Hemodynamic indexes in newborns using the arteriovenous oxygen content difference.
OBJECTIVE
To determine in peripheral blood samples of newborns (NB) cardiac output (Q), cardiac index (CI), systemic vascular resistance index (SVRI), and effective oxygen transport (EO2T), through arteriovenous oxygen content difference ([C(a-v) O2]).


METHODS
Comparative survey.


METHODS
Healthy NBs and NBs in intermediate care in third level medical attention units.


METHODS
Forty-seven NB (17 pre-term) were prospectively studied in August and September/1995. A blood sample of 0.4 mL was taken from the umbilical or femoral vein and from the umbilical, radial or femoral artery. The inferencial statistics were done with a t test and Pearson's correlation coefficient. Significance was considered if p < 0.05.


RESULTS
Cardiac output ranged from 0.3 to 1.4, mean = 0.6 L/min +/- 0.24 (+/- SD); CI ranged from 1.8 to 6.4 L/min/m2 body surface area (mean = 3.3 +/- 1.2); SVRI ranged from 533 to 2,391 dyne/sec/cm-5/m2 BSA (mean = 1,317 +/- 494); EO2T ranged from 307 to 1,017 mL/min/m2 BSA (mean = 549 +/- 186); the [C(a-v) O2] ranged from 3.1 to 10.7% in volume (mean = 6.8 +/- 2.1). No significant differences were found in Q between pre-term and full-term NB nor was there any correlation between Q and gestational age.


CONCLUSIONS
The [C (a-v)O2] is a good alternative to obtain indexes in peripheral blood of NB without cardiopathy, whenever other less invasive and more sophisticated methods are unavailable. In order to calculate the indexes in critically-ill patients, it is necessary to measure O2 consumption prior to applying this method.
Tapia-Rombo
C A
CA
Servicio de Neonatología del Hospital General Centro Médico La Raza, México, D.F. México.
Munayer-Calderon
J
J
Salazar-Acuña
A H
AH
Alvarez-Vazquez
E
E
de-los-Santos-Soriano
H
H
Regalado-Rebolledo
H G
HG
Sanchez-Garcia
L
L
Salas-Lopez
M E
ME
D001724:Birth Weight; D002302:Cardiac Output; D005260:Female; D005865:Gestational Age; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D014655:Vascular Resistance
D010100:Oxygen