Do EDs underutilize MET stones therapy?
Study says 260,000 a year could be spared surgery
According to a new study published online and ahead of print in the journal Urology1, medical expulsive therapy (MET) for urinary stones is underused in American EDs despite evidence of its safety and efficacy.
The study was conducted by John M. Hollingsworth, MD, clinical lecturer in urology and Robert Wood Johnson Clinical Scholar at the University of Michigan School of Medicine in Ann Arbor and a practicing urologist at the University of Michigan Hospital and the Ann Arbor VA Medical Center, and colleagues. They analyzed 2000-2006 data from the National Hospital Ambulatory Medical Care Survey to determine MET use by the prescription for a calcium channel blocker or alpha blocker at ED visits for stones. Although MET use increased over the study period, with the likelihood of being treated with MET doubling with each successive year, the overall prevalence of MET use was only 1.1%. The low prevalence of MET use implies a missed opportunity to spare about 260,000 individuals annually from having to undergo stone surgery, the authors say.
"For those patients who do not require a stent or other diversion, 90% are eligible for what we consider conservative management to see if they can pass the stone spontaneously," Hollingsworth explains. "Traditionally, what had been done was to keep the patient well hydrated, give them pain meds, and hope they pass the stones."
With that kind of paradigm, he says, one-third of the patients would pass the stone. The remaining two-thirds would go on to require some sort of stone-related surgery, including lithotripsy, which is considered minimally invasive stone surgery, Hollingsworth says. "With either a little scope or a shock, there's still measurable risk and it's costly," he says. "If some other sort of treatment can reliably reduce risk, we can improve quality."
MET therapy involves calcium and alpha blockers, such as nifedipine, doxazosin, and terazosin. "It's collective explosive therapy," Hollingsworth explains. "They work on calcium channel and alpha receptors. They basically bond to receptors and relax the ureter, which helps the passage of the stone."
Between 2000 and 2006, says Hollingsworth, roughly 11 studies looked at the use of these agents and showed efficacy in terms of increased rates of stone passage when appropriately applied. "We did a meta-analysis in 2006, and in summary, patients had a 65% higher likelihood of passing the stones vs. traditional methods," he reports. "That's a pretty compelling rationale for use."
James Pribble, MD, an ED physician in the University of Michigan Hospital, started using MET therapy about three years ago and uses it on almost 80% of patients with the appropriate type of stones. "It most likely provides some benefit, and the side effects are very minor," he says. "We have not had a lot of return patients for stones."
Reference
- Hollingsworth JM, Davis MM, West BT, et al. Trends in medical expulsive therapy use for urinary stone disease in U.S. emergency departments. Urology 2009. [Epub ahead of print.] PMID: 19811807 [PubMed — as supplied by publisher].
Why don't more EDs use MET therapy? Despite the fact that several studies have shown medical expulsive therapy (MET) for urinary stones to be safe and efficacious, a new study published online ahead of print in Urology shows the overall prevalence of MET use in American EDs was only 1.1% during 2000-2006. "A lot of the literature to date has been reported primarily in urology journals, and not so much in emergency medicine journals," notes John M. Hollingsworth, MD, clinical lecturer in urology and Robert Wood Johnson Clinical Scholar at the University of Michigan School of Medicine in Ann Arbor, a practicing urologist at the University of Michigan Hospital and the Ann Arbor VA Medical Center, and lead author. "The real end-users are emergency medicine physicians. They need to know about it the most and are the least likely to see the data." However, that answer might address the issue only partially, says James Pribble, MD, an ED physician in the University of Michigan Hospital, which started using MET therapy about three years ago. "My estimation is that it is mostly beneficial, but I do not think the final conclusion is out there yet," he says. "From a physician's perspective, I'd like to see a large, randomized, controlled trial, but I realize they are very difficult and expensive to do." For EDs that wish to use the therapy more often, it is not a big challenge, says Hollingsworth. "These are commonly prescribed meds," says Hollingsworth, pointing to nifebipine, doxazosin, and terazosin, he notes. "We did an educational intervention [at the University of Michigan Hospital] and presented a literature review in the grand rounds for the ED." In addition, he says, information packets were given out to the staff, and MET was made part of departmental guidelines. |
When is it appropriate for staff to use MET? Medical expulsive therapy (MET) for urinary stones is appropriate in most patients who don't require a stent or other diversion, says John M. Hollingsworth, MD, clinical lecturer in urology and Robert Wood Johnson Clinical Scholar at the University of Michigan School of Medicine in Ann Arbor and a practicing urologist at the University of Michigan Hospital and the Ann Arbor VA Medical Center. "It's appropriate for people who have stones or calculi in the ureter and can be used on stones larger than 6 mm," he says. "Stones that are less than a centimeter in size would be appropriate, provided they didn't have any concurrent diagnoses that would mandate diversion, like renal failure or obstruction of a solitary kidney." |
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