The Cardiovascular Instability and Transient Loss of Consciousness during Blind Cervical Nerve Block
Journal of the Korean Pain Research Society (통증)
Journal of the Korean Pain Research Society (통증), Vol.11(1) : 109~113, 2001
Cervical nerve block is frequently used to relieve the pain in occipital area. It is easily performed with good result. Because there are several major blood vessels such as carotid and vertebral arteries around the posterior neck, unintentional injection of the local anesthetics into these vessels may cause the patients to have central nervous system (CNS) toxicity. Some patients might be midly sedated with nausea, and others might have severe consequences such as loss of consciousness (LOC), convulsion, and cardiac arrest.
The risk of acute CNS toxicity during the block involving head and neck area is high because the local anesthetics injected might directly get into the brain through the major vessels. The concentration of local anesthetics in the brain is the key factor determining the severity of the CNS complication. Even minimal dose of local anesthetic can produce the CNS toxicity with very rapid onset.
A 26-year-old male patient was diagnosed with occipital neuralgia. The MRI finding was negative. He was previously treated with stellate ganglion block and cervical plexus block several times. Blind cervical nerve block in C2 level was performed. Right after the block, the patient complained of having nausea, and he lost his consciousness seconds later. He was recovered completely after prompt treatment with oxygen, ephedrine, and atropine.