NIRS - Normal values in newborn

Abstract presented at AAP conference 2009 (Washington, DC)

Cerebral and Somatic NIRS Oximetry in Normal Newborn.

Nicole P. Bernal, George M. Hoffman, Nancy S. Ghanayem, Marjorie K. Arca.

(Editorial note: Somatic = renal, in this abstract)

Purpose: Establishing normal value for newborn during rest and feeding.

Methods:

44 term newborns

Probes in forehead and right flank (T12-L2) over right kidney

Reading collected continuously for 2-8 hrs (1-3 feeds)

Data captured at 0.1 Hz (i.e. every 10 sec) and averaged to 1 min.

Somatic - Cerebral difference - as an index of relative regional oxygen extraction.

Statistics:

Time series fixed effects & Mixed model regression techniques (Stata 10.1) for the following -

Difference over time

Difference between babies

Difference between states (resting vs. feeding)

Results:

n=26

Age 44 +/- 28 hrs

Wt 3.2 +/- 0.48 kg

Mean duration of observation 417 /- 255 min

At rest:

Average Cerebral rSO2 = 77.9

SD:

Overall +/- 8.5

Within babies +/- 6.1 (16-95)

Between babies +/- 6.3 (64-87)

Average Renal rSO2 = 86.8

SD:

Overall +/- 8.1

Within babies +/- 5.9 (40-95)

Between babies +/- 5.8 (74-94)

Average Diff. between Renal to Cerebral rSO2 indices = 8.9%

SD:

Overall +/- 9.4

Within babies +/- 8.0

Between babies +/- 5.2

During feeding:

Cerebral rSO2 index decreased (78.6 +/- 8.4 >>> 78.0 +/- 9.0; p 0.023)

Renal rSO2 index did not change (87.0 +/- 8.1 >>> 87.3 +/- 8.0; p=0.31)

Diff. between Renal to Cerebral rSO2 indices increased (8.5 +/- 9.5 >>> 9.2 +/- 9.1; p=0.014)

Over the first 120 hrs after birth, (Figure 2)

Average Cerebral rSO2 index slightly decreased (p <>

Average Renal rSO2 index was unchanged.