Impact of Preoperative Local Water-Filtered Infrared-A (wIRA) Irradiation on Postoperative Wound Healing
Condition: Wound Infection Rate After Surgery; Impact of Wound Infection on Pain and Wound Healing
MeSH terms: Infections; Communicable Diseases; Wound Infection; Wounds and Injuries
Study type: Interventional

Summary: 
      The purpose of this study is to dermine whether local-water filtered infrared-A (wIRA)
      irradiation can reduce postoperative wound infection. wIRA irradiation is applied 20min
      directly preoperatively, before patients underwent abdominal surgery. The wIRA is a harmless
      light source, that has been described before. We test the impact and clinical outcome of
      patients undergoing a one-time preoperative wIRA irradiation on postoperative wound healing.
    

Detailed description: 
      Wound healing is a complex pathophysiological process that is related to pain, discomfort and
      immobility of patients and when not well controlled may lead to devastating and morbidity
      related wound infections. Furthermore, prolonged hospital stay, increased pain and
      consecutive increased drug consumption is often associated with postoperative wound
      infections. Although the average costs of wound infections are difficult to assess, there is
      no doubt that a prophylactic tool in controlling postoperative wound healing would have
      tremendous potential. Recent studies indicate that the application of different forms of
      thermal energy to the skin surface decreases postoperative wound infections significantly. It
      is known that high-normal arterial oxygen tension levels have decreased surgical wound
      infection from 11% to 5%. The application of water-filtered infrared A (wIRA) irradiation has
      been successfully applied in patients with ulcus cruris and superficial skin-tumors to
      alleviate pain and regulation of the body temperature in neonatology. The simple preoperative
      whole body warming for 30 min before surgery resulted in a statistically reduced occurrence
      of postoperative wound infections. A more recent study showed the beneficial effects of
      postoperative wIRA application on wound healing. The effects of wIRA leading to this success
      in therapy can be explained by thermal and non-thermal effects. A major advantage of the wIRA
      vs. the application of simple warming blankets lies upon the effective penetration of the
      wIRA applied energy within the deep subcutaneous tissue at depths of 2-3 cm. Further effects
      of the applied energy lead to vasodilation of capillaries with consecutive effective
      conduction of energetic blood flow into deeper tissue layers. Non-thermal effects of the wIRA
      application consist of direct stimulation and active immunomodulation by specialized immune
      cells. Furthermore, wIRA can induce protective proteins, e.g. ferritin in the skin and
      potentially influences common cross-talks within cells and extracellular matrices. These
      effects display regulatory roles in wound repair processes that may also be responsible for
      positive cosmetic results. More important for the clinical assessment of wound healing in the
      early phase of hospitalization is the effect of wIRA to significantly reduce postoperative
      pain. Surgery and postoperative pain evoke stress related effects that are induced by
      profound neuroendocrine changes in cytokine activity and related processes. Increased blood
      flow, due to vasodilation, helps to strongly eliminate accumulated pain mediators, lactic
      acid and potential bacterial toxins. The metabolism is induced and mediates also non-thermal
      effects such as attraction of immune cells and potential effects on nociceptors. These direct
      effects of wIRA can be easily followed when postoperative irradiation is performed. The
      problem of developing wound infections may rely within the first hours after and already
      during the operation, when the wound gets "preconditioned" with potential mediators or
      bacteria that may lead to postoperative encountered wound infections. A recent study
      indicated that immediate postoperative warming for 2 hours after hernia surgery may provide
      comparable benefits to seven days of warming. According to the idea of preventing deleterious
      preconditions in the process of wound healing, we tested here, the one time preoperative
      application of wIRA and its impact on postoperative wound healing and related clinical
      questions. Comparable to preoperative antibiotic single shot treatment we relied on the
      expansive impact of preoperative wIRA application.

      The prospective randomized controlled clinical trial is designed to study the effects of
      single time preoperative wIRA irradiation on the postoperative outcome of wound infections
      after visceral surgery.
    

Intervention name(s): wIRA irradiation; visible light only
Intervention type(s): Device; Other
Intervention description(s): wIRA irradiation for 20min prior to surgery. The distance between the light bulb and the skin surface was 27cm.; visible light application at a distance of 27cm from the skin surface with for 20 min.
Other intervention name(s): wIRA (Hydrosun® radiator; Hydrosun Medizinaltechnik, Müllheim, Germany); Standard light bulb with visible normal conventional light.
Allocation: Randomized
Intervention model: Single Group Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Supportive Care
Keywords: wound infection; surgery; surgical wound infection rate; wound healing