The journey of a Preterm baby born at 29 weeks with a large duct (Patent ductus arteriosus)
Baby Aryan (name changed) was born at 29 weeks at Cloudnine Hospital, Whitefield on a warm June night. He came 11 weeks early, weighing 1.6 kg at birth. his mother arrived at the hospital in an advanced labour stage, and it was possible to give one dose of steroid injection just before the delivery. At birth, the baby had breathing difficulty due to premature lung disease. He was put on a ventilator and was also given two doses of surfactant via a breathing tube. Surfactant a lipoprotein which coats the inner lining of the alveoli (terminal part of lungs responsible for gas exchange) is deficient in 3 out four preterm babies born around this gestation. Lack of surfactant causes collapse of alveoli and reduced gas exchange, if not treated, will result in death. Antenatal steroids preferably given 24 hours before delivery helps in lung maturation and also has been shown to prevent bleeding into the brain of preterm babies.
Want to consult: The Best pregnancy doctor in Bangalore
Mannequin Baby on CPAP
The baby was on the ventilator for two days and subsequently, switched over to non-invasive bubble CPAP, to help in breathing. CPAP (Continuous positive airway pressure) helps to open smaller airway, thereby preventing collapse/ atelectasis. High flow nasal cannulae (HFNC) also helps in gas exchange in preterm babies by replacing dead space in upper airways with humidified oxygen and air mixture. Some of the preterm babies need CPAP/ High flow for many weeks, and most of them come off this support and oxygen before the baby’s due date (37 to 40 weeks). These are less invasive compared to ventilators which can cause lung injury.
Must Read: Signs and Symptoms of Preterm Labour
Aryan required significant breathing support initially, and on the 3rd day of life an echocardiogram (“echo”) ultrasound test that uses sound waves to view the heart was conducted showed large Patent ductus arteriosus (PDA)/ Duct. The duct is a blood vessel which bypasses blood from lung (pulmonary) artery to body artery (aorta) before birth, is present in all babies at birth and closes by the third day in mature term babies.
However, in preterm babies, the duct may remain open for many weeks. In some preterm babies, large duct causes increased blood flow to the lungs and cause breathing difficulty. Because of increased blood flow to heart, the heart needs to pump more blood to blood vessels and chambers of heart enlarge. In some babies, it causes less blood flow to the brain, intestines and kidneys and can put these babies at higher risk of bleeding into the brain, gut infection or kidney function impairment. The large duct can be medically treated by giving a course of pain killers (IBUPROFEN OR PARACETAMOL). In 50 % of cases, this works.
PDA, heart chambers and blood flow
The duct is approached from the backside and clipped.
Aryan had two courses of Ibuprofen, and his duct continued to remain prominent. Any efforts to wean him off Non-invasive breathing support (CPAP/ Highflow ) was not possible. He was also given diuretics/ water pills to decrease volume load to the heart and help his breathing. Even after six weeks of conservative treatment duct remained big and Aryan continued to need Non-invasive breathing support.
The family were counselled, and the duct was tied off (heart surgeons use suture/ strong thread to tie it off or use a clip to close it under direct vision ) in operation theatre. Tying off duct helps in preventing more blood flow to the lungs, lessens heart workload and improves blood flow to other vital organs. After the operation, the baby came off breathing support within one week. He was off oxygen by 37 weeks of corrected age and went home two weeks before his due date weighing 2.4 kg.
To Know More: About Premature Baby Care Tips
Also, he required intravenous feeding ( means providing protein, fat and carbohydrate through a small plastic catheter that has a tip in a big blood vessel ) initially, orogastric/ tube feeding, incubator/ heater support, frequent monitoring of blood tests, monitoring of heart rate, blood pressure and oxygen saturation levels. This was provided by expert NICU Nurses and a team of specialist doctors. His brain scans were done periodically. Eyes were tested by a specialised eye doctor as some of these babies require laser or special injection if they develop significant ROP ( retinopathy of prematurity wherein blood vessels on the retina which is the innermost layer of the eye, increase and can cause blindness in some babies).
Baby Aryan is currently doing well at home. He needs to be closely monitored for growth and development. 5 to 10% of preterm babies born at his gestation develop problems (this can be learning difficulty, hearing problems, problems in movement etc.,)
A tiny subset of preterm babies with a large duct requires operation before discharge from the NICU. This can be safely conducted in a well-equipped Neonatal Intensive Care Hospital with coordinated support from the cardiac surgeon, neonatologist, Cardiologist and Anaesthetist. This avoids transport to Cardiac Centre. In the majority of the western world, such babies go to a cardiac centre with a specialised team in a mobile intensive care unit and come back to respective units the same day after the operation.
Preparation is the key. Neonatologist and Anaesthetist must be trained to look after babies requiring duct ligation. Although this is considered to be a simple operation from the cardiac surgeon’s point of view, 1 % of babies below 1 kg die due to complications of surgery in the west.
Must Read: Prematurity Predicaments