Wound Irrigation for Open Fractures
Results of the elegantly designed, well-powered, multi-national FLOW trial provide insights into the type of irrigant and the pressure that should be used when irrigating and debriding an open fracture wound.
Richard Yoon, MD, and Philipp Leucht, MD
The FLOW Investigators. A Trial of Wound Irrigation in the Initial Management of Open Fracture Wounds. N Engl J Med. 2015; 373: 2629-41.
During the 2015 Annual Meeting of the Orthopaedic Trauma Association (OTA), lead author Dr. Mohit Bhandari and his colleagues released the long-awaited results of the Fluid Lavage of Open Wounds (FLOW) trial, simultaneously presenting the results during a keynote address at the meeting and launching the publication online.
The goal of this prospective, randomized controlled trial – which included more than 40 participating centers spanning 5 countries – was to answer 2 simple questions: Should soap or saline be used when irrigating and debriding open fractures? Should the irrigation pressure be high, low, or very low?
The primary endpoint for this elegantly designed, well-powered randomized trial was reoperation, defined as a return trip to the operating room within 12 months of the index procedure to promote further wound or bone healing or for a wound infection. Study design included a 2 x 3 arm trial that split the type of irrigation by pressure: castile soap vs. normal saline; high pressure vs. low pressure vs. very low pressure.
More than 2500 patients were screened and 2447 were included in the final analysis. Among the high pressure, low pressure, and very low pressure groups, reoperation rates were not significantly different: 13.2%, 12.7%, and 13.7%, respectively (hazard ratio 0.92; P=0.53). When compared with the normal saline group, the soap group had a significantly higher rate of reoperation: 14.8% vs. 11.6% (hazard ratio 1.32; P=0.01).
The FLOW investigators concluded that pressure has little effect on the reoperation rate, thus they recommended the cheapest option for ready use (very low pressure/gravity lavage).
Due to the higher reoperation rate with the use of soap, they recommended normal saline as the irrigant of choice in the management of open fractures.
This well-designed, well-powered prospective, multi-national randomized trial has provided answers to 2 very important questions: We learned that including soap in the irrigant does more harm than good, and that when irrigating, the method does not matter.
The clinical impact of answering such simple questions is immense, and helps put to rest years of controversy over the use of castile soap. Previous smaller trials have offered data to suggest that the use of soap is superior, but the FLOW trial has finally debunked that notion.
In addition, when considering the method of irrigation, it may be possible to achieve cost savings by utilizing gravity lavage instead of the more costly pulsatile lavage systems available on the market.
Following presentation of the FLOW data at the OTA meeting, a member of the audience asked: Is irrigation even needed? Is the next step the NO FLOW trial?
Although the audience responded with a light-hearted chuckle, this is a valid question. Traumatologists and generalists alike can agree that thorough debridement is the key to achieving the desired aseptic wound bed – but is irrigation really necessary? And if so, what is the ideal amount?
The results put forth by the FLOW investigators offer a definitive answer to using sterile normal saline alone as an irrigant. We look forward to the subgroup analyses and additional data that will inevitably arise from this impressive trial.
Richard S. Yoon, MD, is Executive Chief Resident in the Department of Orthopaedic Surgery and Philipp Leucht, MD, is an Assistant Professor of Orthopaedic Surgery and Cell Biology at NYU Langone Medical Center – Hospital for Joint Diseases, New York, New York.