Introduction Lignocaine is an amide-type local anaesthetic and a class Ib antidysrhythmic agent, available since 1948. Systemic exposure to large amounts leads to adverse effects on the cardiovascular and central nervous systems (CNS). Local anaesthetics are extremely useful for providing anaesthesia and analgesia for paediatric population of all ages. Our aim is to raise awareness among the clinicians regarding the safety of administration of local anaesthetics.

Case presentation 11 weeks old baby boy brought into the Paediatric Assessment Unit (PAU) by ambulance following an episode of respiratory depression and generalised tonic conic seizures in General Practice (GP) surgery. The patient had undergone a circumcision under local anaesthetia (brand name Xylocaine 1%) shortly prior to the event. He required basic life support to maintain airway and breathing prior to ambulance arrival. Two doses on intranasal midazolam were administered by the paramedics to abort the seizures. A Guedel airway was inserted for airway protection and 100% oxygen was supplied through the non-rebreather mask.

On arrival, he had GCS of 6/15, pupils were pin point, capillary refill time (CRT) was 3–4seconds, tachycardic and hypothermic with temperature of 34.5C. The rest of physical examinations were normal. No obvious haemorrhage on the circumcision site. He was given 20mls/kg of normal saline and started on intravenous Cefotaxime. Temperature was stabilised with thermal mattress and continuous maintenance intravenous fluid and CRT had improved to 2 seconds. Lignocaine toxicity was suspected and he was given Intralipid 20% as per protocol. His conscious level improved momentarily following Intralipid administration but became impaired again. He was intubated and ventilated and was transferred to tertiary Paediatric Intensive Care Unit (PICU) for further management. He made a full recovery and was discharged home.

Discussion Overall safety record of local anaesthesia in paediatric population has been good provided administered within safe guidelines. Patients at the extremes of age and women who are pregnant more susceptible to local anaesthetic toxicity. Rates of severe systemic toxicity (seizures with or without cardiac arrest) occur up to 1:2000 for peripheral nerve blocks, depending on the type of block (Torp KD & Simon LV, 2018). A retrospective study by Fotaine et al (1994), 1358 circumcised male infants revealed that 1022 had a dorsal penile nerve block (DPNB) as the anaesthetic technique and there were no reports of local anaesthetic toxicity in these cases. Despite the apparent safety of lignocaine, extra precautions should be applied in administering the medication in paediatric population. This case could be an example that despite the safety profile of lignocaine, severe toxicity still could occur.

References

1. Fotaine P, Dittberner D, Scheltema KE. (1994) The safety of dorsal penile nerve block for neonatal circumcision. Journal of Family Practice.

2. Torp KD, Simon LV. (Updated 2018) Lidocaine Toxicity, Treasure Island (FL): StatPearls Publishing; 2018 Jan.