Day 1 serum lactate values in preterm infants less than 32 weeks gestation

Abstract

Base deficit and serum lactate concentrations may be important prognostic indicators in preterm infants. We sought to (1) determine the relationship between day 1 serum lactate values and base deficit and (2) determine the relationship between day 1 biochemical parameters and adverse outcome in preterm infants <32 weeks. This was a retrospective study of all patients less than 32 weeks gestation admitted to neonatal intensive care unit over a 6-month period. All blood gases performed during the first 24 h post delivery were analysed. Adverse outcome was defined as death, severe (grade 3 or 4) intraventricular haemorrhage or periventricular leukomalaica on cranial ultrasonography. Patients were excluded if there was a known lethal malformation or cardiac defect. Seventy-two infants had a total of 473 lactate levels performed in the first 24 h. Mean (SD) gestational age was 29 (2.3) weeks, mean (SD) birth weight 1.28 (0.42) kg. Mean (SD) lactate values in first 6 h was 4.63 (3.69), at 12 h 3.08 (2.6), at 18 h 2.47 (2.68) and 2.08 (2.74) mmol/l at 24 h. There was a strong correlation between lactate values and base deficit values (R value 0.8, p < 0.01). Mean base deficit values at 6 h were 5.9 (4.5), at 12 h 3.8 (3.9), at 18 h 3.6 (3.1) and at 24 h 4.1 (3.8) mmol/l. A single lactate value greater than 5.6 mmol/l had a sensitivity of 100% and specificity of 85% of identifying adverse outcome. Persistently elevated or worsening lactates were associated with adverse outcome. There is a strong correlation between lactate values and base deficit on day 1 of life. Serial lactate measurements greater than 5.6 mmol/l predict adverse outcome and may aid the clinician in bedside decision making.

Can a single lactate value predict adverse outcome in critically ill newborn?

“…Furthermore, there is no consensus whether the sample should be drawn from the arterial, peripheral venous, or capillary blood. Most investigators found a satisfactory agreement comparing capillary or venous lactate levels with arterial levels (25)(26)(27)(28). In our opinion, such sampling should therefore be encouraged as patient undergoes this procedure with a minimal risk and inconvenience.…”

“…However, the blood lactate monitoring in critically ill patient remains controversial considering the risk assessment. Some of the discrepancy is due to an uncertainty regarding the appropriate reference interval, whether to perform a single lactate measurement or serial lactate measurements as a screening method of critically ill patient (25,26,28). Furthermore, there is no consensus whether the sample should be drawn from the arterial, peripheral venous, or capillary blood.…”

“…It is almost certain that postnatal lactate level less than 5 mmol/l is never associated with major neurological disorders (10,11,28,(30)(31)(32)(33). However, the increase in lactate concentration taken as a diagnostic threshold value gives rise to sensitivity at the cost of specifi city, and vice versa.…”

“…Actually, in previous studies, it was shown that lactate concentration in the term newborns which is in fi rst 24 hours > 7.5 mmol/l with 94 % sensitivity and 67 % specifi city may indicate the development of the HIE (10,11,(29)(30)(31) and that an early increase in lactate in severe asphyxia > 15 mmol/l was a sure indication of serious consequences or death with 100 % sensitivity of and 88 % specifi city (11,26,28,29). On the other hand, our results showed that somewhat higher lactate concentration indicated the development of more advanced stages of the HIE (with slightly lower sensitivity and higher specifi city), but even signifi cantly lower lactate concentration levels than previously suggested were highly sensitive indicators of death.…”

Management of Hypotension in Preterm Infants (The HIP Trial): A Randomised Controlled Trial of Hypotension Management in Extremely Low Gestational Age Newborns

“…Elevated or increasing values obtained on the first day of postnatal life are associated with increased mortality in preterm and term newborns [38,39]. A single lactate value >5.6 mmol/l obtained on the first day was associated with an increased risk of adverse outcome, defined as death or severe intraventricular haemorrhage [40]. In contrast, Wardle [41] found no difference in lactate levels between normotensive and hypotensive preterm infants.…”