CANPT Score: A Tool to Predict Severe COVID-19 on Admission

Background and Aims: Patients with critical coronavirus disease 2019 (COVID-19) have a mortality rate higher than 50%. The purpose of this study was to establish a model for the prediction of the risk of severe disease and/or death in patients with COVID-19 on admission.Materials and Methods: Patients diagnosed with COVID-19 in four hospitals in China from January 22, 2020 to April 15, 2020 were retrospectively enrolled. The demographic, laboratory, and clinical data of the patients with COVID-19 were collected. The independent risk factors related to the severity of and death due to COVID-19 were identified with a multivariate logistic regression; a nomogram and prediction model were established. The area under the receiver operating characteristic curve (AUROC) and predictive accuracy were used to evaluate the model's effectiveness.Results: In total, 582 patients with COVID-19, including 116 patients with severe disease, were enrolled. Their comorbidities, body temperature, neutrophil-to-lymphocyte ratio (NLR), platelet (PLT) count, and levels of total bilirubin (Tbil), creatinine (Cr), creatine kinase (CK), and albumin (Alb) were independent risk factors for severe disease. A nomogram was generated based on these eight variables with a predictive accuracy of 85.9% and an AUROC of 0.858 (95% CI, 0.823–0.893). Based on the nomogram, the CANPT score was established with cut-off values of 12 and 16. The percentages of patients with severe disease in the groups with CANPT scores <12, ≥12, and <16, and ≥16 were 4.15, 27.43, and 69.64%, respectively. Seventeen patients died. NLR, Cr, CK, and Alb were independent risk factors for mortality, and the CAN score was established to predict mortality. With a cut-off value of 15, the predictive accuracy was 97.4%, and the AUROC was 0.903 (95% CI 0.832, 0.974).Conclusions: The CANPT and CAN scores can predict the risk of severe disease and mortality in COVID-19 patients on admission.

Iodoacetate-induced skeletal muscle contracture: changes in ADP, calcium, phosphate, and pH

The effects of iodoacetic acid (IAA) and ischemic contraction were studied in rat extensor digitorum longus muscles. Ischemic stimulation of IAA-treated muscles produced contracture. We measured total muscle water content, distribution of water between intracellular and extracellular spaces, creatine concentration ([Cr]), creatine phosphate concentration ([PCr]), [ATP], [Pi], intracellular pH, and intracellular Ca2+ concentration ([Ca2+]i) at the onset of contracture. [ADP] was calculated from the equilibrium of the creatine kinase reaction using the measured values of [ATP], [PCr], [Cr], and pH. At the onset of contracture there was a 75% reduction of [PCr], a 12-fold increase in [ADP], and an 11-fold increase in [Ca2+]i compared with unstimulated IAA-treated muscles. [ATP] was not depleted at contracture compared with unstimulated IAA-treated muscles, and [Pi] increased less in muscles at contracture compared with stimulated control muscles. The persistent tension in contractures probably resulted from increased [Ca2+]i combined with increased myofibrillar Ca2+ sensitivity due to elevated [ADP] and relatively reduced intracellular acidification and [Pi].