Effects of thoracic paravertebral block on graft patency in off-pump coronary artery bypass grafting / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effects of thoracic paravertebral block (TPVB) on graft patency in off-pump coronary artery bypass grafting.Methods:Fifty American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients, aged 60-75 yr, weighing 50-80 kg, undergoing elective off-pump coronary artery bypass grafting under combined intravenous-inhalational anesthesia, were divided into 2 groups using a random number table method: control group (group C, n=30) and TPVB group (group T, n=20). In group T, TPVB was performed at T 4, 5 interspace under the guidance of ultrasound, a test dose of 1% lidocaine 5 ml was injected on both sides, and 2 min later 0.375% ropivacaine 15 ml was injected.According to the anatomy of coronary artery, the graft was divided into 4 parts left internal thoracic artery-anterior descending branch (arterial graft), the middle branch or the first diagonal branch, blunt marginal branche, and right posterior descending branch or left ventricular posterior branch.The blood flow was measured and pulsatility index was calculated after graft transplantation.Central venous pressure, mean pulmonary artery pressure, cardiac output, systemic resistance index and pulmonary resistance index were recorded immediately after placement of floating catheter (T 1), immediately after sawing sternum (T 2), immediately after anastomosis of all grafts (T 3) and 5 min before leaving the room (T 4). The intraoperative cardiovascular adverse events and consumption of sufentanil were recorded. Results:Compared with group G, central venous pressure, systemic resistance index and pulmonary resistance index were significantly decreased, cardiac output were increased, the incidence of intraoperative tachycardia was decreased, the incidence of hypotension was increased, the consumption of sufentanil was reduced, the flow of left internal thoracic artery-anterior descending branch was increased, and the pulsatility index was decreased at T 3 and T 4 in group T ( P<0.05). Conclusion:TPVB can improve the patency of left internal thoracic artery-anterior descending branch in off-pump coronary artery bypass grafting.