The effect of levosimendan on the right ventricular function in patients with right ventricular dysfunction undergoing mitral valve surgery

Background

Right ventricular (RV) dysfunction is an important predictor of both immediate and long-term outcomes in valve surgeries. Levosimendan has proven beneficial in improving RV function.

Aims

The objective was to study the effect of the addition of levosimendan to the conventional treatment on RV function in patients with RV dysfunction undergoing mitral valve (MV) surgeries.

Setting and Design

Prospective randomized double-blinded controlled study at a tertiary care institution.

Materials and Methods

Sixty adult patients aged 15-65 years, with preoperative transthoracic echocardiography (TTE) findings of RV dysfunction posted for elective MV surgery, were randomized into levosimendan (L) group and placebo (P) group. Patients in the L group were administered levosimendan at a rate of 0.1 mcg/kg/min after induction for 24 hrs, whereas patients in the P group were given multivitamin infusion at the same rate. Both the groups received standard inotropic therapy. The hemodynamic and echocardiographic parameters of RV function (RV size, Inferior vena cava (IVC) diameter, RV fractional area change (RVFAC) Tricuspid annular plane systolic excursion (TAPSE), and Systolic Pulmonary Artery Pressure (SPAP) were compared between the groups at 6 hrs, 24 hrs, and 7^th day postoperatively.

Results

All hemodynamic and echocardiographic parameters of RV function like RV size, IVC diameter, RVFAC, TAPSE, and SPAP improved from baseline to 24 hrs in both groups. Levosimendan caused a significant improvement in RV function compared to the P group at 24 hrs and 7^th day postoperatively.

Conclusions

The present study concludes that levosimendan is a promising option in patients with RV dysfunction undergoing MV surgeries.

Inadequate response to adenosine infusion during cardiac stress magnetic resonance imaging

Aim:

To determine the factors associated with an inadequate response to adenosine infusion during cardiac stress magnetic resonance imaging (MRI).

Study Design:

It is a retrospective cohort study.

Introduction:

Stress cardiac MRI is a highly accurate and non-invasive method to diagnose coronary artery disease (CAD). Stress MRI is performed by inducing stress with adenosine infusion. There is an increase in systemic and myocardial blood flow (MBF) with vasodilator agents. Capillaries are maximally dilated in a diseased artery and cannot sustain increased myocardial oxygen demand. It results in delayed delivery of contrast, which leads to an area of perfusion defect in the myocardium. These perfusion defects can be accurately seen by cardiovascular magnetic resonance (CMR) and help in the prognosis of patients.

Methods:

A retrospective study on patients subjected to cardiac stress MRI was conducted in a Tertiary Care Cardiac Center from January 2019 to January 2022. In total, 99 patients underwent adenosine stress perfusion cardiac MRI. All patients received an adenosine infusion of 140 mcg/kg/min for 2 min. Subsequently, the dosage was increased by 20 mcg/kg/min every 2 min to a maximum of 210 mcg/kg/min until an adequate stress response was achieved. Adequate stress was defined as two or more of the following criteria: 1) Increase in heart rate >/= 10 beats per minute. 2) Decrease in systolic blood pressure SBP by >/= 10 mm Hg Symptoms like chest discomfort, breathlessness, and headache. Patients who satisfied two or more of the above criteria were labeled as responders and the patients who did not satisfy the above criteria with the maximum dose of 210 mcg/kg/min of adenosine infusion were labeled as non-responders. Multivariable logistic regression analysis with forward and backward stepwise selection was used to identify predictors in non-responders. Basic demographic variables with P value </= 0.2 were examined for inclusion in the model. A P value </= 0.05 was considered significant.

Results:

Nine patients (9.1%) showed inadequate stress response to adenosine infusion even with a maximum dose of 210 mcg/kg/min. Multivariate logistic regression analysis showed that left ventricular end-diastolic volume (LVEDV) was a predictor of inadequate response to adenosine infusion.

Conclusion:

Inadequate stress response to adenosine occurred in 9.1% of subjects with an infusion of 140–210 ug/kg/min. LVEDV is an independent and strong predictor in non-responders.

Perioperative management of a patient with glanzmann's thrombasthenia for mitral valve repair under cardiopulmonary bypass

A 30-year-old male patient presented with Glanzmann's thrombasthenia and mitral valve prolapse. He was in acute decompensated congestive heart failure due to severe mitral and tricuspid regurgitation. After his cardiac failure had been stabilized, the patient was subjected to mitral and tricuspid valve repair. His transfusion requirements were guided by thrombelastography and his bleeding disorder was managed by infusing single donor plasmapheresed platelet transfusions in the perioperative period. The patient underwent surgery uneventfully.

Off-pump Coronary Artery Bypass Surgery in a Patient with Dextrocardia and Situs Inversus: Anesthetic, Surgical Consideration and Role of Transesophageal Echocardiography

Coronary artery bypass surgery (CABG) in dextrocardia with situs inversus patients is reported less in literature. Due to abnormal looping and associated other congenital anomalies, anesthetic implications and surgical difficulties become challenging in these patients. Transesophageal echocardiography examination (TEE) needs multiplane angle adjustments compared to normal heart to obtain the images. Here, we describe a 53-year-old female patient having dextrocardia with situs inversus who underwent CABG and discuss the perioperative management and multiplane adjustments during TEE examination.

Comparison of Epidural Bupivacaine, Levobupivacaine and Dexmedetomidine in Patients Undergoing Vascular Surgery

INTRODUCTION

Levobupivacaine is the s-isomer of racemic Bupivacaine. It is less cardio, neurotoxic and equally potent local anaesthetic compared to its racemate. It is known to cause less Depression of myocardial contractility. Dexmeditomidine when used via epidural route has synergistic effect with local anaesthetics. Majority of patients presenting for vascular surgery are elderly and have associated co-morbidities like diabetes, hypertension, and coronary artery disease. We intend to study safety and efficacy of epidural Levoupivacaine and Dexmedetomidine in this group of patients.

MATERIALS AND METHODS

Sixty adult patients undergoing lower limb vascular surgery under lumbar epidural anaesthesia were randomly allocated to three groups. All groups were preloaded with 10ml/kg of crystalloid solution. B group was scheduled to receive 15 ml of racemic Bupivacaine, L-group was scheduled to receive 15ml of Levobupivacaine and LD-group received 15ml of Levobupivacaine with 0.5 mics/kg Dexmeditomedine. Time to onset of sensory block to T-10, maximum sensory level achieved, Bromage scale, time to two segment regression, time to total regression, sedation level achieved and patients assessment of quality of anaesthesia were assessed. Haemodynamic parameters were monitored throughout study period. Adverse effects were noted and treated appropriately.

RESULTS

Baseline parameters were comparable among all the groups. Time to onset of sensory block to T-10 and maximum level of block achieved, was comparable among the groups. Time to two segment regression and time to total regression was significantly prolonged in LD group compared to other two groups. There was significant bradycardia noted in LD group which required treatment.

CONCLUSION

Levobupivacaine can be safely used in elderly high risk patients undergoing vascular surgery. Addition of dexmedetomidine prolongs the duration of anaesthesia and postoperative analgesia.

Role of perioperative transesophageal echocardiography in the management of adolescent truncus arteriosus: rare case report

Truncus arteriosus (TA) is a rare congenital heart disease defined as a single arterial vessel arising from the heart that gives origin to the systemic, pulmonary and coronary circulations. The truncal valve in majority of the cases is tricuspid though quadricuspid and bicuspid valves have been reported. Patients with TA typically have a large nonrestrictive sub truncal ventricular septal defect. Survival of these infants beyond 1-year is uncommon. Here, we report a unique case of 12-year-old female patient with persistent TA who underwent surgical repair by using transesophageal echocardiography as a monitoring device during the perioperative management.

Comparative study between dexmedetomidine and fentanyl for sedation during mechanical ventilation in post-operative paediatric cardiac surgical patients

AIMS AND OBJECTIVES

To compare the efficacy of sedation and time taken for extubation using dexmedetomidine and fentanyl sedation in post-operative paediatric cardiac surgical patients.

METHODS

A prospective randomized double-blind study involving 60 children undergoing open heart surgery was conducted. The patients were divided into two groups, each involving 30 patients. One group received fentanyl at 1 μg/kg/h (Group A) and the other received dexmedetomidine at 0.5 μg/kg/h (Group B) for post-operative sedation with intermittent rescue fentanyl 0.5 μg/kg bolus in either group as per requirement during suctioning. The efficacy of sedation was assessed using the Ramsay sedation score, paediatric intensive care unit sedation score and the tracheal suction score. The time taken for extubation from the stoppage of infusion was noted.

RESULTS

Haemodynamic parameters between the two groups were comparable. All sedation scores were comparable in the fentanyl and dexmedetomidine groups. Average time (in minutes) required for extubation was 131.0 (±51.06 SD) in the dexmedetomidine group compared with 373.0 (±121.4 SD) in the fentanyl group. The difference in mean time for extubation was statistically significant.

CONCLUSIONS

Dexmedetomidine facilitates adequate sedation for mechanical ventilation and also early extubation as compared with fentanyl.

Myocardial preservation: controlled reperfusion

Reperfusion injury after reestablishing coronary flow by releasing the aortic cross clamp after cardiac surgery with cardioplegic arrest causes myocardial damage and even death. Attenuation of this reperfusion response by controlling the biochemical and physical environment can avoid morbidity and mortality. Use of a warm reperfusate with addition of drugs that are known to decrease reperfusion injury with manipulation of coronary vascular resistance and the physical parameters of the reperfusion environment helps the heart to reestablish coronary perfusion while decreasing the harm produced by the period of ischemia that occurs during cardiac surgery with intermittent cardioplegic arrest.

Preliminary results of supra-hepatic intraaortic perfusion with nitroglycerin for patients with significant hepatic dysfunction

BACKGROUND

Preoperative hepatic dysfunction is a risk factor for postoperative fulminant hepatic failure and death. We noted persistent hepatic artery vasospasm in patients dying of postoperative hepatic failure. We hypothesized that an intra-aortic vasodilator such as nitroglycerin could attenuate vasospasm and prevent hepatic failure.

METHODS

Nineteen consecutive patients with significant preoperative hepatic dysfunction underwent cardiac surgery using cardiopulmonary bypass with continuous infusion of intra-aortic nitroglycerin via a catheter placed above the celiac axis. Serial hepatic artery Doppler studies were done perioperatively with and without the nitroglycerin infusion on. Hepatic artery Doppler, hepatic artery size, alterations in liver function and serum creatinine, and outcomes were noted. Survival was compared to the Euroscore and a hepatic risk score that was based on a historical cohort and reported literature.

RESULTS

One patient could not be weaned off cardiopulmonary bypass. In the remaining 18 patients, reversible hepatic arterial vasospasm was noted, and this persisted at 24 hours in 12 patients and 48 hours in 7 patients. All patients had resolution of vasospasm at 72 hours. Serial paired hepatic artery diameter measurements showed a significant difference (P < .001). There was a significant reduction in mortality (5.2 %) compared to historical control and predicted mortality (logistic Euroscore 37.4%, P = .023). None of the survivors had a significant alteration in hepato-renal function.

CONCLUSION

Intra-aortic nitroglycerin can attenuate hepatic arterial vasospasm induced by cardiopulmonary bypass and preserve hepatic function. This may reduce the risk associated with cardiopulmonary bypass and surgery in patients with liver dysfunction.

Anesthetic implications of total anomalous systemic venous connection to left atrium with left isomerism

Total anomalous systemic venous connection (TASVC) to the left atrium (LA) is a rare congenital anomaly. An 11-year-old girl presented with complaints of palpitations and cyanosis. TASVC with left isomerism and noncompaction of LV was diagnosed after contrast echocardiogram and computed tomography angiogram. The knowledge of anatomy and pathophysiology is essential for the successful management of these cases. Anesthetic concerns in this case were polycythemia, paradoxical embolism and rhythm abnormalities. The patient was successfully operated by rerouting the systemic venous connection to the right atrium.