Pain Management in Children

Mild analgesics such as paracetamol are widely used. A loading dose of 20mg/kg orally or 40mg/kg rectally can be given followed by 15mg/kg 6 hourly (max 90mg/kg).

• have been used following tonsillectomy and dental extraction with conflicting results between studies in the quality of analgesia as well as the degree of opioid sparing achieved.

•  known to be a wide inter-individual variation in dose required for a given analgesic effect and titration of dose against the individual patient response rather than fixed dose regimens may be the key to success with these drugs.

• aspirin is not suitable for children in view of the risk of Reye's syndrome.

Ibuprofen: 5mg/kg 6 hourly if the weight <25kg, in the child >25kg 200mg 8 hourly may be given. Ibuprofen should not be given to neonates or asthmatics.

Diclofenac: 1-3mg/kg/day in divided doses in children >6 months, care in children with impaired renal function and asthmatics.

Mild opioids e.g. codeine have the same potential side effects as strong opioids but in practice they are well tolerated.

• dose of codeine is 1-1.5mg/kg 6 hourly

• given either orally, intramuscularly or rectally.

• must never be given IV as hypotension and cardiovascular collapse can occur.

• can be given IV as either Nurse Controlled Analgesia (NCA) or Patient Controlled Analgesia (PCA).

• maximum dose of 400m g/kg in any 4-hour period may be given after a loading dose of 50-100m g/kg.

The Great Ormond Street Hospital regimes for morphine are:

• neonates <5kg

  • no background infusion

  • boluses of 10-20m g/kg

  • lock-out period of 20-60 minutes.

• >5kg

  • background infusion (0-20m g/kg)

  • boluses of 10-20m g/kg

  • lockout period of 5-10 minutes.

• <50kg

  • background infusion (4m g/kg)

  • boluses of 10-20m g/kg

  • lockout period of 5-15 minutes.

• >50kg

  • no background infusion

  • boluses of 1-2mg

  • lockout period of 5-15 minutes.

All children on IV morphine need to have frequent nursing assessments of pain scores as well as respiratory rate. Ventilatory depression may be treated by stopping the PCA/NCA and administering IV naloxone (4m g/kg, repeated if necessary). A continuous IV infusion is useful only if the patient is nursed in a high dependency area.

Opioid related nausea and vomiting is treated with IV ondansetron 100-200m g/kg 8 hourly.

• may be the most effective method of managing severe post-operative pain.

• epidurals for post-operative analgesia should only be used if there is the nursing back up on the wards to safely manage them.

  • suitable mixture is 0.125% plain bupivicaine plus 0.001% (10m g/ml) preservative free morphine infused at 0.1-0.4ml/kg/hour to a maximum of 15ml/hour.

  • pruritus and urinary retention may be treated by 0.5m g/kg naloxone IV.

• Contrary to previous belief, pain transmission does occur in neonates

• Outcome of surgery may be improved by providing adequate analgesia. 

• Side effects of opioids, particular respiratory depression is seen more frequently in neonates (hence no background NCA rate). Their increased sensitivity is due to:

  • altered pharmacokinetics secondary to immature excretory pathways,

  • increased permeability of immature blood-brain barrier

  • increased concentrations of endogenous opioids in blood and CSF

  • changes in the proportion of mu(m ) receptors in the brain.

• Wide inter-individual variability seen in the sensitivity to opioids and the difference is not predictable on clinical grounds

• May be safer to use fentanyl (1-3m g/kg) as an intra-operative analgesic as, unlike morphine, it does not undergo entero-hepatic recirculation.

• Neonates are also more susceptible to local anaesthetic toxicity and strong solutions of LA (e.g. > 0.25% bupivicaine) are not required as myelination is not yet complete.