Preoperative cognitive dysfunction in older patients at a central hospital

Abstract

Background: Cognitive decline following surgery includes delirium and postoperative cognitive dysfunction. Important risk factors for these include increased age and pre-existing cognitive dysfunction. This study describes preoperative cognitive dysfunction and its associated factors in patients ≥ 60 years old awaiting elective non-cardiac surgery at Chris Hani Baragwanath Academic Hospital. Methods: A prospective, contextual, descriptive study design with consecutive convenience sampling was used. Assessment of cognition was subjective (through casual conversation) and objective (using the Mini-Cog test). Results: A total of 194 outpatients (median age: 65 years) were assessed. A score ≤ 3 was obtained by 111 patients (57.2%). The subjective assessment of cognition was shown to be poor in comparison (sensitivity 47.8%; specificity 70%). Univariate analyses demonstrated significant associations between low Mini-Cog scores and increasing age (rs = −0.1901; p = 0.0079), unskilled occupation (p = 0.0033), low functional status (rs = −0.1831; p = 0.0106), low level of education (p = 0.0005) and frailty (rs = −0.3010; p < 0.0001). Logistic regression showed level of education and frailty to be significant. Patients with grade 11 to tertiary education are 71.8% less likely to obtain a score ≤ 3 (OR: 0.2820; p = 0.0034), and frail patients are 7.54 times more likely to obtain a score ≤ 3 than a robust patient (p = 0.0026). Conclusion: This study found undiagnosed pre-existing cognitive dysfunction to be common in older patients awaiting surgery at Chris Hani Baragwanath Academic Hospital. These “brains at risk” should be identified through brief preoperative screening