Surgical site infections (SSIs) continue to be 1 of the most significant burdens on the health care system, both in the United States and abroad.1 Approximately 500 000 SSIs occur annually in the United States alone, with an associated cost of $10 billion. For orthopedic surgical procedures, SSIs prolong total hospital stays by a median of 2 weeks per patient, approximately double rehospitalization rates, and increase health care costs by 300%.2
SSIs can be especially devastating complications when hardware such as hip or knee prostheses are implanted. Many techniques have been used to minimize the bacterial bioburden at the time of surgery. These include prophylactic antibiotics, laminar flow techniques, ultraviolet light, novel antimicrobial wound drapes, antibiotic-loaded cement, and a myriad of irrigation compounds.3 Although irrigation at the time of wound closure is logical to reduce the bacterial load, no specific irrigation solution has been shown to be universally effective.1 Antibiotic irrigations do not work because antibiotic action requires time to interact with the susceptible bacteria. Surfactants have been demonstrated to have negative effects, such as blood hemolysis, impaired clotting mechanisms, skin irritation, and impaired healing.4 Wound antiseptics have been useful as surgical wound irrigants, but some (such as Dakin’s solution and chlorhexidine) have been reported to be cytotoxic.5,6
Hypochlorous acid (HOCl) has been shown in vitro to have a rapid bacterial kill rate against most pathogens responsible for SSI.7 HOCl is also noncytotoxic and pH-neutral to skin and wound cells. Therefore, unlike other wound cleansing solutions, it is not necessary to rinse HOCl from the wound.
A series of 6 orthopedic procedures involving hip and knee replacement were studied using a pure HOCl without hypochlorites (Vashe Solution, SteadMed Medical LLC, Fort Worth, TX) as a wound irrigant during the operations. The patients included 4 women and 2 men (age range 30 to 55 years). Two (2) of the patients had hip replacement surgery; 4 underwent knee replacements. A pulsed irrigation system (Stryker InterPulse System, Stryker Corp, Kalamazoo, MI) delivered 475 cc of HOCl into the wound just before closure of the fascia and as the subcutaneous tissue was being approximated (see Figure 1). Following final skin closure, an additional 118 cc of HOCl was irrigated onto the suture line (see Figure 2), and HOCl-soaked gauze pads were applied to the wound for 10 minutes before the dressing was placed. The wounds were followed postoperatively to healing and bacterial cultures were routinely obtained.
All wounds healed per primum and no SSI occurred (see Figure 3). All bacterial cultures showed no growth. The time to healing appeared to be more rapid than with our previous wound regimens. On average, SSIs have been reported to extend hospital length of stay by 9.7 days while increasing cost by $20 842 per admission.8 Historically, the etiology of SSI has been attributed to hematologic seeding, contamination from the patient’s own skin or nasopharyngeal flora, or a break in the aseptic barrier in the surgical field. However, more recent data suggest the offending bacteria causing SSI originate from the air and are exogenous rather than endogenous.1 Therefore, an argument can be made that irrigation with an antiseptic solution just before wound closure may play a role in reducing the airborne-derived bacterial bioburden in a surgical wound and lead to a reduction in SSI. The irrigant should be safe, effective, and noninjurious to the wound cells so as not to impede wound healing. HOCl appears to be a surgical irrigant for orthopedic procedures that does not have the problems associated with other irrigation solutions. In this series of hip and knee replacements, there were no SSIs when HOCl irrigation was used.