Risk factors for delirium after orthopedic surgery

Objective To explore the risk factors for delirium after orthopedic surgery. Methods Retrospective analysis of 525 patients who underwent orthopedic surgery from January 2011 to December 2013 was carried out. Among 525 patients, 155 patients experienced internal fixation for intertrochanteric fracture; 64 patients experienced femoral head prosthetic replacement;169 patients experienced total hip replacement; 65 patients experienced total knee arthroplasty and 72 patients experienced shoulder joint surgery. All the 525 patients were divided into delirium group (56 cases) and non-delirium group (469 cases). 17 perioperative factors were recorded, including age, gender, blood type, operation methods, anesthesia mode, preoperative preparation time, basic disease, preoperative and postoperative albumin levels, preoperative and postoperative hemoglobin levels, postoperative electrolyte disturbance, bleeding volume, operation duration, ICU monitoring and blood transfusion volume. Single factor Logistic regression and multi-factor Logistic regression analysis were applied to discuss related risk factors of postoperative delirium. Results Results of single Logistic regression analysis indicate that 9 factors including age, operation methods, preoperative preparation time, preoperative albumin and hemoglobin level, postoperative electrolyte disturbance, operation duration, ICU monitoring and blood transfusion volume might be related to postoperative delirium. Multi-factor Logistic regression analysis show that postoperative delirium occurrence rate of the group with the age 70-80 and the group with the age >80 is higher than that of the group with the age <70.OR values are 12.998 and 36.210. In terms of preoperative preparation time, postoperative delirium occurrence rate of the group with preoperative preparation time of 46 d is higher than that the group with preoperative preparation time more than or equal to 7 d. OR value is 3.903. Postoperative delirium occurrence rate of electrolyte disturbance group is higher than that of normal electrolyte group. OR value is 2.160. Conclusion The old age, insufficient preoperative preparation and postoperative electrolyte disturbance are high risk factors for postoperative delirium. Key words: Postoperative complications; Delirium; Risk factors