Snake Bite Compartments… to cut or not to cut

Author: Brian P. Murray, DO (@bpatmurray, Medical Toxicology Fellow, Emory School of Medicine/CDC ) // Edited by: Cynthia Santos, MD (Senior Medical Toxicology Fellow, Emory University School of Medicine), Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW / Parkland Memorial Hospital), and Brit Long, MD (@long_brit)

Case:

A 22-year-old man presents to the Emergency Department after being bitten on his forearm by his pet rattlesnake. He is experiencing extreme pain at the site where he was bitten as well and distally into his hand. Upon evaluation, ulnar and radial pulses are not palpable, his capillary refill is >5 seconds and the hand is cool to the touch. He does still have some sensation in the hand, but it is decreased compared to his other hand. 

Question:

What is the recommended treatment for this patient’s suspected compartment syndrome?

Pearl:

Compartment syndrome caused by the envenomation by a Crotalinae species snake (pit viper) should be managed with antivenin and not with surgical fasciotomy.

·       Compartment syndrome is a rare but potentially moribund complication of the North American pit viper envenomation.

·       Local tissue effects from the venom can mimic a compartment syndrome (tight compartments, pain out of proportion, pain with passive extension), and therefore a compartment syndrome should not be diagnosed without compartment measurements. [1]

·       Antivenin has been shown to decrease elevated intra-compartmental pressures in canine legs after administration of venom from the southern Pacific rattlesnake. [2]

·       Fasciotomy, at least performed before elevated intra-compartmental pressures, worsens the degree of myonecrosis compared to treatment with antivenin alone. [3]

·       Patients with verified compartment syndrome after rattlesnake bites have been successfully treatment with antivenin in the absence of fasciotomy. [1,4]

·       Guidelines published in 2013 recommend that fasciotomy not be used as a primary therapy in patients with snake bite induced compartment syndrome, as data has not established that it improves outcomes, but does recommend the consideration of fasciotomy in patients who have a clearly diagnosed compartment syndrome and are not responding to treatment with antivenin. [1]

Main Point:

If a concern for compartment syndrome after pit viper envenomation exists, diagnosis can only be made through direct measurement of the compartment pressure or through calculation of a delta pressure measurement. Primary treatment of a true compartment syndrome is with antivenin. Only after failure of antivenin, in coordination with local poison control and surgical consultation, should fasciotomy be attempted in order to prevent end stage neurologic and tissue destruction in the limb.

 References:

1. Toschlog EA, Bauer CR, Hall EL, Dart RC, Khatri V, Lavones EJ. Surgical considerations in the management of pit viper snake envenomation. Journal of the American College of Surgeons. 2013 Oct 1; 217(4):726-35.
2. Garfin SR, Castilonia RR, Mubarak SJ, Hargens AR, Akeson WH, Russell FE. The effect of antivenin on intramuscular pressure elevations induced by rattlesnake venom. Toxicon. 1985 Jan 1;23(4):677-80.
3. Tanen DA, Danish DC, Grice GA, Riffenburgh RH, Clark RF. Fasciotomy worsens the amount of myonecrosis in a porcine model of crotaline envenomation. Annals of emergency medicine. 2004 Aug 31;44(2):99-104.
4. Gold BS, Barish RA, Dart RC, Silverman RP, Bochicchio GV. Resolution of compartment syndrome after rattlesnake envenomation utilizing non-invasive measures. The Journal of emergency medicine. 2003 Apr 30;24(3):285-8.