Hypotensive anaesthesia and blood loss in orthognathic surgery: a clinical study

Objectives: To find out whether hypotensive anaesthesia minimized blood loss during orthognathic surgery. Design: A prospective randomized clinical study. Subjects and methods: 53 consecutive patients, 15–33 years old, who were to have orthognathic operations were admitted to the study. They were randomly allocated to either normotensive or hypotensive anaesthesia. Results: Median (range) blood loss/operation (ml) underhypotensive anaesthesia was 200 (90–400)ml and under normotensive anaesthesia was 350 (130–1575)ml (P= 0.01), and those for maxillary segmental osteotomy under hypotensive anaesthesia were 85 (40–240)ml and, under normotensive anaesthesia, 175 (100–190)ml (P= 0.05). Conclusion: There was pronounced reduction in blood loss during orthognathic operations done under hypotensive anaesthesia compared with those done under normotensive anaesthesia.