Role of Salivary Biomarkers in Pediatric Pain Assessment

Introduction: Pain self-reporting is currently a ‘golden-standard’ tool for pain assessment. However, it varies from patient to patient and could be inaccurately understood by healthcare professionals. According to several studies, acute as well as chronic pediatric pain remains misunderstood, under-diagnosed, and still under-treated. Moreover, accurate pain diagnostic markers are still missing.

Aims: To investigate salivary cortisol and melatonin concentrations in children with acute pain. To compare it with pain severity and vital signs changes.

Methods: We conducted pilot observational study in Kauno Klinikos Pediatric emergency department (PED). Twenty-six patients referred to PED due to acute pain were included into the study. We excluded patients with chronical conditions, under pain-killers or hormonal treatment. We recorded patient’s gender, age, vital signs (heart rate (HR), blood pressure (BP), respiratory rate (RR), temperature (t°) and oxygen saturation (SaO2)), pain characteristics (severity and duration of pain). Saliva samples were collected and stored in -80°C till cortisol and melatonin ELISA analysis.

Results: Sixteen boys and 10 girls were involved in our research. Age median was10 (4-16) years. Fourteen cases were trauma patients, 12 cases referred due to pain of other origin. we observed increased HR and BP due to pain. Other parameters were within age range. The median of cortisol and melatonin were 287.5(68-1330) and 17,6(8.6-46.8) pg/ml respectively. There was tendency of melatonin reduction with increased intensity of pain, however it was not significant (p=0.136). The longer the pain lasted, the higher cortisol levels were identified (p=0.01). No link was found between abnormal vital signs and changes in biomarkers.

Conclusion: Primary results show a cortisol rise with regard to pain duration. A drop in melatonin levels was observed with increasing pain. These results show cortisol and melatonin as potential biomarkers in acute pain diagnostics.