What happens to the fluid balance during and after recovering from septic shock?

OBJECTIVE: We aimed to evaluate the cumulative fluid balance during the period of shock and determine what happens to fluid balance in the 7 days following recovery from shock.

METHODS: A prospective and observational study in septic shock patients. Patients with a mean arterial pressure ≥ 65 mmHg and lactate < 2.0 mEq/L were included < 12 hours after weaning from vasopressor, and this day was considered day 1. The daily fluid balance was registered during and for seven days after recovery from shock. Patients were divided into two groups according to the full cohort's median cumulative fluid balance during the period of shock: Group 1 ≤ 4.4 L (n = 20) and Group 2 > 4.4 L (n = 20).

RESULTS: We enrolled 40 patients in the study. On study day 1, the cumulative fluid balance was 1.1 [0.6 - 3.4] L in Group 1 and 9.0 [6.7 - 13.8] L in Group 2. On study day 7, the cumulative fluid balance was 8.0 [4.5 - 12.4] L in Group 1 and 14.7 [12.7 - 20.6] L in Group 2 (p < 0.001 for both). Afterwards, recovery of shock fluid balance continued to increase in both groups. Group 2 had a more prolonged length of stay in the intensive care unit and hospital compared to Group 1.

CONCLUSION: In conclusion, positive fluid balances are frequently seen in patients with septic shock and may be related to worse outcomes. During the shock period, even though the fluid balance was previously positive, it becomes more positive. After recovery from shock, the fluid balance continues to increase. The group with a more positive fluid balance group spent more time in the intensive care unit and hospital.