Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Flumazenil and EMS – A Box Pandora Should Not Open

Fentanyl is easily titratable, has a more rapid onset than other available opioids, and has a much shorter half life than morphine. The only advantage morphine has is that it is more familiar. As long as people keep advocating this longer lasting, slower onset, more problematic drug, people will be less familiar with the much safer drug – fentanyl. However fentanyl does have a long, safe, predictable history of use with good patient response and good outcome. Should you find it necessary, or just convenient, to use naloxone to reverse iatrogenic respiratory depression, it would be much safer to use an opioid with a similar half life to that of naloxone – again that would be fentanyl. Reversal agents are nice to have. Much more important to remember is that the safest treatment for iatrogenic respiratory depression is supportive care, not a reversal agent. Primum non nocere (First, do no harm). Be able to get out of trouble quickly.

Similarly, midazolam is a safer drug than lorazepam or diazepam. Much shorter acting. Midazolam allows you to treat the patient aggressively for the time the patient is in the care of EMS. Once you are arriving at the hospital, it should be starting to wear off. This is important, because in the ED they do not have the staff to observe the patient as closely as EMS does. In EMS, it is rare that I am more than an arm’s length away from the patient. If I cannot recognize oversedation problems in that setting, I should not be treating patients. In the hospital the nurses will have several patients, and not have the ability to sit next to the patient I bring them. Delivering a patient, who requires continual observation of his breathing, is not helping the ED at all. For violent patients, it becomes a bit of a balancing act. If the patient is still violent, that means there is even more need to pull ED staff away from other patients. Be able to get out of trouble quickly.

Using haloperidol (Haldol), droperidol (Inapsine), ziprasidone (Geodon), or some other non-benzodiazepine sedative also improves the safety of sedating the patient. You won’t find many EDs using just a benzodiazepine to sedate violent patients. That wouldn’t be right. Having EMS use just a benzodiazepine, assuming that EMS is allowed to use any kind of sedative? That is looked at as progressive EMS. Orwell would love it.

Flumazenil is not anywhere near as safe a reversal agent as naloxone. Naloxone that may induce hypertension, flash pulmonary edema, seizures, ventricular tachycardia. If naloxone leads to seizures, in EMS, we have a way to treat the seizures – benzodiazepines. If flumazenil leads to seizures, most EMS providers can only drive faster and hyperventilate (themselves, the patient, or both – but neither is likely to help). Flumazenil has nothing to do with being able to get out of trouble quickly. Flumazenil can create problems that EMS cannot treat.

If EMS carries paralytics, then that is one way to stop the physical seizure activity. I do not oppose well trained medics carrying paralytics. Carrying paralytics to reverse the seizures that may occur because somebody found it necessary, or just convenient, to use flumazenil to reverse iatrogenic respiratory depression? Very bad idea. Paralytics are a last ditch effort to treat seizures. Paralytics do nothing to stop the seizure, they just prevent the physical expression of the activity in the brain.

Maybe nobody would ever decide to use the flumazenil to reverse a possible benzodiazepine overdose, rather than the much safer supportive care. Conversations with those who work in systems that use flumazenil, suggest that if it can be used, it will be used. Should EMS then carry phenytoin, barbiturates, and/or other antiseizure medications to be able to treat iatrogenic seizures?

Flumazenil has a role in procedural sedation/heavy sedation. Does that mean that EMS should be using procedural sedation/heavy sedation? Should EMS be reversing procedural sedation/heavy sedation? When supportive care is the safer treatment, why use flumazenil? If the medics are not good at supportive care, the problem is with the medics, not with the medicine. The problem is in focusing on the signs that can be documented, rather than on what is least risky for the patient. Flumazenil is a box Pandora should hesitate to open, and she was not known for her caution.

Remember, the safest treatment for iatrogenic respiratory depression is supportive care. Primum non nocere. Be able to get out of trouble quickly.

I apologize for not providing any references in this post, but I am having internet connection problems. I will follow up with more on flumazenil.



  1. […] ^ 7 Flumazenil and EMS – A Box Pandora Should Not Open What I coincidentally wrote about flumazenil a few weeks ago. […]

  2. […] [1] Flumazenil and EMS – A Box Pandora Should Not Open Fri, 20 Mar 2009 by Rogue Medic Article […]