Comparision of Cardiac Output Measured by Transthoracic Echocardiography with Continuous Cardiac Output Measured by Pressure Recording Analytical Method

Background: Low cardiac output is a common complication following cardiac surgery and it is associated with higher mortality in the pediatric population. A gold standard method for cardiac output (CO) monitoring in the pediatric population is lacking. The present study was conducted to validate cardiac output and cardiac index measured by transthoracic echocardiography and Pressure recording analytical method, a continuous pulse contour method, MostCare Up in postoperative pediatric cardiac surgical patients. Materials and Methods: This was a prospective observational clinical study conducted at a tertiary care hospital. A total of 23 pediatric patients weighed between 2 and 20 kg who had undergone elective cardiac surgery were included in the study. Results: Spearman抯 correlation coefficient of CO between transthoracic echocardiography (TTE) and Pressure Recording Analytical Method (PRAM) showed of positive correlation (r = 0.69, 95% Confidence interval 0.59?0.77, P < 0.0001) Linear regression equations for CO between TTE and PRAM were y = 0.55 + 0.88x (R2 = 0.46, P < 0.0001). (y = PRAM, x = TTE), respectively. Bland? Altman plot for CO between TTE and PRAM showed a bias of ?0.397 with limits of the agreement being ?2.01 to 1.22. Polar plot analysis showed an angular bias of 6.55� with radial limits of the agreement being ?21.46 to 34.58 for CO and angular bias of 6.22� with radial limits of the agreement being ?22.4 to 34.84 for CI. Conclusion: PRAM has shown good trending ability for cardiac output. However, values measured by PRAM are not interchangeable with the values measured by transthoracic echocardiography.

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 andmyocardial 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 perminute. 2) Decrease in systolic blood pressure SBP by >/= 10mmHg 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.

Comparison of Epidural Analgesia with Ultrasound?Guided Bilateral Erector Spinae Plane Block in Aorto?Femoral Arterial Bypass Surgery

Objective:Thoracic Epidural Analgesia (TEA) was compared with ultrasound?guided bilateral erector spinae plane (ESP) block in aorto?femoral arterial bypass surgery for analgesic efficacy, hemodynamic effects, and pulmonary rehabilitation. Design: Prospective randomized. Setting: Tertiary care centre. Participants: Adult patients, who were scheduled for elective aorto?femoral arterial bypass surgery. Interventions: It was a prospective pilot study enrolling 20 adult patients who were randomized to group A (ESP block = 10) and group B (TEA = 10). Monitoring of heart rate (HR) and mean arterial pressure (MAP) and pain assessment at rest and deep breathing using visual analog scale (VAS) were done till 48?h post?extubation. Rescue analgesic requirement, Incentive spirometry, oxygenation, duration of ventilation and stay in Intensive Care Unit (ICU) were reported as outcome measures. Statistical analysis was performed using unpaired Student T?test or Mann?Whitney U test. A value of P < 0.05 was considered significant. Results: HR was lower in group B than group A at 1 and 2 h post? surgery and at 0.5, 16, 20, and 32 h post?extubation (P < 0.05). MAP were lower in group B than A at 60, 90, 120, 150, 180, 210, 240, 270 minutes and at 0 hour post?surgery and at 4 hours, every 4 hours till 32 hours post?extubation (P < 0.05). Intraoperative midazolam and fentanyl consumption, ventilatory hours, VAS at rest, incentive spirometry, oxygenation, and ICU stay were comparable between the two groups. VAS during deep breathing was more in group A than B at 0.5, 4 hours and every 4 hours till 44 hours post?extubation. The time to receive the first rescue analgesia was shorter in group A than B (P < 0.05). Conclusion: Both ESP block and TEA provided comparable analgesia at rest. Further studies with larger sample size are required to evaluate whether ESP block could be an alternative to TEA in aorto?femoral arterial bypass surgery

ANSiscope™: Can it be the crystal ball of cardiac anesthesia?

Background: Autonomic dysfunction (AD) is infrequently evaluated preoperatively despite having profound perioperative implications. The ANSiscope™ is a monitoring device that quantifies AD. This study aims to determine the potential of the device to predict hypotension following anesthetic induction, occurrence of arrhythmias, and inotrope requirement for patients undergoing off-pump coronary artery bypass surgery (OPCAB). Study Design: Prospective observational double-blinded study. Materials and Methodology: Seventy-five patients undergoing OPCAB had their autonomic function assessed by ANSiscope™. They were classified into four groups based on their AD and compared to perioperative adverse events. Results: Patients with diabetes had a higher ANSindex (P = 0.0263). They had a greater decrease in systolic blood pressure (P = 0.001) and mean arterial pressure (P = 0.004) postinduction, had an increased incidence of arrhythmias (P = 0.009), required higher inotropic support immediately (P = 0.010) and at 24 h after surgery (P = 0.018), and longer duration of postoperative ventilation (P < 0.001). They also had a higher incidence of emergency conversion of OPCAB to on-pump surgery (P = 0.009). Conclusions: An increased association between AD as quantified by the ANSiscope™ and perioperative adverse outcomes was observed. An increased rate of emergency conversion of OPCAB to on-pump surgery with higher dysfunction was noted. The authors opine that the threshold for conversion must be lower in patients deemed to be at a higher risk. Proper evaluation of the autonomic nervous system empowers the anesthesiologist to anticipate and adequately prepare for complications.

Evaluation of risk scores in predicting perioperative blood transfusions in adult cardiac surgery

Objective: Allogeneic blood product transfusions are associated with an increased morbidity and mortality risk in cardiac surgery. At present, a few transfusion risk scores have been proposed for cardiac surgery patients. The present study is aimed to develop a new score and to compare with preexisting scores – Transfusion Risk and Clinical Knowledge (TRACK) and Transfusion Risk Understanding Scoring Tool (TRUST) score. Methodology: A total of 1014 adult patients undergoing cardiac surgery were enrolled in the retrospective study. Independent predictors of allogeneic blood transfusions were selected from TRACK and TRUST scores. A predictive score was developed from six variables using logistic regression analysis, and new score was compared to the other existing scores – TRACK and TRUST. Results: The new score had following predictors: age >58 years, weight <63 kg for males and <49 kg for females, gender (female), complex surgery, hemoglobin <13.5 g/dl, and creatinine >1.36 mg/dl. Validation of new score demonstrated an acceptable predictive power (area under the curve [AUC] 0.749) and a good calibration at the Hosmer–Lemeshow test. New score was comparable with TRACK score with P = 0.578 (AUC of TRACK 0.756 and AUC of new score 0.749). There was a significant difference between new score and TRUST score, P = 0.01 (AUC of TRUST 0.72 and AUC of new score 0.749). Conclusion: New score is a simple risk model based on six predictors having a similar accuracy and calibration in predicting the transfusion rate in cardiac surgery as compared to TRACK score.

Early prediction of acute kidney injury using serum phosphorus as a biomarker in pediatric cardiac surgical patients

Background: Acute kidney injury (AKI) is a strong predictor of morbidity and mortality after cardiac surgery. Lack of valid early biomarkers for predicting AKI has hampered the ability to take therapeutic measures for preventive cause. Hyperphosphatemia that occurs in AKI due to renal excretion defect was not studied in this context and could be simple marker of AKI. Therefore, we tested role of serum phosphorus in prediction of AKI as a biomarker after cardiac surgery in children. Methodology: We prospectively evaluated 51 children aged between 3 weeks and 12 years undergoing elective cardiac surgery. Serum creatinine and phosphorus were measured preoperatively and postoperatively at 24 and 48 h. As per the Kidney Disease Improving Global Outcomes criteria, patients were grouped into AKI and non-AKI on the basis of the development of AKI within 48 h postsurgery. The postoperative diagnostic performance of phosphorus thresholds was analyzed by the area under receiver operating characteristic curves (AUC-ROC). Results: From 51 children included, 10 developed AKI. In AKI group, serum phosphorus increased significantly from 4.47 ± 0.43 baseline to 6.29 ± 0.32 at 24 h postsurgery (P = 0.01) while serum creatinine increased from baseline 0.33 (0.24–0.46) to 0.49 (0.26–0.91) at 24 h which is statistically insignificant (P = 0.16). ROC analysis showed that serum phosphorus at 24 h, the AUC was 0.84 with sensitivity 0.75 and specificity 0.93 for a cutoff value of 6.4 mg/dl. Whereas serum phosphorus at 48 h, the AUC was 0.86 with sensitivity 66.67% and specificity 97.62% for a cutoff value of 5.4 mg/dl. Conclusion: Serum phosphorus can be an alternative biomarker as early as 24 h for early prediction of AKI in pediatric cardiac surgery.

Efficacy of bilateral pectoralis nerve block for ultrafast tracking and postoperative pain management in cardiac surgery

Background: Good postoperative analgesia in cardiac surgical patients helps in early recovery and ambulation. An alternative to parenteral, paravertebral, and thoracic epidural analgesia can be pectoralis nerve (Pecs) block, which is novel, less invasive regional analgesic technique. Aims: We hypothesized that Pecs block would provide superior postoperative analgesia for patients undergoing cardiac surgery through midline sternotomy compared to parenteral analgesia. Materials and Methods: Forty adult patients between the age groups of 25 and 65 years undergoing coronary artery bypass grafting or valve surgeries through midline sternotomy under general anesthesia were enrolled in the study. Patients were randomly allocated into two groups with 20 in each group. Group 1 patients did not receive Pecs block, whereas Group 2 patients received bilateral Pecs block postoperatively. Patients were extubated once they fulfilled extubation criteria. Ventilator duration was recorded. Patients were interrogated for pain by visual analog scale (VAS) scoring at rest and cough. Inspiratory flow rate was assessed using incentive spirometry. Results: Pecs group patients required lesser duration of ventilator support (P < 0.0001) in comparison to control group. Pain scores at rest and cough were significantly low in Pecs group at 0, 3, 6, 12, and 18 h from extubation (P < 0.05). At 24 h, VAS scores were comparable between two groups. Peak inspiratory flow rates were higher in Pecs group as compared to control group at 0, 3, 6, 12, 18, and 24 h (P < 0.05). Thirty-four episodes of rescue analgesia were given in control group, whereas in Pecs group, there were only four episodes of rescue analgesia. Conclusion: Pecs block is technically simple and effective technique and can be used as part of multimodal analgesia in postoperative cardiac surgical patients for better patient comfort and outcome.

Comparison of continuous thoracic epidural analgesia with bilateral erector spinae plane block for perioperative pain management in cardiac surgery

Objective: Continuous thoracic epidural analgesia (TEA) is compared with erector spinae plane (ESP) block for the perioperative pain management in patients undergoing cardiac surgery for the quality of analgesia, incentive spirometry, ventilator duration, and intensive care unit (ICU) duration. Methodology: A prospective, randomized comparative clinical study was conducted. A total of 50 patients were enrolled, who were randomized to either Group A: TEA (n = 25) or Group B: ESP block (n = 25). Visual analog scale (VAS) was recorded in both the groups during rest and cough at the various time intervals postextubation. Both the groups were also compared for incentive spirometry, ventilator, and ICU duration. Statistical analysis was performed using the independent Student's t-test. A value of P < 0.05 was considered statistically significant. Results: C omparable VAS scores were revealed at 0 h, 3 h, 6 h, and 12 h (P > 0.05) at rest and during cough in both the groups. Group A had a statistically significant VAS score than Group B (P ≤ 0.05) at 24 h, 36 h, and 48 h but mean VAS in either of the Group was ≤4 both at rest and during cough. Incentive spirometry, ventilator, and ICU duration were comparable between the groups. Conclusion: ESP block is easy to perform and can serve as a promising alternative to TEA in optimal perioperative pain management in cardiac surgery.

Comparison between noninvasive measurement of central venous pressure using near infrared spectroscopy with an invasive central venous pressure monitoring in cardiac surgical Intensive Care Unit.

Introduction: Central venous pressure (CVP) measurement is essential in the management of certain clinical situations, including cardiac failure, volume overload and sepsis. CVP measurement requires catheterization of the central vein which is invasive and may lead to complications. The aim of this study was to evaluate the accuracy of measurement of CVP using a new noninvasive method based on near infrared spectroscopy (NIRS) in a group of cardiac surgical Intensive Care Unit (ICU) patients. Methodology: Thirty patients in cardiac surgical ICU were enrolled in the study who had an in situ central venous catheter (CVC). Sixty measurements were recorded in 1 h for each patient. A total of 1800 values were compared between noninvasive CVP (CVPn) obtained from Mespere VENUS 2000 CVP system and invasive CVP (CVPi) obtained from CVC. Results: Strong positive correlation was found between CVPi and CVPn (R = 0.9272, P < 0.0001). Linear regression equation ‑ CVPi = 0.5404 + 0.8875 × CVPn (r2 = 0.86, P < 0.001), Bland–Altman bias plots showed mean difference ± standard deviation and limits of agreement: −0.31 ± 1.36 and − 2.99 to + 2.37 (CVPi–CVPn). Conclusion: Noninvasive assessment of the CVP based on NIRS yields readings consistently close to those measured invasively. CVPn may be a clinically useful substitute for CVPi measurements with an advantage of being simple and continuous. It is a promising tool for early management of acute state wherein knowledge of CVP is helpful.

Feasibility of measuring superior mesenteric artery blood flow during cardiac surgery under hypothermic cardiopulmonary bypass using transesophageal echocardiography: An observational study.

Background: Abdominal complications being rare but results in high mortality, commonly due to splanchnic organ hypoperfusion during the perioperative period of cardiac surgery. There are no feasible methods to monitor intraoperative superior mesenteric artery blood flow (SMABF). Hence, the aim of this study was to evaluate the feasibility and to measure SMABF using transesophageal echocardiography (TEE) during cardiac surgery under hypothermic cardiopulmonary bypass (CPB). Methodology: Thirty‑five patients undergoing elective cardiac surgery under CPB were enrolled. Heart rate, mean arterial pressure (MAP), cardiac output (CO), SMABF, superior mesenteric artery (SMA) diameter, superior mesentric artery blood flow over cardiac output (SMA/CO) ratio and arterial blood lactates were recorded at three time intervals. T0: before sternotomy, T1: 30 min after initiation of CPB and T2: after sternal closure. Results: SMA was demonstrated in 32 patients. SMABF, SMA diameter, SMA/CO, MAP and CO-decreased significantly (P < 0.0001) between T0 and T1, increased significantly (P ≤ 0.001) between T1 and T2 and no significant change (P > 0.05) between T0 and T2. Lactates increased progressively from T0 to T2. Conclusion: Study shows that there is decrease in SMABF during CPB and returns to baseline after CPB. Hence, it is feasible to measure SMABF using TEE in patients undergoing cardiac surgery under hypothermic CPB. TEE can be a promising tool in detecting and preventing splanchnic hypoperfusion during perioperative period.

Effect of dexmedetomidine on diseased coronary vessel diameter and myocardial protection in percutaneous coronary interventional patients.

Introduction: Dexmedetomidine is an alpha‑2 agonist used for conscious sedation. It has also been shown to have a myocardial protective effect in off‑pump coronary artery bypass patients. The aim of the study was to assess the effect of dexmedetomidine for myocardial protection in percutaneous coronary interventional patients. Methodology: A total of 60 patients (group dexmedetomidine, n = 30 and group normal saline, n = 30) were enrolled in the study. Dexmedetomidine infusion (1 mcg/kg) over 15 min was given as a loading dose after coronary angiography in group dexmedetomidine (D) while normal saline was given in the control group (C) and later maintenance infusion was started at 0.5 mcg/kg/h in both the groups. Coronary vessel diameter was noted before (T0) and after (T1) loading dose of dexmedetomidine/saline in each group. Troponin T (Trop T) values were noted at baseline (T0), 6 h (T2), 12 h (T3) and 24 h (T4) after starting the loading dose. Hemodynamic variables (heart rate [HR] and blood pressure) were monitored at T0, T1, and at regular intervals till 2 h postprocedure. Results: Coronary vessel diameter and HR significantly decreased in group D as compared to control group (P < 0.05) whereas the decrease in Trop T at 6 h, 12 h, and 24 h were not statistically significant between the two groups. Conclusion: Dexmedetomidine decreases the coronary vessel diameter, but maintains the myocardial oxygen demand‑supply ratio by decreasing the HR. The decrease in Trop T is statistically insignificant at the doses used.

Transesophageal echocardiography estimation of coronary sinus blood flow for the adequacy of revascularization in patients undergoing off-pump coronary artery bypass graft.

Aims and Objectives: Physiologically coronary sinus (CS) drains the left coronary artery (LCA) territory. Stenosis of the branches of LCA may decrease the coronary sinus blood flow (CSBF). Any intervention that aims at restoring the flow of the stenosed vessel increases coronary artery flow that should consequently increase the CSBF. Hence, this study was undertaken to assess the CSBF before and after each branch of LCA to determine the adequacy of surgical revascularization in patients undergoing elective off pump coronary artery bypass grafting (OPCAB) using transesophageal echocardiography (TEE). Materials and Methods: Thirty consecutive patients scheduled for elective OPCAB were enrolled. CSBF was assessed before and after each branch of LCA revascularization using TEE. Left internal mammary artery (LIMA) Doppler was also obtained post LIMA to left anterior descending (LAD) grafting. Results: Hemodynamic and echocardiographic variables were compared by means of Student’s t-test for paired data before and after revascularization. The CSBF per beat (1.28 ± 0.71), CSBF per minute (92.59 ± 59.32) and total velocity time integral (VTI) (8.93 ± 4.29) before LAD grafting showed statistically significant increase to CSBF per beat (1.70 ± 0.89), CSBF per minute (130.72 ± 74.22) and total VTI (11.96 ± 5.68) after LAD revascularization. The CSBF per beat (1.67 ± 1.03), CSBF per minute (131.91 ± 86.59) and total VTI (11.00 ± 5.53) before obtuse marginal (OM) grafting showed statistically significant increase to CSBF per beat (1.91 ± 1.03), CSBF per min (155.20 ± 88.70) and total VTI (12.09 ± 5.43) after OM revascularization. In 9 patients, color flow Doppler of LIMA could be demonstrated which showed diastolic predominant blood flow after LIMA to LAD grafting. Conclusion: Demonstration of CSBF was simple and monitoring the trend of CSBF values before and after each graft of LCA territory will guide to determine the adequacy of surgical revascularization.

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.

Comparison of left internal mammary artery diameter before and after left stellate ganglion block.

Aims and Objectives: Left internal mammary artery (LIMA) is the preferred arterial conduit for coronary artery bypass grafting. Various pharmacological agents are known to increase LIMA blood flow. Sympathetic blockade mediated by stellate ganglion block (SGB) has been used to provide vasodilatation in the upper extremities and in the treatment of refractory angina. We investigated effect of left stellate ganglion block (LSGB) on LIMA diameter. Materials and Methods: In 30 diagnosed patients of triple vessel coronary artery disease, LSGB was given under fluoroscopic guidance by C6 transverse process approach using 10 ml of 1% lignocaine. LIMA diameter was measured before and 20 min after the block at 2nd, 3rd, 4th and at 5th rib level. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) were recorded before and 20 min after the block. Results: The LIMA diameter increased significantly at 2nd (2.56 ± 0.39 vs. 2.99 ± 0.40; P < 0.0001), 3rd (2.46 ± 0.38 vs. 2.90 ± 0.40; P < 0.0001), 4th (2.39 ± 0.38 vs. 2.84 ± 0.41; P < 0.0001) and 5th rib level (2.35 ± 0.38 vs. 2.78 ± 0.40; P < 0.0001). No statistically significant change occurred in HR, SBP, DBP and MAP before and 20 min after LSGB. Conclusions: LSGB significantly increased the LIMA diameter. The LSGB can be considered as an alternative to topical and systemic vasodilators for reducing vasospasm of LIMA.

A comparison of a continuous noninvasive arterial pressure (CNAP™) monitor with an invasive arterial blood pressure monitor in the cardiac surgical ICU.

Accurate measurement and display of arterial blood pressure is essential for rational management of adult cardiac surgical patients. Because of the lower risk of complications, noninvasive monitoring methods gain importance. A newly developed continuous noninvasive arterial blood pressure (CNAP™) monitor is available and has been validated perioperatively. In a prospective study we compared the CNAP™ monitoring device with invasive arterial blood pressure (IAP) measurement in 30 patients in a cardiac surgical Intensive Care Unit (ICU). Patients were either mechanically ventilated or spontaneously breathing, with or without inotropes. CNAP™ was applied on two fingers of the hand contralateral to the IAP monitoring catheter. Systolic, diastolic and mean pressure data were recorded every minute for 2 h simultaneously for both IAP and CNAP™. Statistical analysis included construction of mountain plot and Bland Altman plots for assessing limits of agreement and bias (accuracy) calculation. Three thousand and six hundred pairs of data were analyzed. The CNAP™ systolic arterial pressure bias was 10.415 mmHg and the CNAP™ diastolic arterial pressure bias was −5.3386 mmHg; the mean arterial pressure (MAP) of CNAP™ was close to the MAP of IAP, with a bias of 0.03944 mmHg. The Bland Altman plot showed a uniform distribution and a good agreement of all arterial blood pressure values between CNAP™ and IAP. Percentage within limits of agreement was 94.5%, 95.1% and 99.4% for systolic, diastolic and MAP. Calculated limits of agreement were −4.60 to 25.43, −13.38 to 2.70 and −5.95 to 6.03 mmHg for systolic, diastolic and mean BP, respectively. The mountain plot showed similar results as the Bland Altman plots. We conclude CNAP™ is a reliable, noninvasive, continuous blood pressure monitor that provides real-time estimates of arterial pressure comparable to those generated by an invasive arterial catheter system. CNAP™ can be used as an alternative to IAP.