Issue: February 2012
February 01, 2012
2 min read

Inability to recognize power failures in NPWT devices may have caused wound complications

Power loss of negative pressure device may cause treatment failure and infections.

Issue: February 2012
You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

We were unable to process your request. Please try again later. If you continue to have this issue please contact

Failure to maintain power or recognize impending power failure with negative pressure wound therapy vacuum-assisted closure systems have resulted in trauma patients developing a variety of complications, from lost grafts, to unplanned surgeries and infections, according to findings of a retrospective investigation published in the Journal of Orthopedic Trauma.

First study author Cory Collinge, MD, told Orthopedics Today, “It is typically a failure of staff to recognize that the device is unplugged and the subsequent expiration of power from the unit results in a shutdown of the machine and negative pressure therapy,” that caused these problems. “The most important thing coming out of this paper is this can happen, to be aware of the problem, and avoid unnecessary unplugging of the machine or leaving the machine unplugged for any period of time.”

Collinge and colleagues studied 123 consecutive patients who underwent negative pressure wound therapy (NPWT) at two neighboring trauma centers between May 2008 and November 2008 to determine the number of vacuum-assisted closure systems (Kinetic Concepts Inc; San Antonio) that were powering off, the reasons for the power failures and the consequences of interrupted treatment. They examined patients, their injuries and treatment methods, and analyzed perioperative clinical outcomes. They also focused on wound complications such as infection, graft loss and unscheduled surgery, according to the study.

The devices powered off in 12 patients or 10% of cases. At the time of the power failures, “We had no idea how long [the devices] had been powered off,” Collinge said. “We took them to surgery or intervened in some way to try to clean the wound and minimize the risk of infection.”

In 11 patients, researchers re-applied the device after detecting a problem, with patients undergoing debridement due to the failure as early as 6 hours before the procedures were regularly scheduled. Nine of those patients required unplanned surgery. The NPWT failed in seven of the 12 patients, and they subsequently developed complications. Five patients with failed NPWT developed deep infections, and two patients lost their grafts because the therapy failed.

Collinge noted while the hospital staff are familiar with some battery-operated devices, like intravenous therapy lines, they were not as well educated about vacuum-assisted closure devices and apparently became confused as to whether the device was working. However, basic knowledge about these devices is increasing significantly, but not universally, he said.

Furthermore, despite an alarm on the NPWT machine, “It is no louder than any other alarm in a hospital room or intensive care unit; and we are so deconditioned by alarms that lots of times they do not get enough attention,” Collinge said.

“We are big advocates of the machine. It does great things. A lot of legs and arms have been salvaged because of the invention of this machine,” he said. “This is just something people need to pay attention to and try to prevent from powering off, because when it does power off, there are significant consequences with infection risk.” – by Jeff Craven

  • Collinge C, Reddix R. The incidence of wound complications related to negative pressure wound therapy power outage and interruption of treatment in orthopaedic trauma patients. J Orthop Trauma. 2011; 25:96-100.
  • Cory Collinge, MD, can be reached at Orthopedic Specialty Associates, 800 5th Avenue, Suite 500, Fort Worth, TX; 817-878-5300; email:
  • Disclosure: Collinge is a paid consultant to and received product development royalties from Biomet and Smith & Nephew. He receives product development royalties from Synthes and Advanced Orthopaedic Solutions.