In First Aid for Wounds we talk about the initial assessment of a wound and first aid treatment so as to maximize the healing process. In this article principles and techniques of long term care of deep wounds are discussed including:

• Why leave wounds open
• How wounds heal
• Daily care techniques and products
• Wound healing time line
• Excessive granulation tissue (proud flesh)
• Infection prevention, assessment, and treatment
• Decubital (pressure) sores

When reading medical history books a fact that stands out is that at the beginning of large wars, even as late as the Vietnam War, doctor attended wounds frequently did worse than unattended wounds. The reason? Too many wounds that were not suitable for closing were closed. In the later wars as doctors gained experience and more wounds were left to heal open with regular cleaning and debridement prognosis improved.

This is a very important concept: well-managed wounds heal more safely open than closed. If viable bacteria are left in a wound that is closed the tendency is for the infection to spread to the surrounding tissues, particularly if those tissues have been traumatized in any way. At its worse the infection may get into the blood resulting in septicemia a possible fatal complication. Also, closed wounds may have lower oxygen tensions than open wounds allowing Clostridia to proliferate. These organisms are responsible for gangrene, a spreading toxic infection that can lead to loss of limb and possibly life.

Of course clean wounds that are not too old that have a minimal amount of trauma to the surrounding tissues pose little threat and we sew these up daily without complications. However when a wound does not fall in these guidelines leaving the wound open has many benefits:

• Wound drainage can be removed regularly to help maintain an environment that is not conducive to bacterial growth.
• Daily cleaning and debridement allows removal of devitalized tissues which further discourages bacterial growth.
• Being open, oxygen tension is higher promoting healing, helping prevent anaerobic (Clostridial) infection.
• Topical antimicrobials can be directly applied to the wound further helping to prevent infection.

Too much contamination and devitalized tissue are only some of the reasons for leaving a wound open. Other circumstances would include not enough tissue to close the wound or the wound is in an area that historically takes sutures poorly, such as on a joint face. Some horses can continue to work with an open wound while a sutured wound may require rest and/or limb immobilization.