Analgesia Management for Mitral Valve Repair Via Minithoracotomy - A Case Report.

INTRODUCTION: Minimally invasive cardiac surgery (MICS), via minithoracotomy, is thought to be a fast track to extubation and recovery after surgery. Chronic pain, due to intercostal nerve injury, develops in up to 50% of postthoracotomy patients.A number of regional anaesthesia and analgesia techniques may be employed, and the anaesthesiologists play a key role in facilitating optimal outcomes after surgery.

METHODS: We report a case of postoperative pain management with a local anesthetic infiltration for MICS.

RESULTS: A 63-year-old woman, 80kg, American Society Anaesthesiology (ASA) physical status 3 [arterial hypertension, atrial fibrillation (AF), rheumatic mitral stenosis and class II NYHA heart failure] was presented for an elective minimally invasive mitral valve repair through a minithoracotomy and cryoablation of AF. No relevant facts were found on pre-operative evaluation. Calculated EuroScore II was 1.55%. After premedication with intravenous (IV) midazolam 1.5mg, radial arterial and jugular central venous catether were placed. General anaesthesia was induced with IV remifentanil 1mcg/kg/h, propofol 50mg, rocuronium 1mg/ kg. A transesophageal echocardiography probe was inserted atraumatically, which revealed thickened mitral valve leaflets. ASA standard, invasive blood pressure, central venous pressure, depth of anaesthesia and cerebral oximetry monitoring were used. Urine output and arterial blood gas were measured periodically. A right lateral minithoracotomy was performed. After cardiopulmonary bypass (CPB) by femoral cannulation, cryoablation was performed followed by placement of the mechanical prosthesis. Total bypass time was 186min including 139min aortic cross-clamping time. At the ending of CPB, there was no need for inotropic support. Analgesia with paracetamol 1g, tramadol 100mg and morphine 10mg was performed after protamine reversion. Immediately before closure of skin, catheter was placed nearly to intercostal space (figures 1, 2) and ropivacaine 0,75% 75mg was administered. Anaesthesia and surgery were uneventful. Patient was shifted to intensive care unit (ICU), being extubated 3 hours after surgery. There was no need for additional bolus of ropivacaine during 2 days of ICU stay. She was discharged home on the 4th postoperative day, without complications. In a telephone interview 3 weeks after surgery, the patient referred no pain and good satisfaction with analgesia management.

CONCLUSION: Thoracotomy incisions are associated with severe pain, leading to a decrease in pulmonary function, an increase in metabolic and hormonal activity and increased cardiac morbidity. Regional analgesia techniques have an opioid-sparing effect, reducing stress response and pain chronification. The local infiltration through catheter with local anaesthetics allows excellent analgesia for 8-12 hours, providing a route of additional analgesia according to pain control.