Salivary lactate dehydrogenase levels can provide early diagnosis of hypoxic-ischaemic encephalopathy in neonates with birth asphyxia.

AIM: Timely detection of hypoxic-ischaemic encephalopathy (HIE) is crucial for selecting neonates who are likely to benefit from neuroprotective therapy. This study evaluated the efficacy of salivary lactate dehydrogenase (LDH) in the early diagnosis of HIE among neonates with perinatal asphyxia.

METHODS: We prospectively enrolled 30 neonates who needed resuscitation at birth or had a history of delayed cry into the HIE group if they developed HIE within 12 h of birth. The control group comprised 30 neonates who had no evidence of HIE, but had intrapartum foetal distress or needed resuscitation at birth. LDH was measured using saliva samples collected within 12 h of birth.

RESULTS: Salivary LDH was significantly higher in the HIE group, with a median of 2578 and an interquartile range (IQR) of 1379-3408 international units per litre (IU/L), than in the control group (median 558.5, IQR: 348-924 IU/L, p < 0.001). The test demonstrated excellent discriminating ability: the area under the curve was 0.92 and the levels of 893 IU/L showed a sensitivity of 90% and a specificity of 73.3%.

CONCLUSION: Measuring salivary LDH among neonates with birth asphyxia provided an early and accurate diagnosis of HIE and could be used as a triage tool.