Intraoperative 3-Dimensional Echocardiography-Derived Right Ventricular Volumetric Analysis in Chronic Thromboembolic Pulmonary Hypertension Patients Before and After Pulmonary Thromboendarterectomy.

OBJECTIVES: To assess the change in 3-dimensional (3D) echocardiography-derived right ventricular volumes before and after pulmonary thromboendarterectomy (PTE) and to evaluate the correlation of these variables with right heart catheterization-calculated pulmonary vascular resistance (PVR). SETTING: Single university hospitals. PARTICIPANTS: Patients undergoing elective PTE surgery between November 2016 and February 2018. METHODS: All patients received a pulmonary artery catheter and arterial line, and transesophageal echocardiographic monitoring was performed. Transesophageal echocardiographic monitoring before surgery (pre-PTE) and postsurgery (post-PTE) included comprehensive 2D examinations and 3D right ventricular data set acquisition for offline volumetric analysis. Right ventricular fractional area of change (RVFAC) was measured from a right ventricular-focused midesophageal 4-chamber view. TomTec-Arena 4D RV-Function 2.0 offline software (TomTec Imaging Systems GmbH, Unterschlessheim, Germany) was used to measure right ventricular end diastolic volume (RVEDV), right ventricular end systolic volume (RVESV), and right ventricular ejection fraction (RVEF). Paired t tests were used to evaluate for differences before and after surgery, and echocardiographic variables versus PVR were analyzed with linear regression. RESULTS: Forty patients were scheduled for elective PTE surgery; 35 patients had complete hemodynamic profiles and echocardiographic data sets and were included in the evaluation. Mean pulmonary artery pressure decreased from 40 ± 11 to 28 ± 7 mmHg, and PVR decreased from 708 ± 432 to 285 ± 136 dynes*s/cm5 after PTE. RVEDV decreased from 106 ± 43 to 79 ± 35 cm3 (p < 0.001), and RVESV decreased from 77 ± 36 to 59 ± 31 cm3 (p < 0.001). A statistically significant change was not identified in RVEF or RVFAC post-PTE compared with pre-PTE values. All volumetric analyses and RVFAC correlated poorly with PVR (pre-PTE RVEDV correlation to PVR [R2 = 0.004]; post-PTE RVEDV correlation to PVR [R2 = 0.024]). CONCLUSION: Even though RVEDV and RVESV displayed a statistically significant change after PTE, this study did not identify a correlation between those variables and PVR. In addition, markers of right ventricular systolic function (eg, RVFAC and RVEF) did not correlate with PVR. Therefore, the authors conclude that even though these echocardiographic measurements quantified a statistically significant change after PVR reduction, they cannot be reliably used as a surrogate marker of success immediately after PTE.

Measures of Blood Hemoglobin and Hematocrit During Cardiac Surgery: Comparison of Three Point-of-Care Devices.

OBJECTIVE: The primary objective was to compare I-Stat, HemoCue, and RapidLab in measurements of the hemoglobin concentration during cardiac surgeries using cardiopulmonary bypass. DESIGN: Prospective analysis. SETTING: Single-center, academic, tertiary care cardiovascular center. PARTICIPANTS: Thirty-four consecutive patients undergoing cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: Blood samples have been collected intraoperatively, and the hemoglobin concentration in each sample was measured, or calculated, simultaneously by the 3 point-of-care devices, HemoCue, RapidLab, and I-Stat. MEASUREMENTS AND MAIN RESULTS: Correlation coefficients from the regression analysis for HemoCue versus I-Stat, RapidLab versus HemoCue, and RapidLab versus I-Stat were 0.89, 0.96, and 0.88, respectively. Results of the Bland-Altman analysis of the hemoglobin concentration measurements for each device against one another (Fig 1) were as follows: RapidLab versus I-Stat (bias 0.42; 95% confidence interval [CI], -1.05 to 1.89), I-Stat versus HemoCue (bias 0.23; 95% CI, -1.14 to 1.59), and RapidLab versus HemoCue (bias 0.65; 95% CI, -0.17 to 1.47). It appears that I-Stat slightly underestimated the concentration of hemoglobin when compared with both RapidLab and HemoCue. The results of Bland-Altman analysis of each device to a mean Z value (Fig 2) were as follows: RapidLab versus Z (bias 0.36; 95% CI, -0.29 to 1.01), I-Stat versus Z (bias -0.07; CI -0.97 to 0.84), and HemoCue versus Z (bias -0.29; 95% CI, -0.86 to 0.28). Based on the 174 paired samples used for the Pearson moment analysis, the R2 values for I-Stat versus HemoCue, I-Stat versus RapidLab, and RapidLab versus HemoCue were 0.79, 0.80, and 0.87, respectively CONCLUSIONS: These data support the interchangeability of these 3 devices for the intermittent intraoperative point-of-care assessment of hemoglobin concentrations in cardiac surgery patients. It is important, however, to consider the possible pitfalls associated with each device when making a clinical decision to transfuse.

Plasma vasopressin levels in patients with right-sided heart dysfunction and chronic thromboembolic pulmonary hypertension (CTEPH).

OBJECTIVES: Patients with left-sided heart dysfunction and volume overload often have associated elevations in vasopressin from neuroendocrine activation. The authors investigated perioperative levels of vasopressin in patients with isolated right-sided heart dysfunction from chronic thromboembolic pulmonary hypertension. DESIGN: Prospective, observational study. SETTING: Single center, tertiary hospital. PARTICIPANTS: Patients with chronic thromboembolic pulmonary hypertension undergoing pulmonary thromboendarterectomy. INTERVENTIONS: Vasopressin levels were measured in 22 patients during the perioperative period. MEASUREMENTS AND MAIN RESULTS: Vasopressin was undetectable in 8/22 patients at baseline. As a group, vasopressin levels at baseline and after induction of anesthesia were 0.8 pg/mL (median; 0.5-1.5, interquartile range of 25% and 75%) and 0.7 pg/mL (median; 0.5-1.4, interquartile range of 25% and 75%), respectively. During cardiopulmonary bypass (CPB), vasopressin increased to 13.9 pg/mL (median; 6.7-19.9, interquartile range of 25% and 75%). Vasopressin remained elevated after deep hypothermic circulatory arrest (DHCA) at 10.5 pg/mL (median; 6.5-19.9 interquartile range of 25% and 75%) and after CPB at 19.9 pg/mL (median; 11.1-19.9 interquartile range of 25% and 75%). CONCLUSIONS: Vasopressin levels in PTE patients are in the low-to-normal range at baseline and may be a clinically relevant issue in the hemodynamic management of PTE.

Cardiac output determination from endotracheally measured impedance cardiography: clinical evaluation of endotracheal cardiac output monitor.

OBJECTIVES: To evaluate the accuracy, precision, and trending of a new endotracheally sourced impedance cardiography-based cardiac output (CO) monitor (ECOM; ConMed Corp, Irvine, CA). SETTING: Two university hospitals. PARTICIPANTS: Thirty patients scheduled for elective coronary artery bypass graft (CABG) surgery. INTERVENTIONS: All patients received a pulmonary artery catheter (PAC), arterial catheter, endotracheal CO monitor (ECOM), endotracheal intubation, and transesophageal echocardiographic monitoring. ECOM CO was compared with CO measured with pulmonary artery thermodilution, and left ventricular CO measured with transesophageal echocardiography. MEASUREMENTS: One hundred forty-five pairs of triplicate CO measurements using intermittent bolus pulmonary artery thermodilution (TD) and ECOM were compared at 5 distinct time points: postinduction, postinduction passive leg raise, poststernotomy, post-CABG completion, and post-chest closure. Eighty-seven pairs of triplicate CO measurements using transesophageal echocardiography were obtained at 3 time points: postinduction, post-CABG completion, and post-chest closure and compared with ECOM- and PA-derived CO measurements. The measurements at each time point were compared by using Bland-Altman and polar plot analyses. RESULTS: The mean CO ranged from 2.16 to 9.41 L/min. ECOM CO, compared with TD CO, revealed a bias of 0.02 L/min, 95% limits of agreement of -2.26 to 2.30 L/min, and a percent error of 50%. ECOM CO showed trending with TD CO with 91% and 99% of values within 0.5L/min and 1 L/min limits of agreement, respectively. ECOM CO, compared with TEE CO, revealed a bias of -0.25 L/min, 95% limits of agreement of -2.41 to 1.92 L/min, and a percent error of 48%. ECOM CO showed trending with TEE CO with 83% and 95% of values within 0.5L/min and 1 L/min limits of agreement, respectively. CONCLUSION: ECOM CO shows an acceptable bias with wide limits of agreement and a large percent error when compared with TD CO or TEE CO; however, it shows acceptable trending of CO to both modalities in patients undergoing cardiac surgery. Further studies are required to evaluate ECOM in other patient populations and clinical situations.

Novel Use of Cangrelor With Heparin During Cardiopulmonary Bypass in Patients With Heparin-Induced Thrombocytopenia Who Require Cardiovascular Surgery: A Case Series.

Optimal anticoagulation strategy during cardiopulmonary bypass (CPB) remains uncertain in patients with heparin-induced thrombocytopenia (HIT) who require urgent/emergent cardiac surgery. We describe our strategy and experience with utilizing cangrelor in combination with heparin for anticoagulation during CPB in patients with different phases of HIT undergoing a wide range of urgent/emergent cardiovascular surgery. Cangrelor is an intravenous direct-acting P2Y12 platelet receptor antagonist that achieves therapeutic effect and eliminates rapidly. Its antiplatelet activity is unaffected by stagnation of blood, nor is it influenced by patient's sex, age, renal status, or hepatic function. Our institutional alternative intraoperative anticoagulation strategy for HIT patients is to administer cangrelor with a loading dose of 30 µg/kg, followed by continuous infusion of 4 µg/kg/min throughout CPB via a dedicated intravenous access. VerifyNow P2Y12 reaction unit point-of-care assay is utilized to monitor platelet inhibition throughout surgery. Cangrelor infusion is discontinued 10 minutes prior to heparin reversal with protamine. Ten urgent/emergent cardiovascular surgeries were performed at our institution using cangrelor with heparin for anticoagulation during CPB, and the majority were pulmonary thromboendarterectomy (60%). HIT was confirmed in 3 cases and was suspected in 4 which was found to be negative after the operation. One case of subacute B HIT and 2 cases of remote HIT were included in this series. This novel alternative intraoperative anticoagulation strategy was well tolerated by all patients. There was neither serious postoperative thrombotic event nor major postoperative bleeding complication that required reoperation. One death occurred in a patient with advanced intracardiac malignancy, whose life support was ultimately withdrawn postoperatively. Median postoperative intensive care unit stay was 7.2 ± 5.5 days, while median postoperative hospital stay was 16.3 ± 10.8 days. In patients with various phases of HIT who require urgent/emergent on-pump cardiovascular surgery, the use of cangrelor with heparin may be a convenient, safe, and effective alternative intraoperative anticoagulation strategy providing acceptable outcomes.

Successful Use of Cangrelor and Heparin for Cardiopulmonary Bypass in a Patient With Heparin-Induced Thrombocytopenia and End-Stage Renal Disease: A Case Report.

Heparin is the only well-established anticoagulant medication for cardiopulmonary bypass making selecting an alternative anticoagulant challenging in patients with heparin-induced thrombocytopenia. Other anticoagulant medications can cause significant postoperative bleeding, especially in patients with end-stage renal disease. We present a case of a 63-year-old woman requiring aortic valve replacement with a history of heparin-induced thrombocytopenia and end-stage renal disease. Cangrelor and heparin were successfully used during cardiopulmonary bypass, offering an option for anticoagulation management for a uniquely challenging patient population.

Anesthetic management of the patient undergoing heart transplantation.

Cardiac transplantation is the treatment of choice for patients with end-stage heart failure. Over the years, significant advances in patient selection, donor optimization and selection, and optimization of immunosuppression strategies have markedly improved outcomes. In this review, we highlight patient selection, donor management and procurement, heart transplantation procedure, and intraoperative and postoperative management of heart transplants.