Parasternal Block and TENS for Cardiac Surgery

Patients experiencing pain after undergoing cardiac surgery may also experience prolonged immobilization, insufficient respiratory functions and the inability to cough due to median sternotomy. Invasive and noninvasive interventions such as epidural analgesia, local regional blockade and the use of intravenous (IV) opioids, are used for postoperative pain management. Transcutaneous electrical nerve stimulation (TENS) is a noninvasive technique that is effective for postoperative pain management. It has been demonstrated to produce effective analgesia and reduce postoperative opioid requirements in patients undergoing cardiac surgery, and it has no side effects. Parasternal local anesthetic infiltration around the sternum has been demonstrated to be useful in providing early postoperative analgesia, reducing opioid requirements and, therefore, producing a potential positive effect on recovery. The present prospective, randomized controlled study included 120 patients, 18 to 65 years of age, who were scheduled for elective valve repair or coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass. A random number table was used to randomly allocate patients to one of three treatment groups to relieve postoperative pain during the first 24 h following median sternotomy: parasternal block group (parasternal block combined with levobupivacaine infiltration and PCA(patient controlled analgesia)); TENS group (TENS and PCA); or the control group (PCA alone).

Inclusion criteria

• 18 to 65 years of age,
• who were scheduled for elective valve repair or coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass

Exclusion criteria

• previous sternotomy for CABG or heart valve surgery; emergency surgery
• ejection fraction <40%
• congestive heart failure
• an allergy to amide-based local anesthetics, opioids or benzodiazepines
• inability to provide informed consent
• prolonged cardiopulmonary bypass time (>145 min)
• previous experience with TENS