The purpose of this study is to evaluate the efficacy of terlipressin for treating septic shock.

Septic shock is the most common cause of death in intensive care units and has a mortality rate of 40 to 60%.Vasopressin is commonly used as an adjunct to catecholamines to support blood pressure in refractory septic shock.Recently small sample clinical study suggest that Terlipressin,a vasopressin analogues, was effective in reversing sepsis-induced arterial hypotension and in reducing norepinephrine requirements.But its effect on mortality is unknown.Invesgators hypothesized that Terlipressin as compared with norepinephrine would decrease mortality among patients with septic shock.

Inclusion Criteria:

• Septic shock was defined by the presence of two or more diagnostic criteria for the systemic inflammatory responsesyndrome, proven or suspected infection, and hypotension (exclusion of hypertention other than sepsis)

Exclusion Criteria:

• organ transplantation;
• pregancy or breast-feeding;
• malignancy or other irreversible disease or condition for which has a poor prognosis;
• acute coronary syndrome;
• chronic heart failure(NYHA III or IV)/cardiogenic shock;
• acute mesenteric ischemia;
• greater than 48 hours had elapsed since the patient met entry criteria;
• estimation of incomplite treament due to financial problem;
• use of terlipressin for blood pressure support before entry;
• Raynaud's phenomenon, systemic sclerosis or vasospastic diathesis;
• registration of other clinical trial which will affect the outcome of the current study