Prof. Zhu Hua Dong
Emergency Department of Peking Union Medical College Hospital
Deputy Chairman of Emergency Medical Education Expert Committee
Emergency Medicine Branch of Chinese Medical Association (CMDA)
Prof Zhu Hua Dong is an expert in critical care medicine, specializing in cardiopulmonary resuscitation, shock, infection, mechanical ventilation, emergency ultrasound and other fields. In recent years, his researches focus mainly on the etiology analysis of acute severe infection and the clinical interventions of severe infection. In-depth research has been conducted on the comprehensive treatment of severe infection and certain results have been achieved with a number of academic papers published. The home report of “Emergency Physicians Should Pay Close Attention to the Diagnosis and Treatment of CAP Patients” was delivered at the 2018 Beijing academic annual meeting of emergency medicine.
Q1: As the department with the largest number of severe patients and diseases, and the heaviest tasks of rescue and management, why CAP in emergency department has always been concerned?
A1: According to the epidemiological survey, the annual prevalence of community-acquired pneumonia (CAP) in the general population is about 0.1% ~ 1.16%, and it is about 2.5% ~ 4.4% in the population over 65 years old. The case fatality rate of CAP among outpatients is 1% ~ 5%, 12% averagely among hospitalized patients, and about 40% among ICU patients1.
Q2: Most CAP patients are initially diagnosed and treated in the emergency department. What do you think is the therapeutic goal of CAP in the emergency department?
A2: When treating CAP patients, the primary task of emergency physicians is to stratify patients according to the conditions and not treat all CAP patients in the same way. In severe patients, physicians need to identify life-threatening risk factors early and stabilize organ functions. Another part of CAP patients need to stay in hospital for observation and treatment. Stratify them after reasonable evaluation of the patient’s condition and timely start initial empirical antibacterial treatment2.
Q3: What are the clinical challenges you have encountered in achieving these goals?
A3: Emergency physicians face the most diverse and complex set of infections every day. The main challenges are the complexity of pathogen composition; newly emerging or recognized pathogenic microorganisms such as SARS, H1N1 and H5N1; changes of host composition such as elderly patients, patients with complications and the significantly increased number of immunodeficiency patients caused by various reasons and the increase in the proportion of multidrug-resistant strains3.
Q4: The etiology composition of CAP patients is complex and diverse. What are the differences of pathogen distribution according to the classification and stratification of disease condition and the different treatment places?
A4: According to the classification of patients — outpatients without basic diseases: streptococcus pneumoniae, mycoplasma pneumoniae, haemophilus influenzae, respiratory virus. Outpatient patients with basic diseases and hospitalized (non-ICU) patients: streptococcus pneumoniae, enterobacteriaceae bacteria, haemophilus influenzae, staphylococcus aureus, caramo bacteria, mycoplasma pneumoniae, legionella, respiratory virus, mixed infections. Hospitalized (ICU) patients: streptococcus pneumoniae, staphylococcus aureus, legionella, enterobacteriaceae bacteria, haemophilus influenzae, pseudomonas aeruginosa (with corresponding risk factors) 3.
Q5: In addition, what are the similarities and differences in the composition and resistance characteristics of CAP pathogens in different countries and regions?
A5: Foreign epidemiological survey of CAP shows that streptococcus pneumoniae is the most common pathogenic bacteria, and atypical pathogens and mixed infection are also important causes of CAP4. According to the CARTIPS study, it is China not Canada, Germany, France or the United States where streptococcus pneumoniae has a very high drug resistance to macrolides5-9. The drug resistance rates of mycoplasma pneumoniae to erythromycin and azithromycin are 71.7% and 60.4%, respectively. No drug resistant strains of levofloxacin and tetracycline are found10.
Q6: The diagnosis and treatment of CAP in emergency department has its particularity. Since the emergency doctors do not have much time to wait for the etiology results because of the urgent conditions, most of them rely on the empirical therapies. Your experience in this aspect is beyond doubt. So how do you choose antimicrobial agents in empirical therapies according to your experience?