The achievement of haemostasis in otological surgery is essential for the operation to proceed. This is due to the small scale of the microscopic work taking place. Often, under magnification, a small amount of bleeding can disrupt the surgeon's operative field to such an extent that the procedure may have to be abandoned.
One of the main techniques used to maintain a clear operating field in microscopic ear surgery involves close partnership with the anaesthetist, who can achieve a low operating blood pressure. By allowing the patient to be anaesthetised safely in a hypotensive state, the otologist obtains a drier field in which to operate. Any bleeding that occurs during this period should be immediately recognised and stopped before the whole area becomes engulfed with blood. Other techniques employed to achieve a bloodless field in ear surgery include the use of adrenaline (epinephrine). This is often used initially with a local anaesthetic, such as lidocaine, to inject the subcu-ticular tissues prior to the skin incision. Adrenaline is also used to saturate tiny cotton wool pledgets that can be placed down the ear, over sites of bleeding to stop or slow oozing, helped with the element of compression. An adrenaline-soaked cotton ball is often an adjunct, albeit an important adjunct, to the use of bipolar diathermy for specific bleeding points.
Studies have looked into the effects of hypotension during ear surgery. It is widely recognised that hypotension is a useful technique to improve the operative field in ear surgery, under the microscope. However, the way this is achieved has been debated. The use of sodium nitroprusside is just one example of how a powerful anti-hypertensive has been trialled in such cases. One study using nitro-prusside found it to be problematic, causing frequent tachyphylaxis, and not showing any greater effectiveness over commonly used anaesthetic techniques.3 Another study, however, revealed potential benefits with platelet aggregation.4
Was this article helpful?