Severe hypertension and tachycardia during transforaminal endoscopic discectomy - Is indigocarmine to blame?

Endoscopic transforaminal discectomy is a minimally invasive technique used for the surgical treatment of herniated discs. Indigocarmine is a dye which is widely used to identify the ureteral orifice in urologic procedures. Hemodynamic effects such as hypotension and anaphylaxis in addition to hypertension, bradycardia and atrioventricular block have been reported in intravenous application of indigocarmine. The aim of this case report is to prepare anesthesiologists for such cases and make them consider invasive blood pressure monitorization. Both patients had radicular pain radiating to the leg and scheduled to undergo transforaminal endoscopic discectomy. Intraoperative vital signs were within normal limits, however severe hypertension and tachyarrhythmia developed following the injection. Hemodynamics in both patients returned to normal following lidocaine and nitroglycerine injection.