An 84-year-old female (body weight 56 kg, ASA status III) was scheduled for right artificial femoral head replacement. Her pelvic X-ray revealed a right intertrochanteric fracture. She had hypertension for 35 years and chronic obstructive pulmonary disease (COPD) for 20 years. She took daily oral nifedipine for hypertension, but did not take any treatment for COPD. The result of pulmonary function test showed that the FEV1/FVC was 35% and the bronchodilator test was negative. Cardiac Doppler ultrasonography indicated moderate pulmonary artery hypertension. A chest X-ray revealed pulmonary infection of bilateral lower lobes. Low-molecular-weight heparin was used for prevent thrombus formation at 4000IU per day and stopped 24 hours before surgery. The preoperative visual analogue scale (VAS) score of this patient was 6. The ultrasound guided lumbar SNRB plus T12 paravertebral and sacral plexus blocks were performed on this patient as described in the Methods section, and 25 mL of 0.4% ropivacaine was used for these blocks. The success of these blocks was confirmed by pinprick test. The time of surgery was 42 minutes. She did not complain any painful during surgery and in postanesthesia care unit (PACU). As postoperative analgesia was achieved by patient-controlled analgesia (PCA), the postoperative VAS scores were 0 to 1. This patient discharged on the fifth day after surgery. No postoperative complication was reported with her.
Case 2: A 61 years old male (weight 75 kg, ASA status III) suffered from AS for 20 years, and was scheduled for left total hip arthroplasty (THA). He had a history of coronary heart disease and received coronary stent implantation 7 years ago. A physical examination revealed rigidity of cervical and lumbar spine, severe press pain and immobilization of left hip joints. An X-ray of the neck, chest and lower back revealed bamboo-like changes of the spine. CT of the hip joints reported necrosis of the left femoral head, and ankylosis of left hip joint. He had taken aspirin for anticoagulation therapy for a long term, and was replaced by low molecular weight heparin.