Prognostic significance of the blood urea nitrogen to creatinine ratio in in-hospital cardiac arrest after targeted temperature management

Abstract

Background: Targeted temperature management (TTM) has been reported to improve outcomes in in-hospital cardiac arrest (IHCA) patients but little has been investigated into the relationship between prognoses and the blood urea nitrogen to creatinine ratio (BCR). Methods: A retrospective analysis of data from IHCA survivors treated with TTM between 2011 and 2018 was conducted based on the Research Patient Database Registry of the Partners HealthCare system in Boston. Serum laboratory data were measured during IHCA and within 24 hours after TTM completion. Intra-arrest and post-TTM BCRs were calculated, respectively. The primary outcome was neurologic status at discharge. The secondary outcome was in-hospital mortality. Results: The study included 84 patients; 63 (75%) were discharged with a poor neurologic status and 40 (47.6%) died. Regarding poor neurological outcome at discharge, multivariate analysis revealed that post-TTM BCR was a significant predictor (adjusted OR, 1.081; 95% CI, 1.002–1.165; p = 0.043) and intra-arrest BCR was a marginal predictor (adjusted OR, 1.067; 95% CI, 1.000–1.138; p = 0.050). Post-TTM BCR had an acceptably predictive ability to discriminate neurological status at discharge, with an area under the receiver-operating characteristic curve of 0.644 (95% CI, 0.516–0.773) and a post-TTM BCR cutoff value of 16.7 had a sensitivity of 61.9% and a specificity of 70.0%. Conclusion: Post-TTM BCR was a significant predictor of the neurologic outcome at discharge among IHCA patients receiving TTM. IHCA patients with elevated intra-arrest BCR also had a borderline poor neurological prognosis at discharge.

Blood urea nitrogen and creatinine in in-hospital cardiac arrest patients

“…10 Additionally, the authors found a cutoff value of 16.7 for a post-TTM BCR with a sensitivity of 61.9% and a specificity of 70.0% to predict poor neurological outcome at discharge among IHCA patients. 10 The current article is interesting and worthy of further discussion.…”

“…10 Similarly, after ischemic stroke, lower BCR was associated with better neurological function. 10 All suggest that a higher BCR (poor renal function or severity of AKI) may be associated with worse outcomes, especially for patients with a poor neurological prognosis. We agree with the authors' opinion; however, some concerns should be announced.…”

“…The authors considered the aforementioned parameters as a biomarker, especially for BCR for renal function (acute kidney injury [AKI]), based on showing a promising indicator (BCR) reflecting more than patients' fluid or nutritional status and a positive association with mortality in heart failure, renal disease, COVID-19, and stroke. 10 Similarly, after ischemic stroke, lower BCR was associated with better neurological function. 10 All suggest that a higher BCR (poor renal function or severity of AKI) may be associated with worse outcomes, especially for patients with a poor neurological prognosis.…”

“…The recent publication in the last October issue of the Journal of the Chinese Medical Association entitled “Prognostic significance of the blood urea nitrogen to creatinine ratio in in-hospital cardiac arrest after targeted temperature management,” attempted to use the simple parameters of blood urea nitrogen (BUN) to creatinine (Cr) ratio (BCR) to predict the neurological outcome at discharge among IHCA patients receiving targeted temperature management (TTM). 10 The authors found that elevated post-TTM BCR was a significant predictor (adjusted odd ratio [aOR], 1.081; 95% confidence interval [CI], 1.002-1.165) and elevated intra-arrest BCR was a marginal predictor (aOR, 1.067; 95% CI, 1.000-1.138) for worse neurological outcomes at discharge among IHCA patients. 10 Additionally, the authors found a cutoff value of 16.7 for a post-TTM BCR with a sensitivity of 61.9% and a specificity of 70.0% to predict poor neurological outcome at discharge among IHCA patients.…”

“…In fact, as shown by the authors, the role of BCR was inconformity. 10 Although BUN and Cr concentrations are easily available biomarkers of renal function in clinic, BUN and Cr concentrations of patients could not be totally reflective of real renal function. 14 Many factors influence both BUN and Cr concentrations.…”