Background: This study aimed to compare the serum angiotensin II and its receptor levels (AT1, AT2) in septic patients with catecholamine-responsive or resistant. The effect of hydrocortisone treatment on angiotensin II levels in the catecholamine-resistant septic patients was evaluated.
Methods: This prospective observational study enrolled 40 patients diagnosed with septic shock based on sepsis-3 criteria. Patients were divided into two groups according to the noradrenalin infusion rate required to keep the mean arterial pressure above 65 mmHg: control group and hydrocortisone group (control group: below 0.5 µg/kg/min, hydrocortisone group: above 0.5 µg/kg/min). Serum angiotensin II, AT1, AT2 levels were measured at the time of diagnosis (A), one hour after hydrocortisone treatment (B), and three days later (C).
Results: In the catecholamine-resistant group, angiotensin II and AT1 levels were higher than the catecholamine-responder group in all periods. The sensitivity and specificity of AT-1 was observed to be high in all periods. AT2 levels decreased after hydrocortisone treatment in the catecholamine-resistant group and cut-off value was found 11%.
Conclusions: It was concluded that angiotensin II and AT1 can be used as a biomarker of refractory septic shock and hydrocortisone may provide their blood pressure correcting effect by reducing AT2 level in these patients. AT2 can be a therapeutic target in the catecholamine-resistant septic shock patients.