I will be covering each aspect of this process over several blog posts. Today, I am going to explain my system for dosing adult patients in need of rapid sequence intubation. This procedure can be stressful for prehospital providers. Anything we can do to keep it simple so the provider can focus on the big picture is helpful.
Weight based dosing in the prehospital arena is guesswork at best. Unless you were a carnival worker in a previous life your weight estimates will be anything but accurate. With this in mind I have observed many a paramedic give their absolute best effort in estimating a patient's weight. We are mostly type-A perfectionists. Of course we will do everything we possibly can to determine the patient's weight and drug dosing so it will be absolutely accurate. I've watched providers look at a patient and say 150lbs or 175lbs, and then they begin the calculations to kilograms, consulting complex dosing charts that are in five pound increments. Using this method wastes valuable time and effort. If you are currently doing this type of calculation I submit you are simply wasting brain cells. Brain cells that could be used to figure out more important things such as the underlying cause of the patient's condition. Use those brain cells not to miss the potentially hyperkalemic patient (new onset kidney failure, rhabdomyolysis in an elderly patient laying on the floor of their house for two days, etc.) It is these types of patients that your succinylcholine will most certainly be the kiss of death.
When I am faced with an adult patient needing RSI the first thing I do is classify them as either a small adult (60 kg), a medium adult (80 kg), a large adult (100 kg), or an extra-large adult (120 kg). If you are off by 10 or so kilograms; if they are a little smaller or even a bit larger, trust me, it won't matter. They will still drop like a rock and you will still be able to control their airway without issue of drug effectiveness. The drugs used to induce anesthesia in patients for RSI have a wide margin of error in dosing. Use this to your advantage and estimate their weight in a simple even number of kilograms so your calculations will be easy to perform and easy to confirm.
Take the dosages and drugs you use for RSI and write out a chart for all the sizes given above. You will notice a pattern that forms, as each size increment is exactly 20 kilograms. Once you commit this to memory you will be able to remove this stressor from the incident and be able to concentrate on other aspects of the call such as: safety, airway size-up, delegation of responsibilities, overall scene management, assuring each team member is able to perform their respective functions, and backing-up each team member to assure success!
Once you become accustomed to this type of dosing you will be able to quickly and easily draw up medications for the majority of the population without a second thought. You will be able to determine dosages in your sleep, which may be helpful for that 3:00 AM call of your life.
Another tip for drawing up medications for RSI is to use different size syringes for different types of drugs. I always use a 20 cc syringe for Etomidate, a 10 cc syringe for the paralytic (either Succinylcholine or Norcuron), a 5 cc syringe for Versed, and a 3cc syringe for Fentanyl. An addded bonus for where I work is the order of administration is largest syringe to smallest syringe. This way when the drugs are laid out beside each other they are clearly visible as to their function, order of administration, and should not be confused. I have watched paramedics use several syringes of the same size and place labels on each syringe. This is asking for confusion and just another waste of time.
Just a few thoughts on how to make this type of call go more smoothly for you. Hope it was helpful! Be safe out there!