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

AimTimely 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. MethodsWe 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 12h 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 12h of birth. ResultsSalivary 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 thecontrol group (median 558.5, IQR: 348-924 IU/L, p<0.001). The test demonstratedexcellent discriminating ability: the area under the curve was 0.92 and the levels of 893 IU/L showed asensitivity of 90% and a specificity of 73.3%. ConclusionMeasuring salivary LDH among neonates with birth asphyxia provided an early and accurate diagnosis of HIE and could be used as a triage tool.