Ammonia Inhalants

A book called The Music of the Primes recently crossed my reading table. It s the tale of how millennia of mathematicians have tried to unravel the mysteries of prime numbers (numbers not divisible by anything except themselves, such as 1, 2, 3, 5, 7, etc.). I m not a math guy whatsoever, but the book was interesting in that it showed how mathematicians think and that many of them are just plain nuts. What struck me was how many times someone had thought they made a great discovery just to find that the same result had been presented some time earlier by someone else. It was like a sense of immortality found and then lost, with the heartache more painful each time.

It seems clear that one of the dangers of working in isolation is that you never know who else is writing what. Take the Case of the Month column in JEMS. When I was first asked to participate in it, I happily banged out a few cases, stockpiling them so I could send them off effortlessly when asked. This would give the folks at JEMS the impression that I was a virtuoso, able to generate pages of meaningful material at the drop of a hat. In fact, they were supposed to think that because I was so good at immediate production, they should give me real money to tour EMS systems throughout the world (well, they still ought to do that).

So I ve got this backlog of cases, and while they sit and long for attention, the magazine moves on. And while I ve got a case study about ammonia capsules patiently waiting its turn, the Nemesis (read as Bryan Bledsoe ) manages to sneak in a whole article about ammonia and other rabble-rouser agents ( This Procedure Stinks, March 2003 JEMS). This makes my case study redundant and not publishable for quite a while. But still it calls to me.

Suddenly I realized that I don t have to wait for the print version of JEMS. After all, I ve got Web space. Take that, Texas-boy.

Introduction
Night shift workers often feel, If I m awake, everyone should be. Perhaps that s the reason we focus so much energy in prehospital care on trying to rouse patients with altered levels of consciousness. We ve discussed the hazards of one element of the coma cocktail (flumazenil) in a previous case report. The ubiquitous ammonia capsule may also pose unforeseen hazards.

Case report
At least the coffee has chased down the donuts by the time you get the early morning call. Man down in the lot behind a bar. You know the address well, for you ve been there before. Professionally, that is. It s 7:22 a.m., and you mention to your ride-along EMT student that going to this place during the day will be a novel experience.

You arrive to find a disheveled white male lying face up in the dirt surrounded by police and firefighters. Your initial assessment reveals that the patient has an intact airway and good pulses, and his vital signs are within normal limits. He rouses minimally to a sternal rub, with a groan, and shows no reaction to your voice. He has multiple contusions of various ages over his face and hands, and the overpowering odor of a beverage commonly associated with alcohol assaults your senses. Nobody seems to know how long he has been there, and, despite the efforts of the police, nobody seems to know who he is. The one thing you re sure of is that he s drunk, and that you ve got an EMT student to impress, so it s time to break out the ammonia and demonstrate your prehospital skills.

The patient responds as expected when you snap open the capsule, with a loud grunt and wild thrashing of the head and neck. Yep, he s just a drunk. But you re cognizant of the bruises, and there s the student to think of, so you properly logroll and immobilize the patient. As you do, you note some bruising on the back of the head and neck.

You transport the patient without incident, and you re getting a cup of coffee from the ED nurse s lounge when one of the doctors beckons you into the X-ray room. Hey, look at this, he says, pointing out a C6 fracture on the radiograph. Pretty cool, huh? Can t move his arms or legs. Good thing you tied him down. You smile, hoping that the paralysis was there before you administered the ammonia.

Discussion
Ammonia (NH3) is a direct respiratory irritant. When an ammonia capsule is broken open under a patient s nose, the irritative effect on nasal and pharyngeal mucus membranes produces a sudden, violent avoidance response. The head and neck thrash about, recoiling from the stimulus. If the patient is not restrained, the arms protectively cover the face and swipe at the nose, while the body quickly curls away from the capsule.

If you re looking for it to produce a response, it usually does. But the response to ammonia really doesn t mean very much. Arousal from the inhalation of ammonia fumes is non-specific irritant and cannot be linked to the use of any particular agent (like naloxone for opiates) or a specific disease state. Patients with strokes, in shock, with head injuries or intoxications may all respond similarly to the use of ammonia, but in no case is the response of help in sorting out the cause of an altered level of consciousness, nor in determining optimal care plans for different emergency conditions.

There are other hazards associated with the prehospital use of ammonia. As noted, ammonia is a direct respiratory irritant. Patients with respiratory distress or airway compromise due to airway edema from infection or inflammation may acutely worsen with administration of this drug (there s a reason hazmat teams are wary of ammonia spills). The violent physical response to ammonia may compromise the integrity of the spinal canal in patients with potential cord injury. The wild and forceful motions of the extremities may also pose challenges to patient and caregiver safety. Ammonia inhalation will increase intracranial pressure, making it relatively contraindicated in patients with head injury or intracranial bleeding (and it s often impossible to accurately diagnose these conditions in the field). Ammonia use may also produce coughing, nausea and vomiting, which can increase the risk of aspiration in patients with an impaired gag reflex.

A further point concerns the need for a neurologic assessment both before and after spinal immobilization. Any time one is to subject a patient to a clinical procedure, the relevant parts of the history and exam must be documented before and after the procedure has been performed. It doesn t have to be a major production simply asking the patient to move their fingers and toes and asking if they can feel your touch may be enough. It s crucial to recall that even the patient with an altered LOC can still be assessed for neurologic deficits by measuring pain response in the extremities (the withdrawal from pain is a reflex response not dependent upon conscious control or sensation).

Conclusion
The key to prehospital medicine is careful patient assessment accompanied by strict attention to the ABCs. The aggressive use of such agents as ammonia may place patients at risk. The only thing that should impress an EMT student is knowledgeable patient care.

All this being said, I do have to share one amusing ammonia factoid. Where I did my residency, we had an enlightened view of ammonia. In the spirit of equality and fairness that characterizes our Constitution and the Natural Rights of Man, everyone deserved a chance to get some. I remember walking around with a pocketful of capsules in my lab coat and how tough it was to drive home the day I accidentally sat on them in the car. But mostly I remember a diagnostic technique called walrusing the patient, in which one of the white mesh-covered capsules was placed in each nostril, and the two tusks were then broken against the septum. In the days when CT scanning was something you could get only after calling the radiologist to come in from home, and even then it had better not be after midnight because the results wouldn t be available by morning, this was the only sure way you had to guarantee the patient had a real head injury. We found the method worked best when the staff recited Jabberwocky to the melody of White Rabbit in the background. Ah, for simpler times.

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