Discussion
In this study of consecutive older patients presenting with trauma, delirium was common, with advancing age, frailty and a history of dementia associated with increased risk. Delirium was associated with long LOS, but not with in-hospital death. Furthermore, delirium was independently associated with higher likelihood of prolonged hospitalization, consistent with literature pertaining to other cohorts of older patients.4 5 7 However, early screening for delirium was suboptimal, despite evidence-based recommendations that this be implemented early in the hospital stay. Holistic delirium care includes a combination of assessment, prevention and appropriate management. Few patients were diagnosed with delirium on arrival, highlighting the opportunity for potential prevention during the hospital stay.
In this cohort, both frailty and history of dementia were independent risk factors for delirium. Almost half of the group were frail prior to admission, and one in six had a history of dementia. The overall numbers of individuals with dementia are climbing, and this will likely be reflected in increasing trauma presentations. Dementia is a risk factor for presentation with traumatic injury due to increased risk of falls,23 car crashes (although rates may fall in latter stages due to limited driving),24 pedestrian injuries,25 and elder abuse.26 Frailty and delirium are intricately linked,12 with common risk factors such as age and dementia. In our cohort, delirium was independently associated with LOS, whereas frailty was not. This contrasts with Cheung et al’s27 study, in which preadmission frailty was associated with adverse discharge outcomes. Differences from our study, which may contribute to the discrepancy, include their lack of delirium as a variable, older 7-point CFS, higher frailty cut-off, and lower rates of frailty in their study, and that we may have been underpowered to detect a relationship.
Contrasting with the plethora of studies describing delirium in ‘medical’ patients—and even other surgical cohorts—data pertaining to delirium in older trauma patients are more limited. A number of North American studies have included delirium as an outcome measure, usually in the context of assessing geriatric and/or multicomponent interventions for frail older patients.28–31 Some authors have explored delirium in particular trauma subgroups, with delirium observed in 25% of patients with rib fracture in a Danish study,32 and two-thirds of trauma patients requiring ICU and mechanical ventilation for >24 hours.10
The causes of delirium are myriad, and typically the syndrome is multifactorial. Over a third of cases are thought to be preventable.7 In keeping with this, the strongest evidence for prevention hails from multifaceted strategies.33 Traumatic injury can be associated with significant pain, and both pain and opioid analgesics are risk factors for delirium. In this setting, interventions focusing on pain control, sensible opiate prescribing, and regional anesthesia have proven promising.34 35
Despite the vulnerability of our cohort, delirium screening was suboptimal. Exploring the reasons for poor adherence was beyond the scope of this study, and the subject of ongoing quality improvement efforts. To improve pick-up of delirium in this study, we did not rely solely on CAM screening, but also included delirium diagnosis recorded in the medical notes.
In terms of treating delirium, the mainstay of delirium treatment is treatment of the underlying cause, complimented by prevention of complications (such as falls, pressure injuries).7 Other interventions, for example, non-pharmacological multicomponent strategies,7 33 or dexmedetomidine in the ICU setting,36 have shown limited benefit in terms of reducing the duration or severity of delirium.7 33 36
There is some evidence that specialist aged care teams may have benefit in the care of older surgical patients, including those presenting with trauma. In the present study, three-quarters of patients were not seen by the geriatric medical team, and despite known poor long-term sequelae after delirium, and vulnerability to further episodes of delirium, few patients had follow-up arranged with a specialist geriatrician after discharge, examples of potential ‘missed’ opportunities for optimal delirium management in both acute and later settings. While orthogeriatric care for the subset of patients with hip fractures is relatively embedded in healthcare settings, the role of aged care specialists in trauma is rather embryonic, with some exceptions.29–31 37–39 The potential benefits of early geriatric team involvement in trauma care are manifold, with studies describing improvements in diagnosis of medical morbidity, anticipatory care planning, functional outcomes, ICU and total hospital LOS, and death.28–30 37 Eagles et al’s systematic review and meta-analysis of trauma patients noted a reduction in LOS associated with geriatric team input, but noted heterogeneity among studies including delirium as an outcome measure.38 The relationship between geriatric specialist review and delirium in trauma patients is complex. Marcantonio et al noted a reduction in both delirium incidence and severity with proactive geriatrician input in patients with hip fracture.9 However, geriatric physicians may improve detection of delirium, leading to an apparent ‘increase’ in incidence and/or prevalence,17 30 or there may be a selection bias whereby trauma teams are more likely to seek consultation where delirium is already evident.29 On the other hand, early involvement of aged care specialists may lead to improved prevention and reduced incidence.9 28 31
Our study’s limitations include data drawn from a single-center study in a level 1 trauma center. As such, our findings may not necessarily be extrapolated to all scenarios. However, the rates of delirium we observed are not dissimilar to those observed in other settings.4–7 17 28–32 Our numbers were not large, which may mean we were underpowered to detect other potential associations, for example, with mortality (type II error), and the confidence for our observed associations was wider (less precise) than may have been observed with a larger sample size. Although Leratowicz31 investigated the use of a geriatric consultation in a before-and-after study of 486 older trauma patients—reporting a decrease in delirium incidence with same—few authors have focused on delirium in cohorts of more than a couple of hundred older trauma patients.10 17 28–30 32 34 The lack of large-scale studies highlights the need for more robust evidence to guide management of this vulnerable group. As this was a retrospective study, we relied on available documentation. A notable proportion of patients did not undergo early delirium screening, which may have led to missed or delayed diagnosis. The rationale for early routine screening is that validated standardized assessment tools improve pick-up,40 and early recognition can facilitate rapid instigation of a management plan.7 16 Real-life practice deficits highlight the need for ongoing education and training of healthcare professionals in the assessment and management of delirium.15 Likewise, in terms of etiology, we were reliant on available documentation and the assessment of the treating clinical team. We did not assess delirium severity, duration or later cognitive outcomes, all of which would be of interest, and will be areas for future research. We chose to focus on older patients, defined as ≥65 years, but also acknowledge that younger trauma patients may also be at risk of delirium. In a study of 115 trauma patients admitted to surgical ICU, Bryczkowski et al noted that the risk of delirium increased by 10% per year after age 50.41
Strengths of this study include the use of consecutive sampling—probably the best of all non-probability sampling,42 inclusion of patients presenting with diverse injuries and severity, and our ability to adjust for factors such as frailty and non-delirium complications in our outcome analyses. Our findings also highlight that delirium risk screening in real-world practice is suboptimal, despite the vulnerability of older trauma patients.
