Former preterm infant with anaemia and recent coryza for elective hernia repair
A male infant born at 27 weeks' gestation, now 52 weeks' postmenstrual age and weighing 4.9 kg, is booked for elective bilateral inguinal hernia repair. He spent six weeks on nasal CPAP and had apnoeas of prematurity until around 38 weeks' postmenstrual age; the last documented apnoea was six weeks ago. He has mild bronchopulmonary dysplasia, with SpO2 97% on room air and occasional mild wheeze but no current oxygen requirement. Haemoglobin is 8.4 g/dL and the haematocrit is 26%. He has had a runny nose for two days but is afebrile and feeding normally. The surgery is scheduled as a day case. The family lives 45 minutes from the hospital by car.
1. Is this infant suitable for day-case surgery? What is the evidence-based recommendation for postoperative apnoea monitoring?
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No. He has three independent risk factors for postoperative apnoea and bradycardia: a postmenstrual age below 60 weeks, a history of apnoea of prematurity, and anaemia with a haematocrit below 30%. Infants born preterm who are under 60 weeks' postmenstrual age are the recognised at-risk group, and consensus guidance from paediatric anaesthesia societies recommends postoperative monitoring with pulse oximetry and apnoea detection for 12 hours in this population. Some units stratify by postmenstrual age and use shorter monitoring for older infants, but this child's haematocrit of 26% and residual bronchopulmonary dysplasia place him firmly at the higher-risk end.
The 45-minute journey home is a further argument against day-case surgery: if he has an apnoeic event at home, help is not immediately available.
So the plan should be: admit for overnight monitoring with continuous pulse oximetry and apnoea alarms, with the family counselled in advance; ensure the infant is fed, warm and in a cot with monitoring before transfer; and give the parents explicit instructions to seek help for pauses in breathing, dusky episodes or poor feeding. If the hospital cannot provide overnight infant monitoring, the case should be rescheduled to a centre that can.
2. How does the choice between spinal and general anaesthesia affect the risk of apnoea, and what specific precautions would you take with general anaesthesia?
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Spinal anaesthesia is associated with a lower incidence of postoperative apnoea and desaturation than general anaesthesia in ex-preterm infants, and in experienced hands it is the preferred technique for this operation. The caveats are important: it can fail or be inadequate, it may require sedation (which reintroduces some apnoea risk), it can produce a high block with bradycardia and hypotension, and it must be performed by someone with paediatric regional experience. Where spinal anaesthesia is not feasible or fails, general anaesthesia with a controlled technique is acceptable, provided monitoring is in place.
Precautions if general anaesthesia is used:
- Avoid opioids and, where possible, neuromuscular blockers; provide analgesia with an ilioinguinal/iliohypogastric block using 0.25% bupivacaine 0.5 mL/kg (about 2.45 mL, below the 2.5 mg/kg ceiling).
- Use a face mask or laryngeal mask rather than intubation if the airway allows, avoiding instrumentation and the associated risk of laryngospasm in a child with bronchopulmonary dysplasia and a current coryzal illness.
- Sevoflurane with oxygen and air, maintaining normocapnia, normothermia and normoglycaemia; avoid hyperoxia and avoid deep extubation.
- Extubate or remove the airway awake, and observe in a monitored area before transfer.
- Some units give a single dose of caffeine citrate (10 mg/kg) as an adjunct; the evidence is limited outside apnoea of prematurity protocols, so it should not replace monitoring.
3. How would you manage the anaemia and the recent coryzal illness?
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Anaemia: a haematocrit of 26% in an ex-preterm infant is a recognised risk factor for postoperative apnoea, and it also reduces the margin of safety if he desaturates or bleeds during surgery. He should have iron studies and reticulocyte count, and be started on oral iron. For an infant with bronchopulmonary dysplasia and a planned general anaesthetic, a transfusion threshold of haemoglobin 9-10 g/dL (haematocrit about 30%) is commonly used, so I would discuss transfusion with the neonatal team before surgery rather than proceeding as planned. If transfusion is declined, the case should still go ahead but only with overnight monitoring, and the risk should be documented.
Coryzal illness: an active upper respiratory tract infection increases the risk of laryngospasm, bronchospasm, atelectasis and desaturation, and this child has residual bronchopulmonary dysplasia, which magnifies the risk. The illness is mild and he is afebrile and feeding, but the surgery is elective. My approach would be to defer for two to four weeks and reschedule after recovery, with the parents counselled on the signs of incarcerated hernia (a firm, tender, irreducible swelling, vomiting, distress) so that they can bring him back urgently if needed. If the hernia were irreducible or symptomatic, I would proceed with a regional technique, no airway instrumentation and overnight monitoring. Either way, the day-case plan is abandoned.