Ceftazidime avitbatan sodium is a broad-spectrum antibiotic with an antimicrobial spectrum covering resistant gram-negative bacteria. Its use in pediatric intensive care for severe infections is not unusual. Pathophysiological changes in severe sepsis can lead to significant changes in pharmacokinetics and pharmacodynamics during continuous renal replacement therapy.This research aims to study change of pharmacokinetic and pharmacodynamic in severe infection children with extracorporeal life support, thus improve the treatment of severe sepsis and sepsis shock.

This study is an observational clinical study. Subjects were recruited from children with severe infection receiving ceftazidime avitbatan sodium under routine clinical diagnosis and treatment routine. There is no control, no double-blind randomized design, and the normal treatment schedule of patients was not interfered with, and the disease risk of patients was not increased.All subjects had received at least 5 doses of ceftazidime avitbatan Sodium before enrollment.

Blood sampling time points of ceftazidime avitbatan sodium are listed as follow:

Before administration (0 min); 5,30 min,1 h,2 h,4 h and 8 h after administration, if blood purification is received, one blood sample will be collected before and after the filter at the same time point.

The concentration of ceftazidime avitbatan sodium in whole blood will be analyzed at Huashan Hospital of Fudan University.

Inclusion Criteria:

• Children who are admitted in the pediatric intensive care unit receiving ceftazidime avitbatan sodium

Exclusion Criteria:

• No Informed Consent signed
• Participate in other clinical trials

Children receiving cefatadine and averbactam sodium in pediatric intensive care unit including but not limited to children with liver insufficiency, hypoproteinemia, ECMO treatment, CRRT treatment or sepsis.