NEONATAL SOCIETY ABSTRACTS
Raised blood lactate in infants <30 weeks gestation is a marker of significant periventricular haemorrhage
Presented at the Neonatal Society 2003 Summer Meeting (programme).
Jackson A, Lyon A
Simpson Centre for Reproductive Health, Royal Infirmary Edinburgh, Little France, Edinburgh EH16 4SU
Introduction: Raised lactate has been associated with poor outcome in neonates (1,2), in particular with death and neurodevelopmental abnormalities. This study aimed to determine if a high or rising blood lactate level in infants <30 weeks gestation was specifically associated with the development of significant (grade 3 or 4) periventricular haemorrhage (PVH).
Methods: It is normal practice in our unit to measure lactate at the same time as routine repeated measurements of blood glucose (YSI 2300 Stat plus, Yellow Springs). The first part of this study was a retrospective review of all infants <30 weeks gestation admitted between January 2002 and October 2002. Their maximum lactate, after 6 hours and before 4 completed days of age, was recorded along with the worst cranial ultrasound scan result. This showed a strong association between a blood lactate value >=3 mmol/l and grade 3/4 PVH (table). The next part of the study matched infants <30 weeks gestation, admitted between October 1999 and October 2002, and who had a significant PVH with 2 controls of similar gestation, birthweight and sex who had no or only grade 1 or 2 PVH. For each infant, the lactate value every 6 hours was plotted to create a profile of lactate over time, from 6 hours to 4 completed days of age. Simultaneous values of mean blood pressure, heart rate, and central-peripheral temperature difference were recorded.
Results: Cohort study (n=50):
Of the 4 with lactate >3 but no grade 3 or 4 PVH, 3 had a lactate >3mmol/l immediately pre death.
Case control study (cases n=14 controls n=28):
There was a marked difference between the 2 groups. The controls showed little variation in lactate values, but those with significant PVH showed one of 2 patterns:
1. A high lactate from birth slowly falling, associated with early
2. Lactate rising to a peak (>=3 mmol/l) later in the first 4 days. In some infants there was a definite temporal relationship between the rise in lactate and the scan findings.
There was no correlation between lactate and markers of tissue perfusion.
Conclusions: As this was a retrospective study the timing of the scans was not controlled. It is therefore impossible in many of the cases to relate the timing of the PVH to the rise in lactate. However compared to matched controls, infants with a blood lactate >=3mmol/l in the first 4 days, but out with the first 6 hours, appear to be at high risk of significant periventricular haemorrhage.
1. Deshpande SA, Platt MP: Arch Dis Child Fetal Neonatal Ed 1997 Jan;76(1):F80.
2. Groenendaal F et al: Biol Neonate 2003;83(3):171-6.