Controlled hypotension during surgery—hypotensive anesthesia—is widely practiced and considered suitable for various surgeries including maxillofacial surgeries. Hypotensive anesthesia limits the blood loss during surgery and facilitates speed of surgery by making the surgical field bloodless. Maintaining normal blood pressure (BP) during any surgery is an index of skillful anesthesia, as the organ perfusion is preserved between the normal BP limits. Achieving optimum hypotension is a skill, as excess lowering of BP may be hazardous due to the reduced perfusion to essential organs such as brain, heart, and kidneys. Reduction in mean arterial pressure (MAP) by 30% is considered adequate. This results in systolic BP of 80–90 mm Hg and MAP of 50–65 mm Hg. Surgeries of ear, nose, and throat (ENT) pose great challenges for surgeons as well as for the anesthesiologists due to dense vascularity of the region, repeated infections leading to fibrosis, increased blood loss during surgery, and limited operative field. Nowadays, endoscopic sinus surgeries and microscopic surgeries are demanding controlled hypotensive anesthesia, and so it is the need of the time.
https://www.jmedsciences.com/doi/JMEDS/pdf/10.5005/jp-journals-10045-00132