A 52-year-old man with chronic lower back pain due to lumbar spondylosis is scheduled for epidural steroid injection. During the procedure, the anesthesiologist notes a sudden onset of severe headache, neck stiffness, and photophobia 2 hours post-procedure. The patient's temperature is 37.8°C, and CSF analysis shows pleocytosis with lymphocytic predominance. What is the most likely complication and its probable etiology?

Explanation

## Clinical Presentation Analysis The patient presents with classic meningeal signs (headache, neck stiffness, photophobia) occurring 2 hours post-epidural injection, accompanied by fever and CSF pleocytosis with lymphocytic predominance. This temporal relationship and CSF profile are pathognomonic for aseptic meningitis. ## Differential Diagnosis | Complication | Onset | CSF Profile | Fever | Mechanism | |---|---|---|---|---| | **Aseptic meningitis** | 2–24 hrs | Lymphocytic pleocytosis, normal glucose | Often present | Contaminated injectate, needle, or chemical irritation | | Post-dural puncture headache | 24–48 hrs | Normal | Absent | Positional, worse on standing | | Bacterial meningitis | 12–48 hrs | Neutrophilic, low glucose, high protein | High fever | Skin flora (Staph, Strep) | | Epidural hematoma | Minutes to hours | Bloody | Absent | Vascular injury, coagulopathy | ## Key Point: **Aseptic meningitis** following epidural injection is a known complication, typically caused by: 1. Contamination of the epidural injectate (especially with preservatives or particulate matter) 2. Inadvertent introduction of skin flora or needle contamination 3. Chemical irritation from injectate components (e.g., methylprednisolone acetate) ## High-Yield: The **lymphocytic CSF profile** with normal glucose distinguishes aseptic meningitis from bacterial meningitis (which shows neutrophilic predominance and low glucose). The **2-hour onset** is too rapid for bacterial meningitis and too early for typical post-dural puncture headache. ## Clinical Pearl: Aseptic meningitis is usually **self-limited** and managed supportively with NSAIDs, hydration, and observation. Antibiotics are NOT indicated unless bacterial infection is proven. Recovery typically occurs within 24–72 hours. ## Mnemonic: ASEPTIC MENINGITIS CAUSES **ASEPTIC** = Anesthesia/Analgesia injectate, Sterile technique breach, Epidural/spinal procedures, Preservatives in injectate, Talc/particulates, Iodine-based contrast, Chemical irritants [cite:Miller's Anesthesia 8e Ch 45]