Department of Pediatrics, Bokaro General Hospital, Bokaro Steel City, Jharkhand, India.
Department of Pediatrics, Jawaharlal Nehru Medical College, A.M.U., Aligarh, Uttar Pradesh, India.
J Neonatal Perinatal Med. 2021;14(2):245-251. doi: 10.3233/NPM-200442.
Phototherapy is the primary treatment for hyperbilirubinemia in neonates. Hypocalcemia is a lesser known but potential detrimental effect of phototherapy. It has been hypothesized that phototherapy inhibits pineal secretion of melatonin, which blocks the effect of cortisol on bone calcium. Therefore, unchecked cortisol increases bone uptake of calcium and induces hypocalcemia. Covering head during phototherapy in order to prevent light reaching to the pineal gland which eventually leads to the prevention of hypocalcemia is hypothesized to prevent hypocalcemia but it lacks sufficient evidence worldwide.
It is a prospective, randomized controlled study. 112 neonates were randomized into two groups of 56 neonates. Group A underwent phototherapy without head cover and group B with head covered by a cap.
The mean decline in serum ionic calcium after 48 hours of phototherapy in group A and group B was 0.57±0.37 mg/dl and 0.34±0.24 mg/dl respectively. This decline in serum ionic calcium was significantly higher in group A. (p < 0.001). 26.8% newborns from group A developed hypocalcemia while in group B only 14.3% developed hypocalcemia however it was not found to be statistically significant. Incidence of symptomatic hypocalcemia between the two groups was also not significant.
There was significant reduction in serum calcium in neonates undergoing phototherapy without head cover as compared to neonates with head cover but risk of hypocalcemia was not significant. Further studies with larger sample size including preterm are recommended.
光疗是新生儿高胆红素血症的主要治疗方法。低钙血症是光疗潜在的但已知的有害影响。有人假设光疗抑制松果体分泌褪黑素，从而阻断皮质醇对骨钙的作用。因此，不受控制的皮质醇增加骨对钙的摄取，并导致低钙血症。有人假设在光疗时遮盖头部以防止光线到达松果体，从而最终预防低钙血症，但这在全球范围内缺乏足够的证据。
这是一项前瞻性、随机对照研究。112 名新生儿随机分为两组，每组 56 名新生儿。A 组行光疗时不遮盖头部，B 组用帽子遮盖头部。
A 组和 B 组在光疗 48 小时后血清离子钙的平均下降分别为 0.57±0.37mg/dl 和 0.34±0.24mg/dl。A 组血清离子钙的下降明显更高（p<0.001）。A 组有 26.8%的新生儿发生低钙血症，而 B 组只有 14.3%的新生儿发生低钙血症，但差异无统计学意义。两组间症状性低钙血症的发生率也无显著差异。
与遮盖头部的新生儿相比，不遮盖头部行光疗的新生儿血清钙明显下降，但低钙血症的风险并不显著。建议进行包括早产儿在内的更大样本量的进一步研究。
