An hour-specific nomogram for transcutaneous bilirubin values in term and late preterm Hispanic neonates.

We sought to determine percentile values for hour-specific transcutaneous bilirubin (TcB) measurements in Hispanic neonates during the first 72 hours of age. Neonates with gestational age >or= 35 weeks and body weight >or= 2100 g were included. All neonates were screened with JM-103 TcB measurements at a minimum of every 24 hours by nursing personnel, and only TcB values obtained in Hispanic neonates with postnatal ages of 10 to 74 hours were analyzed. The 5th, 25th, 50th, 75th, and 95th percentile curves were determined. These data were compared with a previously published TcB nomogram predominantly composed of white, non-Hispanic neonates. A total of 3284 TcB values were measured in 2005 neonates. A nomogram was constructed for this exclusively Hispanic population, identifying the 5th, 25th, 50th, 75th, and 95th percentile curves. The 95th percentile values at 24, 48, and 72 hours were 7.6, 11.0, and 12.4 mg/dL, respectively. The comparison between our results and those of the previously published study indicated that small but consistent differences between the two study populations were apparent, with the Hispanic neonates having significantly higher TcB values at the majority of time points analyzed. These observations were made despite a higher proportion of neonates >or= 40 weeks' gestation ( p < 0.001) and a lower proportion exclusively breast-fed ( p < 0.001) in the Hispanic population versus those in the previous study. Although higher bilirubin levels for certain populations are well documented, such differences in Hispanic neonates have not been confirmed. A TcB nomogram for Hispanic neonates is presented as a tool that will aid the clinician in the management of jaundice for this population. Compared with the previous study, this report indicates that although differences were relatively small, significantly higher TcB values were observed in the Hispanic population.

Linear and nonlinear analysis of heart rate variability during propofol anesthesia for short-duration procedures in children.

OBJECTIVE: To determine whether heart rate variability metrics provide an accurate method of monitoring depth of anesthesia, assessing the response to painful stimuli, and assessing neuroautonomic regulation of cardiac activity in children receiving propofol anesthesia for short-duration procedures. DESIGN: Prospective, case series. SETTING: Sixteen-bed pediatric intensive care unit, oncology unit, and endoscopy suite in a tertiary care children's hospital and ophthalmology examination rooms in an associated eye institute. PATIENTS: Thirty-three pediatric patients undergoing propofol anesthesia for short procedures. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Heart rate variability metrics studied included mean, SD, low- and high-frequency power, detrended fluctuation analysis (represented by correlation coefficient, alpha), and approximate entropy. Compared with the initial anesthetized state, we found increased heart rate SD (3.17 +/- 1.31 vs. 7.05 +/- 0.26 bpm, p <.0001), heart rate low-frequency power (3.69 +/- 0.36 vs. 4.48 +/- 0.41 bpm(2)/Hz, p <.0001), heart rate low-/high-frequency ratio (1.47 +/- 0.26 vs. 1.26 +/- 0.24, p =.001), and heart rate alpha (1.12 +/- 0.24 vs. 1.35 +/- 0.21, p <.0001) during painful procedure. Mean heart rate (105.8 +/- 13.4 vs. 101.5 +/- 12.4 bpm, p =.005) and heart rate approximate entropy decreased with painful procedure (0.75 +/- 0.19 vs. 0.53 + 0.16, p <.001), whereas there was no significant change in heart rate high-frequency power (3.04 +/- 0.63 vs. 3.16 +/- 0.71 bpm(2)/Hz, p =.26). CONCLUSIONS: We conclude that power spectral analysis of heart rate variability may be an accurate and clinically useful measure of depth of propofol anesthesia. We speculate that high-frequency heart rate power during propofol anesthesia correlates with depth of anesthesia, whereas low-frequency power allows for assessment of the patient's sympathetic response to pain.

Interactive Web sites for families and physicians of pediatric intensive care unit patients: a preliminary report.

OBJECTIVE: To describe our experience with a Web-based communications program for the patients, families, and referring physicians of patients admitted to our pediatric intensive care unit. DESIGN: Prospective descriptive case series for a 32-month period from April 2000 through January 2003. SETTING: Sixteen-bed multidisciplinary medical-surgical pediatric intensive care unit (PICU). SUBJECTS: Seventy-three of 78 patients admitted to the PICU for > or =3 days and their families participated in the study, along with 26 referring physicians. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: We found that 77% (474/619) of surveyed family members and friends thought that the Web page helped them share information, 13% (82/619) were unsure, and only <1% (4/619) thought it did not help them share information. When comparing respondents who thought the Web page helped them share information with those who did not or those who did not know, internet use was significantly associated with thinking that the Web page helped them share information (p =.0007). Seventy-three percent (19/26) of physicians thought that Web page-based communication was easier than present methods to convey patient information, and 62% (16/26) replied that the Web-based communication met their expectation. Fifty-four percent (14/26) of physicians thought they were more likely to refer patients to our PICU because of the Web-based communication; this was significantly associated with physician assessment that the Web-based communication was easier than the present methods of communicating with referring physicians (p =.003). CONCLUSIONS: We conclude that both families and referring physicians find Web-based communications during a child's PICU hospitalization to be very helpful. We suggest that the Web-based PICU communications be developed and studied for both medical and economic impact.

Chromatographic studies of unusual on-column degradations of aniline compounds on XBridge Shield RP18 column in high pH aqueous mobile phase.

This paper reports unusual on-column degradations of aniline compounds on Waters XBridge Shield RP18 column when ammonium hydroxide in water and acetonitrile were used as mobile phases in liquid chromatography. The change of the level of on-column degradation of a model compound (Compound 1) with time was observed in the first fifteen injections when started at 60 °C. During a subsequent cooling program from 60 °C to 10 °C with a 10 °C interval, the levels of the degradation products of Compound 1 changed with the change of temperature and reached a maximum at 40 °C. The on-column degradation of Compound 1 was observed when started at 10 °C in the first injection, however, the magnitude of the change of the level of on-column degradation of Compound 1 with time in the first fifteen injections was much smaller than that at 60 °C. During a subsequent heating program from 10 to 60 °C with a 10 °C interval, the levels of the degradation products of Compound 1 increased with the increase in temperature but without a maximum. The change of the degradation product levels of this model compound in the heating process is not super-imposable with that in the cooling process, which demonstrates the degree of the degradation also depends on the heating or cooling process. Column history studies demonstrated that the on-column degradation of Compound 1 changed dramatically on the used columns at both starting temperatures while the dependency of heating and cooling processes on on-column degradation still existed. The unusual on-column degradation of Compound 1 on the used columns can be regenerated in a very similar fashion with an acetic acid column-wash procedure, but is not identical to that on the new column. Similar degradations of other commercially available aniline compounds were also observed with this high pH aqueous mobile phase system.

Pulse oximetry screening at 4 hours of age to detect critical congenital heart defects.

OBJECTIVE: The purpose of this prospective study was to assess the feasibility and reliability of pulse oximetry screening to detect critical congenital heart defects in a newborn nursery. METHODS: The study was performed in a large urban hospital with an exclusively inborn population. Stable neonates who had a gestational age of >or=35 weeks and birth weight of >or=2100 g and in whom a critical congenital heart defect was not suspected were admitted to the newborn nursery. When the 4-hour pulse oximetry reading was <96%, pulse oximetry was repeated at discharge, and when the pulse oximetry reading remained at persistently <96%, echocardiography was performed. RESULTS: Of 15299 admissions to newborn nursery during the 12-month study period, 15233 (99.6%) neonates were screened with 4-hour pulse oximetry. Pulse oximetry readings were >or=96% for 14374 (94.4%) neonates; 77 were subsequently evaluated before discharge for cardiac defects on the basis of clinical examination. Seventy-six were normal, and 1 had tetralogy of Fallot with discontinuous pulmonary arteries. Pulse oximetry readings at 4 hours were <96% in 859 (5.6%); 768 were rescreened at discharge, and 767 neonates had a pulse oximetry reading at >or=96%. One neonate had persistently low pulse oximetry at discharge; echocardiography was normal. Although 3 neonates with a critical congenital heart defect had a 4-hour pulse oximetry reading of <96%, all developed signs and/or symptoms of a cardiac defect and received a diagnosis on the basis of clinical findings, not screening results. CONCLUSIONS: All neonates with a critical congenital heart defect were detected clinically, and no cases of critical congenital heart defect were detected by pulse oximetry screening. These results indicate that pulse oximetry screening does not improve detection of critical congenital heart defects above and beyond clinical observation and assessment. Our findings do not support a recommendation for routine pulse oximetry screening in seemingly healthy neonates.

Physiologic data acquisition system and database for the study of disease dynamics in the intensive care unit.

OBJECTIVE: To describe a real-time, continuous physiologic data acquisition system for the study of disease dynamics in the intensive care unit. DESIGN: Descriptive report. SETTING: A 16-bed pediatric intensive care unit in a tertiary care children's hospital. PATIENTS: A total of 170 critically ill or injured pediatric patients. INTERVENTIONS: None. MAIN OUTCOME MEASURES: None. RESULTS: We describe a computerized data acquisition and analysis system for the study of critical illness and injury from the perspective of complex dynamic systems. Both parametric (1 Hz) and waveform (125-500 Hz) signals are recorded and analyzed. Waveform data include electrocardiogram, respiration, systemic arterial pressure (invasive and noninvasive), central venous pressure, pulmonary arterial pressure, left and right atrial pressures, intracranial pressure, body temperature, and oxygen saturation. Details of the system components are explained and examples are given from the resultant physiologic database of signal processing algorithms and signal analyses using linear and nonlinear metrics. CONCLUSIONS: We have successfully developed a real-time, continuous physiologic data acquisition system that can capture, store, and archive data from pediatric intensive care unit patients for subsequent time series analysis of dynamic changes in physiologic state. The physiologic signal database generated from this system is available for analysis of dynamic changes caused by critical illness and injury.