PEM and ex-Prems

Author: Katie Knight / Peer Reviewed: Charlotte Durand / Editor: Nikki Abela, Liz Herrieven / Reviewer: Laura Riddick / Code: RC2, SLO5 / Published: 07/11/2016 / Reviewed: 30/07/2024

Neonatal care is a huge success story of modern medicine. It is now possible for babies born even at 22 weeks gestation to survive (although often with profound and wide-ranging long-term problems) while those survivors in older groups (born 28 weeks plus) are doing better than ever.

If youre working in a paediatric Emergency Department (ED) it wont be long until you come across a NICU graduate.

Most EM trainees wont have had the benefit of ever working in neonatal intensive care, so this is a short primer which will hopefully help you understand a bit more about this particular group of babies.

Some definitions

22 weeks is now the accepted limit of viability in the UK there are very few survivors who are born this early.

Statistics for morbidity and mortality of preterm infants can be found here.

What does corrected gestational age mean?

Parents might say that the child is eight months old, but six months corrected. Corrected gestational age is how old the baby should be if they had been born on time.

Or if you are mathematically challenged like me – this website calculates corrected age for you.

The Story of Noah – A typical NICU journey

There is no typical NICU stay, but this fictional story of Noah describes what a NICU parent may have been through

(Stock photo by Ceejayoz on wikimedia commons)

Noah is an extreme pre-term born at 28 weeks, weighing a mere 1kg his mum developed an infection and went into early labour at her local district general hospital. At birth Noah is floppy and not breathing. The neonatal team intubate him straight away. Noah is taken to NICU, and put on a ventilator. The neonatal team put in an umbilical venous catheter (to give fluids), an umbilical arterial catheter (for central blood pressure monitoring) and start antibiotics and fluids. The blood pressure keeps dropping despite the fluid so a dopamine infusion is needed. Because of the severe infection the ventilation is difficult to manage, and at 12 hours old Noah needs an emergency transfer across the city to a tertiary NICU.

Mum is still unwell herself and has not been able to meet her baby yet. Dad runs between mum and Noah all night checking they are both OK. He has not been able to touch or hold his son either.

Stock photo by Tbmurray in wikipedia commons

Dad makes the difficult decision to go with Noah in the ambulance which means leaving his partner behind in ITU.

At the tertiary hospital Noah spends a week on a ventilator. A head scan shows that there is a bleed into one of the ventricles (common in this age group- up to 20%). The long-term effects of this are unpredictable at the moment. He is jaundiced, so the incubator is lit with blue phototherapy lights. He is too sick to be fed through a NG tube, so is on parenteral nutrition. After three days mum is finally well enough to come and see Noah for the first time. She gets her first cuddle.

At the tertiary hospital Noah spends a week on a ventilator. A head scan shows that there is a bleed into one of the ventricles (common in this age group- up to 20%). The long-term effects of this are unpredictable at the moment. He is jaundiced, so the incubator is lit with blue phototherapy lights. He is too sick to be fed through a NG tube, so is on parenteral nutrition. After three days mum is finally well enough to come and see Noah for the first time. She gets her first cuddle.

Turning a corner after a week on antibiotics, Noah is extubated and put on CPAP (via a nasal mask). He does well and two days later is well enough to go back to the local NICU.

At three weeks old (corrected age 31 weeks gestation), suddenly Noah has an apnoea. His parents watch as the neonatal doctors resuscitate him. Another infection is suspected. He has to be intubated and ventilated again for a couple of days, but this time can stay in his local unit. Feeding is set back because of this; mum is running out of breast milk and the stress is not helping.

At four weeks old (corrected age 32 weeks gestation), Noah has made it off CPAP but still needs oxygen through nasal cannulae. This means he has chronic lung disease (defined by still needing oxygen after four weeks of age). He is fed via a NG tube as he still doesnt have a sucking reflex. Mum has to pump her breast milk and give it to the NICU nurses to keep in the fridge for Noah.

His parents are travelling between home and hospital several times a day. Only the immediate family are allowed onto the NICU for infection control reasons.

At 35 weeks corrected gestation, Noah is able to take some breast feeds, but this is tiring for him and he still needs the NG tube. He has finally stopped needing oxygen. He has another two days on antibiotics after seeming a bit unsettled with a few large vomits. Luckily, this time the blood cultures are negative.

At 36 weeks the feeding is going better, and at 2.0kg Noah has put on just enough weight to be discharged home. He had a repeat head scan which shows the bleed on the brain has resolved. He still needs long-term follow up to monitor his development. The family have by this point been in the NICU for 8 weeks, and they feel lucky to have had a relatively straightforward stay. Many other NICU parents theyve met will still be there for months.

Insider knowledge

NICU parents may have had an unwelcome crash course in neonatal medicine, but the advantage of this is that they will be able to give you a very detailed history if you know the right questions to ask.

Respiratory problems

These are probably the most common reason for ex-prems to come to the ED. Most pre-terms will have had some form of respiratory support on the NICU, and as you can probably guess, babies who needed longer periods of respiratory support are the ones to worry about more.

So, ask parents how many days/weeks the baby was on a ventilator for, how long they needed CPAP or high flow oxygen, and how long they needed oxygen via nasal cannulae. If they needed steroids to get off the ventilator, needed any form of oxygen after 28 days of chronological age, or are still on home oxygen or respiratory support now, these are indicators of chronic lung disease of prematurity (CLD). The major causes of death in babies with CLD (in NICU and after discharge) are sepsis, respiratory infection, respiratory failure or pulmonary hypertension.

CLD is related to gestational age at birth and also birth weight (the more premature and the smaller you are, the more likely you are to have CLD). Ante- and postnatal infections, whether antenatal steroids were received, mechanical ventilation and oxygen therapy also contribute to the development of CLD. Using some form of mechanical ventilation and oxygen is pretty much unavoidable in premature babies, but modern neonatal care focuses on keeping ventilation pressures as low as possible to avoid barotrauma, with tightly controlled oxygen levels.

If any ex-prem baby not just those with CLD attends ED with a respiratory complaint, however minor, it is pretty unusual for them not to be admitted or reviewed by paediatrics. Even well-appearing babies of this group can decompensate fast and need close observation.

Infection

Babies who are born prematurely may not have the same immunity as others, so may be at greater risk from infection and sepsis. In addition, some preterm babies develop adrenal insufficiency due to prolonged courses of steroids on the NICU, and they will require emergency dosing of steroids if they become unwell.

Surgery

The most common surgical procedures premature babies undergo are repair of inguinal hernias (this might happen electively or as an emergency if the hernia strangulates), closure of a patent ductus arteriosus (PDA), and less commonly bowel resection, and possibly colostomy formation, if they have suffered necrotising enterocolitis (NEC). Scars from these operations will be there if you know where to look (its a left lateral thoracotomy scar for a PDA closure).

PDA and its tell-tale repair scar

Feeding

Many pre-terms are discharged home on nasogastric feeds which parents are trained to do at home. Taking a good feeding history is really important covering which milk they use, how many feeds a day, how long a break they have from feeds overnight.

A smaller subset of babies (for example those with neurological problems or severe reflux) will be PEG or jejunally fed. Problems with feeding (or tubes) are a common reason to present to the ED; any child who is at home needing feeding support like this will have a community nurse who is a good point of contact for information.

Vaccines

Premature babies get these at their chronological age, rather than their corrected age. So, they should have had their 2, 3 and 4 month vaccines 2, 3 and 4 months after their ACTUAL birthday rather than their due date. Also, some ex-prems (exact criteria vary slightly from hospital to hospital) receive an extra winter vaccine Palivizumab against RSV, the main culprit of bronchiolitis (Ed: watch out for roll-out of RSV vaccine to pregnant woman and other babies soon, hopefully, after a recent JCVI recommendation).

As ex-premature babies are so fragile, it is important that they are kept in a side-room away from all the other snotty, viral older children in the ED (hopefully your triage will have sorted this out).

Development

Starting life in NICU can have huge effects on development, even if the baby did not suffer any brain injury. The NICU environment is stressful despite the efforts we make to try and minimise this, and babies will not have the normal amount of interaction and stimulation from their parents. Their development is more likely to follow their corrected, rather than chronological age.

Alarm bells

  Babies who needed oxygen for over a month on NICU, or are on home oxygen these babies have chronic lung disease of prematurity. Bronchiolitis, or any viral URTI, could be catastrophic.

  Recent discharge from NICU – the baby may be suddenly unwell or maybe the parents arent coping with the overwhelming anxiety of being at home after spending months in intensive care. Handle with care.

  Parental concern this goes for all areas of paediatrics a parents instinct is usually spot on, but even more so in parents of ex-prems who have spent literally months sitting at an incubator watching their babys every move.

Take home messages

  1. Have an extremely low threshold for concern whatever the presenting complaint
  2. The default assumption should be that the baby will need admission
  3. Consider discussion with the paediatric team if in any doubt

References and further reading

  1. EPICure: Population based studies of survival and later health status in extremely premature infants
  2.  Complete routine immunisation schedule. UK Health Security Agency, 2014. Updated: 2024.
  3. Eichenwald EC, Stark AR. Pathogenesis and clinical features of bronchopulmonary dysplasia. UpToDate, 2024.
  4. Tommy: Premature labour and birth. Information for parents: Tommys.org

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