Interference of heart and transcutaneous oxygen monitoring in the measurement of bioelectrical impedance analysis in preterm newborns

How is bioelectrical impedance used in neonatal intensive care? A scoping review

Poor growth and nutrition management in the neonatal period can have a negative impact upon both the short- and long-term outcomes for the infant. Improvements in bioelectrical impedance technology and accompanying licencing agreements now make this enhanced device available for use in infants as small as 23 weeks gestational age. An exploration of this technology and its use is now timely. The aim of the scoping review was to answer the following question: in preterm and sick term infants in the neonatal intensive care unit, how is bioelectrical impedance being utilized, in what situations, and when? The scoping review was conducted using Arksey and O'Malley's (Int J Soc Res Methodol 8(1):19-32, 2005) framework. Forty-nine papers were initially identified and 16 were included in the scoping review. Three studies were experimental designs, and 13 were observational studies. The review found that BIA was used in neonatal intensive care in three main ways, for, (1) fluid status evaluation, (2) as a measure of adequate nutrition and growth, (3) to validate the technology as an outcome measure in neonates.

CONCLUSION

There is a paucity of recent robust research papers which investigate the use of bioelectrical impedance in preterm neonates. Available evidence spans a range of 30 years, with technological advancement reducing the application of older studies to the modern neonatal setting. Although this technology may be helpful for decision-making around fluid management and nutrition, in preterm infants, robust evidence is needed to demonstrate the clinical benefit of bioelectrical impedance beyond that of usual care.

WHAT IS KNOWN

• Clinical decisions regarding neonatal nutrition and fluid management are currently based upon the interpretation of vital signs, fluid balance, weight trend, biochemical markers, and physical examination. • Bioelectrical Impedance Analysis (BIA) is a non-invasive method of assessing body composition which is now available to be used in infants as small as 23 weeks gestation.

WHAT IS NEW

• Bioelectrical Impedance has been used in three main ways in the NICU, for fluid status evaluation, for measuring nutrition and growth and to validate BIA as an outcome. • There is a lack of recent robust research data to support the use of the device within clinical decision making in neonatal intensive care.

Evaluation of the bioimpedance technique in newborns with a focus on electrode positioning: A prospective, randomized, crossover study

BACKGROUND

Bioelectrical impedance analysis (BIA) is a good alternative for assessing total body water in newborns. However, the lack of standardization of the method for its use in the neonatal population raises doubts about its reliability and external validation.

OBJECTIVE

To compare resistance (R) and reactance (Xc) values measured by BIA with electrodes placed in the anatomical position and with electrodes placed at 5-cm intervals.

METHOD

Prospective, randomized, crossover study, in which R and Xc values were measured using monofrequency BIA. The choice of the first position of the electrodes to be analyzed in each NB was performed by a simple randomization, and subsequent measurements were performed in rapid succession. The calculated sample size was 203 evaluations. The paired t test was used to compare the means of R and Xc, and the Bland-Altman plot and linear regression were used to analyze how much the measured values were influenced by the electrode position.

RESULTS

Significant differences were found in the R (855.25 ± 147.79 vs 618.95 ± 93.28 Ω) and Xc (50.94 ± 17.34 vs 39.76 ± 18.35 Ω) values measured with electrodes in the anatomical position and at 5-cm intervals, respectively. The electrodes in the anatomical position produced R and Xc values 37.7% and 16.6%, respectively, higher on average when compared with 5-cm intervals.

CONCLUSIONS

The distance between the electrodes influences the measurement of R and Xc by BIA. These results highlight the importance of defining a standard for the placement of electrodes in newborns for the use of these measures in neonatal clinical practice.

Using bioelectrical impedance analysis to compare the treatment of edema with the Unna's boot and noncompression in individuals with venous ulcers

Venous insufficiency is related to aging. Edema, pathological evolution of venous insufficiency, favors the appearance of venous ulcers as the main complication. Leg ulcers can be treated with compression, the Unna's boot being one of them, and noncompression therapies (conventional dressing). Bioelectrical impedance analysis accurately measures the patient's body fluids. The objective of this study was to evaluate the edema evolution of the venous ulcer-affected lower limb by means of electric bioimpedance with the use of Unna's boot and noncompressive dressing. Fifteen legs with active ulcers were treated from September 2014 to December 2016. The legs were treated with Unna's boot and noncompression therapies on different days with randomized order of events. Bioimpedance was performed in the morning and afternoon to evaluate the increase in edema over the day. All patients were female with ages ranging from 50 to 76 years (mean age: 63 years). According to bioimpedance, the volume of the legs increased with both types of therapy. However, compression therapy was significantly more effective than noncompression therapy. Bioimpedance confirmed that compression therapy (Unna's boot) gives better results than noncompression therapy in relation to the formation of edema over a day in patients with chronic venous ulcers.