Search

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 -5 until day -1). FSVD varied widely, but in the PosInf-group, we found a 10% decline from day -5 to day -1 (p = 0.013). There was no significant change over time in the NegInf-group (p = 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.

Background The aim of this study was to determine the effects of HIV type-1 (HIV-1) infection and antiretroviral therapy (ART) on placental mitochondria.Methods HIV-1-infected pregnant women and HIV-1 -uninfected controls were enrolled prospectively. Placental mitochondrial DNA (mtDNA) copy numbers were determined by quantitative PCR, subunits II and IV of cytochrome coxidase (COX) were quantified by western blot and mitochondrial ultrastructure was evaluated by electron microscopy. Venous blood lactate was measured in newborns.Results In total, 45 HIV-1-infected pregnant women on ART and 32 controls were included. Mean ±sd mtDNA copy numbers were significantly reduced in ART and HIV-1-exposed placentas (240 ±118 copies/ cell) in comparison with controls (686 ±842 copies/cell; P<0.001). The mean COX II/IV ratio was 48% lower in the investigational group compared with controls (P<0.001). There was no evidence of severe ultrastructural damage within mitochondria of HIV-1-infected ART-exposed placentas. Although lactate levels between newborns did not differ, they were negatively correlated with placental mtDNA levels. There was no clear association between mitochondrial parameters and a particular nucleoside reverse transcriptase inhibitor (NRTI), the number of NRTIs or time of NRTI exposure.Conclusions Placental tissue of HIV-1-infected ART-exposed pregnancies shows evidence of mtDNA depletion with secondary respiratory chain compromise. The clinical effects of this finding warrant further investigation.

Changes in microcirculation have been recognized as central to many disease processes. The aim of this study was to evaluate factors, which influence the microcirculation of the skin during the first month of life in premature infants. Red blood cell (RBC) velocity, vessel diameter, and functional small vessel density (FSVD) were measured daily for the first 30 d on the upper arm in preterm infants with gestational age <30 wk. Orthogonal polarization spectral (OPS) images were analyzed off-line with the CapiScope-Image program. In 25 infants, FSVD decreased significantly from week 1 (mean ± SD 236 ± 33 cm/cm2) to week 4 (207 ± 30 cm/cm2) and correlated directly with Hb levels and incubator temperature. Vessel diameters and RBC velocity did not change significantly, nor did clinical parameters such as blood pressure, heart rate or body temperature. Microvascular parameters were not dependent on gestational or postnatal age. The microcirculation of the skin might be an easily accessible window to obtain better understanding of circulatory changes in the postnatal period. Our data are essential as basis for further studies in this field. Hb levels and possible incubator temperatures have a substantial influence on functional small vessel density and therefore need to be taken in account.

Background: Red blood cell (RBC) transfusion practices for neonates are controversial, variable, and based on limited scientific information. To decrease donor exposure satellite packs are used leading to the transfusion of older RBCs. Transfusion of stored RBCs in a hemodiluted animal resulted in significant malperfused and underoxygenated microvasculature that was not detected at the systemic level.Objective: Does the age of transfused erythrocytes influence functional vessel density (FVD) in the skin in premature infants?.Design Methods: 17 preterm infants with birth weight < 1500g received RBC transfusion, 11 infants repeatedly from the same donor. The age of RBCs at repeated transfusions was significant higher than at the first transfusion.Using Sidestream Dark Field Imaging all preterm infants were examined before and 2, 24 and 48 hours after transfusion. Images were blinded and analyzed with Microvision Analysis Software.Results: FVD before first and repeated transfusion did not differ. In the 2nd, 24thand 48thhour after the treatment the Functional Vessel Density (FVD) was significantly lower after the repeated transfusion with longer storage time (2nd: 250 vs. 238 cm/cm2, p=0.045; 24th: 259 vs. 231 cm/cm2, p=0.001; 48th: 234 vs. 220 cm/cm2, p=0.035).The proportion of vessels with altered sluggish blood flow was also significantly higher when older RBCs were transfused (24h: 0.3% vs 2.5%, p=0.017; 48h: 1% vs. 3.3%, p=0.013).Conclusions: Similar to the animal model longer storage of the red blood cells reduces functional vessel density in the skin of premature infants and more vessels display sluggish blood flow.

Background: Orthogonal polarization spectral (OPS) imaging is a novel method to examine the microcirculation non-invasively.Methods: Red blood cell velocity (RBC vel), vessel diameter (Diam) and functional capillary density (FCD) were measured daily in the first month of life on the upper arm in neonates with gestational age less than 30 weeks. OPS images were recorded on videotape and analysed off-line with the CapiScope program.Results: In 25 preterm infants (median (95% CI): gestational age of 28 (26.18–27.58) weeks; birth weight 900 (807.9–992.8) g) Diam ranged from 7 to 24 µm, RBC vel from 171.8 to 726.3 µm/s with no significant change. RBC vel correlated with hemoglobin levels (r2= 0.25, 95% CI (0.14–0.74), p = 0.0083) and inversely with mean systolic blood pressure (r2= 0.36, 95% CI (-0.8 to -0.29), p = 0.0009). FCD decreased significantly from day 7 (mean 236.4 µm/s; 95% CI 218.5–254.2) to day 28 (mean 206.9 µm/s; 95% CI 190–223.3; p = 0.0028). FCD correlated directly with hemoglobin levels (r2= 0.58, 95% CI (0.54–0.89), p < 0.001). There was an inverse correlation between FCD and heart rate (r2= 0.39, 95% CI (-0.8 to -0.32), p < 0.001) and systolic blood pressure (r2= 0.32, 95% CI (-0.78 to -0.24), p = 0.0021). Clinical variables, such as blood pressure, heart rate or body temperature did not change significantly. Hemoglobin decreased significantly over time (p < 0.0001), which explains the concurrent decrease in FCD. Preterm neonates from 23 to 26 and from 28 to 30 weeks did not differ in RBC, Diam and FCD.Conclusion: We have shown that tissue perfusion can be monitored reliably by OPS imaging in premature infants in the first month of life.