Background: Who's hitting what now?
The precordial thump is a popularized emergency medicine procedure performed on medical television shows where the practitioner, slams their fist onto the patient's chest- the patient then wakes up, thanks the doctor, and is then seen walking out of the hospital.
Of course real life is hardly as fun as it can be on television shows- or is it actually? Though I wasn't there to bear witness, I'm told of two relatively recent examples by my colleagues where they've used the technique. In one event, the patient remained in the same rhythm as they started, and in the second example, the patient was, well, thumped right out of their pulseless Vtach. This POTD is inspired by those events. When should I be considering the precordial thump? How does it work? Does it even work?
First descriptions of this procedure date back to the 1920s. The idea is to deliver enough force with a physical blow to cause coordinate cardiac depolarization, replacing the effect that the shock of defibrillation has on the heart during a shockable rhythm. There are anecdotes of patients with unstable rhythms getting "shocked" out of rhythms when the ambulance they were in ran over a pothole, converting them to sinus rhythm. Most ED physicians would tell you of the low success rates of the thump, but most also seem to know a doc, who knows a doc, with whom the precordial thump saved a life.
Indications: When a patient has a witnessed, monitored, unstable ventricular rhythm when a defibrillator is not immediately available. This namely applies to vfib and pulseless vtach. Depending on who you ask, this could done on a patient who starts decompensating before your eyes and before the defibrillator pads are attached. The blow is thought to generate about 5 joules (or maybe 10 if Q does it). Though hardly the amount of joules delivered by defibrillation, and though unlikely to cause depolarization, it can perhaps be justified if the red cart and pads are just a bit too far away.
How to do it: With the patient supine, position your hand 20-30cm above a patient's chest, and strike with the ulnar surface of your fist onto the lower 1/3 of the patient's chest (bonus points if you say "Live, Dammit!" the moment before the strike). Immediately recoil the fist post strike.
But...does it work?
A quick dive into the literature reveals....its ultimately not very effective, especially when compared to defibrillation. But as with any medical topic with poor supporting literature, the efficacy for the precordial thump are mixed.
Many case reports, and a study by Pellis et al., showed up to 25% of patients treated with a precordial thump regained ROSC.
Other reports like Koster et al. showed that an initial precordial thump performed immediately at onset of ventricular arrhythmia only terminated the rhythm of 2 out of 153 patients.
Nehme et al showed, in a retrospective study looking at 434 patients with VF or pulseless VT, 103 were first treated with a precordial thump (followed by defibrillation if unsuccessful) and the other 325 were treated immediately with defibrillation. In the thump group, 5/103 patients achieved ROSC , and for the immediate defibrillation group 188/325 achieved ROSC. Additionally, for the thump group, 10 of the 103 shifted into a more dangerous rhythm, such as VF to asystole.
Possible side effects: Though the precordial thump is attempted in the event of an unstable, shockable rhythm, it can precipitate the opposite effect, and send the patient into a more unstable rhythm or asystole. Blunt intrathoracic trauma can also noted, including rib/sternal fractures, and if performed incorrectly, intraabdominal injury such as liver laceration from a broken xiphoid.
Conclusion: Between the precordial thump and defibrillating the patient with an unstable ventricular rhythm, don't even think: defibrillation is vastly superior. If defibrillation is available, use it every time. The precordial thump should NOT delay defibrillation and early CPR. It should NOT be used for unwitnessed out of hospital cardiac arrest. But if access to defibrillation is not immediately accessible, this is another possible tool in your arsenal. Just don't expect it to work very well.
Sources: https://www.ncbi.nlm.nih.gov/books/NBK545174/