Comparison of oral metoprolol versus telmisartan premedication on blood loss and hypotensive anesthesia in patients treated for Orthognathic Surgery

Purpose: This study was aimed to compare blood pressure reducing effects of oral metoprolol versus telmisartan premedication as adjuvant to fentanyl and sevoflurane on various parameters of anesthesia during orthognathic surgery. Additional use of nitroglycerin (NTG) was also seen as an efficacy parameter for inducing deliberate hypotension. Materials and Methods: Ninety patients to be operated for orthognathic surgeries were enrolled in the study and were ran­domly assigned to one of three groups as group A (n=30), an angiotensin receptor antagonist group, given telmisartan 40 mg orally and group B (n=30) given cardio-selective β blocker metoprolol 100 mg orally, and group C (n=30) given inactive placebo as control group. The drugs were given per orally 1 h before anesthesia induction. Inj NTG was used as an adjuvant to achieve deliberate hypotension in case mean arterial blood pressure (MAP) was not adequately controlled inspite of administering maximum dose of fentanyl and sevoflurane. Results: The blood loss was significantly reduced in group A and group B when compared to group C. There was significant increase in over the target range of MAP percentage in group C as compared to groups A and B during deliberate hypotension (DH). The amount of NTG used was significantly lower in group A and B when compared to group C. Conclusion: Premedication with both oral telmisartan 40 mg and metoprolol 100 mg along with fentanyl and sevoflurane anesthesia decreased blood loss. There was also achievement of satisfactory DH during orthognathic surgery with both the drugs. The outcome of anesthesia was better with telmisartan and metoprolol like reduced surgery duration, reduced duration of blood loss and reduced additional use of drugs than given only placebo group.