Analysis of clinical prognosis in patients with non-hepatic hyperammonemia

The aim of this study was to evaluate the association of non-hepatic hyperammonemia (NHH) with the prognosis of critically ill patients with NHH. According to the serum ammonia level, the patients with NHH (n = 498) were retrieved by us. The risk factors of the mortality with NHH patients were investigated by conducting univariate and multivariate logistic regression analyses. A nomogram to predict the risk of hospital mortality was constructed. Receiver operating characteristic curve (ROC) analysis was conducted to compare nomogram (ammonia into a prognostic model, P1) with the simplified acute physiology II (SAPSII) and quick sequential organ failure assessment (qSOFA). Five independent factors for the mortality in patients with NHH were identified, including age, platelets, bun, hemoglobin, and ammonia. Models P1 using ammonia showed good prediction power. The AUROC of P1 (AUROC, 0.755 [95% CI, 0.713–0.796]) was higher than that of qSOFA (AUROC, 0.500 [95% CI, 0.449–0.551]), and SAPS II (AUROC, 0.703[95% CI, 0.658–0.748]). Ammonia was an independent prognostic predictor of mortality for NHH patients. We developed a nomogram that can predict hospital mortality with patients. Nomogram had superior discriminative power to qSOFA and SAPS II, indicating that the nomogram may have clinical utility.