Wound management – haemorrhage

A dry wound (i.e. one with minimal oozing) is an essential prerequisite for successful closure to achieve the best result with minimal formation of fibrous tissue. Failure to achieve adequate control of bleeding:

• Keeps the wound edges apart and thus requires a larger gap to be bridged, which leads to a greater deposition of fibrous tissue
• May result in a haematoma:
• An accumulation of clot which is lysed and may require release before the wound edges can be opposed
• May lead to infection:
• A haematoma is an ideal place in which bacteria can multiply

The 3 main techniques used to stop bleeding are:

• Compression
• Ligation
• Thermal coagulation

Compression:

• Packing a bleeding cavity or applying pressure to a bleeding area are both particularly useful if there is widespread oozing
• 5 minutes of compression allows normal haemostasis to take place by:
• Contraction of the mouths of small vessels
• Platelet aggregation
• Clotting

• However, these processes must be normal for the effective arrest of bleeding

Ligation:

• The mouth of the divided vessel which bleeding is picked up with special forceps (haemostats) and tied off with a ligature (either absorbable or non-absorbable)
• Absorbable sutures:
• Have a clear advantage in that, once the vessel has been occluded and has thrombosed behind the point of ligature, the suture ultimately disappears so that the foreign body reaction is minimal
• However, they may degrade too fast, especially in the presence of sepsis and, in consequence, secondary haemorrhage may occur

• For this reason, large vessels are more often ligated with non-absorbables, which may be braided for easy handling
• Blood vessels and other small tubes (e.g. the cystic duct) may also be closed with stainless steel clips carried on a special forceps
• Larger vessels may be transected using vascular stapling instruments

Thermal coagulation:

• This involves the use of diathermy (or cautery in the USA)
• Is a high-frequency electric current
• The pathway of current is either:
• Unipolar (from the point of application through the body of the patient to a large area contact plate and thence to earth )
• Bipolar (between 2 points of the instrument)

• Small blood vessels can be precisely dealt with using either technique and the method is also used for cutting soft tissues with minimal bleeding when a continuous waveform is produced and an arc is generated between the electrode and the tissue
• Vaporisation of the water in the cells occurs with disruption of tissue continuity (so-called cutting diathermy)