Special Feature

Changing to a Closed Model of ICU Organization: Why and How

James E.McFeely,MD, Medical Director Critical Care Units, Alta Bates Summit Medical Center, Berkeley, CA is Associate Editor for Critical Care Alert.

Over the last decade there has been a growing trend from an open to a closed model of ICU care delivery. The open model is an ICU where day-to-day management decisions are made by an admitting physician with the assistance of consultants. The admitting physician may be any member of the medical staff and need not necessarily have any particular expertise in the provision of critical care services. There are many models of closed unit care. The most stringent example requires a trained intensivist to be completely responsible for admission, management, and discharge of all patients in the intensive care unit, with the aid of consulting physicians. There are also a number of intermediate patterns between these two. In this article I will review some of the relevant literature comparing these two modes of care delivery and discuss issues related to changing from a more open to a more closed unit structure.

What Does the Literature Show?

Carson et al1 retrospectively reviewed 120 medical ICU patients before and after changing from an open to a closed ICU system. They showed that while patients admitted after the change to a closed system tended to be sicker (APACHE II score, 20.6 vs 15.4), there was no appreciable difference in hospital mortality. There was a trend towards decreased actual mortality as compared to predicted mortality, although it was not statistically significant. Despite increased severity of illness of patients admitted during the closed system, there was no significant difference in ICU or hospital length of stay or resource utilization. Interestingly, patient families felt that communication with physicians was easier in the closed format; and the nursing staff reported they felt more confident in the clinical judgment of physicians in the closed system compared with the open system.

Multz et al2 used a slightly different technique, comparing ICU outcomes in 2 hospitals in the same city, one that had changed to a closed system and one that continued with an open model. They found that ICU and hospital stays were shorter and days on a mechanical ventilator were decreased under the closed system, while mortality was unaffected.

Other studies also point to the comparative advantages of a closed system. For example, a retrospective comparison of data before and after closing a surgical ICU showed that among this diverse group of surgical patients mortality was lower, the complication rate was statistically reduced, and resource utilization was relatively unchanged in the closed system.3 In another study, changing to a closed system of care at the Hammersmith Hospital in London was associated with a decrease in crude hospital mortality by nearly half (OR 0.51; CI, 0.32-0.82; P > 0.005).4 More recent data from a developing country shows similar results—in a prospective and retrospective comparison of outcomes after closing an ICU and adding an intensivist to manage the unit, patients were approximately 4.5 times more likely to survive their hospital stay during the closed policy than during the open ICU era.5 As with the other papers mentioned, patients admitted during the period when the ICU was closed tended to be sicker.

While there certainly are pitfalls in this type of organizational research, essentially all of the data published in the last 10 years has come to a similar conclusion, favoring a closed vs open unit structure.6 A literature review in 2002 came to a similar conclusion.7

How to Set Up a Program

Presuming one agrees that a closed ICU structure is beneficial as compared with an open structure, the difficult question then is how to implement such a change. There will be a unique solution for each hospital and ICU depending on a number of factors, including needs, resources, and talents available in the local community, as well as the size of the unit, the number of patients available to be seen, the economic resources of the hospital, and the number of physicians in the community. Options range from mandatory intensivist consultation for all patients admitted to the ICU at a minimum, to a closed ICU with 100% management by intensivists and 24-hour on-site physician coverage.

One appropriate option may be use of a remotely connected intensivist (eICU).8 Another option is simply to add daily rounds by an ICU physician, which has been shown to result in a 3-fold decrease in in-hospital mortality in patients undergoing abdominal aortic aneurysm surgery.9 Some institutions may use a hospitalist as part of the team with an intensivist as backup at night. This has been shown to improve survival and shorten length of ICU stay (as compared with house-staff) in a pediatric unit.10 Any one of these options may be appropriate for a given institution.

Once a decision has been made to go to a more closed unit structure, buy-in will need to be obtained from the relevant parties affected by the decision. Certainly the medical staff leadership will have to be brought into the process. One possible mechanism for implementing the change, for instance, is the use of credentialing to develop a set of ICU management privileges for participating physicians. In this case, minimum standards that should be objective as possible will be required for physician credentialing. Depending on the resources available, completion of a critical care training program may be an appropriate benchmark, with consideration given to grandfathering those trained prior to availability of formal critical care training programs.

The nursing department will also be integral to the development of the program, as it may require changes to nursing policy and procedures. Among ICU nurses, it will unquestionably result in a significant change in mindset in terms of how patient care is coordinated and with whom they interact for various problems and management decisions. Nurses generally prefer a closed ICU system, as it makes their jobs easier. Instead of having to call doctor X for fluids, doctor Y for ventilator orders, and doctor Z for vasopressors, they now have one-stop shopping. In a closed system, phrases such as "managing physician," "captain of the ship," and "I’ll take care of that for you" suddenly appear in the physician vocabulary, to the delight of the nursing staff. If a system is developed with 24 hr on-site physician coverage, night shift nurses in particular will benefit and will feel more a part of the overall care team. This can be a particular benefit in units with relatively inexperienced nurses working at night, providing them ready access to a trained experienced physician.

Hospital administration will also have to be brought in early in the process. Depending on the volume of work available for a critical care physician, there may be a need for monetary supplementation of the program, either through the use of medical directorships or perhaps payment for on call services until such time as the program can be independently economically viable.

Barriers to Implementation

There are a number of obstacles to overcome in developing a closed ICU structure. The most formidable may be reluctance on the part of the affected members of the medical staff. Physicians, in particular general internists, currently practicing in an open ICU environment, almost certainly see themselves as capable of continuing the care they have provided in the past. Younger physicians who trained in institutions with a closed ICU program may have less difficulty adapting to a closed system. The physicians most difficult to convince may be the more senior, classically trained, general internists who have long managed their patients (though infrequently) in the ICU and who pride themselves on their ability to provide such care. These physicians often regard the change to a closed system as taking away a part of their practice—a part they value both intellectually and economically. When added to the other invasions into their practice style associated with managed care, reduced ability to care for hospitalized patients through the use of hospitalist services, and increasing pressure for more office productivity, this can become yet another chink in the armor of the already battered general internist physician.

Acknowledging these issues directly is important. Objectively using the medical literature as a point to start the discussion is probably the best way to proceed, and physicians should always be reminded that they are welcome to continue to follow their patients while in the ICU and bill appropriately for those services they provide. They should certainly be included in, and are important to, discussions about overall goals of care and maintaining continuity outside the ICU.

Hospitalists may also be opposed to development of a closed ICU structure, especially if they feel excluded either because of economic or turf related issues. Given the lack of critical care physicians in this country, and the rise of hospitalist services even in small institutions, development of cooperative models of care between an intensivist-driven closed ICU and a hospitalist service is probably a wave of the future. Development of a closed ICU structure may require additions of intensivists to the staff, which in turn could require monetary input from an already financially strapped hospital. In negotiating with hospital administration, one can refer to the literature showing reductions in length of stay, and decreases in mortality and in resource utilization, to help convince reluctant hospital administrators of a reasonable return on their investment.11 Once the change has been implemented, measuring improvements in quality and cost reductions will be important feedback to all parties affected by the change.


Moving to an intensivist-led closed ICU system seems to be the natural evolution of critical care. In this change, all members of the care team have a role to play, and these roles should be based on training and expertise and backed up by the literature. Any one unit may need to evolve in steps toward a closed system, as resources and mindsets change. When working through the process, remember to under-promise and over-deliver. Be as objective as possible in setting up the rules, and attempt to document the value of your interventions with the collection of local data.


1. Carson SS, et al. JAMA. 1996;276(4):322-328.

2. Multz AS, et al. Am J Respir Crit Care Med. 1998;157(5 Pt 1):1468-1473.

3. Ghorra S, et al. Ann Surg. 1999;229(2):163-171.

4. Baldock G, et al. Intensive Care Med. 2001;27(5): 865-872.

5. Topeli A, et al. Crit Care Med. 2005;33(2):299-306.

6. Hall JB. Crit Care Med. 1999;27(2):229-230.

7. Pronovost PJ, et al. JAMA. 2002;288(17):2151-2162.

8. Breslow MJ, et al. Crit Care Med. 2004;32(1):31-38. Erratum in: Crit Care Med. 2004;32(7):1632.

9. Pronovost PJ, et al. JAMA. 1999;281(14):1310-1317.

10. Tenner PA, et al. Crit Care Med. 2003;31(3):847-852.

11. Pronovost PJ, et al. Crit Care Med. 2004;32(6): 1247-1253.