How Speed Bumps Help Predict Appendicitis
Time is a killer when it comes to appendicitis. Ignore that howling stomachache long enough, and you risk a burst appendix and infected belly. But the condition is notoriously difficult to diagnose—maybe it’s gas, maybe it’s cramps—and emergency surgery carries risks all its own. For doctors, it’s a choice between two lousy options; the rate of “negative appendectomy,” where the sac is removed only to be found uninflamed, is as high as 42 percent.
As with many diseases, early-stage diagnosis is something of a guessing game. Does the pain seem to migrate from your belly button toward your right hip? Does it ease when you apply pressure, but ache when you let up? What about speed bumps—does it shriek when you bounce over one?
That last question, popular with some ER doctors as a bit of trusty folk medicine, was at the center of a British study which appeared recently inBMJ. Can speed bumps, such as those found in hospital parking lots, be an effective tool for diagnosing—or ruling out—appendicitis in patients with aggravated stomach pain?
With no formal funding, physicians at Stoke Mandeville Hospital, in Buckinghamshire, decided to run a small experiment. They asked 101 suspected appendicitis patients to record whether they recalled hitting any speed bumps on their way to the ER, and if their pain changed as a result. Of the 34 patients who eventually underwent surgery and were found to have a blocked appendix, 33 were “speed bump positive”—in other words, the pain had been jarring.
Of course, there were plenty of patients who reported painful speed bumps and weren’t found to have appendicitis. Statisticians refer to this as “positive” vs. “negative” predictive value: In this case, not experiencing speed bump pain was a good indicator that a patient did not have appendicitis, allowing a doctor to safely rule it out. But bump pain was less useful as a tool to definitively diagnose—or, rule in—the condition.
Like many diagnostic tools doctors rely on, “the speed bump test” narrowed the list of possible suspects, even if it didn’t finger the culprit. And in several cases, it turned up equally dangerous abnormalities, including ruptured ovarian cysts and diverticulitis.
The authors note that, when it comes to appendicitis, asking about speed bump pain is as specific—and thus helpful—a diagnostic tool as asking about nausea, migratory pain, and rebound tenderness. And compared to the cost of a CT scan, the speed bump test is about as cheap as they come.
Ambulance drivers and urban planners, take note.