Interventions to circumvent intensive care access block: a retrospective 2-year study across metropolitan Melbourne

Graeme J Duke, Michael D Buist, David Pilcher, Carlos D Scheinkestel, John D Santamaria, Geoff A Gutteridge, Peter J Cranswick, David Ernest, Craig French and John A Botha
Med J Aust 2009; 190 (7): 375-378. || doi: 10.5694/j.1326-5377.2009.tb02452.x
Published online: 6 April 2009

Intensive care units (ICUs) in Australian hospitals compare favourably with international benchmarks,1 but these results mask the outcome of patients who cannot access intensive care services when required. Intensive care access block occurs in all Australian states,2 but Victoria has a relatively low number of intensive care beds (5.4 beds/100 000 people, compared with the national mean, 6.1/100 000).3,4 Occupancy rates are high (95%),4 and for several days each month there is no reserve capacity.3,5,6

Intensivists are faced with the competing demands of being gatekeepers,7 patient advocates, and attending clinicians. When the ICU has no reserve capacity, intensivists must select one of several less suitable options for new patients.6 Each option has risks, but aims to minimise harm and continue treatment until an intensive care bed becomes available.8

Five main interventions are used to deal with access block. Firstly, interhospital transfer may be undertaken if it is safe for the patient.9,10 Secondly, treatment may be commenced in another high-acuity area, such as the emergency department (ED)11-14 or the post-anaesthesia care unit,6 until an intensive care bed is available. These areas do not have the same equipment, expertise and staffing levels as an ICU. Thirdly, in selected cases, a trial of standard care in a low-acuity ward may be considered; up to 25% of such trials fail and require intensive care rescue.6 Fourthly, major elective surgery for which postoperative intensive care is mandatory (eg, cardiac surgery) may be cancelled or postponed.3,6 Lastly, triage decisions may lead to increased turnover of intensive care patients — a recovering patient occupying an intensive care bed is transferred to a low-acuity ward sooner than planned to give access to another critically ill patient;15-18 this can increase risks for both patients.

We aimed to determine the prevalence of these interventions to circumvent intensive care access block in Melbourne, Victoria, and to estimate the attributable mortality and additional hospital bed-days associated with each of them.


We categorised interventions according to the Australian and New Zealand Intensive Care Society (ANZICS)2 and the Australian Council on Healthcare Standards:19

  1. Interhospital transfer of an intensive care patient due to the absence of an available bed in the ICU of the sending hospital, excluding patients transferred for specialist therapy not normally provided by the sending hospital (Box 1, A).

  2. Prolonged stay (> 8 hours) in an ED for a patient awaiting and eventually admitted directly to the ICU, excluding patients included in (1).

  3. Cancellation or postponement of elective major surgery due to the absence of an available intensive care bed (Box 1, B).

  4. After-hours (between 18:00 and 06:00) step-down of an intensive care patient to a standard care (low-acuity) ward.

  5. Premature transfer of an intensive care patient to a low-acuity ward based on the intensivist’s clinical judgement, excluding patients included in (4).

From 1 July 2004 to 30 June 2006, adult public hospitals with an ICU in metropolitan Melbourne recorded the frequency of each of these interventions. These data were submitted to the Victorian Government Department of Human Services (DHS). The reported numbers were verified and additional hospital data were extracted from several other reports, including ANZICS2 and DHS annual reports.4,20,21

We excluded paediatric patients (< 17 years of age), readmissions to the ICU during the same hospital stay, requests for intensive care services from other hospitals, postoperative admission delays, and patients initially given a trial of standard care (due to the lack of a reliable definition).

As our study used de-identified patient and hospital data available from several sources, the need for formal ethics committee approval was waived.


Sufficient data for analysis were available from 11/12 eligible public hospitals, and 21 896 intensive care admissions (91% of eligible admissions) were screened. There were 3039 inhospital deaths (13.9%).

The median hospital LOS was 9.5 (IQR, 5.4–18.7) days, including a median of 1.8 (IQR, 0.9–4.0) days of intensive care. The most common referral sources were the operating theatre (48%), the ED (26%) and other hospitals (17%).

The mean number of available (staffed) ICU beds was 118 in 2004–05 and 120 in 2005–06 — equivalent to 81% of the hospitals’ declared total physical ICU bed capacity.2 There were no significant differences in the admission rates (mean, 29.3 v 30.6 per day; P = 0.3) or the overall mortality rates (14.0% v 13.8%; P = 0.7) between the 2 years.


We found that access block occurred in all hospitals and that interventions to deal with it appeared to increase over the 2 years. The number of interventions for access block was higher than previously reported rates.6 These interventions amplify risks to patients, resulting in increased patient mortality and LOS. Our results add to the growing body of evidence that access block may lead to patient harm.

Our estimates are a rough approximation, but they are consistent with other reports11,13 and were derived using the best available data. The relative risks were based on Australian data, adjusted for casemix and illness severity, and are comparable with those published in other countries.6,13,15

The high rate of after-hours ICU exit is of particular concern. The risk associated with step-down from intensive care to standard care appears to be greatest when it occurs after hours (18:00 to 06:00).18 Overnight, nurse–patient ratios remain constant in the ICU, but in low-acuity wards they fall to half their daytime levels, and medical staff are even scarcer.

Our research raises questions about the financial implications of access block. These may be considerable, but detailed analysis would be needed to determine their full extent. If improved access to intensive care reduces the total number of patient bed-days, the solution may be partly self-funding. Intensive care is not necessarily expensive when compared with the alternative of suboptimal care resulting in increased mortality and LOS.23

Up to 19% of intensive care beds were reported as unavailable2 during the study period, possibly due to a lack of staff.6 In response, the DHS has increased funding for intensive care services across Melbourne over the past 2 years (2008–2009), and has indicated a commitment to long-term solutions regarding ICU bed numbers, staffing, and monitoring of access block in Victorian hospitals.5

Access block should be routinely monitored and reported by health services as a key performance indicator of resources,24 as recommended by the Australian Council on Healthcare Standards.19 Reporting should cover all critically ill patients, not only those who receive intensive care. Those responsible for health service policy and funding decisions need these data.

There were important limitations to our methodology. Data collection was voluntary, the audit was retrospective and observational, and the attributable effects were based on historical estimates (with wide confidence intervals) rather than on actual outcomes.

Our methodology for calculating attributable effects assumed independence between each intervention, assumed a causal link between each intervention and outcome (mortality or LOS), and assumed that these effects were cumulative. These assumptions may have led to an overestimation of attributable effects.

The true rate of access block may be higher than reported here. With the exclusion of one hospital, and incomplete data from four other hospitals, and the exclusion of some intervention categories (such as a trial of standard care), it is likely that we have underestimated the true incidence of access block.

Assessment of the appropriateness of intensive care admission criteria and triage was beyond the scope of this study. This may warrant investigation to ensure that finite resources are used wisely. In Australia, trained and experienced intensivists control access to intensive care services.7 We believe that inappropriate admission is unlikely.

These preliminary results suggest that access block has a significant impact on survival and resource use, and further study on the topic is warranted. Reporting solely on the quality of care provided to those fortunate enough to receive intensive care ignores the inequality of care to those who are unable to access those services.

  • Graeme J Duke1
  • Michael D Buist2
  • David Pilcher3
  • Carlos D Scheinkestel4
  • John D Santamaria5
  • Geoff A Gutteridge6
  • Peter J Cranswick7
  • David Ernest8
  • Craig French9
  • John A Botha10

  • 1 Critical Care Department, Northern Hospital, Melbourne, VIC.
  • 2 Intensive Care Department, Dandenong Hospital, Melbourne, VIC.
  • 3 ANZICS Centre for Outcome and Resource Evaluation, Melbourne, VIC.
  • 4 Intensive Care Department, Alfred Hospital, Melbourne, VIC.
  • 5 Intensive Care Department, St Vincent’s Hospital, Melbourne, VIC.
  • 6 Austin Hospital, Melbourne, VIC.
  • 7 Intensive Care Department, Maroondah Hospital, Melbourne, VIC.
  • 8 Box Hill Hospital, Melbourne, VIC.
  • 9 Intensive Care Department, Western Hospital, Melbourne, VIC.
  • 10 Intensive Care Department, Frankston Hospital, Melbourne, VIC.


Competing interests:

None identified.

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