Echocardiographic detection of free-floating thrombus in left ventricle during coronary artery bypass grafting

We report an incident of detection of a free-floating thrombus in the left ventricle (LV) using intraoperative two-dimensional (2D) and three-dimensional (3D) transesophageal echocardiography (TEE) during proximal coronary artery bypass graft anastomosis. A 58-year-old man presented to us with a 6-month history of chest pain without any history suggestive of myocardial infarction or transient ischemic attacks. His preoperative echocardiography revealed the systolic dysfunction of LV, mild hypokinesia of basal and mid-anterior wall, and the absence of an aneurysm. He was scheduled for on-pump coronary artery bypass surgery. On intraoperative TEE before establishing cardiopulmonary bypass (CPB), a small immobile mass was found attached to LV apical area. After completion of distal coronary artery grafting, when the aortic cross-clamp was removed, the heart was filled partially and beating spontaneously. TEE examination using 2D mode revealed a free-floating mass in the LV, which was suspected to be a thrombus. Additional navigation using biplane and 3D modes confirmed the presence of the thrombus and distinguished it from papillary muscles and artifact. The surgeon opened the left atrium after re-establishing electromechanical quiescence and removed a thrombus measuring 1.5 cm Χ 1 cm from the LV. The LV mass in the apical region was no longer seen after discontinuation of CPB. Accurate TEE-detection and timely removal of the thrombus averted disastrous embolic complications. Intraoperative 2D and recent biplane and 3D echocardiography modes are useful monitoring tools during the conduct of CPB

Effect of QTc interval on prediction of hypotension following subarachnoid block in patients undergoing cesarean section: A comparative study

Background: Previous studies have revealed that QTc interval is prolonged in pre-eclamptic parturients. Another study reflected the relationship between the sympathetic block and QTc interval. Subarachnoid block was safely administered in patients with severe pre-eclampsia. It has also been noticed that hypotension in response to spinal anesthesia is relatively less in pre-eclamptic patients than normal parturients. Aim: To compare the QTc values in normal and pre-eclamptic term parturients and to establish whether any correlation exists between the QTc interval and the systemic hypotension following subarachnoid block. Materials and Methods: Twenty-five pre-eclamptic patients (Group A) and 25 normotensive patients (Group B) were included in this study. QTc interval was recorded for each patient before subarachnoid block for cesarean section. Changes in arterial blood pressure and heart rate were measured in both the groups and compared. Results: Baseline QTc was significantly higher in the pre-eclamptic group (Group A: 0.47 ± 0.11) with that of control (Group B: 0.36. ± 0.02). Significant fall in blood pressure was seen only in one group with QTc between 0.38 and 0.39 in Group A. Hypotension was significantly more in normotensive mothers (Group B). However, no statistical correlation could be drawn from this study between QTc interval and hypotension, although a trend toward increasing hypotension with decreasing QTc was present. Discussion : The prolonged QTc intervals seen in pre-eclamptic patients may be due to the contributory effects of sympathetic hyperactivity, hypertension, and hypocalcemia secondary to underlying vasoconstriction. Decreased vagal control of heart in pre-eclampsia may have produced the difference in change in hemodynamic status between pre-eclamptic and normotensive parturient. Conclusion: Any consistent correlation between QTc and hypotension following subarachnoid block could not be derived from this study. To achieve a statistical significance a larger sample size may be required

Effect of magnesium infusion on thoracic epidural analgesia

Introduction: Patients of lung volume reduction surgery (LVRS) having an ASA status III or more are likely to be further downgraded by surgery to critical levels of pulmonary function. Aim: To compare the efficacy of thoracic epidural block with (0.125%) bupivacaine, fentanyl combination and (0.125%) bupivacaine, fentanyl combination with adjunctive intravenous magnesium infusion for the relief of postoperative pain in patients undergoing LVRS. Methods: Patients were operated under general anesthesia. Thirty minutes before the anticipated completion of skin closure in both groups, (Group A and Group B) 7 ml of (0.125%) bupivacaine calculated as 1.5 ml/thoracic segment space for achieving analgesia in dermatomes of T4, T5, T6, T7, and T8 segments, along with fentanyl 50 ΅g (0.5 ml), was administered through the catheter, activating the epidural block, and the time was noted. Thereafter, in patients of Group A, magnesium sulfate injection 30 mg/kg i.v. bolus was followed by infusion of magnesium sulfate at 10 mg/kg/hr and continued up to 24 hours. Group B was treated as control. Results and Analysis: A significant increase in the mean and maximum duration of analgesia in Group A in comparison with Group B (P<0.05) was observed. Total epidural dose of fentanyl and bupivacaine required in Group A was significantly lower in comparison with Group B in 24 hours. Discussion: Requirement of total doses of local anesthetics along with opioids could be minimized by magnesium infusion; therefore, the further downgradation of patients of LVRS may be prevented. Conclusion: Intravenous magnesium can prolong opioid-induced analgesia while minimizing nausea, pruritus, and somnolence