Hospital‐associated deconditioning: Brain health issues beyond physical factors

Background Hospital‐associated deconditioning (HAD) or post‐hospital syndrome is a multisystem decline that leads to poor functional performance after acute hospitalization. Although hospitalization is supposed to treat an acute condition and improve the overall outcome, HAD may be significant, especially in older people. Recommendations for the management of HAD still lack, partly due to the poor understanding of the underlying processes. We aim to review existing data on mechanisms, risk factors, natural history, measuring tools, and intervention in HAD, with a specific focus on brain health. Method We searched PubMed, sCielo and Cochrane database for relevant articles published between 1 January 2009 and 31 December 2019. Search terms were “post‐hospitalization syndrome” OR “deconditioning” OR “hospital‐associated functional decline” OR “pre‐existing frailty” OR “unrecognized vulnerability”. Three researchers independently selected papers according to title relevance and then re‐checked for abstract relevance. Results We first selected 63 studies based on the title relevance and 14 of them were excluded after reviewing the abstract. Research on this field has been mainly led from a physical perspective, in geriatrics or rehabilitation settings. 25 studies were related to mechanisms; 18 to risk factors and trajectories; 10 to measuring and predictive tools and 5 to interventions. Mechanisms referred to the inevitable change imposed by the hospitalization (e.g. reorganization of sensorimotor cortex, maladaptive cognitive schemas, vascular deconditioning) and to the own frail condition of the population at risk. Risk factors varied from older age to nutritional status, mobility or functional status before admission among others. Cognitive impairment, ability for ADLs and IADLs at admission and depression were also predictors of functional decline. Assessment of those items worked as a useful tool to identify vulnerable patients for HAD. Regarding interventions, all but one was devoted to physical rehabilitation and environmental modifications. Only one study focused on cognitive stimulation. Conclusions Several studies have focused on HAD in the last decade, with some consistent findings. Cognitive impairment, depression and neurological changes may have a role in hospital deconditioning pathophysiology and may be useful to identify patients and risk. Cognitive rehabilitation and neurological interventions should be evaluated as well in deconditioning prevention and treatment.