Background Coronavirus disease 2019 (COVID-19), a highly infectious disease, has been rapidly spreading all over the world and remains a great threat to global public health. Patients diagnosed with severe or critical cases have a poor prognosis. Hence, it is crucial for us to identify potentially severe or critical cases early and give timely treatments for targeted patients. In the clinical practice of treating patients with COVID-19, we have observed that the neutrophil-to-lymphocyte ratio (NLR) of severe patients is higher than that in mild patients. We performed this systematic review and meta-analysis to evaluate the predictive values of NLR on disease severity and mortality in patients with COVID-19. Methods We searched PubMed, EMBASE, China National Knowledge Infrastructure (CNKI) and Wanfang databases to identify eligible studies (up to August 11, 2020). Two authors independently screened studies and extracted data. The methodological quality of the included studies was assessed by Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Results Thirteen studies involving 1579 patients reported the predictive value of NLR on disease severity. The pooled sensitivity (SEN), specificity (SPE) and area under curve (AUC) were 0.78 (95% CI 0.70–0.84), 0.78 (95% CI 0.73–0.83) and 0.85 (95% CI 0.81–0.88), respectively. Ten studies involving 2967 patients reported the predictive value of NLR on mortality. The pooled SEN, SPE and AUC were 0.83 (95% CI 0.75–0.89), 0.83 (95% CI 0.74–0.89) and 0.90 (95% CI 0.87–0.92), respectively. Conclusions NLR has good predictive values on disease severity and mortality in patients with COVID-19 infection. Evaluating NLR can help clinicians identify potentially severe cases early, conduct early triage and initiate effective management in time, which may reduce the overall mortality of COVID-19. Trial registry This meta-analysis was prospectively registered on PROSPERO database (Registration number: CRD42020203612).

BackgroundRegional citrate or heparin is often prescribed as an anticoagulant for continuous renal replacement therapy (CRRT). However, their efficacy and safety remain controversial. Therefore, we performed this meta-analysis to compare these two agents and to determine whether the currently available evidence is sufficient and conclusive by using trial sequential analysis (TSA).MethodsWe searched for relevant studies in PubMed, Embase, the Cochrane Library databases and the China National Knowledge Infrastructure (CNKI) Database from database inception until September 2015. We selected randomized controlled trials comparing regional citrate with heparin in adult patients with acute kidney injury (AKI) who were prescribed CRRT.ResultsFourteen trials (n = 1134) met the inclusion criteria. Pooled analyses showed that there was no difference in mortality between the regional citrate and heparin groups (relative risk (RR) 0.97, 95 % confidence interval (CI) 0.84, 1.13, P > 0.05), which was confirmed by TSA. Compared with heparin, regional citrate significantly prolonged the circuit life span in the continuous venovenous haemofiltration (CVVH) subgroup (mean difference (MD) 8.18, 95 % CI 3.86, 12.51, P < 0.01) and pre-dilution subgroup (MD 17.51, 95 % CI 9.85, 25.17, P < 0.01) but not in the continuous venovenous haemodiafiltration (CVVHDF) subgroup (MD 28.60, 95 % CI −3.52, 60.73, P > 0.05) or post-dilution subgroup (MD 13.06, 95 % CI −2.36, 28.48, P > 0.05). However, the results were not confirmed by TSA. A reduced risk of bleeding was found in the regional citrate compared with the systemic heparin group (RR 0.31, 95 % CI 0.19, 0.51, P < 0.01) and TSA provided conclusive evidence. Fewer episodes of heparin-induced thrombocytopoenia (HIT) (RR 0.41, 95 % CI 0.19, 0.87, P = 0.02) and a greater number of episodes of hypocalcaemia (RR 3.96, 95 % CI 1.50, 10.43, P < 0.01) were found in the regional citrate group. However, TSA did not provide conclusive evidence.ConclusionIn adult patients with AKI, there is no difference in mortality between the regional citrate and heparin treated groups. However, regional citrate is more efficacious in prolonging circuit life span and reducing the risk of bleeding and should be recommended as the priority anticoagulant for critically ill patients who require CRRT.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-016-1299-0) contains supplementary material, which is available to authorized users.

Objective To compare the acute effects of 0.9% saline versus a balanced electrolyte solution on acute kidney injury in a rat model of sepsis. Design Controlled laboratory experiment. Setting University laboratory. Subjects Sixty adult, male Sprague-Dawley rats. Interventions We induced sepsis by cecal ligation and puncture and randomized animals to receive fluid resuscitation with either 0.9% saline or Plasma-Lyte solution for 4 hours after 18 hours of cecal ligation and puncture (10 mL/kg in the first hour and 5 mL/kg in the next 3 hr). Blood and urine specimens were obtained from baseline, 18 hours after cecal ligation and puncture, immediately after 4 hours fluid resuscitation, and 24 hours later. We measured blood gas, plasma electrolytes, creatinine, interleukin-6, cystatin C, and neutrophil gelatinase-associated lipocalin concentrations. We also analyzed urine for cystatin C and neutrophil gelatinase-associated lipocalin. We used Risk, Injury, Failure, Loss and End-stage criteria for creatinine to assess severity of acute kidney injury. We observed all animals for survival up to 1 day after resuscitation. Surviving animals were killed for kidney histology. Finally, we carried out an identical study in 12 healthy animals. Measurements and Main Results Compared with Plasma-Lyte, 0.9% saline resuscitation resulted in significantly greater blood chloride concentrations (p < 0.05) and significantly decreased pH and base excess. Acute kidney injury severity measured by RIFLE criteria was increased with 0.9% saline compared with Plasma-Lyte resuscitation (p < 0.05), and these results were consistent with kidney histology and biomarkers of acute kidney injury. Twenty-four-hour survival favored Plasma-Lyte resuscitation (76.6% vs 53.3%; p = 0.03). Finally, in healthy animals, we found no differences between fluids and no evidence of acute kidney injury. Conclusion Volume resuscitation with Plasma-Lyte resulted in less acidosis and less kidney injury and improved short-term survival when compared with 0.9% saline in this experimental animal model of sepsis.