广州市儿童和青年新型冠状病毒Delta变异株感染患者临床特征

 目的 探讨儿童和青年新型冠状病毒（SARS-CoV-2） Delta变异株患者的临床特征。方法 选取广州医科大学附属市八医院2021年5月21日—6月18日收治的SARS-CoV-2 Delta突变株感染者，根据年龄分为儿童组（2~14岁）和青年组（15~35岁），比较两组患者临床、实验室指标及影像学的差异。结果 儿童组21例，青年组24例，两组均无重症患者。儿童以家庭聚集性发病为特征，青年组普通型比儿童组更常见（66.7% VS 33.3%，P<0.05）。与青年组临床表现比较，儿童组咳嗽（33.3% VS 87.5%）、咳痰（33.3% VS 66.7%）和咽喉不适（28.6% VS 70.8%）少见（均P<0.05），儿童发热时间更短（2.5 d VS 4 d，P<0.05），但两组患者发热（76.2% VS 83.3%）差异无统计学意义。与青年组生化学指标比较，基线时儿童组C-反应蛋白（CRP）、血清淀粉样蛋白A （SAA）和白介素-6（IL-6）更低（均P<0.05），但淋巴细胞（LYM）、嗜酸性粒细胞（EOS）、乳酸脱氢酶（LDH）和肌酸激酶同工酶（CK-MB）更高；第1周儿童组CRP和SAA更低，但LYM、EOS、LDH和CK-MB更高（均P<0.05）。儿童基线CK-MB和LDH升高更常见（均P<0.05）。儿童组基线时LYM减少5例（23.8%），EOS减少3例（14.3%），第1周LYM和EOS均恢复正常。胸部CT显示儿童组7例（33.3%）肺部感染，单侧受累为主；青年组16例（66.7%）肺部感染，双肺受累为主。儿童组SARS-CoV-2核酸转阴时间中位日数为17（12，25） d，青年组核酸转阴时间中位日数为19（15，21） d，两组患者均预后良好。结论 儿童SARS-CoV-2 Delta变异株感染以家庭聚集性发病为主要特征。与青年患者比较，儿童患者呼吸道症状、炎症反应、免疫细胞和肺损伤更轻，免疫细胞恢复更快。儿童患者基线CK-MB和LDH升高更常见，需关注急性心肌损伤的可能性。青年和儿童患者SARS-CoV-2核酸转阴时间长，需延长监测上呼吸道核酸的时间。

Clinical observation on polymyxin B-based combination therapy for severe pneumonia caused by extensively drug-resistant bacteria

Objective To investigate the therapeutic efficacy and side effect of polymyxin B-based combination therapy for the treatment of severe pneumonia caused by extensively drug-resistant Acinetobacter baumanii (XDR-AB)and XDR Klebsiella pneumoniae (XDR-KP), and provide support for clinicians in the treatment of severe pneumonia caused by XDR bacteria. Methods Patients who were admitted to the department of critical care medicine of a hospital from April 1, 2018 to April 30, 2019 and received polymyxin B-based combination therapy for pathogenic confirmed extensively XDR-AB and XDR-KP severe pneumonia were selected as research objects. Therapeutic efficacy, microbial treatment efficacy, liver and kidney function damage, pigmentation of skin and other side effects were observed. Results A total of 24 patients with XDR bacterial severe pneumonia were selected, 26 times of treatment were conducted, clinical therapeutic effective rate was 73.1%. A total of 139 sputum cultures were sent for examination, 138 times of antimicrobial susceptibility results showed that bacteria were sensitive to polymyxin B (MIC 0.5-1 μg/mL), only one time was resistant to polymyxin B (MIC=8 μg/mL). Bacterial clearance rate of Acinetobacter baumannii was higher than that of Klebsiella pneumoniae (60.9% vs 7.7%), difference was statistically significant (P=0.004). Incidence of acute kidney injury (AKI) was 42.3%, only one patient ended treatment in advance because of renal function damage; renal function of the survival patients with AKI (survival rate 60.0%) all recovered to normal, incidence of pigmentation of skin was 20.8%, drug-related liver damage and other complications were not found. Conclusion Efficacy of polymyxin B-based combination therapy for XDR-AB and XDR-KP severe pneumonia is high, although strains are sensitive to polymyxin B, bacterial clearance rate is relatively low, polymyxin B has certain nephrotoxicity, and the renal damage of patients who survived after active treatment of primary disease is generally reversible.