Post spinal headache with nausea is the most common complication; it often responds to analgesics and infusion of fluids. It was long taught that this complication can often be prevented by strict maintenance of a supine posture for two hours after the successful puncture; this has not been borne out in modern studies involving large numbers of patients. Merritt's Neurology (10th edition), in the section on lumbar puncture, notes that intravenous caffeine injection is often quite effective in aborting these so-called "spinal headaches."