Risk factors contributing to postoperative delirium in geriatric patients postorthopedic surgery.

INTRODUCTION: Postoperative delirium is a common clinical manifestation in geriatric patients, resulting in prolonged hospitalization and increased economic burden, in addition to higher morbidity and mortality rates. Therefore, identifying non-obvious risk factors that contribute to the development of postoperative delirium in geriatric patients is crucial.
METHODS: From January 2011 to June 2013, 200 geriatric patients of over 65 years of age scheduled for orthopedic surgery were randomly selected and statistically analyzed with respect to the effects of the following 12 factors on postoperative delirium: sex, age, anesthesia type, surgical type (i.e. spine, hip replacement, and pelvic or femoral fracture repair), operative duration, intraoperative hypoxia, intraoperative hypercapnia, intraoperative hypotension, intraoperative blood loss, preoperative affective state, postoperative sleep disorders, and underlying disease (i.e. hypertension, coronary heart disease, diabetes, hyperlipidemia, and chronic bronchitis).
RESULTS: Seven factors--age, anesthesia type, duration of operation, intraoperative hypercapnia, intraoperative hypotension, preoperative affective state, and postoperative sleep disorders--were found to be significantly differentiated, suggesting that these factors have an impact on the development of postoperative delirium. Sex, surgical type, intraoperative hypoxia, intraoperative blood loss (with 300 ml as a cutoff value), and underlying disease were not directly related to the development of postoperative delirium. DISCUSSION: Advanced age (>70 years), the use of general anesthesia, longer surgical duration (>3 hours), the presence of intraoperative hypercapnia and hypotension, the presence of preoperative affective dysfunction, and the presence of postoperative sleep disorders appear to be associated with the development of postoperative delirium in geriatric patients after orthopedic surgery.