Make it a venti: Caffeine for post-LP headache

In the Pediatric ED we encounter post-LP headache (PLPHA) less frequently than our colleagues who take care of grown ups. Nonetheless, it is an important topic to review. This post focuses specifically on caffeine, though before moving on to the not-quite Starbucks sponsored portion of the post it is a good idea to review PLPHA in general:

• The estimated incidence is 10-30% of patients receiving an LP
• The headache is frontal/occipital
• It occurs within 12-24 hours of the procedure in most cases
• It is worse when upright and improved when supine
• Bed rest doesn’t definitively decrease the risk
• Females, patients with a prior history of headache, young age (<50), and needle oriented perpendicular to the dural fibers seem to increase the risk
• If you use a smaller needle and orient the bevel parallel to the fibers you decrease the risk
• Most actually resolve spontaneously
• The ultimate treatment in patients refractory to conserevative therapies is a epidural blood patch

All-right, back to caffeine which (we think) works through cerebral vasoconstriction. It can be dosed IV with sodium benzoate which increases the solubility. Those suggested dose is 500mg given over 1 hour. A second dose can be repeated in 4 hours of dose #1 is ineffective. Oral dosing may be effective as well – more on that later.

Thinking about the hierarchy of studies we would want to see RCTs to best elucidate the therapeutic benefit. Basurto Ona et al in asystematic review from the Cochrane Database highlighted an RCT of 41 patients that were randomized to either 500mg of IV caffeine sodium benzoate or saline. A higher proportion of caffeinated patients had relief. More patients assigned to intravenous caffeine (500 mg ) versus normal saline reported relief of headache within two hours of the infusion 75% vs 15%.

Oral caffeine is less well studied. Anecdotally I’ve had it work a few times, but the existing research leans towards adults, especially post-partum women. One such RCT in 40 post-partum noted a slightly better pain score at 4 hours in the caffeine group. This difference was not large, but was statistically significant (p=0.014). 30% of the caffeinated patients in this study had recurrence at 24 hours. One final piece of data may help you consider oral caffeine as a therapy and its potential effectiveness.