Haemorrhage (bleeding) is a problem during surgery for a number of reasons:
- It obscures the surgical field
- It may cause hypovolaemic shock and death
- It provides a medium for bacterial growth
- If left, it forms haematomas in dead space, inhibiting proper healing, and further increasing the risk of infection by providing a growth medium for bacteria.
Haemorrhage should not induce panic, but the blood loss should be controlled as quickly, completely and with as little trauma, as possible. This may be done using the following three techniques:
Pressure
- Digital pressure through a moistened gauze swab pressed onto the source for at least 2 minutes, (which can seem like a very long time). A clot should form to seal the hole. Further digital pressure can be used for up to five minutes if bleeding has not ceased after the first two minutes of digital pressure. This should be timed on a clock or watch, if it is not effective then a different method should then be selected.
- Crushing pressure from haemostatic forceps. The source of haemorrhage should be identified, and then the forceps accurately applied to it. If the bleeding is from a low pressure, small vessel simply crushing it and leaving the forceps in place for a few minutes may be effective. If the vessel is larger than about 2 mm diameter then it should either be isolated and tied off with a simple ligature or sealed using another method such as electrocautery (see below).
Electrocautery
- This method uses electrical current to seal the vessel, e.g. diathermy.
Ligatures
- Metal clips can be used for clamping vessels but cost often precludes their use.
- Absorbable suture material should be used for ligatures when controlling haemorrhage, as non-absorbable material is a persistent foreign body and can act as a focus for infection.
- In small patients, what appears to be a small amount of blood loss can be a significant proportion of the animal’s circulating blood volume. Blood loss should be carefully monitored in any animal and significant loss should be replaced by the administration of fluids (see Anaesthesia for Minor Procedures)