Predicting intraoperative cardiovascular complication in patients with anterior mediastinal mass-role of central venous pressure monitoring
A 30-year-old male presented to the pre-anaesthetic clinic with history of dry cough for 9 months and recent onset of weight loss. There was no history of dyspnoea at any position. Dysphagia, muscular weakness, fatigue and drooping of eye lids were not elicited. On examination, he was conscious, comfortable without clinical evidence of either tracheal or SVC obstruction. The Pemberton's sign was negative. The chest X-ray showed mediastinal widening []. The CT scan [] revealed a large, 10.2 × 9.3 × 6.3 cm well-defined heterogeneous mixed density mass lesion lying over the brachiocephalic confluence, SVC, right atrium (RA) and right ventricular (RV) out flow tract without any pericardial or pleural effusion. The fat plane above pericardium was preserved and separate from the mass. The normal airway caliber was maintained. The CT guided biopsy was non informative with respect to the pathology of the lesion. Hence, this asymptomatic young, fit patient was posted for therapeutic excision of the anterior mediastinal mass with an uncertain chance of SVC and RV outflow obstruction during anaesthetic intervention.\nA sequential plan of thoracic epidural and inhalational induction was planned. An epidural catheter was inserted at T4-T5 interspace. Invasive monitoring which included left radial artery for systemic pressure monitoring, right internal jugular vein (IJV) for CVP and left femoral vein for inferior vena cava (IVC) access were established under local anaesthesia with titrated dose of intravenous midazolam and morphine. After recording the baseline parameters, segmental epidural anaesthesia (T1-T6) was established with incremental dose from 6-10 ml of 1% preservative free lignocaine. Increasing amount of Sevoflurane with gas oxygen mixture was used for induction of anaesthesia. During this period, the CVP progressively increased from 15 mmHg to 24 mmHg with stable systemic pressures, oxygen saturation and heart rate. The airway was secured with size 4 Proseal laryngeal mask airway (LMA) without any relaxant and the surgeon was requested to proceed with sternotomy and take control of the mass. But the CVP dropped and stabilized at around 20 mmHg following application of sternal retractor. Still, the systemic pressures were maintained around 100 mmHg systolic without vasopressors. The mass was predominantly a bag of necrotic material arising from thymus which was removed in toto with the accompanying pericardial and pleural window. The patient was breathing spontaneously throughout the procedure and as the pleural window was opened, we started assisted ventilation with the proseal LMA. With this, CVP stabilized at around 8 mmHg till the end of the procedure. The Proseal LMA was removed at end of the surgery and the patient was shifted to the postoperative ward with intercostal drain (ICD) in situ. The patient was asymptomatic and the ICD was removed after 2 days. The analgesia was maintained with epidural bupivacaine infusion.