Predictors of delirium during in-hospital rehabilitation in elderly patients after hip arthroplasty

Abstract

SIR—In their article published recently, Freter et al. [1] assessed the feasibility of incorporating the Delirium Elderly At-Risk (DEAR) instrument into routine nursing care of elective orthopaedic patients and evaluated its usefulness to predict post-operative delirium. We would like to contribute to this topic with personal data. We assessed predictors of delirium during in-hospital rehabilitation in elderly patients who underwent an elective hip arthroplasty. All patients (n= 244) consecutively admitted to our unit for this reason from 1 January 2002 to 28 February 2004 underwent a multidimensional assessment including sociodemographic (age, gender, living condition), Geriatric Depression Scale (GDS), Charlson Index, body mass index and Barthel Index (BI) referring to 1 month before surgical intervention (BI pre-surgery) and to admission (BI admission). Delirium was ascertained on admission and during in-hospital rehabilitation according to the DSM IV criteria using the Confusion Assessment Method (CAM) [2]. The Mini-Mental State Examination (MMSE) was administered within 72 hours of admission or, in the case of delirium, after 3 consecutive days of negative CAM. Appendix 1 (available as supplementary data on the journal’s website, www.ageing.oxfordjournals.org) shows the characteristics of all patients stratified into two groups (delirium and no delirium). In comparison with the others, patients with delirium were significantly older, predominantly male, more impaired in cognitive and functional status, and had a higher comorbidity detected with the Charlson Index. When the effect of all variables that were significantly associated in the univariate model was tested in a multiple logistic regression, male gender (OR= 13.7, 95% CI 2.8–65.5, P= 0.001), greater comorbidity, as measured by a Charlson Index score ≥ 3 (OR= 9.4, 95% CI 1.3–66.9, P= 0.02), a MMSE score <29/30 (OR= 6.6, 95% CI 1.1– 39.6, P= 0.03) and a BI pre-surgery score <100 (OR= 3.8, 95% CI 1.1–15.0, P= 0.05) significantly and independently predicted onset of delirium. Our study only partially supports that of Freter et al. Indeed, although it indirectly confirms that delirium is a common event in post-operative patients and that the identification of those at risk is possible with a routine multidimensional assessment, it also emphasises the need to assess comorbidity, which appears to be difficult for nurses. On the basis of our data we are persuaded that a standardised multidimensional geriatric assessment may be more useful than a specific pre-operative instrument. GIUSEPPE BELLELLI1,2*, SALVATORE SPECIALE1,2, MARCO TRABUCCHI3 1Rehabilitation Department, ‘Ancelle della Carita’, Hospital Cremona, Cremona, Italy 2Geriatric Research Group, Brescia, Italy 3University Tor Vergata, Rome, Italy *To whom correspondence should be addressed Fax: (+39) 03725357700 Email: bellelli-giuseppe@poliambulanza.it