Demand for elective and emergency intensive care unit (ICU) beds for elderly patients is increasing.1 There are many potential factors that may be driving this demand, including: an ageing population, increasing proportions of elderly patients having surgical procedures that require peri-operative high dependency care and changing expectations about the appropriateness of admitting elderly patients to ICU.
One common reason for admission to the ICU is to monitor and treat hypotension or shock. In this issue of the NZMJ, Keet et al report the mortality rate of patients admitted to Tauranga Hospital ICU with shock, the most common aetiology, of which was sepsis. Mortality data are provided for patients aged less than 75 years, 75–84 years and for those greater than 85 years of age. Mortality rates at hospital discharge were 22%, 42.5% and 23.1% respectively; by one year these mortality rates had increased to 34.8%, 61.6% and 61.5% respectively. While an independent association between patient age and short-term mortality after an admission to ICU has been reported previously,1,2 the data presented in the current study are not adjusted for case-mix, co-morbidities or illness severity, so it is not possible to establish whether the age of the patients independently influenced mortality rates.
While the investigators conclude that acceptable long-term outcomes are possible for elderly patients with septic shock, we submit that a more nuanced conclusion is appropriate. The data presented demonstrate that more than 60% of the patients 75 years or older who were admitted to ICU with shock were in the last year of their lives. As there are no data presented on the quality of life of the survivors at one year, it is difficult to know whether truly acceptable long-term outcomes were achieved or not. Quality of life is a crucial issue because elderly patients who are admitted to ICU with severe sepsis appear to have an increased risk of moderate to severe cognitive impairment and of developing new functional disability in the year following their admission.3 Moreover, only one quarter of octogenarians admitted to ICU for any reason in one study regained their baseline level of physical function at one year.4 The majority of octogenarians who survived to hospital discharge in one tertiary Australian ICU were discharged to a hospital-level care facility, rehabilitation facility or nursing home.5 All of these factors mean that there is a high risk that elderly patients who survive ICU will have a relatively poor quality of life.
At the very least, the high observed one-year mortality rate in the current study suggests that in elderly patients admitted to ICU with shock, a discussion about advanced care planning should be strongly considered prior to hospital discharge.6 Careful consideration of the appropriateness of ICU admission is prudent for every patient, but it is important to emphasise that in a population of patients that may have a limited life expectancy, short-term survival may not be the principal outcome to consider. For the elderly patients with septic shock in particular, whether or not to admit to ICU at all is a decision that should primarily be made by considering whether or not the ICU admission is likely to leave the patient with a satisfactory quality of life if they survive to hospital discharge and/or whether it increase the chances of a “good death”.
Even if mortality is considered the most important outcome, it is often unclear whether admission to ICU will reduce mortality risk compared to ward-based care. Among the oldest cohort of patients in the current study, five out of 13 patients did not require vasopressor support. These patients may have been admitted to ICU for haemodynamic monitoring only without ultimately requiring any ICU-level intervention. This may not be an uncommon scenario. In one multi-centre prospective observational study of mainly medical patients in an emergency department with an indication for ICU admission, ICU admission compared with admission to a standard ward did not improve six-month survival of patients aged 80 years and older after adjustment for confounders such as illness severity and co-morbidities.7 A cluster-randomised trial investigating the effect of systematic ICU admission on long-term mortality for selected critically ill elderly patients vs standard ICU admission triage practice is currently underway and should provide further useful information.8
When considering ICU care for elderly patients in the New Zealand context there are a number of issues that are important. Firstly, is there currently equality of access to ICU for older New Zealanders between hospitals and regions? That is, are older patients with similar diagnoses, illness severities and comorbidities equally likely to be admitted to ICU in different parts of the country? Although previous data suggest that in relation to an ICU admission triage decision where a previously healthy 95-year-old patient age unexpectedly required ICU admission after elective surgery approximately 90% of intensive care specialists would admit the patient,9 there are no studies that specifically evaluate ICU triage decision-making of New Zealand specialists for elderly patients in other scenarios. Moreover, case-mix and illness severity of elderly patients admitted to similar ICUs around New Zealand have never been systematically compared. It is also unknown whether the outcomes of elderly patients admitted to New Zealand ICUs are similar after adjusting for case-mix or whether they are similar to the outcomes of patients admitted to ICUs elsewhere in the world. Finally, it is unknown whether the threshold for ICU admission to elderly patients is reducing with time and, if it is, whether the resultant increases in ICU admissions for elderly patients are a sound investment of healthcare dollars. This latter issue is perhaps the most important and, as outlined above, can only be determined if one considers more than just survival.
Keet et al’s data should prompt clinicians to reflect on the goals of care when ICU admission is considered. When triaging ICU referrals, the primary considerations ought to be not only whether the patient has a reasonable chance of surviving for the next year, but whether ICU treatment is likely to result in an outcome that is consistent with individual patient’s views of an acceptable outcome.10 Even if elderly patients with septic shock survive to hospital discharge, they appear to remain at very high risk of dying in the next year and should be encouraged to adjust their life priorities and treatment priorities accordingly.