Local and regional venom effects can lead to extensive swelling of an entire limb, especially with bites from certain species of snakes. Such symptoms are observed following bites from numerous crotalid species, many viperid species and some elapid species.
Generally this involves swelling of the skin and subcutaneous tissue that nearly always resolves with conservative treatment (Curry et al. 1985, Garfin 1982, Hardy 1991, Kitchens 1992, pers. comm.). Fasciotomy is only necessary in very rare cases. The indication for fasciotomy must be substantiated by measurement of intra-compartmental pressure. There should be clinical suspicion of compartment syndrome if the affected extremity is extremely painful and muscular weakness is present that can be attributed to the muscle group in the affected compartment. In addition there is dysaesthesia in the distribution area of those nerves whose course includes the affected compartment. A palpable peripheral pulse does not exclude compartment syndrome (Matsen 1980).
The intra-compartmental pressure is measured by inserting a probe (cannula) connected to a measuring device into the relevant compartment. If the pressure is over 45 mmHg (60 cmH₂O), there is a high risk of intra-compartmental ischaemic necrosis and fasciotomy is indicated. However, to date there has been no evidence that such a measure is able to limit intra-compartmental damage caused by snakebites (Garfin et al. 1984).
If a fasciotomy is carried out, adequate haemostasis must be ensured. The importance of establishing this is due to the fact that most snake venoms that caused marked local and regional envenoming also contain haemostatically active components (Warrell 1990b).