Sacral Canal Block for Hip Replacement the Efficacy and Safety of Controlled Intraoperative Hypotension

Sacral canal block: The patient lies on their side, with the back perpendicular to the edge of the operating table. The knee joints of the lower limbs are flexed, the thighs are close to the abdomen, and the waist is arched backward as much as possible, resembling a "shrimp" shape. The space between the sacrum and coccyx of the patient (sacral hiatus) is fully exposed. By using a low-frequency probe (such as 2-5 MHZ), the strong echo of the sacrum, the low echo of the sacral canal, and the echo of the surrounding soft tissues can be clearly seen. At the located sacral hiatus, hold the puncture needle and slowly insert it perpendicularly to the skin. When the puncture needle passes through the sacrococcygeal ligament, there will be a distinct "breakthrough sensation", which indicates that the puncture needle has entered the sacral canal. The general depth of needle insertion is about 2 to 3cm. However, the specific depth varies depending on factors such as the patient's body type.

General anesthesia: Midazolam (0.2mg/kg), sufentanil (0.2-0.4μg/kg), etomidate (0.15-0.3 mg/kg), and rocuronium (0.6 mg/kg) were induced. After the patient's muscles were completely relaxed, a laryngeal mask was placed. Connect the anesthesia machine and set the ventilator parameters: Vol.Mode, tidal volume 6-8ml/kg, frequency 10-14 times /min, inhalation-exhalation ratio 1:2, and maintain EtCO2 at 35-45mmHg during the operation. Propofol (4-12mg/kg/h) and remifentanil (0.05-2ug/kg/min) were maintained. According to the operation course, rocuronium (0.15mg/kg) and sevoflurane inhalation (1% - 7%) could be administered at a single time. Anesthesiologists adjust the drug infusion rate based on the patient's hemodynamic indicators SBP, MAP, HR and clinical experience. When HR was less than 45 times /min during the operation, atropine was intravenously injected (0.25-0.5mg per time). When MAP is less than 55mmHg and lasts for more than 3 minutes, ephedrine (6-12mg each time) is given.