Changes in Microcirculation as Early Markers for Infection in Preterm Infants—An Observational Prospective Study

Abstract

ABSTRACT:In adults with severe sepsis, the disturbances of the sublingual microcirculation can be quantified with orthogonal polarization spectral imaging. We investigated the cutaneous microcirculation of preterm infants with proven infection (PosInf) and with suspected but unproven infection (NegInf). In 25 infants, orthogonal polarization spectral images were obtained daily, videos of the images were blinded, and analyzed off-line. Functional small vessel density (FSVD) was prospectively calculated from day 3 to day 30 of life. There were 17 episodes of proven and nine episodes of suspected but unproven nosocomial late onset infection. Four infants remained healthy. The data were analyzed for the 5 d before the start of antibiotics (day Ϫ5 until day Ϫ1). FSVD varied widely, but in the PosInf-group, we found a 10% decline from day Ϫ5 to day Ϫ1 (p ϭ 0.013). There was no significant change over time in the NegInfgroup (p ϭ 0.58). Thus, in infants with proven infection, FSVD decreases already 1 d before changes in laboratory parameters. However, these changes in FSVD during infection are not represented by absolute values, but must be identified by daily intraindividual observation. (Pediatr Res 66: 461-465, 2009) V ery low-birth weight infants are at increased risk for episodes of nosocomial infection, which contributes significantly to mortality and morbidity (1). Early diagnosis and prompt administration of appropriate antibiotics are crucial to improve outcome but clinical signs of infection are very unspecific. White blood cell count has not been shown to improve early diagnosis; C-reactive protein (CRP) is quite specific but not very sensitive for neonatal infection. Cytokines such as interleukine (IL)-6 increase early in neonatal infection before the rise of CRP, and the combination of both increases sensitivity and specificity (2). The need for early treatment in combination with nonspecific clinical signs leads to significant iatrogenic blood loss (3) and an increased exposure to antibiotics.Most clinical signs of infection such as change of skin color, a prolonged capillary filling time, and temperature instability are caused by altered microcirculation. Changes in microcirculation play an important role in the development of septic organ dysfunction (4,5) and the severity of change may even predict outcome (6). Improved technology has made observation and quantification of microcirculatory parameters possible. One of the most promising instrumentation in the regard is the orthogonal polarization spectral (OPS) imaging technique, which allows new insights in the human microcirculation and semiquantified assessment. This method provides high-resolution images of the microvascular architecture to a depth of 1 mm. OPS has been validated by multiple studies in animals and humans (7,8). Using OPS Sakr et al. (6) recently found an association between microcirculatory alterations, organ dysfunction, and death in patients with septic shock. We have previously shown that OPS imaging and measurement of small vess...

C reactive protein: impact on peripheral tissue oxygenation and perfusion in neonates

“…In adults, studies on sublingual microcirculation using OPS imaging in septic patients have shown associations between microcirculatory distress, disease severity and response to therapy 5 7 23. In preterm neonates, Weidlich et al used OPS to identify changes in microcirculation as an early marker of infection 24. The routine clinical use of OPS and SDF is limited by the relatively difficult application and especially the complicated and time-consuming analysis.…”

The microcirculation of the critically ill pediatric patient

“…Top and co-workers reported that such alterations also occur in the buccal mucosa of septic children [59]. In premature neonates with sepsis, microcirculatory alterations were observed in the skin using OPS imaging [58]. Furthermore, neonates with severe respiratory failure have depressed microcirculatory parameters [57].…”

Transcutaneous Microcirculatory Imaging in Preterm Neonates

“…The microcirculation is the area where the final step of the oxygen transport chain occurs. Observational studies have demonstrated a relation between microcirculatory deterioration over time and the presence of bacterial infections 14 . As deterioration of the peripheral microcirculation is one of the first signs of sepsis in preterm infants, it is generally hypothesised that the peripheral microcirculation can help predict the development of sepsis.…”