The cost and efficacy of two wound treatments - effectivness of saline and hydrogel dressings

AORN Journal, May, 2003 by Virginia A. Capasso, Barbara Hazard Munro

Among patients undergoing surgery for critical limb ischemia, impaired wound healing is a significant problem. Up to 25% of patients who undergo infrainguinal arterial bypass surgery may sustain wound (ie, surgical, ischemic) complications, which require an average of 4.2 months (ie, range of 0.4 months to 48 months) to heal. (1) The implication is that patients with perioperative wound complications will need wound care in the home after hospital discharge. As a consequence of shortened hospital stays and capitated payment systems for Medicare beneficiaries' home health care, the products and strategies used for wound care must promote efficient and effective healing. (2)

In the home care setting, wet-to-dry normal saline gauze dressings are second only to dry gauze dressings as the most frequent topical wound treatment. (3) This therapy is resource-intensive due to the frequent home nursing visits required for dressing changes and delayed healing caused by desiccation of the wound bed and repetitive disruption of the formation of new granulation tissue by removal of dried, adherent dressings.

Wound care specialists anecdotally report more rapid wound healing when amorphous hydrogel dressings are used instead of normal saline dressings. (4) Amorphous hydrogel dressings maintain a moist wound environment, thereby preventing desiccation of the wound bed when removed.

In laboratory and animal studies, the ability of amorphous hydrogel to maintain its structure after absorbing wound fluid determines its contribution to a moist wound environment. Less viscous types liquefy after absorbing small amounts of wound fluid (ie, 2 mL to 3 mL), thus adding fluid to the wound. It is hypothesized that more viscous types maintain their structure and form a protective barrier over the wound, sequestering wound fluid and increasing the bioavailability of enzymes and growth factors for autolytic debridement and wound repair. (5)

Only one previously published study has compared the effectiveness of wet-to-dry normal saline gauze dressings and dressings containing the standard formulation of amorphous hydrogel in human wound healing. (6) That study focused on pressure ulcers, and there was no significant difference in wound healing between the two treatment groups. There have been no studies of the efficacy of the two treatments in managing perioperative wound complications or arterial or diabetic ulcers, nor has there been a study comparing the cost effectiveness of the two treatments.

The clinical use of amorphous hydrogel dressings as an alternative to wet-to-dry normal saline gauze dressings is limited by lack of scientific evidence of their effectiveness in managing arterial and diabetic wounds. The purpose of this nonexperimental research, therefore, was to compare the rate of wound healing and cost of wound care associated with wet-to-dry normal saline gauze dressings to the rate of wound healing and cost of wound care associated with amorphous hydrogel dressings for patients with infrainguinal arterial disease and diabetes. These patients were discharged from the hospital to home care for management of perioperative arterial surgical wound dehiscence and nonhealing ulcerations. Identifying the best approach and, for equally effective treatments, the most cost-effective strategy helps perioperative nurses make autonomous and collaborative treatment decisions.

RESEARCH QUESTIONS

The following research questions were asked.

* After controlling for age and comorbid conditions as a combined score using the Charlson comorbidity index (CCI), are there significant differences in the rate of wound healing between the two treatment groups (ie, wet-to-dry normal saline gauze dressings and amorphous hydrogel dressings)? Are there significant differences in the rate of wound closure over time? Is there a significant interaction between treatment and time

in relation to wound closure?

* After controlling for age and comorbid conditions as a combined score using the CCI, are there significant differences in the cost of care between the two treatment groups?

DEFINITION OF TERMS

Age was defined as chronological age in years when participants entered the study. Comorbid conditions were measured using the CCI, which was calculated by combining a weighted comorbidity subscore and an age subscore. (7) Wound healing was defined as the progressive reduction in wound surface area from the beginning of the study (ie, time one) through three data collection points to the end of the study (ie, time four). Cost of care was estimated by calculating the sum of total charges for

* home nursing visits,

* wound care supplies, and

* treatment of wound complications or conditions that adversely affected wound healing during the study period, if applicable.

THEORETICAL FRAMEWORK

The acute wound healing process has three phases--inflammation, proliferation, and maturation. (8) The inflammatory phase is characterized by clot formation-resolution and inflammation. Fibroplasia, depositing of collagen, angiogenesis, and formation of squamous epithelium distinguish the proliferative phase. The dual process of matrix breakdown and matrix synthesis predominate in the maturation phase.