: a cohort analysis." BMC surgery 11.1 (2011): 18.

Weissman, Gary E., and Scott D. Halpern. "Evidence supports the superiority of closed ICUs for patients and families: no." (2016): 1-4.

Vincent, Jean-Louis. "Evidence supports the superiority of closed ICUs for patients and families: yes." (2016): 1-2.

Guidet, B., N. Kentish-Barnes, and H. Wunsch. "Evidence supports the superiority of closed ICUs for patients and families: we are not sure." (2016): 1-3.