Scripties UMCG - Rijksuniversiteit Groningen
English | Nederlands

The course of cerebral, renal, and splanchnic oxygen tissue extraction in preterm infants in the first 48 hours after the diagnosis of a clinical sepsis

(2012) Schat, T.E.

Sepsis is an important cause of circulatory failure in newborn infants admitted to the neonatal intensive care unit (NICU) and is associated with severe morbidity and mortality. Conventional hemodynamic parameters are insufficient to detect circulatory failure in these infants in a timely manner. Near infrared spectroscopy (NIRS) is a non-invasive method that can be used to measure the regional tissue oxygenation and calculate the fractional tissue oxygen extraction (FTOE), an indicator of tissue perfusion. Since cerebral perfusion could be maintained due to cerebral autoregulation in infants with sepsis at risk of circulatory failure, monitoring of the oxygenation of somatic organs might give a better impression of systemic blood flow in these infants.
To analyze the course of cerebral, renal, and splanchnic FTOE (cFTOE, rFTOE, sFTOE) in preterm infants in the first 48 hours after the diagnosis of a sepsis.
As part of the NEonatal Monitoring of tissue Oxygenation in newborn infants at risk of circulatory failure (NEMO) study, preterm infants, who were admitted to the Neonatal Intensive Care of the University Medical Center Groningen (UMCG) between August 2011 and June 2012, were selected. Inclusion criteria consisted of a gestational age < 32 weeks and a clinically suspected sepsis. Hemodynamic parameters were collected prospectively. After informed consent was obtained, NIRS monitoring was started within 24 hours after the diagnosis of a sepsis and was continued for 48 hours. Neonatal NIRS-Somasensors were placed on the left frontoparietal side of the newborns head, the left posterior flank between T10 and L2, and below the umbilicus. To identify the course of cFTOE, rFTOE, and sFTOE in the first 48 hours after diagnosis, mean FTOE values were calculated every 3 hours for 48 hours. We related the course in the first 24 hours and between 24 and 48 hours after diagnosis to blood culture positivity, to the administration of dopamine and dobutamine and to conventionally used hemodynamic parameters.
Fourteen infants were included with a mean gestational age of 28 weeks (standard deviation (SD) 2), a mean birth weight of 1088 grams (SD 337) and a mean postnatal age at clinical presentation of 11 days (SD 11). sFTOE measurements were not available in three infants. The blood culture was positive in six infants. Three infants received dopamine and dobutamine for circulatory support. Median cFTOE, rFTOE, and sFTOE in the first 24 hours after diagnosis were 0.21 (range -0.03– 0.60), 0.32 (range 0.04 – 0.83), and 0.55 (range 0.07 – 0.82), respectively. Median cFTOE, rFTOE, and sFTOE values between 24 and 48 hours were 0.22 (range -0.04 – 0.52), 0.34 (range 0.08 – 0.83), and 0.56 (range 0.29 – 0.83), respectively. rFTOE was significantly lower in the first 24 hours after diagnosis in infants with a positive blood culture compared to infants with a negative blood culture. Furthermore, significant higher cFTOE values were seen during the entire study period in infants who received dopamine and dobutamine. Finally, significant positive correlations were observed between cFTOE and heart rate (r=0.482) and sFTOE and pH (r=0.636). A significant negative correlation was found between rFTOE and pH (r=-0.291).
Cerebral perfusion seems to be maintained within the normal range in the first 48 hours after diagnosis of a sepsis in preterm infants. On the contrary, somatic perfusion seems to be decreased, possibly to ensure an adequate perfusion to the brain. Further studies in a larger population are necessary to confirm these results.

To top