Thirst Perception and Osmoregulation of Vasopressin Secretion Are Altered During Recovery From Septic

Objective: Vasopressin (AVP) secretion during an osmotic challenge is frequently altered in the immediate post-acute phase of septic shock. We sought to determine if this response is still altered in patients recovering from septic shock. Design: Prospective interventional study Setting: Intensive care unit (ICU) at Raymond Poincaré and Etampes Hospitals. Patients: Normonatremic patients at least 5 days post discontinuation of catecholamines given for a septic shock. Intervention: Osmotic challenge involved infusing 500 mL of hypertonic saline solution (with cumulative amount of sodium not exceeding 24 g) over 120 minutes. Measurements and main results: Plasma AVP levels were measured 15 minutes before the infusion and then every 30 minutes for two hours. Non-responders were defined as those with a slope of the relation between AVP and plasma sodium levels less than < 0.5 ng/mEq. Among the 30 included patients, 18 (60%) were non-responders. Blood pressure and plasma sodium and brain natriuretic peptide levels were similar in both responders and non