Enteral feeding and caloric intake in neonates after cardiac surgery

BACKGROUND

Adequate enteral nutrition may be difficult to achieve early in neonates after cardiac surgery, but it is essential for growth, wound healing, and immune function.

OBJECTIVE

To assess caloric intake in neonates receiving enteral nutrition after surgery.

METHODS

A retrospective chart review was conducted of daily enteral caloric intake in the cardiac intensive care unit of a tertiary children's hospital. Data on the institution of enteral feeding and the discontinuation of parenteral nutrition were assessed for full-term neonates who had undergone cardiac surgery.

RESULTS

Caloric intake was assessed in 100 patients, 52 with biventricular cardiac defects and 48 with a functional single ventricle. The median duration of stay in the cardiac intensive care unit was 13 days (range, 4-69), and patients received enteral feeding exclusively for a median of 5 days (range, 1-43). In total, 705 patient days were evaluated. The median caloric intake per day was 93 kcal/kg (range, 43-142). A goal of 100 kcal/kg was achieved for 48.4% of patient days and 120 kcal/kg for only 19.7% of patient days. Median weight change for the period of enteral feeding was -20 g (range, -775 to 1485 g).

CONCLUSIONS

Enteral feeding alone is often suboptimal after neonatal cardiac surgery. New strategies to improve caloric intake may enhance postoperative recovery.

Naphthol- and resorcinol-based azo dyes as metal ion complexants in aqueous biphasic systems

Aqueous biphasic systems (ABS) are comprised of both a polymer-rich phase (e.g., polyethylene glycol, PEG) and a salt-rich phase [e.g., (NH4)2SO4] such that both phases are 80% water on a molar basis. ABS have demonstrated applications as environmentally-friendly methods to separate relatively hydrophobic anionic species, such as pertechnetate and mercury halide anionic complexes, from high ionic strength solutions although partitioning of hydrated metal ions, such as Fe3+ and actinides, to the PEG-rich phase is negligible without the addition of a metal ion complexant to the system. Four naphthol- or resorcinol-based dyes; 1-(2-pyridylazo)-2-naphthol (PAN), 1-(thiazolylazo)-2-naphthol (TAN), 4-(2-pyridylazo)-resorcinol (PAR) and 4-(2-thiazolylazo)-resorcinol (TAR), each incorporating a naphthol or resorcinol with an ortho azo functional group, have been studied as metal ion extractants in ABS as a function of pH. In the PEG-2000/ (NH4)2SO4 ABS, the distribution ratios of Fe3+, Co2+ and Ni2- were enhanced by several orders of magnitude at high pH in contrast to the behavior of Cs+, Cd2+ and Eu3+ whose partitioning behavior was largely unaffected by the presence of these extractants at any pH. The three extracted metal ions, Fe3+, Co2+ and Ni2+, could be stripped by contact with a fresh salt phase at low pH.

Radiant cured polymer optical waveguides on printed circuit boards for photonic interconnection use

We report a simple technique for patterning channelized optical waveguides on standard electronic printed circuit card material. The technique exploits the abundance of transparent, radiant-curing polymer adhesives in the fiber optics and the dental industries. The process is compatible with standard printed circuit card fabrication processes; hence its applicability to optical interconnection scenarios. We report typical guide losses in the 0.4-0.6-dB/cm range. Measurements were made using an automated noninvasive, nondestructive technique, also briefly described here. Simple structures, such as splitters, bus lines, and 90 degrees bends were fabricated and are described. Optical coupling to the waveguides from packaged devices is also discussed.

Pulse mode saturation properties of photomultiplier tubes

The response of an RCA-4522 photomultiplier tube (35ET bialkali photocathode, 14 dynode stages) in the saturation region has been studied as a function of ambient background light intensity, photocathode illumination area, magnetic field orientation, and ambient temperature. These studies were made using various high-speed pulsed light sources. It is found that the phototube's response does vary with some of these parameters (in particular, photocathode temperature effects). However, its response is reproducible and highly successful operation in this region is possible through a series of calibrations.