The Problem:
Issues involved in postoperative wound care are multi-focal, complex, and are codependent. One goal is to minimize postoperative bleeding and drainage, blister formation, hematoma formation, and wound breakdown. All of these may lead to pain, stiffness, and infection. A second goal includes the need for optimal function. In the case of knee replacements, dressings must allow the knee a free range of motion without creating blistering from shear and in the case of hip replacements avoiding cumbersome hip spica dressings which interfere with bathing and hygiene.
When I was in my residency we were taught the classic toe to proximal thigh compression dressing for knee replacements. The joke was that you needed a separate operative dictation for this type of dressing since it was such an involved ritualistic process. The benefits of this type of dressing were mainly avoidance of hematoma, but it risked peroneal palsy at the fibular neck, inhibited ROM, and risked significant blistering of the skin with aggressive flexion from shear stress. Further, this type of wound dressing does not allow a specific amount of compression to be applied and does not allow quantification of wound drainage. Alternatively not using a compression type dressing leads to the serious risk of hematoma formation, which dramatically increases the risk of infection, as well as stiffness and pain. Indeed a recent JBJS paper on hematoma formation after TKR concludes, "Patients who return to the operating room within thirty days after the index total knee arthroplasty for evacuation of a postoperative hematoma are at significantly increased risk for the development of deep infection and/or undergoing subsequent major surgery. These results support all efforts to minimize the risk of postoperative hematoma formation."
To further highlight the importance of this issue, I would point out the findings of a recent academy podium presentation concerning the complications in super morbidly obese patients undergoing TKR. "Overall, there were 54 (40.6%) surgical complications and 15 (14.3%) medical complications including 2 perioperative deaths. Surgical complications included 20 knees with prolonged wound drainage, 4 knees with cellulitis or stitch abscesses, and 6 legs with residual neuropathy for a minor complication rate of 22.6%. There were 19 (14.3%) re operations/major complications including 9 irrigation and debridements with component retention, 6 resection arthroplasties for deep infection."
When we combine the needs of a postoperative dressing we agree on the need for efficient evacuation of drainage fluid, wound compression that can be maintained at a specific level, allowance for ROM and function, ease of hygiene, minimal shear and blister formation, ability to assess and quantify the amount wound drainage, and to minimize the need for postoperative dressing changes (as early dressing changes can tear at the skin).
The most logical answer for an optimal wound dressing was suggested to me several years ago when one of the KCI Representatives (wound vac company) suggested that the classic wound vac could be used as a postoperative dressing. This dressing would address all of the aforementioned requirements including compression (as the sponge compresses over the skin, there is a pressure effect). The only issue is the significant expense of this commercial system. During this time, I reasoned that the same effect could be achieved with sterile gauze, a hemovac drain, and covering tegaderm, and otherwise the principles are the same. Just as with a wound vac, the pressure is set between 125 and 150 mm, using hospital wall suction. As it turned out a literature search turned out good clinical data in 4 journal articles to support this concept (using the exact same technique), and I have found that this approach minimizes wound problems, especially in my co morbid group of obese diabetic patients that are receiving lovenox (or other blood thinners). In addition, in the vast majority of these patients, the initial postoperative dressing remains dry throughout the hospital stay and therefore does not need to be changed.
CR Wheeless MD
crw3@datatrace.com
As an addendum, the question has been raised as to whether hospital wall suction is reliable for this purpose and whether it could cause skin necrosis if there were significant fluctuations in the wall suction pressure. I think that the answer to this is quite simple. First, the most common use of wall suction would probably include nasogastric tubes on "low wall suction." If there were major fluctuations in the suction, then we would expect to see problems in these patients noting the delicate nature of the gastric lining (as compared to skin). Second there are papers in the general surgery literature that discuss the use of low and high internal suction drainage of the subcutaneous space for mastectomies (with no problems), and finally there are two orthopaedic papers that discuss using wall suction pressures as high as 300 mm Hg without complications (ref). I think that it is clear that hospital wall suction set at 150 mm Hg is quite safe for orthopaedic patients.
- References for external closed suction drainage dressings:
- Suction dressings: a new surgical dressing technique.
- Suction dressings in total knee arthroplasty--an alternative to deep suction drainage.
- External suction drainage in primary total joint arthroplasties. (full text article)
- Incisional Vacuum-Assisted Closure Therapy
- General Surgical References:
- Half versus full vacuum suction drainage after modified radical mastectomy for breast cancer- a prospective randomized clinical trial
- A prospective randomized trial of high versus low vacuum drainage after axillary dissection for breast cancer.
- Misc References:
- Early Return to Surgery for Evacuation of a Postoperative Hematoma After Primary Total Knee Arthroplasty
- Blood loss after total hip replacement: a prospective randomized study between wound compression and drainage.
- Wound complications after hip surgery using a tapeless compressive support
- Wound oozing after total hip arthroplasty.
- Factors associated with prolonged wound drainage after primary total hip and knee arthroplasty.
- Is a fat stitch required when closing a hip hemiarthroplasty wound without a drain?
- Blood loss after total hip replacement: a prospective randomized study between wound compression and drainage.
- Wound complications after hip surgery using a tapeless compressive support.
