A clinical study on the effectiveness of intraoperative percutaneous electrical stimulation of the Neiguan acupoint in preventing myocardial ischaemia in elderly patients with fractures

INTERVENTION: Experimental group (Part 1: The Effects of Transcutaneous Electrical Acupoint Stimulation of the Neiguan Acupoint on Coronary Sinus Blood Flow Parameters):The physician conducting the trial located the patient’s Neiguan acupoint, disinfected the area with an alcohol swab, applied specialized acupoint stimulation electrodes, and connected them to the electronic acupuncture device (Huatuo SDZV model). For patients in the experimental group, after turning on the electronic acupuncture device, the practitioner selects the "sparse‐dense wave" mode with a frequency of 2 Hz. The current intensity is adjusted to a level where the patient feels comfortable and experiences a mild sensation of numbness and distension—known in traditional Chinese medicine as the "deqi sensation"—typically ranging from 6 to 9 mA. The intervention duration is 20 minutes.;Control group (Part 1: The Effects of Transcutaneous Electrical Acupoint Stimulation of the Neiguan Acupoint on Coronary Sinus Blood Flow Parameters):The patient is connected to the electroacupuncture device but is not receiving stimulation.;Group A (Part 2:Dose‐response relationship of transcutaneous electrical acupoint stimulation at the Neiguan acupoint on coronary sinus blood flow parameters):Apply an electroacupuncture patch to the Neiguan acupoint, connect it to an electroacupuncture device, set the stimulation frequency to 2 Hz, and stimulate for 15 minutes.;Group B (Part 2: Dose‐response relationship of transcutaneous electrical acupoint stimulation at the Neiguan acupoint on coronary sinus blood flow parameters):Apply an electroacupuncture patch to the Neiguan acupoint, connect it to an electroacupuncture device, set the stimulation frequency to 2 Hz, and stimulate for 25 minutes.;Group C (Part 2: Dose‐response relationship CONDITION: Ischemic cardiomyopathy PRIMARY OUTCOME: Coronary sinus blood flow parameters; SECONDARY OUTCOME: Inferior vena cava respiratory variation;Cardiac output;Hemodynamic parameters (heart rate, mean arterial pressure, oxygen saturation);Myocardial oxygen consumption;Coronary sinus blood flow parameters;Inferior vena cava respiratory variation;Cardiac output;Vital signs;Intraoperative medication use;Postoperative pain score;Incidence of cardiovascular adverse events within 1 month postoperatively; INCLUSION CRITERIA: 1. Age > 70 years; ASA physical status grades I–V; gender; 2. 18<=BMI<=30; 3. Normal cognitive function at admission (Mini‐Mental State Examination score >= 28); 4. Full understanding of this trial, willingness to participate in this clinical trial, and signing of the informed consent form.