Lower preoperative serum uric acid level may be a risk factor for postoperative delirium in older patients undergoing hip fracture surgery: a matched retrospective case-control study

Abstract

Background Postoperative delirium (POD) is a common complication after hip fracture surgery that is associated with various short- and long-term outcomes. The mechanism of POD may be associated with the oxidative stress process. Uric acid has been shown to provide a neuroprotective effect in various neurodegenerative diseases through its antioxidant properties. However, it is unclear whether lower preoperative serum uric acid levels are associated with the development of POD after hip fracture surgery. Therefore, this study assessed the association of lower preoperative uric acid levels in patients with POD during hospitalization. Methods This is a matched retrospective case-control study that included 96 older patients (≥65 y) who underwent hip fracture surgery. POD was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Patients diagnosed with POD (cases) were matched 1:1 with patients without POD (controls) on the basis of age, sex, and anesthesia type. The relationship between preoperative uric acid and POD was analyzed by multivariable analysis. Results The POD and non-POD groups each had 48 patients. In the univariate analysis, lower log preoperative serum uric acid value, higher neutrophil-to-lymphocyte ratio, and cerebrovascular disease were more likely in patients with POD than in those with no POD. Multivariable conditional logistic regression analysis showed that lower log preoperative serum uric acid (adjusted odds ratio [aOR], 0.028; confidence interval [CI], 0.001–0.844; p = 0.040), higher neutrophil-to-lymphocyte ratio (aOR, 1.314; 95% CI, 1.053–1.638; p = 0.015), and increased surgery duration (aOR, 1.034; 95% CI, 1.004–1.065; p = 0.024) were associated with increased risk of POD. Conclusions Lower preoperative serum uric acid levels may be an independent risk factor for POD after adjustment for possible confounding factors. However, large prospective studies are needed to confirm this finding.

High ASA Physical Status and Low Serum Uric Acid to Creatinine Ratio are Independent Risk Factors for Postoperative Delirium Among Older Adults Undergoing Urinary Calculi Surgery

“… 36 , 37 A recent study verified that low SUA level was associated with the increased risk of POD in older patients with hip fracture surgery. 29 Yet surprisingly, no significant difference in the UA level was observed between two groups in our study, however, our multivariate analysis revealed that the SUA/Cr ratio was an independent risk factor for POD in elderly patients undergoing urinary calculi surgery after adjusting confounding factors. The SUA/Cr ratio, an indicator of renal function-standardized UA, has been verified to be relevant to adverse outcomes in multiple diseases, such as metabolic and cardiovascular diseases (CVD), etc.…”

“… 28 Meanwhile, we carefully examined all medical and nursing records to evaluate delirium. Referring to the study by Xu et al, 29 patients were included in the POD group according to the following conditions: (1) if the case noted delirium was diagnosed by a psychiatrist; (2) if the doctor’ advice revealed the use of antipsychotics, specifically olanzapine, haloperidol, and quetiapine; (3) if two or more experienced anesthesiologists agreed on the diagnosis of POD by the review of electronic medical records (delirium was screened regularly by trained nurses two times one day). Supplementary Table 1 shows the abstracted symptoms related to DSM-V criteria.…”

Postoperative Hyperuricemia—A Risk Factor in Elective Cardiosurgical Patients

“…There is discordant evidence regarding the association of serum UA concentrations with postoperative delirium, with some authors finding low serum UA concentrations to be associated with delirium, while others found the same for high serum UA concentrations. Xu et al found a protective effect of high preoperative UA serum concentrations ( p = 0.040) regarding the development of postoperative delirium [ 46 ]. Liu et al found that a lower serum UA concentration to serum creatinine concentration (SUA/SCr) ratio significantly increases the risk of postoperative delirium ( p < 0.001) [ 47 ].…”

Delirium syndrome in the postoperative period

“…A prospective cohort study [81] Delirium and long-term psychopathology following surgery in older adults [82] CAM-ICU DSM-V ICD- Postoperative delirium is an independent factor influencing the length of stay of elderly patients in th intensive care unit and in hospital [83] A processed electroencephalogram-based brain anesthetic resistance index is associated with postoperative delirium in older adults: a dual center study [84] Independent external validation of a preoperative prediction model for delirium after cardiac surgery: a prospective observational cohort study [85] Lower preoperative verbal memory performance is associated with delirium after coronary artery bypass graft surgery: a prospective cohort study [86] Effect of regional vs. general anesthesia on incidence of postoperative delirium in older patients undergoing hip fracture surgery [ Lower preoperative serum uric acid level may be a risk factor for postoperative delirium in older patients undergoing hip fracture surgery: a matched retrospective case-control study [90] Risk factors and effect of postoperative delirium on adverse surgical outcomes in older adults after elective abdominal cancer surgery in Taiwan [91] High ASA physical status and low serum uric acid to creatinine ratio are independent risk factors for postoperative delirium among older adults undergoing urinary calculi surgery [92] W wybranej do analizy literaturze najliczniejszą grupę badaną tworzyło 10 755 (36,6%) chorych po operacjach kardiochirurgicznych, a odsetek występowania majaczenia pooperacyjnego dotyczył 2043 chorych. Pozostałe prace dotyczyły odpowiednio 7812 (26,6%) chorych po operacjach ortopedycznych, 5227 (18%) chorych po operacjach brzusznych, 689 (2,3%) chorych po operacjach torakochirurgicznych, 484 (1,6%) chorych po operacjach naczyniowych, 2678 (9,1%) chorych po operacjach neurochirurgicznych, 1714 (5,8%) chorych po operacjach urologicznych.…”