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 NICaSHemodynamicNavigator systemand the gold standardTDmethod using pulmonary artery catheterin patients undergoingOPCAB.Atotal 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.

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.

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 defi ciency 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 defi ciency of protein S predisposes to venous thrombosis. Further investigation revealed that it was an organized calcifi ed 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.

Cardiac output estimation after off-pump coronary artery bypass: a comparison of two different techniques.

The present study compares the cardiac output (CO) estimated by a new, non-invsive continuous Doppler device (Ultrasonic cardiac output monitor-USCOM) with that by bolus thermodilution technique (TD). Thirty post off-pump coronary artery bypass graft surgery patients were studied in this prospective nonrandomized study. Right heart CO estimation by USCOM and TD was performed and measured in quadruplet. A total of 120 paired observations were made. The mean CO was 4.63 and 4.76 Llmin as estimated by TD and USCOM respectively. For TD and USCOM, the CO had a mean bias (tendency of one technique to differ from other) of -0.13 L/min and limits of agreement (mean bias +/- 2SD) at -0.86 and 0.59 L/min. The study reveals very good agreement between the values of CO estimated by USCOM and TD.

Pulmonary Artery Catheter Placement in High-risk Coronary Artery Bypass Grafting: Should it be done Before or After Induction of Anaesthesia?

Pulmonary artery catheter (PAC) is generally inserted after induction of general anaesthesia (GA). However, in high-risk coronary artery disease patients (left main disease / ejection fraction (35%), it may be desirable to insert it before the induction of GA. Thirty patients with left main coronary artery disease and / or left ventricular ejection fraction < 35% undergoing coronary artery bypass grafting (CABG) surgery were prospectively randomized into 2 groups of 15 each. In group A, pulmonary artery catheter was inserted before induction and in group B, after induction of GA. Haemodynamic parameters like heart rate (HR), mean arterial pressure (MAP), cardiac index (CI) and other derived parameters were obtained serially up to 10 min after tracheal intubation in group A and the haemodynamic management was based on these parameters. In group B, the haemodynamic management was based on HR and MAP. The demographic data was similar in both the groups. The time required for insertion of PAC was also similar in the two groups (7.6 +/- 1.8 and 6.2 +/- 1.3 min, p > 0.05). The number of interventions in the form of infusions of volume, nitroglycerin or dopamine were significantly more in group A before tracheal intubation. The patients in group A maintained better haemodynamics at 10 min after tracheal intubation as compared with group B (CI 2.8 +/- 0.67 vs 2.1 +/- 0.49, p < 0.05; stroke volume 54 +/- 18 vs 51 +/- 0.65, p < 0.05; systemic vascular resistance 1431 +/- 409 vs 1724 +/- 430, p < 0.05; pulmonary vascular resistance 109 +/- 34 vs 181 +/- 110, p < 0.05). Insertion of PAC before induction of GA provides informative data and can be utilized to treat haemodynamic alterations in high-risk patients undergoing CABG.

Peri-operative Considerations in Total Endoscopic Atrial Septal Defect Repair with Robotic Assistance.

The development of minimally invasive techniques represents a significant improvement in the repair of atrial septal defect by total endoscopy. Robot-assisted repair obviates the need for a sternotomy or thoracotomy. This is the case report of a 45-year-old male, who underwent atrial septal defect repair through the total endoscopic technique. The peri-operative management and associated problems in the post-operative period have also been described.