Microvascular flow is compromised early in neonatal infection
Background and Aims: The early diagnosis of neonatal infection remains a challenge. Recent studies using Orthogonal Polarization Spectral (OPS) imaging techniques, have reported microcirculatory alterations in adult patients with severe sepsis and septic shock1,2. The objective of this study was to compare microcirculatory flow and vascular density between healthy (H) and sick newborns (I) with neonatal infection.
Methods: We obtained prospectively OPS images from the ear conch of 46 infants on their 1st, 2nd and 3rd day of life. Infection was defined as IL–6>50pg/mL and CRP>0,5mg/dL. The OPS sequences were analyzed off-line, blinded to clinical status of the infant, using a semiquantitative assessment of flow based on the work of Sakr2 and Boerma3.
Results: In the 16 infants of group I the percentage of vessels with impaired flow was significantly elevated (mean I [95%CI]: 31% [19–44] vs. H: 9% [6–13] p=0,0003) whereas the trend to lower vascular density did not reach statistical significance (I: 5,9 [5,5–6,5]vs. H: 6,5 [6,2–6,8] vessels/mm). Most episodes of infection were not severe (median CRP: 1, 05mg/dL; median IL–6: 98,2 pg/mL). In 69% of the infection cases, microcirculatory changes were seen a day before CRP was elevated. Birth weight an gestational age did not differ between the groups.
Conclusion: Even in infants with mild to moderate signs of infection, microcirculatory flow is impaired in a large proportion of vessels early in the course of disease. Since these changes can be easily recognized at the external ear, an on-line evaluation of microcirculatory flow could be an important screening tool for infection in the future.