Lactate Level Predicts HIE

Lactate Level Predicts HIE

Postnatal Lactate as an Early Predictor of Short-Term Outcome after Intrapartum Asphyxia. Shah S, Tracy M, and Smyth J. J Perinatol (2004); 24:16-20.

Objectives: To compare the predictive value of pH, base deficit and lactate for the occurrence of moderate-to-severe hypoxic ischaemic encephalopathy (HIE) and systemic complications of asphyxia in term infants with intrapartum asphyxia.

Study Design: We retrospectively reviewed the records of 61 full-term neonates (37 weeks gestation) suspected of having suffered from a significant degree of intrapartum asphyxia from a period of January 1997 to December 2001. The clinical signs of HIE, if any, were categorized using Sarnat and Sarnat classification as mild (stage 1), moderate (stage 2) or severe (stage 3). Base deficit, pH and plasma lactate levels were measured from indwelling arterial catheters within 1 hour after birth and thereafter along with every blood gas measurement. The results were correlated with the subsequent presence or absence of moderate-to-severe HIE by computing receiver operating characteristic curves.

Results: The initial lactate levels were significantly higher (p=0.001) in neonates with moderate-to-severe HIE (mean±SD=11.09±4.6) as compared to those with mild or no HIE (mean±SD=7.1±4.7). Also, the lactate levels took longer to normalize in these babies. A plasma lactate concentration >7.5±mmol/l was associated with moderate-or-severe HIE with a sensitivity of 94% and specificity of 67%. The sensitivity and negative predictive value of lactate was greater than that of the pH or base deficit.

Conclusions: The highest recorded lactate level in the first hour of life and serial measurements of lactate are important predictors of moderate-to-severe HIE.

Comments: Plasma lactate level > 7.5 mmol/L appears to be a very good predictor of moderate to severe HIE. This test should be compared to the amplitude-integrated EEG as a predictor of long-term outcome in asphyxiated neonates. Wouldn’t it be great is we could rely on such a simple test (lactate level) to predict which depressed neonates should be candidates for hypothermia treatment. See 3-060 and 1-027 for a discussion of using hypothermia to treat HIE. ABK.

Date: 06 Feb 2004
Time: 19:22:50

Comments:

It would make life much easier if we had a simple test to predict outcome in this devistating sequale of perinatal asphyxia. In clinical practice we have seen many babies who present with very high markers of tissue hypoxia, only to resolve later with minimum sequele clinically, we definately have seen babies with lactate levels more than 10 with slow resolution but with good neurological outcome. As we know lactate level is a measure of tissue hypoxia and subsequent anaerobic metabolism, the question here is does brain tissue hypoxiemia and subsequent brain cell death necessarily follow tissue hypoxia(in the body).Last, the relatively high SDs for lactate level in both groups(in this study) makes it very difficalt to use this cut limit as a predictor of what to come in clinical practice. I think we are still in square one searching for more sensitive and specific marker/predictor of outcome in HIE.

UserName: M.Alajmi
Institution: RCH, Melbourne

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