Objective To determine the effects of ephedrine premedication on hemodynamics in the elderly patients with low physical capacity receiving analgesic gastroscopy under intravenous anesthesia. Methods A total of 70 elderly patients with low physical capacity who were scheduled for analgesic gastroscopy in the Affiliated Hospital of Xuzhou Medical College from April to August 2017 were recruited in this study. They were randomly assigned to propofol group (control group) and propofol+ephedrine group (ephedrine group), with 35 patients in each group. Gastroscopy was performed only after the patients falling asleep, with eyelash reflex disappearance and steady breathing. Heart rate (HR), mean arterial pressure (MAP) and pulse oxygen saturation (SpO₂) were observed and measured at the following time points:before the induction of anesthesia (T₁), 1 min after induction of anesthesia (T₂), at the time or in 3 min after gastroscope placement (T₃ and T₄), at the time or in 5 min after gastroscope withdrawing (T₅ and T₆), and at the time of waking-up (T₇). The amount of propofol, anesthetic effect (excellent rate), discharge time and occurrence of adverse reactions were recorded in both groups. SPSS statistics 22.0 was used to perform the statistical analysis. Student’s t test, rank sum test, repeated measures analysis of variance or Chi-square test was employed for different data types. Results In the control group, HR was lower at the time points T₂-T₆ than at T₁ (P<0.05), and the rate was also lower at T₄ and T₆ than T₁ in the ephedrine group. The ephedrine group had significantly higher HR at T₂ and T₃ than the control group [(76.29±10.59) vs (69.46±8.49) times/min, (81.09±10.16) vs (74.97±8.16)times/min, P<0.05]. MAP was lower in both groups at the time points of T₂-T₇ than T₁ (P<0.05),but the ephedrine group had obviously higher MAP than the control group at T₂-T₆ [(88.71±6.75) vs (77.29±9.82)mmHg, (93.60±7.38) vs (86.97±10.79)mmHg, (87.09±5.90) vs (81.51±9.92)mmHg, (90.26±5.58) vs (86.34±11.81)mmHg, (83.60±6.56) vs (75.66±10.36)mmHg, P<0.05]. For SpO₂, the value was notably lower in the 2 groups at T₆ than T₁ (P<0.05), and it at T₂, T₃ and T₅ was significantly increased than that of T₁, but there was no significant difference in SpO₂ between the 2 groups at every time point (P>0.05). Compared with the control group, the pain rate and pain score in the ephedrine group were significantly lower [7(20%) vs 14(40%), 1(0,2) vs 0(0,1) scores, P<0.05]. The incidence of blood pressure decrease was significantly reduced in the ephedrine group than in the other group [3(9%) vs 20(57%), P<0.05], and the incidence of other adverse reactions was not statistically significant. Conclusion Premedication of ephedrine can reduce the variability of hemodynamics in the elderly patients with low physical capacity undergoing analgesic gastroscopy. It is helpful to maintain the stability of the circulatory function, and can reduce the incidence and intensity of pain, with safety and reliability.