PURPOSE: Vasopressin is used as an adjunct or alternative vasopressor agent in patients with severe septic shock refractory to fluid resuscitation and traditional vasopressors. However, which patients with refractory septic shock will respond to vasopressin is not known. The purpose of our study was to delineate the characteristics of severe septic shock patients who will respond to vasopressin. The response to vasopressin was arbitrarily defined as fifty percent reduction in vasopressor dosage within 24 hours of initiation of vasopressin.
METHODS: Medical records of 68 patients from October 2004 to February 2006 who received vasopressin for severe septic shock were reviewed for demographics, severity of illness, mortality and response to vasopressin.
RESULTS: Of 68 patients 54% were females. All patients received adequate fluid resuscitation, corticosteroids if required (69% of the patients), and at least one vasopressor (dopamine, norepinephrine or phenylephrine) before the initiation of vasopressin. Average acute physiology and chronic health evaluation (APACHE II) score was 24.7 and was higher in non responders. Patients who did not respond had higher rate of positive blood cultures (51% vs. 30%, P 0.03). APACHE II score (P 0.003)and mortality (P 0.008) were significantly higher in the non responders. Vasopressin was initiated with the dose (0.04 units/min) within 24 hours of initiation of traditional vasopressor for 54 patients. Of these, 17 patients (31%) responded within 24 hours of initiation therapy.
CONCLUSION: Not all patients with septic shock will respond to vasopressin. Those who did not respond had higher APACHE II score and positive blood cultures with high mortality rate (81% vs. 41%). The response was observed with early initiation of the vasopressin infusion, with the most significant response rate in the first 24 hours.
CLINICAL IMPLICATIONS: Early aggressive initiation of vasopressin in the first 24 hours of refractory septic shock may improve outcome for severe septic shock.
DISCLOSURE: Sharon Ngan, None.