Question

What are the techniques for controlled hypotensive anaesthesia?

Hint:

Always monitor organ perfusion during controlled hypotension to prevent ischemic damage to vital organs.

Answer 1

Step 1: Vasodilator Use.
Controlled hypotension can be achieved through the administration of vasodilators that cause systemic vasodilation. Commonly used agents include:
- Nitroglycerin: A potent vasodilator that reduces both preload and afterload.
- Sodium nitroprusside: An intravenous vasodilator that directly affects both arterial and venous smooth muscle to reduce blood pressure. These agents are titrated to achieve the desired blood pressure reduction while maintaining perfusion to critical organs.

Step 2: Manipulation of Anaesthetic Agents.
General anaesthetic agents such as volatile anaesthetics (e.g., sevoflurane, desflurane) can cause vasodilation. The depth of anaesthesia is adjusted to increase the effect of the vasodilators and maintain the target hypotensive state.

Step 3: Controlled Blood Loss.
In some surgeries, controlled blood loss techniques are employed to minimize the risk of bleeding and maintain a low blood pressure. This can be particularly useful in surgeries requiring minimal bleeding, such as in neurosurgery or ophthalmic surgeries.

Step 4: Conclusion.
Controlled hypotensive anaesthesia is a technique used to reduce intraoperative bleeding and improve surgical visibility. The use of vasodilators, manipulation of anaesthetic depth, and controlled blood loss are all effective strategies to achieve this goal.