Prehospital airway and operational management of severe ammonia intoxication: a case report

Ammonia inhalation can cause rapid airway compromise and noncardiogenic pulmonary oedema. Although hospital management has been described, prehospital strategies in severe cases remain largely undocumented.

A 44-year-old obese male (160 kg) was exposed to an ammonia cloud at a decommissioned power plant. He presented with mucosal burns, severe dyspnoea, and hypoxemia despite high-flow oxygen. Prehospital providers initiated nebulized adrenaline, performed ocular irrigation, and prepared for surgical airway backup. Rapid sequence intubation was conducted under video laryngoscopy. Immediately post-intubation, copious foamy secretions confirmed fulminant pulmonary oedema. Despite FiO₂ 1.0 and a PEEP of 12 cmH₂O, oxygenation remained marginal at 89-90%. Intravenous corticosteroids were administered, burns were covered, and the patient was transported by helicopter to a burn and critical care centre. On-scene decontamination was deferred due to instability; the EMS team underwent full decontamination after patient handover. Ground transport to the nearest regional centre would have required approximately 60 min; HEMS transport directly to the tertiary burn centre (MHH Hannover) took approximately 35 min. Beyond transport time, HEMS use involved inherent aeromedical risks: residual ammonia off gassing in the confined cockpit and cabin posed a risk of mucosal irritation or pilot incapacitation, and inadvertent chemical contamination of sensitive avionics or airframe components posed a corrosion risk. These were weighed against clinical urgency and the absence of adequate regional ICU or burn capacity. No formal risk-based framework currently exists to guide HEMS transport of CBRN-exposed patients; this case underscores the need for one.

This case demonstrates the unique prehospital challenges of ammonia inhalation: the need for early definitive airway management, refractory hypoxemia beyond the capacity of prehospital ventilators, and operational dilemmas such as delayed decontamination, patient weight, and limited local ICU resources. It highlights the urgent need for structured EMS protocols for caustic inhalation events. Beyond the clinical case, this report addresses the complexity of transport decision-making in critically ill patients with incomplete decontamination, including civil aviation safety considerations and the absence of a risk-based framework for CBRN aeromedical transport.