Epidural steroid injection is a common treatment for the management of pain in
a wide variety of patients. It is generally well tolerated and perceived to have few
side effects, with a low risk of serious complications. Only a handful of reports exist
that describe life-threatening complications such as subdural hematoma, respiratory
depression, vasovagal response, and pneumocephalus. This is a case report of a
67-year-old woman with a relatively unremarkable past medical history, other than
rheumatoid arthritis, osteoarthritis, and hypertension, who suffered from chronic
neck pain treated with cervical epidural steroid injection at the C6-C7 level. She went
into immediate cardiopulmonary arrest following the injection. She was brought to
the emergency department by ambulance and resuscitated, and was found to have
pneumocephalus. Ultimately, she made a relatively full recovery over the following
weeks.
Cardiopulmonary arrest is a rare but potentially deadly side effect of epidural steroid
injection. To the best of our knowledge, this is the first report of such an arrest
following a steroid injection in the cervical spinal region. There are several possible
mechanisms for the immediate arrest, including cardioacceleratory center blockade,
severe vasovagal response, iatrogenic pneumocephalus, and involvement of the
phrenic nerve followed by apnea. Our conclusion in this case is that the most likely
scenario was injection of the C6-C7 level led to a blockade of the cardiac accelerator
fibers located just below in the T1-T4 spinal level, causing a sympathetic blockade and
profound bradycardia, leading to cardiopulmonary arrest.
Key words: Cardiopulmonary arrest, cervical epidural steroid injection,
pneumocephalus, cardiac accelerator, vasovagal, chronic neck pain.