The clinical implication of secondary pulmonary bacterial infection for the outcome of critically ill patients with Covid-19

Abstract Background Covid-19 is an emerging and evolving infectious and communicable diseases which gravely endanger the lives of critically ill patients with it. It is crucial to determine the clinical implication of secondary pulmonary bacterial infection for the outcome of critically ill patients with severe Covid-19.Methods All critically ill patients with Covid-19(30 deceased and 35 discharged) between January 26, 2020 and March 15, 2020 in two ICUs of Jinyintan Hospital, Wuhan, China, were retrospectively reviewed, to investigate the clinical implication of secondary pulmonary bacterial infection in the prognosis of critically ill patients with severe Covid-19.Results The fatality rate between patients with positive and negative sputum bacterial culture is 75.0%vs 33.3% (P = 0.003). The ROC analyses demonstrate that NLR[0.921(0.858–0.984)P༜0.001], CRP[0.908(0.837–0.978)P༜0.001],neutrophil[0.832(0.728–0.937)P༜0.001],lymphocyte[0.858(0.755–0.960)P༜0.001],leucocyte[0.753(0.626–0.879)P༜0.001] and PCT [0.733(0.605–0.860)P = 0.001] have the discrimination power for the fatality. The Kaplan-Meier analyses show that the patients with negative sputum bacterial culture(P༜0.001) have higher cumulative overall survival rates, in comparison with the opposite. The positive sputum bacterial culture is positively correlated with leukocyte(r = 0.706), CRP(r = 0.733), NLR(r = 0.554) and PCT(r = 0.549)(all P༜0.001). A multivariate Cox regression analysis shows that sputum bacterial culture[15.36(4.291–54.980) P༜0.001], CRP[2.022(2.013–2.030) P༜0.001] and NLR[2.012(2.000-2.024) P = 0.045] are positively correlated with the fatality of the patients.Conclusions The critically ill patients with severe Covid-19 who are complicated with secondary pulmonary bacterial infection may have an unfavorable outcome, in comparison with those who are not. Secondary pulmonary bacterial infection is an independent factor for the fatality of critically patients with Covid-19.