ICU Staffing


  • In most of the world, critically ill patients are managed in closed ICUs, the closed vs open-model debate is primarily of interest in the USA
  • Traditionally, ICUs had an ‘open’-model, patients would be admitted by primary physicians under their own care
  • Though still controversial, the weight of evidence suggests that intensivist led closed ICUs lead to better patient outcomes
  • In the USA more than half of ICUs do not have any intensivists coverage


  • Closed ICU: All patients are cared for by 1 team of intensivists in collaboration with a primary service. Only intensivists have admitting privileges to the ICU. Also called mandatory transfer.
  • Open ICU: Any physician can admit patients to the ICU. Elective consultation Intensivists are available for consultation at the discretion of the responsible physician
  • Choice ICUs: An ICU in which an intensivist is the responsible physician for some patients but not others; presumably an open ICU with elective consultation
  • No-choice ICU: An ICU in which there is no choice about intensivist care—either all patients or no patients have an intensivist as their responsible physician
  • Intensivist: A physician with specialty training in intensive care medicine
  • High-intensity staffing: Includes both closed and mandatory consult models
  • Low-intensity staffing: Any model other than closed or mandatory consult model


Closed units may be beneficial for the following reasons:

  • more timely patient evaluation and treatment initiation
  • intensivists are specifically skilled in treating critically ill patients with multi-system organ dysfunction
  • more frequently create and use clinical protocols, reminders, and checklists, which can improve the reliable provision of other aspects of evidence-based critical care
  • tend to have better nurse-to-patient ratios and more experienced nurses
  • more readily foster an interdisciplinary team-based approach to critical care with enhanced coordination, communication, and collaboration
  • decreased resource use because intensivists may be better at reducing inappropriate admissions, preventing complications that prolong length of stay, and recognizing opportunities for prompt discharge
  • intensivists provide a leadership role at the intensive care unit organizational level


  • Systematic reviews find that high-intensity ICU physician staffing is associated with reduced mortality and length of stay in the hospital and the ICU
  • 24 hour on-site intensivists do not affect mortality or length of stay if there is high-intensity ICU physician staffing
  • However, a cross-sectional study using the Project IMPACT database, including 101,000 patients in 123 ICUs, found that adjusted hospital mortality was higher for patients with intensivists involved in their care (OR, 1.42; P < .001) – most of the patients in this cohort received care in choice ICUs, where someone, presumably a physician, decided whether to involve an intensivist (indication bias).
  • interpreting the evidence is difficult because of numerous differences between studies in ICU administration, team composition and function, physician practice, and other variables


  • the potential benefit and cost-effectiveness of having intensivists working night-shifts in the ICU are uncertain
  • Retrospective data from a database of 65,000 patients suggests that night-shift intensivists do not provide a mortality benefit in high intensity ICUs, a potential benefit was only found in ICUs where intensivist care during the day was not mandated. Based on this, night-shift intensivists may provide a benefit if there is not a daytime intensivist making 24 hour plans.
  • A single-center RCT in an academic center found no benefit (mortality or length of stay) for a night-shift intensivist compared to having an intensivist on call from home via phone contact. This trial may not be generaliseable to other centers with less skilled junior staff, lower intensity ICUS or open ICUs.
  • Some experts argue that hospital wide systems (e.g.weaning practices, decision and timing of extubation, and administrative delays in discharging patients) may need to be modified for night-shift intensivists to be beneficial, so that care can be progressed overnight.
  • Others argue that other outcomes are relevant and that other studies should look at the enhanced opportunities for education of junior staff, end of life care and other patient-centered metrics. Oe study suggests that night-shift intensivists lead to improved end-of-life care, for instance.


  • In some settings, such as the USA, there is a shortage of trained intensivists
  • Non-physician providers, innovative physician staffing models and telemedicine may offset the shortage
  • optimal ICU staffing and organisational models may differ based on ICU type, size, case mix, and other factors

References and Links

Journal articles

  • Garland A, Gershengorn HB. Staffing in ICUs: physicians and alternative staffing models. Chest. 2013 Jan;143(1):214-21. doi: 10.1378/chest.12-1531. Review. PubMed PMID: 23276844. [Free Full Text]
  • Juneja D, Nasa P, Singh O. Physician staffing pattern in intensive care units: Have we cracked the code? World J Crit Care Med. 2012 Feb 4;1(1):10-4. doi: 10.5492/wjccm.v1.i1.10. eCollection 2012 Feb 4. PMC3956065.
  • Levy MM, Rapoport J, Lemeshow S, Chalfin DB, Phillips G, Danis M. Association between critical care physician management and patient mortality in the intensive care unit. Ann Intern Med. 2008 Jun 3;148(11):801-9. PMC2925263.
  • Levy MM. Intensivists at night: putting resources in the right place. Crit Care. 2013 Oct 14;17(5):1008. PMC4057471.
  • Pronovost PJ, Holzmueller CG, Clattenburg L, Berenholtz S, Martinez EA, Paz JR, Needham DM. Team care: beyond open and closed intensive care units. Curr Opin Crit Care. 2006 Dec;12(6):604-8. PMID: 17077695.
  • Rubenfeld GD, Angus DC. Are intensivists safe? Ann Intern Med. 2008 Jun 3;148(11):877-9. PMID: 18519933.
  • Wilcox ME, Chong CA, Niven DJ, Rubenfeld GD, Rowan KM, Wunsch H, Fan E. Do intensivist staffing patterns influence hospital mortality following ICU admission? A systematic review and meta-analyses. Crit Care Med. 2013 Oct;41(10):2253-74. PMID: 23921275.

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Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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