Neonatal Jaundice 新生兒黃疸

History 病人是自然產出生一天大的男嬰；母親 是 24 歲 G2P1A1 客家人，產前實驗室檢 查正常，懷孕過程順利， group B streptococcus 檢查是陰性，母親血型是 O positive ，破水時間是 1 小時。男嬰出 生體重是 3270 克， Apgar scores 分別是 8 與 9 分，懷孕週數是 40 週。男嬰出生第 一天的餵食良好，體重只下降 10 克。他 已有解尿及排便，家族史無特別發現。

男嬰在出生滿 24 小時呈現黃疸症狀，測 腳底微血管的 bilirubin 值為 17 mg/dl ，轉 至病嬰室接受進一步檢查與治療 History

Physical Exam General appearance: Jaundiced infant in no distress Skin: Jaundiced HEENT: Icteric sclera Neck: Supple without masses Lungs: Clear without increased work of breathing Heart: Regular heart beat, no murmur Abdomen: Soft, nontender, no masses or organomegaly Hips: Normal Pulses: Normal

What is your differential diagnosis? Physiologic jaundice Breast milk jaundice Hemolytic disease of the newborn Congenital viral infection Breastfeeding jaundice Glucose-6-phosphate dehydrogenase (G6PD) deficiency

Re-Evaluation of Differential Diagnosis Physiologic jaundice Explanation: Jaundice that appears at birth or within the first 24 hours of life is always pathologic. Physiologic jaundice can be diagnosed by ruling out disorders by history, clinical findings, or laboratory results. Because this infants bilirubin was elevated prior to 24 hours of life, it is not physiologic.

Breast milk jaundice Explanation: Breast milk jaundice develops in breastfed infants at approximately the first week of life. It gradually decreases over 3-10 weeks. It is an indirect hyperbilirubinemia. Jaundice developed too early in this newborn. Re-Evaluation of Differential Diagnosis

Hemolytic disease of the newborn Explanation: Whenever the indirect bilirubin increases quickly, especially in the first 24 hours of life, hemolytic disease of the newborn must be considered. The mothers blood type is O positive, which would put the infant at risk with a blood type of A or B. Re-Evaluation of Differential Diagnosis

Congenital viral infection Explanation: Congenital viral infections usually are associated with an increase in direct or conjugated bilirubin. These infections may be associated with growth restriction, hepatosplenomegaly, microcephaly, and rashes Re-Evaluation of Differential Diagnosis

Breastfeeding jaundice Explanation: Breastfeeding jaundice occurs in the first days of life. It is associated with decreased milk intake and possibly dehydration. This infants history reveals good intake with minimal weight loss. Re-Evaluation of Differential Diagnosis

Glucose-6-phosphate dehydrogenase (G6PD) deficiency Explanation: G6PD deficiency must be considered in a newborn with an indirect bilirubin approaching exchange levels or a level that is not responding to phototherapy. Re-Evaluation of Differential Diagnosis

What laboratory or x-ray studies would you order? Total bilirubin Direct or conjugated bilirubin Liver function tests Coombs test Complete blood count Liver ultrasound Reticulocyte count G6PD level

Laboratory and Radiologic Studies Total bilirubin Explanation: A newborn who appears jaundiced requires a total bilirubin level be drawn. Estimation of the total bilirubin cannot be made by observation.

Direct or conjugated bilirubin Explanation: Conjugated bilirubin needs to be checked with the first laboratory draw in a jaundiced newborn. A direct bilirubin 2 mg/dL or 20 of the total bilirubin is always pathologic and requires a more extensive workup for liver disease and metabolic abnormalities. Laboratory and Radiologic Studies

Liver function tests Explanation: Liver function tests do not need to be checked, unless there is evidence of liver disease on examination or an increase in conjugated bilirubin (infection, hemorrhage, hemolysis, galactosemia, hypothyroidism). Laboratory and Radiologic Studies

Coombs test Explanation: Hemolysis is a common cause of indirect hyperbilirubinemia in the first 24 hours. A common cause is ABO incompatibility. Coombs test is usually positive. Rh incompatibility is not in the differential diagnosis of this patient because the mother is Rh positive. Laboratory and Radiologic Studies

Complete blood count Explanation: Because hemolysis is a common cause of indirect hyperbilirubinemia, the complete blood count is needed to check for anemia, and the smear is needed to look for signs of hemolysis or other causes of anemia. Laboratory and Radiologic Studies

Liver ultrasound Explanation: There is no evidence of liver disease from examination or from an increase in direct bilirubin. At this point, there is no reason to perform an ultrasound scan of the liver. Laboratory and Radiologic Studies

Reticulocyte count Explanation: The reticulocyte count may help determine if hemolysis is present. ~~ ↑ when hemolysis/hemorrhage ≥ 3 days Laboratory and Radiologic Studies

G6PD level Explanation: If the workup for hemolytic disease of the newborn is negative, other causes of a rapid increase in indirect bilirubin must be sought. Laboratory and Radiologic Studies

CBC: WBC 24.6; Hb ; platelets 550 Blood type: O + Coombs: Negative Total bilirubin 19.8 mg/dl; direct bilirubin 0.3 mg/dl Reticulocyte count 8.4% G6PD level 0.85 kU/L; RBC /uL normal adult ; newborn 50 higher

Final Diagnosis G6PD deficiency

Treatment 開始用 intensive phototherapy 治療， 每 6 小時監測血中 bilirubin 值， 已建立靜脈點滴，仍鼓勵時常餵食奶水。

結果 血液測得 total bilirubin 不曾上升高於 20 mg/dl ， 接下來的 4 天緩慢下降至 13 mg/dl ，男嬰出院 後在門診複診追蹤 bilirubin 與 Hemotocrit 。 他將在小兒血液科門診追蹤，大多數 G6PD deficiency 的病人在新生兒期之後有良性的臨 床病程，所有的病人必須被教導避免接觸氧化 物，例如：蠶豆，樟腦，奈丸，某些藥物 (antimalarials, sulfa drugs including sulfamethoxazole, nitrofurantion, and methylene blue) 以儘可能減少 hemolytic anemia 的發生。