To evaluate the value of ransesophageal echocardiography (TEE) in evaluating the effect of dexmedetomidine (Dex) on cardiac output and cardiovascular response in patients with laparoscopic cholecystectomy under general anesthesia at different age groups.

A total of 120 patients undergoing laparoscopic cholecystectomy under general anesthesia at our hospital from June 2017 to June 2019 were selected, and according to age, they were divided into a youth group (20-39 years old, 37 patients), middle-aged group (40-59 years old, 41 patients), and elderly group (≥60 years old, 42 patients). All patients were given Dex when hemodynamics stabilized after induction of anesthesia. Before Dex injection after induction of anesthesia (T₀) and at Dex injection for 10 min (T₁), 30 min, and Dex injection for 60 min (T₃) after induction of anesthesia, TEE was used to measure patients' heart rate, mean arterial pressure (MAP), blood oxygen saturation (SpO₂), velocity time integral (VTI), stroke volume (SV), cardiac output, visual analog scale (VAS) score, and Ramsay sedation score. Plasma cortisol and blood sugar and epinephrine at each time point were measured. Cardiovascular adverse reactions and the occurrence of agitation were recorded. The paired t-test or chi square test was used for between-group comparisons, and one-way ANOVA and repeated measures ANOVA were used for comparisons among three groups.

The heart rate, MAP, and SV at T₃ and the cardiac output at T₂ and T₃ were significantly lower than those at T₀ in the youth group and middle-aged group (P＜0.05). The heart rate, MAP, and SV at T₁, T₂, and T₃ and the cardiac output at T₂ and T₃ were significantly lower than those at T0 in the elderly group (P＜0.05). The heart rate, MAP, SV, and cardiac output at T₂ and T₃ in the elderly group were significantly lower than those of the youth group and middle-aged group at the same time points (P＜0.05). Plasma cortisol and blood sugar at T₃ and plasma epinephrine at T₂ and T₃ were significantly higher than those at T₀ in the youth group and middle-aged group (P＜0.05). Plasma cortisol and blood sugar at T₂ and T₃ and plasma epinephrine at T₁, T₂, and T₃ were significantly higher than those at T₀ in the elderly group (P＜0.05). Plasma cortisol at T₃, blood sugar at T₂ and T₃, and plasma epinephrine at T₁, T₂, and T₃ in the elderly group were all significantly higher than those of the young and middle-aged groups at the same time points (P＜0.05). The VAS scores and Ramsay sedation scores at T₁, T₂, and T₃ in the young, middle-aged, and elderly groups were all significantly lower than those at T₀ (P＜0.05). There was no statistically significant difference in the scores between the groups (P＞0.05). The incidence of hypotension and bradycardia in the elderly group was significantly higher than that in the young group and middle-aged group (χ²=4.702, 5.194, 6.766, and 4.822, P=0.030, 0.023, 0.009, and 0.028, respectively).

Dex at the same dose has significantly different cardiovascular response in general anesthesia patients of different ages, and it has a more obvious impact on the hemodynamics and cardiac output of elderly patients. Elderly patients are more likely to have cardiovascular adverse reactions such as hypotension and bradycardia.