Persistent low microcirculatory vessel density in nonsurvivors of sepsis in pediatric intensive care

Objective: To investigate the time course and predictive value of microvascular alterations in children with severe sepsis. Design: Single-center, prospective observational study. Setting: Intensive care unit of a level III university children's hospital. Patients: Patients with septic shock, requiring the administration of fluid and vasopressor agents and/or inotropes after the correction of hypovolemia, who were intubated and ventilated, were included. Interventions: None. Measurements and Main Results: The microcirculation was assessed in the buccal mucosa, using orthogonal polarization spectral imaging, within 24 hrs after admission. Subsequent measurements were performed every 24 hrs for 3 days. The measurements were discontinued when the patient was extubated. There were no significant differences in the functional capillary density or microvascular flow index for all vessel types between survivors and nonsurvivors on day 1. In the survival group, the functional capillary density increased significantly between day 1 and day 2 from 1.7 cm/cm(2) (0.8-3.4) to 4.3 cm/cm(2) (2.1-6.9) (p = .001). Functional capillary density values in nonsurvivors did not change (day 1: 3.2 cm/cm(2) [0.8-3.8]; day 2: 1.9 cm/cm(2) [1.0-2.1]). The median functional capillary density on days 2 and 3 were significantly lower in nonsurvivors (day 2: 1.9 cm/cm(2) [1.0-2.1] vs. 4.3 cm/cm(2) [2.1-6.9], p = .009; day 3: 1.8 cm/cm(2) [1.0-2.0] vs. 4.7 cm/cm(2) [2.1-8.6], p = .01). The microvascular flow index for all vessel types improved in survivors and did not change in nonsurvivors. Differences in microvascular flow index values between survivors and nonsurvivors were not significant. Conclusion: Persistent microcirculatory alterations can be prognostic for survival in children with septic shock. (Crit Care Med 2011; 39:8-13