Perioperative Dexmedetomidine Reduces Delirium after Coronary Artery Bypass Graft Surgery: A Prospective, Single?blind, Observational Study

Background:Delirium is a commonly seen complication of cardiac surgery. Dexmedetomidine, by its anti?inflammatory properties and other effects, can attenuate postoperative delirium. Aims: The aim of this work was to study the incidence of delirium after coronary artery bypass graft surgery, and to compare the effects of dexmedetomidine and propofol on the incidence of postoperative delirium in coronary artery bypass graft surgery patients. Materials and Methods: A prospective, observational study was conducted on 180 consecutive patients undergoing off?pump or on?pump coronary artery bypass graft surgery. The patients were administered either intravenous dexmedetomidine (n = 90) or propofol (n = 90) after hemostasis was achieved, till they were ready for weaning from the ventilator. The Confusion Assessment Method was used to assess the incidence of postoperative delirium. Measurements and Main Results: A total of 25 (13.8%) patients developed delirium after coronary artery bypass graft surgery. Sedation with dexmedetomidine was associated with a significantly reduced incidence of postoperative delirium (8.9% v 18.9% propofol, P = 0.049). Subgroup analyses showed reduced incidence of postoperative delirium in off?pump patients compared to on?pump coronary artery bypass graft patients (3.3% vs. 20%, P = 0.009 dexmedetomidine group and 11.6% vs. 33.3%, P = 0.047 propofol group respectively). The mean age of the patients who had delirium was significantly more (64.9 ± 8.1 years vs. 52.5 ± 5.8 years, P = 0.046) compared to those who did not have delirium. Conclusion: Administration of dexmedetomidine?based sedation resulted in the reduced incidence of postoperative delirium compared to propofol?based sedation in patients after coronary artery bypass graft surgery

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.

Guidelines of the Indian Association of Cardiovascular and Thoracic Anaesthesiologists and Indian College of Cardiac Anaesthesia for perioperative transesophageal echocardiography fellowship examination.

During current medical care, perioperative transesophageal echocardiography (TEE) has become a vital component of patient management, especially in cardiac operating rooms and in critical care medicine. Information derived from echocardiography has an important bearing on the patient’s outcome. The Indian Association of Cardiovascular and Thoracic Anaesthesiologists (IACTA) has promoted the use of TEE during routine clinical care of patients undergoing cardiac surgery. An important mission of IACTA is to oversee training and certify anesthesiologists in the perioperative and intensive care use of TEE. The provision of “Fellowship” is by way of conducting IACTA – TEE fellowship (F‑TEE) examination. This has been done annually for the past 7 years using well‑established curriculums by accredited national and international societies. Now, with the transformation and reconstitution of IACTA education and research cell into the newly formed Indian College of Cardiac Anaesthesia, F‑TEE is bound to meet international standards. To ensure that the examinations are conducted in a transparent and foolproof manner, the guideline committee (formulated in 2010) of IACTA has taken the onus of formulating the guidelines for the same. These guidelines have been formally reviewed and updated since 2010 and are detailed here to serve as a guide to both the examinee and examiner ensuring standardization, efficiency, and competency of the IACTA F‑TEE certification process.

An update on transesophageal echocardiography views 2016: 2D versus 3D tee views.

In 1980, Transesophageal Echocardiography (TEE) first technology has introduced the standard of practice for most cardiac operating rooms to facilitate surgical decision making. Transoesophageal echocardiography as a diagnostic tool is now an integral part of intraoperative monitoring practice of cardiac anaesthesiology. Practice guidelines for perioperative transesophageal echocardiography are systematically developed recommendations that assist in the management of surgical patients, were developed by Indian Association of Cardiac Anaesthesiologists (IACTA). This update relates to the former IACTA practice guidelines published in 2013 and the ASE/EACTA guidelines of 2015. The current authors believe that the basic echocardiographer should be familiar with the technical skills for acquiring 28 cross sectional imaging planes. These 28 cross sections would provide also the format for digital acquisition and storage of a comprehensive TEE examination and adds 5 more additional views, introduced for different clinical scenarios in recent times. A comparison of 2D TEE views versus 3D TEE views is attempted for the first time in literature, in this manuscript. Since, cardiac anaesthesia variability exists in the precise anatomic orientation between the heart and the oesophagus in individual patients, an attempt has been made to provide specific criteria based on identifiable anatomic landmarks to improve the reproducibility and consistency of image acquisition for each of the standard cross sections.

Role of hybrid operating room in surgery for the right atrial thrombus, pulmonary thrombi, and ventricular septal rupture after myocardial infarction.

Free‑floating right heart thrombi are uncommon and need emergency treatment in view of their tendency to dislodge and cause pulmonary embolism. We report a successful surgical management of a patient who had large mobile right atrial thrombus, bilateral pulmonary thrombi, coronary artery disease, and postmyocardial infarction ventricular septal rupture (VSR). The patient underwent coronary angiography, inferior vena cava filter placement, removal of thrombi from the right atrium and pulmonary arteries, repair of VSR, and coronary artery bypass graft surgery in a hybrid operating room.

Perioperative utility of goal‑directed therapy in high‑risk cardiac patients undergoing coronary artery bypass grafting: “A clinical outcome and biomarker‑based study”.

Goal‑directed therapy (GDT) encompasses guidance of intravenous (IV) fluid and vasopressor/inotropic therapy by cardiac output or similar parameters to help in early recognition and management of high‑risk cardiac surgical patients. With the aim of establishing the utility of perioperative GDT using robust clinical and biochemical outcomes, we conducted the present study. This multicenter randomized controlled study included 130 patients of either sex, with European system for cardiac operative risk evaluation ≥3 undergoing coronary artery bypass grafting on cardiopulmonary bypass. The patients were randomly divided into the control and GDT group. All the participants received standardized care; arterial pressure monitored through radial artery, central venous pressure (CVP) through a triple lumen in the right internal jugular vein, electrocardiogram, oxygen saturation, temperature, urine output per hour, and frequent arterial blood gas (ABG) analysis. In addition, cardiac index (CI) monitoring using FloTrac™ and continuous central venous oxygen saturation (ScVO2) using PreSep™ were used in patients in the GDT group. Our aim was to maintain the CI at 2.5–4.2 L/min/m2, stroke volume index 30–65 ml/beat/m2, systemic vascular resistance index 1500–2500 dynes/s/cm5/m2, oxygen delivery index 450–600 ml/min/m2, continuous ScVO2 >70%, and stroke volume variation <10%; in addition to the control group parameters such as CVP 6–8 mmHg, mean arterial pressure 90–105 mmHg, normal ABG values, oxygen saturation, hematocrit value >30%, and urine output >1 ml/kg/h. The aims were achieved by altering the administration of IV fluids and doses of inotropes or vasodilators. The data of sixty patients in each group were analyzed in view of ten exclusions. The average duration of ventilation (19.89 ± 3.96 vs. 18.05 ± 4.53 h, P = 0.025), hospital stay (7.94 ± 1.64 vs. 7.17 ± 1.93 days, P = 0.025), and Intensive Care Unit (ICU) stay (3.74 ± 0.59 vs. 3.41 ± 0.75 days, P = 0.012) was significantly less in the GDT group, compared to the control group. The extra volume added and the number of inotropic dose adjustments were significantly more in the GDT group. The two groups did not differ in duration of inotropic use, mortality, and other complications. The perioperative continuation of GDT affected the early decline in the lactate levels after 6 h in ICU, whereas the control group demonstrated a settling lactate only after 12 h. Similarly, the GDT group had significantly lower levels of brain natriuretic peptide, neutrophil gelatinase‑associated lipocalin levels as compared to the control. The study clearly depicts the advantage of GDT for a favorable postoperative outcome in high‑risk cardiac surgical patients.

Retrospective study on prognostic importance of serum procalcitonin and amino‑terminal pro‑brain natriuretic peptide levels as compared to Acute Physiology and Chronic Health Evaluation IV Score on Intensive Care Unit admission, in a mixed Intensive Care Unit population.

Background: Timely decision making in Intensive Care Unit (ICU) is very essential to improve the outcome of critically sick patients. Conventional scores like Acute Physiology and Chronic Health Evaluation (APACHE IV) are quite cumbersome with calculations and take minimum 24 hours. Procalcitonin has shown to have prognostic value in ICU/Emergency department (ED) in disease states like pneumonia, sepsis etc. NTproBNP has demonstrated excellent diagnostic and prognostic importance in cardiac diseases. It has also been found elevated in non-cardiac diseases. We chose to study the prognostic utility of these markers on ICU admission. Settings and Design: Retrospective observational study. Materials and Methods: A Retrospective analysis of 100 eligible patients was done who had undergone PCT and NTproBNP measurements on ICU admission. Their correlations with all cause mortality, length of hospital stay, need for ventilator support, need for vasopressors were performed. Results: Among 100 randomly selected ICU patients, 28 were non-survivors. NTproBNP values on admission significantly correlated with all cause mortality (P = 0.036, AUC = 0.643) and morbidity (P = 0.000, AUC = 0.763), comparable to that of APACHE-IV score. PCT values on admission did not show significant association with mortality, but correlated well with morbidity and prolonged hospital length of stay (AUC = 0.616, P = 0.045). Conclusion: The current study demonstrated a good predictive value of NTproBNP, in terms of mortality and morbidity comparable to that of APACHE-IV score. Procalcitonin, however, was found to have doubtful prognostic importance. These findings need to be confirmed in a prospective larger study.

The role of neutrophil gelatinase‑associated lipocalin in predicting acute kidney injury in patients undergoing off‑pump coronary artery bypass graft: A pilot study.

Objective: Acute kidney injury (AKI) is a commonly encountered postoperative complication after cardiac surgery especially in high risk patients. AKI though seen more commonly after conventional on pump coronary artery bypass surgery (CCABG), is not uncommon after off pump coronary bypass surgery (OPCAB). Various biomarkers have shown promise over last one decade as an early marker for predicting AKI postoperatively. NGAL is one such biomarker whose concentration is increased in urine after any nephrotoxic and ischemic insult. The objective of this study was to assess the role of urine NGAL in predicting AKI after OPCAB in patients with increased risk of developing AKI. Design: A prospective cohort study. Setting: A clinical study in a multi specialty hospital. Participants: Eighty patients. Materials and Methods: study was approved by the hospital research ethics committee. 80 patients posted for OPCAB with an increased risk of developing AKI defined as having a Cleveland Clinic Foundation Acute renal failure scoring System score of ≥6 were included in the study. Patients with coronary angiography (CAG) within 48 hrs prior to surgery, pre-existing AKI, preoperative renal replacement therapy (RRT) and CKD stage 5 were excluded. Urine NGAL level before the start of surgery baseline and at 4 hrs post surgery were done. Renal function tests were assessed on the day of surgery (4 hrs post surgery) and on the next three days. Result: Seven patients developed AKI as defined by acute kidney infection network (AKIN) and risk injury failure loss end stage (RIFLE) criteria for AKI. NGAL value at 4 hrs in patients who developed AKI was significantly higher than in those patients who did not develop AKI (P < 0.05). Conclusion: urine NGAL is an early biomarker of acute kidney injury in patients undergoing OPCAB surgeries. However, large multicentre studies may be needed to confirm it.

Management of refractory hypoxemia.

Mechanical ventilation remains the cornerstone in the management of severe acute respiratory failure. Acute respiratory distress syndrome (ARDS) is the most common cause of respiratory failure. It is associated with substantial mortality, and unmanageable refractory hypoxemia remains the most feared clinical possibility. If hypoxemia persists despite application of lung protective ventilation, additional therapies including inhaled vasodilators, prone positioning, recruitment maneuvers, high‑frequency oscillatory ventilation, neuromuscular blockade (NMB), and extracorporeal membrane oxygenation may be needed. NMB and prone ventilation are modalities that have been clearly linked to reduced mortality in ARDS. Rescue therapies pose a clinical challenge requiring a precarious balance of risks and benefits, as well as, in‑depth knowledge of therapeutic limitations.

Intraoperative aortic dissection.

Intraoperative aortic dissection is a rare but fatal complication of open heart surgery. By recognizing the population at risk and by using a gentle operative technique in such patients, the surgeon can usually avoid iatrogenic injury to the aorta. Intraoperative transesophageal echocardiography and epiaortic scanning are invaluable for prompt diagnosis and determination of the extent of the injury. Prevention lies in the strict control of blood pressure during cannulation/decannulation, construction of proximal anastomosis, or in avoiding manipulation of the aorta in high‑risk patients. Immediate repair using interposition graft or Dacron patch graft is warranted to reduce the high mortality associated with this complication.

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.