Morocco
Morocco (المغرب)
Management of Pain at Arteriovenous Fistula Puncture: Cryotherapy versus Lidocaine/Prilocaine
Dialysis patients have to navigate a lot to successfully complete just one hemodialysis session. We all know about the risks of intra-dialytic complications, such as arrhythmias, hypotension, angina, and muscle cramping (just to name a few). Often we don't focus as much on many of the pre-treatment complications...namely access cannulation. Using a relatively small gauge (large diameter) needle to puncture a fistula can hurt. "Fistula needling" is just one of the reasons why patients insist on the buttonhole technique (Figure 1). That technique uses a blunt needle and cannulates the same area repeatedly. It decreases pain associated with fistula needling but increases the risk of infection (Figure 2).
Figure 1: Buttonhole Cannulation Protocol | Courtesy Dr. Aisha Shaikh (zoom in for details)
Figure 2: Buttonhole technique and rates of bloodstream infections | Courtesy Dr. Michelle Mokrzycki
And so this year's NephroWorldCup team from Morocco decided to assess a simple intervention to minimize cannulation pain: ice. In this prospective trial, Moroccan scientists compared topical lidocaine/prilocaine against good ol' ice. Thirty-two in-center hemodialysis patients who reported cannulation pain using the Visual Analog Score (VAS) (38% prevalence in their unit) were first topically administered lidocaine/prilocaine. Patients had to wait between 30-60 minutes after application for cannulation to begin. The following week, these same patients were topically administered ice over their fistula. Patients waited 5 minutes after application before cannulation occurred.
Figure 3: Change in VAS with lidocaine/prilocaine and, subsequently, ice.
Figure 3 shows the tremendous improvement in using ice over lidocaine/prilocaine. The data really favor ice administration especially because of its ease of use, ready availability, near zero cost, and only a 5 minute lead time before cannulation (versus 30-60 minute lead time). The downfall of this team, however, is the lack of a randomized group. Patients were first administered lidocaine/prilocaine and had a 2-3 day "washout" period before starting ice. Could the remnant effects of lidocaine/prilocaine be captured by the VAS score during the cryotherapy period?
A good attempt at addressing an under-appreciated and impactful symptom. Trial design limits interpretation and may not be enough for a first-round exit. Could the Moroccan team pull off a surprise victory?