Search

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 We have previously shown that orthogonal spectral imaging (OPS imaging) can be used to measure microcirculatory parameters such as Red Blood Cell Velocity (RBC Vel) and Functional Capillary Density (FCD). As neonatal infections often manifest unspecificly in e. g. paleness and prolonged capillary refill time we examined if a decrease in FCD can predict neonatal infection.Methods in 25 preterm infants (gestational age of 28 (26,18 - 27,58) wks; birth weight 900 (807,9 - 992,8) g) RBC Vel and FCD was determined from d 3 till d 30 of life. OPS imaging was applied to the upper arm near the axilla, images were stored on videotape and analyzed off-line with the CapiScope Program.Results There were 17 episodes of proven infections (PosInf) with either increased C-reactive Protein or increased interleukine-6. The day when antibiotic treatment was started was defined as d 0 of infection and the evaluation was concentrated on five days before (d -5 until d -1) and five days after (d +1 until d +5). In nine cases the suspected infection was not confirmed biochemically (NegInf). Four infants had no episode of infection for entire time. In PosInf we found a statistical significant decrease in FCD from d -5 to d -1 (mean (95% CI) 231 (187 - 236) cm/cm2 versus 234 (190 - 257) cm/cm2 ; p = 0,0127), but not for NegInf ( p = 0,58). RBC Vel did not change from d -5 to d -1 nor during infection.Conclusion A decreasing FCD correctly identified episodes of infections already one day earlier than changes in laboratory parameters. OPS-Imaging could be used for early diagnosis of secondary infection in preterm infants. However, these changes in FCD during infection are not represented by absolute values, but must be identified by daily intra-individually.

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.

Aims: The study investigates the influence of gestational age (GA), Apgar, pH-value, blood pressure and indicators for infection on the success of indomethacin in closing a PDAMethods: All 118 preterm infants treated with indomethacin between 1997–2002 sorted in following therapeutic outcome groups: Success: A haemodynamic sig. PDA was closed by (maybe multiple) treatments with indomethacin or became haemodynamic not sig. At the end of the observation period the PDA was closed. Non-success: A haemodynamic sig. PDA was not closed by (maybe multiple) application of indomethacin. At the end of the observation period the PDA was haemodynamic significant. A logistic model was created to analyse GA, Apgar 10min, minimal pH-value of the day indomethacin was started, elevated CRP as indicator for infection, maximal CRP-value, microbiol growth, endotracheal colonisation with Ureaplasma urealyticum (Uu) and blood pressure. To account for the age dependency of blood pressure a new variable (MAD-deviation) was calculated: The MAD deviation is the difference of mean arterial pressure from the reference value which corresponds to the weeks of GA.Results: 85 (72%) of the 118 preterm infants were treated successfully, 22 (19%) of the 33 treatment failures received surgical ligation, 5 died with PDA, 6 were transferred with PDA (3 because of NEC). Higher GA (p= 0,0001) and higher MAD-deviation (p= 0,04) increase the chance of a successful medical treatment (Odds Ratio (OR) 2,27/1,22). (Mean-Success 27,8± 2,3 weeks/10,3±6,6mmHg; Mean non-success 25,2±1,8 weeks/6,4±3,6mmHg). In non-success group the blood pressure amplitude was significant lower than in the success-group (16±4,8 mmHg vs. 20±6,3 mmHg; p= 0,0001).The chance of successful medical treatment will decrease if there is an endotracheal colonisation with Uu (p= 0,028/OR= 0,165). Surprisingly pos. microbiological cultures are associated with a higher success rate of indomethacin treatment (OR= 7,2/p= 0,011). No association with treatment outcome were found for pH, Apgar and CRP.Conclusion: Gestational age remains the main determining factor for success of indomethacin. The low mean arterial pressure in treatment failures might be indicative of a higher shunt volume. Chronic inflammation with Uu might cause prostaglandin activation which impedes the closure of the PDA. Taking these risk factors for treatment failure in account, might help in the decision whether to ligate the PDA surgically or try repeated courses of indomethacin.