CABG Wound Care Best Practices are Elusive

Following the best wound care practices related to coronary artery bypass graft (CABG) surgery may not always be easy, since there are few specific official recommendations, says Deverick Anderson, MD, MPH, assistant professor of medicine in the division of infectious diseases at Duke University Medical Center.

Patients are given antiseptic soap that contains chlorhexidine to use prior to surgery, but currently there is no specific wound care practice that is performed post-operatively, except that bandages are changed every day, or more often if necessary, Anderson says.

Some specific recommendations that are available, Anderson notes, are in 1999 guidelines from the Centers for Disease Control and Prevention (CDC). They advise the following:

• protect the wound with a sterile dressing for 24-48 hours after surgery 

• wash hands before and after dressing changes 

The sterile dressing component is probably well followed throughout the United States, but there is no data that looks specifically at handwashing in the post-op period, Anderson says.

However, There is substantial evidence that healthcare workers do a pretty poor job of handwashing in general, he says.

Surgery teams that complete CABG surgeries receive special training that is related specifically to CABG, and surgeons typically complete a cardiothoracic (CT) fellowship, Anderson says. CT surgeons and general surgeons alike need to be up to date with the latest evidence and guidelines, specifically regarding antimicrobial prophylaxis, he adds.

The Centers for Medicare & Medicaid (CMS) will on Oct. 1, 2008, stop reimbursing for certain nosocomial infections, including infections related to CABG procedures. As such issues of hospital compensation and public reporting continue to rise, hospitals and surgeons will explore all available options to improve outcomes, Anderson says.

Post-op care is not receiving a great deal of attention currently (most attention is placed on pre- and peri-operative periods traditionally the highest risk period for infection), but I imagine this may change, he adds.

Practice is vital, but materials are too. One product, Apligraf®, has shown success in improving wound healing in sternal and leg wound complications after coronary artery bypass surgery.¹ Between 1998 and 2001 at Cardiovascular Institute of the South, and Southwest Medical Center, both in Lafayette, La., a research team set out to test Apligraf, a skin repair therapy that is created from biological ingredients found in healthy human skin. The material resembles a thin, circular piece of living skin and is used to heal sores such as diabetic foot and venous leg ulcers that are not healing after 3-4 weeks of conventional therapy. It delivers fresh cells, nutrients and proteins directly to the wound.² 

The study involved 1,550 patients who underwent coronary artery bypass surgery using the saphenous vein. In 45 (2.9 percent) of 1,550 patients, leg wound complications developed. This was referred to as group A.¹ 

In 15 (0.9 percent) of 1,550 patients, sternal wound complications developed. This was referred to as group B. Apligraf was used as the primary treatment for 30 (66 percent) of 45 leg wounds and for 9 (60 percent) of 15 sternal wounds. Traditional wound care included debridement and daily wet-to-dry dressings.¹ The length of wound healing ranged from 26 to 72 days (mean, 46) for Apligraf group A and from 34 to 120 days (mean, 84) for the traditional wound care group A.¹ 

The length of wound healing ranged from 21 to 80 days (mean, 39) for Apligraf group B, and from 36 to 110 days (mean, 62) for traditional care group B.¹ 

The researchers concluded that Apligraf significantly improves wound healing in patients with leg and sternal wound complications.¹ 

In a normal healing process proteins and growth factors stimulate the production of new skin. When illness such as diabetes or circulatory issues impede on the process, the skin sometimes lacks important biological substances. As a result, ulcers or sores can form.² Like actual skin, Apligraf contains an outer and an inner layer of protective skin cells.² Another useful resource for wound care is silver ion technology. According to a 2003 study titled, Importance of assessment and wound bed preparation in the treatment of chronic wounds, silver ion technology reduces bioburden of properly prepared wound beds and assists in the progression of healing phases.

Silver ion technology has been shown to be an effective, yet economically-sound antimicrobial treatment, the authors write. The new silver dressing applications can be utilized to support the optimal moist wound healing environment.

The authors focused on the case of a 60-year-old woman who had a history of noninsulin-dependent diabetes mellitus (NIDDM). Her most recent hospitalization resulted with a CABG X 4 vessels and she was eventually admitted to home health services where she was well nourished and had stable blood sugars.³ 

The harvest sites, on the right lower extremity were full-thickness dehisced surgical wounds, the authors write. The physician ordered dressing changes NS moistened gauze formechanical debridement, BIDThis treatment was continued for nine weeks. The wound had not improved significantly and the (wound ostomy and continence nurse) WOCN specialist was called to reassess the wound and the wound care regimen.

The wound was approximately 20 percent slough and 80 percent pink with mixed granular and non-granular tissue. The treatment was changed to negative pressure therapy. The wound progressed for several weeks and then exhibited a foul odor and a dramatic increase in drainage. An alginate dressing was initiated and the wound culture was positive for a moderate growth of methicillin-resistant Staphylococcus aureus (MRSA).³ 

Silver ion therapy was initiated because of the dressings antimicrobial properties as well as its fluid handling capabilities, the authors write. The wound continued to progress until closure at 12 weeks of silver ion therapy.

Sternal surgical site infections (SSI) after CABG surgery increases patient morbidity and mortality and costs for patients, payors, and the healthcare system. The incidence of SSI reportedly is low (from 1 percent to 5 percent), but the effects can be deforming and fatal.⁴

A study recorded in a paper titled, Preoperative skin preparation of cardiac patients, set out to discover whether one method of skin preparation is better than others for reducing postoperative sternal SSIs in CABG patients who are at high risk for developing SSIs.

Researchers focused on a 900-bed tertiary hospital in the southwestern United States where they tried to optimize the preoperative skin preparation of patients who were undergoing CABG. The goal was to reduce sternal SSI risks.

Some factors that put CABG patients at greater risk for infection include age, chronic obstructive pulmonary disease (COPD), the use of the internal mammary artery (IMA) for grafting, prolonged mechanical ventilation, surgical time, the use of bone wax, preoperative nasal carriage of Staphylococcus aureus, and the extensive use of electrosurgery.⁴

Eight cardiovascular surgeons at the hospital practiced various methods of preoperative skin preparation before performing open heart surgery. The majority used povidone-iodine paint only, one used a 5-minute povidone-iodine scrub and paint, and another used a one-step iodophor/alcohol water insoluble film.

According to the researchers, it is difficult to determine which use and type of antimicrobial agents are absolutely better than another.

This is due in part to the fact that much of the research that has been conducted compares only two types of agents or the sample sizes are entirely too small to assume significance, the authors write.

Even among the different iodine, CHG, and alcohol families, effectiveness varies depending on concentration, temperature, level of acidity, the particular germ or virus, contact time, and dry versus wet states, they continue. Each article points out different strengths and weaknesses. 

References 

1. Allie DE, Hebert CJ, et al. Novel treatment strategy for leg and sternal wound complications after coronary artery bypass graft surgery: Bioengineered Apligraf. The Annals of Thoracic Surgery. 2004.

2. www.apligraf.com/index.html 

3. Rose SB, et all. Importance of assessment and wound bed preparation in the treatment of chronic wounds. Presented at the 16th-Annual Symposium on Advanced Wound Care, Las Vegas. April, 2003.

4. Segal CG, Anderson JJ. Preoperative skin preparation of cardiac patients. AORN Journal. Nov. 2002.