Re: Clinico-radiological Observations in Meconium Aspiration Syndrome - Letter to The Editor
Journal of Nepal Medical Association
We thank the reader for their interest in our paper and providing us an opportunity to offer our views on a few pertinent issues. The point-wise replies to the reader's query are as follows: Reply: 1. MAS is defined as respiratory distress in a neonate born through meconium-stained amniotic fluid (MSAF) with characteristic radiological findings (hyperinflation and patchy opacities) whose symptoms cannot be explained otherwise. 1 We classified meconium aspiration syndrome as a) presence of
... ) presence of meconium stained amniotic fluid (MSAF) and staining of nails, skin and cord with meconium; b) presence of meconium below the vocal cords; c) clinical respiratory distress shortly after birth; and/or abnormal chest x-ray consistent with aspiration pneumonitis. All babies fulfilling the first and any of the remaining criteria for diagnosing MAS admitted to NICU, during the above mentioned period were included in the study. Presence of meconium below the vocal cords will obviously lead to respiratory distress. It is very unlikely in a neonate to have meconium below vocal cords and without respiratory distress. In the other hand, clinical presentations in MAS varies, it can range from no respiratory distress to severe distress. 2 Therefore, the authors feel that the above used classification is as per available literature. The severity of MAS was graded on the basis of requirement of respiratory support as: 1) mild MAS-requiring <40% oxygen for <48 hours, 2) moderate MAS-requiring more than 40% oxygen for more than 48 hours with no air leaks, and 3) severe MAS-requiring assisted ventilation for more than 48 hours and often associated with persistent pulmonary hypertension (PPHN). 3, 4 We also classified newborns in to severe MAS who had to be intubated and ventilated (invasive or CPAP) within 48 hours. 2. Birth asphyxia as per NNPD network is defined as-a) Moderate asphyxia: slow gasping breathing or an Apgar score of 4 to 6 at one minute, and b) Severe asphyxia: No breathing or and Apgar score of 0-3 in one minute. Although the American Academy of Pediatrics and American College of Obstetrics and gynaecology (ACOG) criteria provides more accurate classification of birth asphyxia [includes cord blood gas (metabolic or mixed acidosis, PH <7.2), Apgar score, signs of neonatal neurological dysfunction and multi-organ involvement], 5,6 the facility of getting cord blood gas done in majority of hospitals in low and middle income countries is still a challenge. Therefore, the use of Apgar score in such conditions can be a useful tool to assess asphyxia.