RESUMO
PURPOSE: This study investigated the effects of dexmedetomidine on cardiovascular response during the decannulation period of general anesthesia in patients with different genotypes of angiotensin-converting enzyme (ACE) and essential hypertension. METHODS: The present study enrolled patients with essential hypertension and American Society of Anesthesiologists class II or III who were scheduled to undergo abdominal surgery under general anesthesia. Patients were assigned to 1 of 6 groups according to ACE genotype, as detected by polymerase chain reaction-restriction fragment length polymorphism, as follows: DD; ID; II; and DD, ID, and II each with dexmedetomidine (Dex). Dexmedetomidine was intravenously infused at 0.5 µg/kg/h for 30 min before the end of surgery in groups DD (Dex), ID (Dex), and II(Dex). Anesthesia was induced and maintained by the same anesthetics in all patients. Systolic and diastolic blood pressure, heart rate (HR), ECG, and rate-pressure product were recorded before anesthesia induction; at 30 min before the end of surgery; at the end of surgery; and at 0, 1.5, 5, and 10 min after extubation. FINDINGS: A total of 210 patients were enrolled (n = 35 per genotype). After extubation, systolic and diastolic blood pressure, HR, and RPP were increased markedly from baseline in groups DD, ID, and II; the increases were greater in groups DD and ID than in group II. No significant changes in blood pressure, HR, or RPP were found, and proper sedative was achieved in groups DD (Dex), ID (Dex), and II(Dex). The prevalences of cardiac arrhythmia were higher in groups DD and ID than in groups II, DD (Dex), ID (Dex), and II(Dex). IMPLICATIONS: Patients essential hypertension and the ACE D allele had a strong hemodynamic response to tracheal extubation, on which dexmedetomidine was found to have both a prevention and treatment effect.