Cochrane Abstracts

Background

Hyperbaric oxygen therapy (HBOT) is used as a treatment for acute wounds (such as those arising from surgery and trauma); however, the effects of HBOT on wound healing are unclear.

Objectives

To determine the effects of HBOT on the healing of acute surgical and traumatic wounds.

Search strategy

We searched the Cochrane Wounds Group Specialised Register (August 25, 2010), the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2010, Issue 3), Ovid MEDLINE (1950 to August 2010, Week 2), Ovid MEDLINE (In-Process & Other Non-Indexed Citations; August 24, 2010), Ovid EMBASE (1980 to 2010, Week 33), and EBSCO CINAHL (1982 to August 20, 2010).

Selection criteria

Randomized controlled trials (RCTs) comparing HBOT with other interventions or comparisons between alternative HBOT regimens.

Data collection and analysis

Two review authors conducted selection of trials, risk of bias assessment, data extraction, and data synthesis independently. Any disagreements were referred to a third review author.

Main results

Three trials involving 219 participants were included. The studies were clinically heterogeneous; therefore, a meta-analysis was inappropriate.

One trial (48 participants with burn wounds undergoing split skin grafts) compared HBOT with usual care and reported a significantly higher complete graft survival associated with HBOT (95% healthy graft area risk ratio [RR] = 3.50; 95% confidence interval [CI] = 1.35-9.11). A second trial (36 participants with crush injuries) reported significantly more wounds healed with HBOT than with sham HBOT (RR = 1.70; 95% CI = 1.11-2.61) and fewer additional surgical procedures required with HBOT (RR = 0.25; 95% CI = 0.06-1.02) and significantly less tissue necrosis (RR = 0.13; 95% CI = 0.02-0.90). A third trial (135 people undergoing flap grafting) reported no significant differences in complete graft survival with HBOT compared with dexamethasone (RR = 1.14; 95% CI = 0.95-1.38) or heparin (RR = 1.21; 95% CI = 0.99-1.49).

Many of the predefined secondary outcomes of the review, including mortality, pain scores, quality of life, patient satisfaction, activities daily living, increase in transcutaneous oxygen pressure (TcpO₂), amputation, length of hospital stay, and costs, were not reported. All 3 trials were at unclear or high risk of bias.

Authors’ conclusions

There is a lack of high-quality, valid research evidence regarding the effects of HBOT on wound healing. While 2 small trials suggested that HBOT may improve the outcomes of skin grafting and trauma, these trials were at risk of bias. Further evaluation by means of high-quality RCTs is needed.

Synopsis

Acute surgical and traumatic wounds occur as a result of a trauma or surgical procedures, and while many heal uneventfully, sometimes poor local blood supply, infection, damage to the blood vessels, or a combination of factors results in acute wounds taking longer to heal. Hyperbaric oxygen therapy (HBOT), which involves placing the patient in an airtight chamber and administering 100% oxygen for respiration, at a pressure greater than 1 atmosphere, is sometimes used with the aim of speeding wound healing. The aim is to bathe all fluids, tissues, and cells of the body in a high concentration of oxygen.

This review did not find any high-quality research evidence showing that HBOT is beneficial for wound healing. Two poor-quality studies suggested benefits associated with HBOT. The first in patients with crush injuries showed improved wound healing and fewer adverse outcomes. The second reported improved survival of split skin grafts. A third trial reported no benefits associated with HBOT for skin grafts.

Furthermore, better quality research is needed to determine the effects of HBOT on wound healing.

Background

Surgical site infections are a continuing concern in health care. Microbial sealant is a liquid applied to the skin immediately before surgery. It is thought to contribute to reducing surgical site infections by sealing in the skin flora to prevent contamination and infection of the surgical site.

Objectives

To assess the effects of the preoperative application of microbial sealants (compared with no microbial sealant) on the rates of surgical site infection in people undergoing clean surgery.

Search strategy

We searched the Cochrane Wounds Group Specialised Register (searched May 10, 2010), the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library 2010, Issue 2), Ovid MEDLINE (1950 to April 2010, Week 3), Ovid MEDLINE (In-Process & Other Non-Indexed Citations; searched May 10, 2010), Ovid EMBASE (1980 to 2010, Week 18), and EBSCO CINAHL (1982 to May 10, 2010). We searched bibliographies and contacted manufacturers of microbial sealants for unpublished studies. There were no restrictions based on language, date, or publication status.

Selection criteria

Randomized controlled trials (RCTs) were eligible for inclusion if they involved people undergoing clean surgery in an operating theatre and compared the use of preoperative microbial sealants with no microbial sealant.

Data collection and analysis

All review authors independently extracted data on the characteristics, risk of bias, and outcomes of the eligible trial.

Main results

One small trial (177 participants undergoing hernia repair) met the inclusion criteria. There was no statistically significant difference in the rates of surgical site infection (3 patients in the control group developed a surgical site infection compared with none in the intervention group; risk ratio = 0.17, 95% confidence interval = 0.01-3.19, P = .23).

Authors’ conclusions

There is currently insufficient evidence as to whether the use of microbial sealants reduces the risk of surgical site infection in people undergoing clean surgery and further rigorous RCTs are required.

Synopsis

Surgical site infection is a serious complication of surgery. Microbial sealant is a liquid applied to the surface of the skin immediately before surgery to seal in any bacteria living on the skin that may pose a risk of infection. Before applying the sealant the skin at the operation site is usually prepared with a solution of 10% povidone-iodine. Only 1 eligible randomized trial was identified that compared the impact on surgical site infection rates of sealant compared with no sealant; this trial was too small to detect any important difference in surgical site infection rates as statistically significant; therefore, further research is needed.