Recent advances in cardiac anaesthesia.

The speciality of cardiac anaesthesia has rapidly evolved over the past few decades with advances in technology, including artificial intelligence (AI), newer devices, techniques, imaging, pain relief and a better understanding of the pathophysiology of disease states. Incorporation of the same has led to improved patient outcomes in terms of morbidity and mortality benefits. With the advent of minimally invasive surgical methods, minimising the dose of opioids and ultrasound-guided regional anaesthesia for pain relief, enhanced recovery after cardiac surgery has been made possible. Perioperative imaging including 3D transoesophageal echocardiography, newer devices and drugs and AI algorithms will play a significant role in cardiac anaesthesia. This review briefly addresses some of the recent advances that the authors believe can impact the practice of cardiac anaesthesia.

Normative Transesophageal Echocardiographic Values of Cardiac Structures in the Indian Population-Indian Normative TEE Measurements (INTEEM) Study.

OBJECTIVES: Information on normative reference values for cardiac structures is critical for the accurate application of echocardiography for guiding clinical decision-making. Many studies using transthoracic echocardiography (TTE) have shown that Indians have smaller diameters of various cardiac structures. There are no normative studies for transesophageal echocardiography (TEE). The authors observed dimensions of various cardiac structures in healthy Indian patients under general anesthesia using TEE and compared them with existing guidelines from non-Indian data. DESIGN: The Indian Normative TEE Measurements study was a multicenter, prospective observational study conducted in India. SETTING: Operating rooms for noncardiac surgeries in tertiary care-level hospitals. PARTICIPANTS: Adult patients undergoing noncardiac surgery who were free from any cardiac, respiratory, and renal diseases and had no contraindications for TEE. INTERVENTIONS: After inducing general anesthesia and achieving stable hemodynamic conditions, a comprehensive TEE examination was performed and various measurements were made. MEASUREMENTS AND MAIN RESULTS: For each of the 83 patients undergoing noncardiac surgery, 39 various measurements for left ventricle, right ventricle, both atria, and all valves were made. This included diameters and functional parameters. They were analyzed in a vendor-neutral software off-line. The absolute values of many of the measurements were higher in men, but when indexed to body surface area (BSA) they were similar in both sexes. The values were lower than most of the Western data but matched previous Indian studies using TTE. CONCLUSIONS: The authors present normative values of various echocardiographic parameters using TEE. Because of its variations, it is recommended to use India-specific data to make decisions in Indian patients. It may be prudent to use BSA-indexed values during decision-making.

Practice patterns of left-sided double-lumen tube: Does it match recommendation from literature - A single-centre observational pilot study.

Context: Choosing appropriate-size double-lumen tube (DLT) has always been a challenge as it depends on existing guidelines based on gender, height, tracheal diameter (TD), or personal experience. However, there are no Indian data to match these recommendations. Aim: To find out whether the size of DLT used correlates with height, weight, TD, or left main stem bronchus diameter (LMBD). We also documented clinical consequences of any of our current practice. Setting and Design: Single-center observational pilot study. Subjects and Methods: Prospective, observational study of 41 patients requiring one-lung ventilation with left-side DLT. The choice of DLT was entirely on the discretion of anesthesiologist in charge of the case. Data were collected for TD, LMBD, height, weight, age, sex, and amount of air used in the tracheal and bronchial cuff. Any intraoperative complications and difficulty in isolation were also noted. Statistical Analysis: The statistical analysis was done with the National Council of Statistical Software version 11. Results: Average TD and LMBD were 16.5 ± 0.9 and 10.7 ± 0.8 mm for males and 14.2 ± 1.1 and 9.4 ± 1.1 mm for females, respectively. There was a weak correlation between DLT size and height (R2 = 0.0694), TD (R2 = 0.3396), and LMBD (R2 = 0.2382) in the case of males. For females, the correlation between DLT size and height (R2 = 0.2656), TD (R2 = 0.5302), and LMBD (R2 = 0.5003) was slightly better. Conclusion: Although there was a weak correlation between DLT size and height, TD, and LMBD, the overall intraoperative outcome and lung isolation were good.

Effect of levosimendan on hemodynamic changes in patients undergoing off-pump coronary artery bypass grafting: a randomized controlled study.

AIMS AND OBJECTIVE: We tested the hypothesis that use of levosimendan would be associated with better perioperative hemodynamics and cardiac function during off-pump coronary artery bypass grafting (OPCAB) in patients with good left ventricular function. MATERIALS AND METHODS: Thirty patients scheduled for OPCAB were randomized in a double-blind manner to receive either levosimendan 0.1 µg/kg/min or placebo after induction of general anesthesia. The hemodynamic variables were measured after induction of anesthesia, at 6 minute after application of tissue stabilizer for the anastomoses of left anterior descending artery, diagonal artery, left circumflex artery, and right coronary artery and at 6, 12, 18, and 24 hours after completion of surgery. RESULTS: Compared with placebo group, cardiac index (CI) was significantly higher and systemic vascular resistance index (SVRI) was significantly lower at 6, 12, 18, and 24 hour after surgery in levosimendan group. Norepinephrine was infused in 60% of the patients in the levosimendan group compared to 6.7% in the control group ( P < 0.05). Lactate and mixed venous oxygen saturation were not significantly different between groups. CONCLUSIONS: Levosimendan significantly increased CI and decreased SVRI after OPCAB but it did not show any outcome benefit in terms of duration of ventilation and intensive care unit stay.

The effects of preemptive pregabalin on attenuation of stress response to endotracheal intubation and opioid-sparing effect in patients undergoing off-pump coronary artery bypass grafting.

The clinical study was designed to evaluate and compare single preoperative dose of pregabalin to a placebo regarding hemodynamic responses to laryngoscopy and endotracheal intubation, to assess perioperative fentanyl requirement and any side-effects. It was a randomized, double-blind, placebo-controlled, parallel assignment, efficacy study. The study was done at a tertiary university hospital. This study was a comparison between two groups of 30 adult patients scheduled for elective off pump coronary artery bypass surgery. In the control group, the patients were given placebo capsules, and in the pregabalin group, the patients were given pregabalin 150 mg capsule orally 1 h before surgery. The patients were compared for hemodynamic changes before the start of the surgery, after induction, 1, 3, and 5 min after intubation. Additionally, fentanyl requirement during surgery and the first postoperative day was also compared. The present study shows that a single oral dose of 150 mg pregabalin given 1 h before surgery attenuated the pressor response to tracheal intubation in adults, but the drug did not show any effect on perioperative opioid consumption and was devoid of side-effects in the given dose.

The effects of dexmedetomidine on attenuation of stress response to endotracheal intubation in patients undergoing elective off-pump coronary artery bypass grafting.

This study was designed to study the efficacy of intravenous dexmedetomidine for attenuation of cardiovascular responses to laryngoscopy and endotracheal intubation in patients with coronary artery disease. Sixty adult patients scheduled for elective off-pump coronary artery bypass surgery were randomly allocated to receive dexmedetomidine (0.5 mcg/kg) or normal saline 15 min before intubation. Patients were compared for hemodynamic changes (heart rate, arterial blood pressure and pulmonary artery pressure) at baseline, 5 min after drug infusion, before intubation and 1, 3 and 5 min after intubation. The dexmedetomidine group had a better control of hemodynamics during laryngoscopy and endotracheal intubation. Dexmedetomidine at a dose of 0.5 mcg/kg as 10-min infusion was administered prior to induction of general anaesthesia attenuates the sympathetic response to laryngoscopy and intubation in patients undergoing myocardial revascularization. The authors suggest its administration even in patients receiving beta blockers.

Early extubation in tetralogy of Fallot patients after complete repair.

AIM: To document the feasibility of early extubation and to know the effect of age, weight, and post-operative right ventricle/left ventricle ratio in early extubation in intracardiac repair for tetralogy of Fallot. MATERIALS AND METHODS: This is a prospective study of 76 consecutive patients undergoing intracardiac repair between January, 2010 and April, 2010. The patients were compared between duration of ventilation with age, weight, and post-operative left ventricle/right ventricle ratio. RESULTS: In the age group less than 10 years, 47 patients were extubated within 4 hours and 12 after 4 hours. In the age group of 10-20 years, eight patients were extubated within 4 hours and seven patients after 4 hours. In the more than 20 years category, one patient was extubated within 4 hours and the other after 4 hours. In the weight category less than 10 kilograms, 17 patients were extubated within 4 hours and seven patients after 4 hours. In the 10-20 kilogram category, 27 patients were extubated before 4 hours and four patients after 4 hours. In the more than 20-kilogram category, 12 patients were extubated before 4 hours and nine patients after 4 hours. Where the ratio was less than 0.5, 47 patients were extubated within 4 hours and 14 patients after 4 hours. Where the ratio was greater than 0.5, nine patients were extubated within 4 hours and six patients after 4 hours. CONCLUSION: There was no correlation between duration of ventilation with age, weight, and right ventricle/left ventricle ratio. Early extubation in patients after intracardiac repair in tetralogy of Fallot is safe and effective.

Lower ministernotomy and fast tracking for atrial septal defect.

We report our experience with a 3-5-cm lower ministernotomy incision for closure of atrial septal defect in 53 patients. Fibrillatory arrest was used in 19 patients, and crossclamping with cardioplegia in 33. One patient had to be converted from fibrillatory arrest to crossclamping with cardioplegic arrest. The mean bypass time was 39.6 +/- 13.1 min, arrest time was 9.9 +/- 4.5 min, and crossclamp time was 20.7 +/- 8.69 min. All patients recovered without adverse events. They were fast tracked to recovery and extubated after 63.4 +/- 9.2 min. The mean intensive care unit stay was 1.07 +/- 0.33 days, and hospital stay was 3.07 +/- 0.38 days. The ministernotomy approach was used successfully in 51 patients; in the other 2, it had to be converted to a full sternotomy because of technical difficulties. Our experience confirms that this technique offers satisfactory cosmetic results, stable sternal reconstruction, good surgical exposure, minimal interference with respiratory mechanics, and minimal pain, allowing extubation in the operating room and a speedy recovery.