The study measures the plasma concentrations of imipenem in septic shock patients and non-septic shock patients and observes hypoalbuminemia and the impact of the severity of critical illness on Vd

Severe sepsis and septic shock are major causes of mortality in intensive care unit(ICU) patients.Correct and adequate antibiotic coverage is essential but can be complex as a result of fluid resuscitation, hypoalbuminemia, organ dysfunction, the application of extracorporeal support modalities and the impact of critical illness on pharmacokinetics(PK).Such changes will significantly distort the normal anti-biotic PK profile, resulting in drug exposure that is markedly different from the 'healthy volunteer.'The apparent volume of distribution is one of important PK parameters.Vd determines the loading dose. This review article considers these issues in detail, summarizing the key changes in antibiotic Vd in the critically ill, and providing general suggestions how to optimization of antibiotic dosing to manage Vd challenges.50 patients who receives the theapy of imipenem are included in this study.Whether hypoalbuminemia, organ dysfunction, the application of extracorporeal support modalities and the impact of critical illness on Vd will be evaluted.

Inclusion Criteria:

1. age between 18 years old and 80 years old;
2. Admitted to the ICU;
3. Patients diagnosed as septic shock requiring the therapy of imipenem(0.5g q6h or 1.0g q8h;

Exclusion Criteria:

1. Patient participated in another interventional trial before enrollment
2. Allergy, hypersensitivity or a serious reaction to imipenem;
3. Pregnancy.
4. patients with ECMO and(or)CRRT.
5. tumors.

septic shock patients and non-septic shock patients with the therapy of imipenem in the ICU of Zhongda hospital