Emergency department medical care during civil unrest: a narrative review

Civil unrest is a critical societal challenge in many parts of the world. Crowd control weapons (including conducted energy devices, chemical irritants, kinetic impact projectiles, acoustic devices, and water cannons) produce agent-specific injuries that do not precisely map onto standard trauma frameworks. This narrative review synthesises the available evidence on the mechanisms, health effects, and emergency department management of casualties inflicted by crowd-control weapons.

Emergency department preparedness for civil unrest rests on surge capacity planning across staffing, supplies, space, and systems, with additional demands imposed by chemical decontamination, unpredictable patient volumes, and risks to staff safety. Conducted energy devices cause injury primarily through falls during neuromuscular incapacitation and through probe penetration of sensitive structures; cardiac risk is low but may be amplified by comorbidities and intoxication. Routine cardiac monitoring is not supported for alert, asymptomatic patients after brief exposures. Riot control agents (principally 2-chlorobenzylidene malononitrile [CS], chloroacetophenone [CN], and oleoresin capsicum) activate nociceptive ion channels, producing ocular, respiratory, and dermal injury that is largely self-limiting but can be severe, especially in enclosed spaces or vulnerable populations such as infants, elderly and patients with asthma. Management centres on decontamination and supportive care. Kinetic impact projectiles are responsible for the highest burden of permanent disability, particularly ocular injury; initial presentations may appear deceptively benign, and clinicians must maintain a high index of suspicion for occult internal injury guided by mechanism rather than surface findings. Acoustic devices and water cannons cause auditory barotrauma and blunt trauma, respectively, while improvised incendiary devices produce combined burn and inhalation injury patterns. Each mechanism imposes specific demands on triage, imaging, specialist consultation, and disposition.

Emergency clinicians should be familiar with the distinct injury profiles associated with crowd-control weapons and be prepared to manage them within the emergency care setting. Preparedness planning, mechanism-guided clinical assessment, and awareness of agent-specific pathology are essential to optimising outcomes for casualties of civil unrest.