Spinal Anesthesia — Technique and Complications

A 52-year-old male patient undergoes spinal anesthesia for lower limb orthopedic surgery. Regarding the complications of spinal anesthesia, all of the following are true EXCEPT:

A 38-year-old woman undergoing spinal anesthesia for cesarean section develops sudden onset of severe headache, neck stiffness, and fever (38.5°C) on postoperative day 2. CSF analysis shows pleocytosis (WBC 450/μL, predominantly lymphocytes), elevated protein (120 mg/dL), and normal glucose. Gram stain and bacterial culture are negative. What is the most appropriate next step in management?

Which clinical feature best distinguishes post-dural puncture headache (PDPH) from meningitis following spinal anesthesia?

A 52-year-old man undergoes spinal anesthesia for total knee replacement. During the procedure, he develops sudden onset of severe headache, neck stiffness, and photophobia within 2 hours of the block. Which is the most common cause of this complication?

A 52-year-old man with a history of chronic back pain and hypertension (on amlodipine 5 mg daily) is scheduled for elective right knee arthroscopy under spinal anesthesia. During the procedure, his blood pressure drops from 140/90 mmHg to 88/52 mmHg within 8 minutes of spinal injection. He develops mild dyspnea and reports feeling lightheaded. Pulse is 48 bpm. The anesthesiologist notes that the sensory level has reached T4 bilaterally. What is the most likely cause of his hemodynamic instability?