Original contribution
Experience with Chitosan Dressings in a Civilian EMS System

Presented in part at the Society for Academic Emergency Medicine, Western Regional Research Forum, Los Angeles, California, March 17, 2006.
https://doi.org/10.1016/j.jemermed.2007.05.043Get rights and content

Abstract

The HemCon® Bandage (HemCon Medical Technologies Inc., Portland, OR) is a hemostatic dressing made of chitosan, a complex carbohydrate derived from chitin. The objective of this study was to determine the effectiveness of the HemCon® Bandage in a civilian emergency medical services system. The HemCon® Bandage was added to the trauma kits of a fire agency and data were collected from June 1, 2005 to August 31, 2006. The dressing was to be used when conventional treatment (pressure and gauze dressings) failed to control external bleeding wounds or for obvious arterial bleeding. Paramedics documented time to cessation of bleeding after HemCon® Bandage application as well as wound characteristics and suspected bleeding type. There were 37 uses and complete data were available for 34 cases. Wound location involved the head, neck, or face in 13 subjects and extremities in 18 subjects. There was one case each involving the chest, abdomen, and axilla. The bandage controlled hemorrhage in 27/34 (79%) cases, 25/34 (74%) within 3 min of application. In 25/34 cases, direct pressure had initially failed to control bleeding and the HemCon® Bandage was effective in 19/25 (76%). The HemCon® Bandage failed to stop bleeding within 10 min in 7 cases. User error was a factor in 6 of the 7 failures. The HemCon® Bandage is an effective adjunct for uncontrolled external hemorrhage when traditional measures, such as pressure and gauze dressings, fail.

Introduction

Hemorrhage is the second leading cause of death in civilian trauma and the leading cause of death from battlefield trauma in the military (1, 2, 3, 4). There has been little advancement in the control of external hemorrhage, as evidenced by our reliance on gauze dressings and direct pressure, which has remained unchanged for hundreds of years. As such, there recently has been a significant interest in the development of new external hemostatic agents to achieve hemostasis when conventional methods fail. One of these products is the HemCon® Bandage (HemCon Medical Technologies, Inc., Portland, OR), which is a 10 cm × 10 cm × ∼2 mm-thick square bandage (Figure 1) composed of chitosan and a non-absorbable backing in a vacuum-sealed pouch.

Chitosan is a biodegradable, non-toxic, complex carbohydrate derivative of chitin (poly-β[1→4]-N-acetyl-D-glucosamine), a naturally occurring substance (5). Numerous animal studies have demonstrated its effectiveness as a hemostatic agent in controlling bleeding from both arterial and venous sources, as well as in coagulopathic subjects (6, 7, 8, 9, 10, 11). There are several factors that are thought to contribute to the hemostatic function of chitosan, the most important being its inherent mucoadhesive properties. Additional mechanisms thought to be involved include platelet activation, vasoconstriction, and interactions with red blood cells through ionic forces and cell surface proteins (12, 13, 14, 15, 16). Other possible beneficial attributes of chitosan have been proposed as well, including antimicrobial activity and improved wound healing compared with standard dressings (17).

The military has been the first to employ many new hemostatic agents in humans and the HemCon® Bandage has been distributed to medical personnel involved with combat operations in Iraq and Afghanistan. A retrospective review of 64 uses from these two conflicts suggests that the HemCon® Bandage is an effective hemostatic agent for pre-hospital combat casualties when standard methods are unsuccessful (5). Given that significant morbidity and mortality also can result from uncontrolled external hemorrhage in civilian emergency medical services (EMS) systems, it was hypothesized that a chitosan-based dressing also may control hemorrhage in wounds not responding to direct pressure.

Section snippets

Study Design

Data for this case series were obtained through a retrospective chart review of prospectively completed data collection forms after each HemCon® Bandage use, as well as the accompanying pre-hospital case record. The data form was adapted from the one used by the military. The institutional review board at the Oregon Health & Science University (OHSU) approved the study, and waived the requirement of informed consent.

Study Setting and Population

The HemCon® Bandage was added to the trauma kits of all 22 frontline

Results

Thirty-seven uses of the HemCon® Bandage were reported within the 15-month study time period. Complete data on the primary outcome variable were present for 34 cases (Table 1). In three cases, the time to cessation of bleeding after HemCon® Bandage application was not recorded and these cases were eliminated from further analysis.

Of the 34 uses analyzed, no adverse events or complications were reported. Most of the wounds were extremity wounds (53%) with lacerations to the head, neck, and face

Discussion

In recent years, the U.S. Food and Drug Administration has approved several hemostatic agents and bandages for hemorrhage control. Unfortunately, human clinical data are lacking and most of these products have been tested only in animal models of severe hemorrhage. Chitosan-based dressings have been successfully used in swine models of splenic trauma, liver lacerations, and aortic perforation. (7, 8, 10). The only reported human experience to date comes from use in Operation Iraqi Freedom and

Limitations

Due to the observational nature of this study, there are several limitations that deserve attention. Our findings are limited by the small sample size and factors inherently present in EMS studies. Data collection was based on written accounts by the EMS providers and could not be independently verified. For example, we could not confirm whether the sources of bleeding were indeed venous or arterial. In addition, the amount of pressure and duration of compression used with gauze dressing

Conclusions

The chitosan-based HemCon® Bandage is beneficial in stopping uncontrolled external hemorrhage in the civilian EMS setting when traditional methods such as pressure and gauze fail. Proper training in the use of the bandage is essential because user error was a contributing factor in most of the documented failures. Future trials should attempt to address the differences in morbidity and mortality using traditional methods vs. the HemCon® Bandage.

Acknowledgment

We thank Tualatin Valley Fire EMS Chief Mark Stevens, Alec Belman, md, and Staci McAdams of HemCon Medical Technologies, Inc. for their collaborative efforts with this study.

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