Nasal airflow and thoracoabdominal motion in children using infrared thermographic video processing.

The assessment of apnea and asynchronous breathing requires the application of a facemask connected to a pneumotachograph and inductive transducer bands placed around the chest wall. These contact devices may alter the breathing pattern and are difficult to implement, especially in infants and children. This study validates a contactless image-processing system that simultaneously retrieves breath-related thermal variations from nasal, ribcage, and abdomen regions of interest (ROI) from infrared thermographic video recordings of children. Thermographic videos were obtained in 17 supine, spontaneously breathing unsedated children (0.33-13.75 years), including 8 patients with respiratory pathology. Representative thermographic signals were obtained from each ROI on a frame-by-frame basis. Cronbach's Alpha reliability coefficient assessed the correlation between control nasal pressure period, the visually scored respiratory rate and the fundamental period in the frequency domain of thermographic signals. A cross-correlation function calculated the time delay and the phase angle between ribcage and abdomen variability. A Cronbach's Alpha value of 0.976 (0.992-0.944 95% CI) suggests a small-scale measurement error between thermographic and control periods. The ribcage-abdomen time delay in children with respiratory disease (-0.42 ± 0.707 sec) significantly differed from healthy children (0.22 ± 0.426 sec, P = 0.0125). This novel system reliably acquired time-aligned nasal airflow and thoracoabdominal motion estimates without relying on attached sensor performance and detected asynchronous breathing in pediatric patients.

Ventricular assist device application with the intermediate use of a membrane oxygenator as a bridge to pediatric heart transplantation.

Extracorporeal membrane oxygenation and ventricular assist devices are currently used for the treatment of severe heart failure as a bridge to transplantation. The use of ventricular assist devices is limited by respiratory failure. We report a patient with severe heart failure and respiratory failure who was successfully bridged to transplantation, initially with extracorporeal membrane oxygenation and afterwards with an EXCOR biventricular assist device (Berlin Heart AG, Berlin, Germany) and a membrane oxygenator (Jostra Quadrox D, Maquet Cardiopulmonary, AG Hirrlingen, Germany) intercalated in the outflow cannula of the left pump.

Airway pressure alters wavelet fractal dynamics and short-range dependence of respiratory variability.

We sought to quantify the autocorrelation properties and fractal dynamics of interbreath interval (IBI) variability to see if short-term airway pressure (Paw) increases affected scaling behaviour. Data were collected in anaesthetised children at basal (Ba), medium (Me) and high (Hi) Paw. Consistent with short-range dependence, the autocorrelation function was significant at five (Ba) to three (Hi) lags but lost its significance at Me. Wavelet variance assessed in IBI suggests biphasic power law correlations with scale. In the low scale window for the crossover point, the positive exponents differed from the uncorrelated components in surrogate series at Ba (p<0.007) and Hi (p<0.002), supporting the existence of deterministic, persistent properties. On the contrary, white noise output was captured at Me and an antipersistent, random pattern characterised the high scale window. Intermediate Paw seems to reset the system to a stochastic, less complex behaviour while basal and high Paw would amplify the gain of non-random, correlated processes. This Paw-dependent modulation of IBI fractality and short-term memory indicates that integrative breathing control has an inherent multi-scaling structure.

Anesthetic uptake of sevoflurane and nitrous oxide during an inhaled induction in children.

The uptake of sevoflurane and nitrous oxide (N(2)O) was characterized during the mask induction of anesthesia in healthy children. We assessed concentration and second gas effects by determining the influence of two different inspiratory N(2)O concentrations on the rate at which the estimated alveolar concentration (FA) increased to the inspired gas concentration (FI). Eighteen children aged 4-12 yr old were randomly assigned to receive a 6% sevoflurane mixture with either a large or a small N(2)O concentration with balance O(2). End-tidal and inspiratory concentrations of respiratory and anesthetic gases were continuously assessed during the induction. The FA/FI for the small N(2)O was 0.87 +/- 0.09 (mean +/- SD) and increased to 0.92 +/- 0.08 for the large N(2)O (P < 0.01). Both groups differed significantly at 3, 4, and 5 min. The FA/FI for sevoflurane increased but more slowly than for N(2)O. The mean only differed significantly at 3 min. Equilibration between FA and FI for N(2)O and sevoflurane was attained rapidly. Consistent with their respective blood/gas partition coefficients, the FA/FI for N(2)O increased more rapidly than that for sevoflurane. Increasing FI-N(2)O produced a leftward shift in gas equilibration curves. A concentration effect was confirmed with N(2)O and a brief second gas effect, probably explained by the higher solubility of sevoflurane.

Anaesthetic management of a patient with microvillus inclusion disease for intestinal transplantation.

We report the anaesthetic management of a 3-year-old-child with microvillus inclusion disease undergoing isolated small bowel transplantation. He required long-term total parenteral nutrition which was complicated with numerous episodes of catheter related sepsis. This resulted in thrombosis of the major blood vessels which critically restricted vascular access available for intravenous nutrition, becoming a life-threatening condition for the patient. Haemodynamic, respiratory parameters and urinary output were well preserved throughout the procedure. Besides a transitory increase in potassium following graft revascularization, biochemical changes were small. Anaesthetic management included comprehensive preoperative assessment, central venous angiography to depict accessibility of central and peripheral veins, assurance of additional vascular access through the intraoperative catheterization of the left renal vein, perioperative epidural analgesia and preservation of splanchnic perfusion to ensure implant viability.