Methaemoglobinemia induced by a low dose of prilocaïne during interscalenic block.

Methaemoglobinemia is a rare but well known complication of the use of prilocaïne in locoregional anaesthesia. We report a case of methaemoglobinemia following the administration of a low dose of prilocaïne for an interscalenic bloc. We suggest some hypotheses to explain this phenomenon. This case illustrates the necessity of pulse oximetry monitoring in all patients receiving prilocaïne during locoregional anaesthesia.