Capillary refill time (CRT) is a simple means of cardiovascular assessment which is widely used in clinical care. Currently, CRT is measured through manual assessment of the time taken for skin tone to return to normal colour following blanching of the skin surface. There is evidence to suggest that manually assessed CRT is subject to bias from ambient light conditions, a lack of standardisation of both blanching time and manually applied pressure, subjectiveness of return to normal colour, and variability in the manual assessment of time. We present a novel automated system for CRT measurement, incorporating three components: a non-invasive adhesive sensor incorporating a pneumatic actuator, a diffuse multi-wavelength reflectance measurement device, and a temperature sensor; a battery operated datalogger unit containing a self contained pneumatic supply; and PC based data analysis software for the extraction of refill time, patient skin surface temperature, and sensor signal quality.Through standardisation of the test, it is hoped that some of the shortcomings of manual CRT can be overcome. In addition, an automated system will facilitate easier integration of CRT into electronic record keeping and clinical monitoring or scoring systems, as well as reducing demands on clinicians.Summary analysis of volunteer (n = 30) automated CRT datasets are presented, from 15 healthy adults and 15 healthy children (aged from 5 to 15 years), as their arms were cooled from ambient temperature to 5°C. A more detailed analysis of two typical datasets is also presented, demonstrating that the response of automated CRT to cooling matches that of previously published studies.

Inter-hospital transport of premature infants is increasingly common, given the centralisation of neonatal intensive care. However, it is known to be associated with anomalously increased morbidity, most notably brain injury, and with increased mortality from multifactorial causes. Surprisingly, there have been relatively few previous studies investigating the levels of mechanical shock and vibration hazard present during this vehicular transport pathway. Using a custom inertial datalogger, and analysis software, we quantify vibration and linear head acceleration. Mounting multiple inertial sensing units on the forehead and torso of neonatal patients and a preterm manikin, and on the chassis of transport incubators over the duration of inter-site transfers, we find that the resonant frequency of the mattress and harness system currently used to secure neonates inside incubators is ~9Hz. This couples to vehicle chassis vibration, increasing vibration exposure to the neonate. The vibration exposure per journey (A(8) using the ISO 2631 standard) was at least 20% of the action point value of current European Union regulations over all 12 neonatal transports studied, reaching 70% in two cases. Direct injury risk from linear head acceleration (HIC15) was negligible. Although the overall hazard was similar, vibration isolation differed substantially between sponge and air mattresses, with a manikin. Using a Global Positioning System datalogger alongside inertial sensors, vibration increased with vehicle speed only above 60 km/h. These preliminary findings suggest there is scope to engineer better systems for transferring sick infants, thus potentially improving their outcomes.

Background Skin blood flow is highly variable accounting for 5-33% of cardiac output (Kenny 2011), and is often one of the first organs to change during early shock. In children, capillary refill time (CRT) is a crucial component of cardiovascular assessment and, despite marked variability, it remains a useful predictor of significant illness in children (Tibby 1999, Craig 2010. To allow development of new technologies to assess cutaneous blood flow a simple but valid model of reduced perfusion is required. Aims 1) Develop an acceptable paediatric model for reduced cutaneous perfusion, 2) Assess the ability of laser Doppler (LD) and green light photoplethysmography (gPPG) to detect these changes. Participants and methods Healthy children (5-17 years) were recruited. Simultaneous forearm LD blood flow and gPPG CRT measurements were obtained at baseline (room temperature) and during localised cooling of the arm (4 o C microenvironment). gPPG CRT was measured using a reflectance mode gPPG coupled with an automated pressure application system. Results Ten children completed the study over a typical timeframe of 45 min. Median LD blood flow decreased significantly from baseline during the cold exposure (P < 0.01) whilst gPPG CRT increased (P < 0.05) (see Figure).Conclusion This model appears to be both feasible and acceptable to children. Confirmation of reduced blood flow is observed using LD. Our automated CRT utilising gPPG appears useful in this model. After additional validation, the suitability and usefulness of automated CRT could be assessed in paediatric clinical trials with a view to improving recognition of early shock.

count, glucose, proteins and blood leukocyte and differential count, CRP, PCT were studied at the time of suspected ventriculitis. CD64in was measured by flow cytometry (Trillium Diagnostics, LLC, Brewer, ME). Wilcoxon-test was used for comparison between groups and diagnostic accuracy determined by the area under the ROC curves (AUC) was defined for each marker.Results Thirty-three episodes of clinically suspected ventriculitis in twenty-one children (male 14, female 7, median age: 9 months, range: 8 days-167 months) were observed during a 26-month period. Episodes were classified into those with microbiologically proven ventriculitis (13 episodes: 9 Gram-positive and 4 Gram-negative) and those with microbiologically negative CSF (20 episodes). CD64in was the only CSF marker that could differentiate between groups (p = 0.0003); its diagnostic accuracy was 0. Background Capillary refill time (CRT) is widely used in paediatrics to assess cardiovascular status, especially during the early phase of shock when skin perfusion is reduced, but is prone to marked variability (Pickard 2011). CRT is used in early warning scores aimed at identifying and quantifying severity of illness and effectiveness of resuscitation efforts (APLS 2011). CRT is one of the most sensitive predictors of dehydration and bacterial infection in children, and it correlates with markers of end organ perfusion (Tibby 1999, Craig 2010. Automating CRT using photoplethysmography (PPG) with a pressure application system may improve its accuracy and reliability. Aim Establish if a green light PPG and a pressure application system could detect an increase in CRT after skin cooling. Methods Healthy children (aged 5-18 years) underwent selective arm cooling as a model of reduced skin blood flow through the microcirculation (Roustit and Cracowski 2013). An automated green light PPG CRT device was attached to their forearm and their arm was then placed into a refrigeration device at 4°C for 20 min. Using 7 min rolling averages, the trough (early phase) and peak (late phase) CRT values were compared. Ethical approval was given. Results Participants (n = 16) demonstrated a significant increase in CRT (as assessed by green PPG) in 15 of the 16 cases (P < 0.001)(see Figure). Conclusions It is feasible to measure changes in the microcirculation of children using an automated device that mimics CRT testing. Further work in clinical settings is needed to establish if this has clinical utility. Background Neonatal extracorporal membrane oxygenation (ECMO) for pulmonary failure is characterised by small cannulas and low flow rates. Novel rotary pumps with diagonal blood flow and a reduced priming volume are now available. Bench studies in different in-vitro models and the short-term use for cardio-pulmonary bypass in paediatric patients are encouraging. However, little data exist on the effect of these devices on hemolysis in the defined group of neonates with respiratory failure. Design We prospectively studied circuit settings, plasma-free haemoglobin (fHb), lact...