Authors of a previous paper in the Annals of Emergency Medicine surmised from the available evidence that the Moscow emergency services had not been informed of the use of the agent, but were instructed to bring opioid antagonists. Not knowing to expect hundreds of patients exposed to high doses of strong opioids, the emergency workers did not bring enough naloxone or naltrexone (the two most commonly-used opioid antagonists) to counteract the carfentanil and remifentanil and save the lives of many of the victims. 125 people exposed to the gas used in the rescue attempt are confirmed to have died from both respiratory failure and aerosol inhalation during the incident.