Comparative study of cardiac output measurement by regional impedance cardiography and thermodilution method in patients undergoing off pump coronary artery bypass graft surgery.

Background: An ideal CO monitor should be noninvasive, cost effective, reproducible, reliable during various physiological states. Limited literature is available regarding the noninvasive CO monitoring in open chest surgeries. Aim: The aim of this study was to compare the CO measurement by Regional Impedance Cardiography (RIC) and Thermodilution (TD) method in patients undergoing off pump coronary artery bypass graft surgery (OPCAB). Settings and Design: We conducted a prospective observational comparative study of CO measurement by the noninvasive RIC method using the NICaS Hemodynamic Navigator system and the gold standard TD method using pulmonary artery catheter in patients undergoing OPCAB. A total of 150 data pair from the two CO monitoring techniques were taken from 15 patients between 40-70 years at various predefined time intervals of the surgery. Patients and Methods: We have tried to find out the accuracy, precision and cost effectiveness of the newer RIC technique. Mean CO, bias and precision were compared for each pair i.e.TD-CO and RIC-CO as recommended by Bland and Altman. The Sensitivity and specificity of cutoff value to predict change in TD-CO was used to create a Receiver operating characteristic or ROC curve. Results: Mean TD-CO values were around 4.52 ± 1.09 L/min, while mean RIC- CO values were around 4.77± 1.84 L/min. The difference in CO change was found to be statistically not significant (p value 0.667). The bias was small (-0.25). The Bland Altman plot revealed a mean difference of -0.25 litres. The RIC method had a sensitivity of 55.56 % and specificity of 33.33 % in predicting 15% change in CO of TD method and the total diagnostic accuracy was 46.67%. Conclusion: A fair correlation was found between the two techniques. The RIC method may be considered as a promising noninvasive, potentially low cost alternative to the TD technique of hemodynamic measurement.

Recurrent cardiac myxoma: A case report.

Cardiac myxomas are the most common benign tumors of the heart. They are most commonly found in the left atrium, followed by a right atrium and rarely in the left ventricle. Herein, we report a rare case of left ventricular myxoma in a patient who had twice undergone removal of left atrial myxoma. Complete removal of the tumor through aortotomy, without causing fragmentation led to the uneventful recovery of the patient.

Left ventricle pseudoaneurysm-recurrence following surgical repair.

Left ventricular (LV) pseudoaneurysm is a rare complication following free wall rupture post transmural myocardial infarction or left ventricular surgery. A lot of imaging modalities like echocardiography, computerised tomography and cardiac magnetic resonance imaging are available to diagnose it. Echocardiography plays a significant role in delineating the cavity, orifice and impact on the surrounding structures. We present a case of LV pseudoaneurysm recurrence following surgical repair.

A case of left atrial dissection after mitral valve replacement.

Left atrial dissection (LatD) is a rare complication of cardiac surgery due to creation of a false chamber through a tear in the mitral valve annulus that extends into the left atrium wall. It is primarily associated with mitral valve surgery although other etiologies have also been defined. Perioperative transesophageal echocardiography (TEE) is a key to the diagnosis. This is a case report of management of LatD after mitral valve replacement.

Cardiac surgery in a patient with implanted vagal nerve stimulator.

The prevalence of epilepsy worldwide is around 0.5%-2% of the population. Antiepileptic medications are the first line of treatment in most of the cases but approximately 25%-30% epilepsy patients are refractory to the single or combination therapy. The surgical option for temporal lobe epilepsy is temporal lobectomy, which has its inherent risk of neurological deficits after the surgery. Patients who are either refractory to combination therapy or do not want surgical temporal lobectomy are the candidates for electrical stimulation therapy. Refractory cases require implantable device such as vagal nerve stimulator (VNS). We are reporting perioperative management of a patient, with an implanted VNS, posted for pericardiectomy. It is important for the anesthesiologist to be familiar with the mechanism of VNS for proper perioperative care.

Nonanalgesic benefits of combined thoracic epidural analgesia with general anesthesia in high risk elderly off pump coronary artery bypass patients.

OBJECTIVE: Epidural anesthesia is a central neuraxial block technique with many applications. It is a versatile anesthetic technique, with applications in surgery, obstetrics and pain control. Its versatility means it can be used as an anesthetic, as an analgesic adjuvant to general anesthesia, and for postoperative analgesia. Off pump coronary artery bypass (OPCAB) surgery triggers a systemic stress response as seen in coronary artery bypass grafting (CABG). Thoracic epidural anesthesia (TEA), combined with general anesthesia (GA) attenuates the stress response to CABG. There is Reduction in levels of Plasma epinephrine, Cortisol and catecholamine surge, tumor necrosis factor-Alpha( TNF ά), interleukin-6 and leucocyte count. DESIGN: A prospective randomised non blind study. SETTING: A clinical study in a multi specialty hospital. PARTICIPANTS: Eighty six patients. Material and Methods/intervention: The study was approved by hospital research ethics committee and written informed consent was obtained from all patients. Patients were randomised to receive either GA plus epidural (study group) or GA only (control group). Inclusion Criteria (for participants) were -Age ≥ 70 years, Patient posted for OPCAB surgery, and patient with comorbidities (diabetes mellitus, chronic obstructive pulmonary disease, cerebrovascular disease, peripheral vascular disease, renal dysfunction). Serum concentration of Interlukin: - 6, TNF ά, cortisol, Troponin - I, CK-MB, and HsCRP (highly sensitive C reactive protein), was compared for both the group and venous blood samples were collected and compared just after induction, at day 2, and day 5 postoperatively. Time to mobilization, extubation, total intensive care unit stay and hospital stay were noted and compared. Independent t test was used for statistical analysis. PRIMARY OUTCOMES: Postoperative complications, total intensive care unit stay and hospital stay. Secondary Outcome: Stress response. RESULT: Study group showed decreased Interlukin - 6 at day 2, TNF ά at day 2 and 5,troponin I at day 5, and decreased total hospital stay ( p < 0.05). CONCLUSION: Thoracic epidural anesthesia decreases stress and inflammatory response to surgery and decreases hospital stay. However a large multicentre study may be needed to confirm it.

Newer methods of cardiac output monitoring.

Cardiac output (CO) is the volume of blood ejected by each ventricle per minute and is the product of stroke volume and heart rate. CO can thus be manipulated by alteration in heart rate or rhythm, preload, contractility and afterload. Moreover it gives important information about tissue perfusion and oxygen delivery. CO can be measured by various methods and thermodilution method using pulmonary artery catheter (PAC) is till date considered as gold standard method. Complications associated with PAC led to development of newer methods which are minimally or non-invasive. Newer methods fulfil other properties like continuous and reproducible reading, cost effective, reliable during various physiological states and have fast response time. These methods are validated against the gold standard with good level agreement. In this review we have discussed various newer methods of CO monitoring and their effectiveness in clinical use.

Asymptomatic type B right atrial thrombus in a case with protein S deficiency.

Thirty seven year old asymptomatic male underwent routine medical examination which revealed an abnormal mass in the right atrium. Family history was not suggestive of any cardiac or malignant disease. Detailed investigation detected deficiency of protein S, which is a vitamin K dependent protein and a cofactor for activated protein C mediated cleavage of factor Va and VIIIa. The deficiency of protein S predisposes to venous thrombosis. Further investigation revealed that it was an organized calcified thrombus in right atrium occupying almost whole of the cavity. Various approaches including surgical excision, thrombolysis and anticoagulation has been used to manage such thrombosis. However therapeutic approach is still a question of debate. Atriotomy and excision of mass was done using cardiopulmonary bypass.

Headache and seizures after cervical epidural injection in a patient undergoing coronary artery bypass grafting.

Epidural analgesia is widely used in cardiothoracic surgery. Most of the complications associated with epidural analgesia are related to the insertion techniques of epidural catheter. A 68-year-old obese patient posted for coronary artery bypass grafting surgery developed headache followed by seizures after insertion of the thoracic epidural catheter. Magnetic resonance imaging revealed air in the basal cisterns and in the left frontal region. The patient was managed conservatively and the symptoms subsided after 24 h. Later, the patient underwent coronary angioplasty.

Comparison of continuous thoracic epidural and paravertebral block for postoperative analgesia after robotic-assisted coronary artery bypass surgery.

Minimally invasive surgery with robotic assistance should elicit minimal pain. Regional analgesic techniques have shown excellent analgesia after thoracotomy. Thus the aim of this study was to compare thoracic epidural analgesia (TEA) technique with paravertebral block (PVB) technique in these patients with regard to quality of analgesia, complications, and haemodynamic and respiratory parameters. This was a prospective randomised study involving 36 patients undergoing elective robotic-assisted coronary artery bypass grafting (CABG). TEA or PVB were administered in these patients. The results revealed no significant differences with regard to demographics, haemodynamics, and arterial blood gases. Pulmonary functions were better maintained in PVB group postoperatively; however, this was statistically insignificant. The quality of analgesia was also comparable in both the groups. We conclude that PVB is a safe and effective technique for postoperative analgesia after robotic-assisted CABG and is comparable to TEA with regard to quality of analgesia.