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.

Repair of recurrent pseudoaneurysm of the mitral-aortic intervalvular fibrosa: Role of transesophageal echocardiography.

Pseudoaneurysm of mitral‑aortic intervalvular fibrosa (P‑MAIVF) is a rare cardiac surgical condition. P‑MAIVF commonly occurs as a complication of aortic and mitral valve replacement surgeries. The surgical trauma during replacement of the valves weakens the avascular mitral and aortic intervalvular area. We present a case of P‑MAIVF recurrence 5 years after a primary repair. Congestive cardiac failure was the presenting feature with mitral and aortic regurgitation. In view of the recurrence, the surgical team planned for a double valve replacement. The sewing rings of the two prosthetic‑valves were interposed to close the mouth of the pseudoaneurysm and to provide mechanical reinforcement of the MAIVF. Intra‑operative transesophageal echocardiography (TEE) helped in delineating the anatomy, extent of the lesion, rupture of one of the pseudoaneurysm into left atrium and severity of the valvular regurgitation. Post‑procedure TEE confirmed complete obliteration of the pseudoaneurysm and prosthetic valve function.