Treatment intensity and outcome of nonagenarians selected for admission in ICUs: a multicenter study of the Outcomerea Research Group

In a selected population of very elderly patients, this French multicenter study showed that intensity and monitoring of treatment were quite similar between octogenarian (80–90 years) and nonagenarian patients (90 years), except for lower use of invasive arterial monitoring and of RRT and overuse of urinary catheter. ICU and hospital mortality were not significantly different.

Very elderly patient population will greatly increase in the future, and one of the tough challenges of intensivists will be to adapt resources to benefit of care [1]. While the rate of very elderly patients admissions clearly increased among hospital admissions [1], overall ICU admissions rate of patients aged 80 and over remained stable, around 15 % in Europe: France 18 % [7], Netherlands 13.8 % [22], and Italy 19.2 % [23] as worldwide: Australia and New Zeeland 13 % [9]. This stable rate was probably explained by a stringent triage [24, 25]. Two studies, each comparing practices to 10 years apart, reported similarly that age 85 remained an independent factor hampering ICU admission [10, 11].

Few studies reported the percentage of nonagenarians in ICU admissions. In our study, nonagenarians represented around 8 % of ICU admissions, higher than the rates observed in a Brazilian [13], Norway [26], or French study [6] 3, 2.5, or 1 %, respectively. The percentage of patients aged 85 years and over represented only 3.4 % in the Eldicus study [25]. As shown in a previous study [27], our study showed that, after having submitted nonagenarian’s patients to a stringent selection process, ICU physicians provided similar treatment as to octogenarian patients, namely ventilation procedures, and vasoactive drugs administration, except for the use of RRT for nonagenarians. Interestingly, this was in agreement with very elderly’s wishes [12]. Intensity of treatment provided to the very elderly has changed overtime. In the last decade, age could be an obstacle for delivering treatment for acute coronary disease [28, 29] or ICU treatment [15]. In a more recent period, Lerolle et al. [5], in a single-center study over a decade, showed that selecting good candidates (mean age: 83 years) with benefit of ICU treatment was associated with improvement of mortality rates, even if they were severely ill at ICU admission, thus requesting greater intensity of treatment (vasoactive drugs and RRT). In a subgroup analysis by 5-year age groups, Andersen et al. [26] reported significant lower time on and use of mechanical ventilator support among the 738 patients of the nonagenarian subgroup compared with other age groups. Improving the process selection is difficult [10, 30–33]; recently, evaluation of frailty [34] was added to the making decision process [35, 36]. Selecting better candidates for ICU admission will be an ongoing process: Will a 90-year-old person in 2030 be as frail and thus have the same risk of ICU admission as in 2015? The global progress in medicine will lead to admit more healthy very elderly in ICU, and the results of ICU treatment of very elderly will probably improve. Of note, scarce studies of trauma centenarians are available [37].

Transferring a patient to a geriatric unit for a geriatric assessment after ICU discharge did not improve hospital mortality. A geriatric assessment is “a combination of a multidimensional interdisciplinary approach and diagnostic process focused on determining in a frail old person, medical, psychological and functional capacity in order to develop a coordinated plan for treatment and recovery” [38]. The benefit of geriatric assessment seems to be more in the post-hospital period. A review of 22 randomized trials having included 10,315 patients showed that geriatric assessment was more often associated with being alive in their own home 1 year after hospital discharge [39]. Our study reported that only 14 % of patients were transferred to a geriatric unit. Due to the retrospective analysis of the study and the long period of inclusion, we were not able to report whether these patients have benefit of a geriatric assessment. Further studies involving more patients and using a randomized process at ICU discharge are needed to explore this point.

One of our study strengths was to include a control group of youngest patients, i.e., octogenarians, to analyze comparatively the intensity of treatment and outcome.

This study has also several limitations. First, our study described practices in France and may not be extrapolated in other countries. Second, the main limitation of the study was the lack of follow-up regarding the outcome of the post-intensive care syndrome [40], namely physical, cognitive, or mental sequelae which funded the benefit of ICU admission. These outcomes were not in our database, and their specific research was difficult due to the high number of female, registered under different names (maiden name or married name) in the hospital register and in the appropriate register death office. Third, our database did not contain measurement of frailty index, which is now used to better describe ICU and hospital outcome [4]. Fifth by fourth, the study was on a 15-year period with possible changes in selection and care of elderly people. Sixth by fifth, age being a continuous variable, using it to compare groups for outcome may appear artificial.

In conclusion, this multicenter study reported that nonagenarians represented a small part of ICU patients. When admitted to ICU, these highly selected patients received similar life-sustaining treatments as octogenarians, except RRT and invasive monitoring for blood pressure. Hospital mortality was not influenced by post-ICU care. Further research is needed to elucidate recovery in this nonagenarian population.