Coronary Vascular (DYS) Function and Invasive Physiology Assessment: Insights into Bolus and Continuous Thermodilution Methods.

A considerable number of patients with angina or myocardial ischemia have no significant coronary artery disease on invasive angiography. In recent years, several steps towards a better comprehension of the pathophysiology of these conditions, angina or ischemia with non-obstructive coronary arteries (ANOCA/INOCA), have been made. Nevertheless, several gaps in knowledge still remain. This review is intended to provide a comprehensive overview of ANOCA and INOCA, with a particular focus on pathophysiology, recent diagnostic innovations, gaps in knowledge and treatment modalities.

Comparison of Respiratory and Hemodynamic Parameters of COVID-19 and Non-COVID-19 ARDS Patients.

BACKGROUND: COVID-19 can cause a clinical spectrum from asymptomatic disease to life-threatening respiratory failure and acute respiratory distress syndrome (ARDS). There is an ongoing discussion whether the clinical presentation and ventilatory parameters are the same as typical ARDS or not. There is no clear understanding of how the hemodynamic parameters have been affected in COVID-19 ARDS patients. We aimed to compare hemodynamic and respiratory parameters of moderate and severe COVID-19 and non-COVID-19 ARDS patients. These patients were monitored with an advanced hemodynamic measurement system by the transpulmonary thermodilution method in prone and supine positions. PATIENTS AND METHODS: Data of 17 patients diagnosed with COVID-19 and 16 patients diagnosed with other types of diseases with moderate and severe ARDS, mechanically ventilated, placed in a prone position, had advanced hemodynamic measurements with PiCCO, and stayed in the intensive care unit for more than a week were analyzed retrospectively. Patient characteristics and arterial blood gases analysis recorded at admission and respiratory and advanced hemodynamic parameters during the first week were compared in prone and supine positions. RESULTS: No difference was observed in the respiratory parameters including respiratory system compliance between COVID-19 and non-COVD-19 patients in prone and supine positions. In comparison of advanced hemodynamic parameters in the first week of intensive care, the extravascular lung water and pulmonary vascular permeability indexes measured in supine position of COVID-19 ARDS patients were found to be significantly higher than non-COVID-19 patients. Duration of prone position was significantly longer in patients diagnosed with COVID-19 ARDS. CONCLUSIONS: The results of this study suggested that COVID-19 ARDS is a variant of typical ARDS with a different pathophysiology. HOW TO CITE THIS ARTICLE: Asar S, Acicbe Ö, Sabaz MS, Tontu F, Canan E, Cukurova Z, et al. Comparison of Respiratory and Hemodynamic Parameters of COVID-19 and Non-COVID-19 ARDS Patients. Indian J Crit Care Med 2021;25(6):704-708.

Comparing the Mutual Interchangeability of ECOM, FloTrac/Vigileo, 3D-TEE, and ITD-PAC Cardiac Output Measuring Systems in Coronary Artery Bypass Grafting.

OBJECTIVE: The aim of this study was to compare the mutual interchangeability of 4 cardiac output measuring devices by comparing their accuracy, precision, and trending ability. DESIGN: A single-center prospective observational study. DESIGN: Nonuniversity teaching hospital, single center. PARTICIPANTS: Forty-four consecutive patients scheduled for elective, nonemergent coronary artery bypass grafting (CABG). INTERVENTIONS: The cardiac output was measured for each participant using 4 methods: intermittent thermodilution via pulmonary artery catheter (ITD-PAC), Endotracheal Cardiac Output Monitor (ECOM), FloTrac/Vigileo System (FLOTRAC), and 3-dimensional transesophageal echocardiography (3D-TEE). MEASUREMENTS AND MAIN RESULTS: Measurements were performed simultaneously at 5 time points: presternotomy, poststernotomy, before cardiopulmonary bypass, after cardiopulmonary bypass, and after sternal closure. A series of statistical and comparison analyses including ANOVA, Pearson correlation, Bland-Altman plots, quadrant plots, and polar plots were performed, and inherent precision for each method and percent errors for mutual interchangeability were calculated. For the 6 two-by-two comparisons of the methods, the Pearson correlation coefficients (r), the percentage errors (% error), and concordance ratios (CR) were as follows: ECOM_versus_ITD-PAC (r = 0.611, % error = 53%, CR = 75%); FLOTRAC_versus_ITD-PAC (r = 0.676, % error = 49%, CR = 77%); 3D-TEE versus ITD-PAC (r = 0.538, % error = 64%, CR = 67%); FLOTRAC_versus_ECOM (r = 0.627, % error = 51%, CR = 75%); 3D-TEE_versus ECOM (r = 0.423, % error = 70%, CR = 60%), and 3D-TEE_versus_FLOTRAC (r = 0.602, % error = 59%, CR = 61%). CONCLUSIONS: Based on the recommended statistical measures of interchangeability, ECOM, FLOTRAC, and 3D-TEE are not interchangeable with each other or to the reference standard invasive ITD-PAC method in patients undergoing nonemergent cardiac bypass surgery. Despite the negative result in this study and the majority of previous studies, these less-invasive methods of CO have continued to be used in the hemodynamic management of patients. Each device has its own distinct technical features and inherent limitations; it is clear that no single device can be used universally for all patients. Therefore, different methods or devices should be chosen based on individual patient conditions, including the degree of invasiveness, measurement performance, and the ability to provide real-time, continuous CO readings.

Comparison of Cardiac Output from the Thermodilution Method versus a Transesophageal Doppler Ultrasound Monitor (Hemosonic 100(TM)) / 대한마취과학회지

BACKGOUND: The measurement of cardiac output (CO) is an important part of anesthetic practice in patients undergoing major surgery. The thermodilution method (TDM), using a pulmonary artery catheter, is still accepted as the standard procedure. However, the use of the method is associated with several limitations and severe complications. The use of a transesophageal Doppler ultrasound monitor (EDUM; Hemosonic 100(TM)) is less invasive and calculates CO from a simultaneous measurement of blood flow velocity and diameter of the descending aorta. The aim of this study was to compare the cardiac output measured by the use of the TDM and an EDUM. Methods:In 20 patients undergoing major abdominal surgery, CO and other hemodynamic profiles were measured simultaneously by the use of the TDM and an EDUM. RESULTS: The cardiac output, cardiac index, and the systemic vascular resistance monitored by both devices were highly correlated (correlation coefficients range from 0.63 to 0.88). Bland and Altman analysis showed a consistently negative mean bias for an EDUM and the TDM. This finding indicates an overestimation of the hemodynamic profile by the use of an EDUM. CONCLUSIONS: Although Bland and Altman analysis showed a significant bias, the use of an EDUM results in cardiac output, cardiac index, and total systemic vascular resistance measurements that are considerably similar to those obtained using the TDM, and a strong correlation exists for the use of the two methods.

Reliability of Noninvasive Measurement of Cardiac Output Using Partial CO2 Rebreathing: A Comparison with Thermodilution Method / 대한마취과학회지

BACKGROUND: A noninvasive method for estimating cardiac output was tested in dogs. The technique is based on a differential CO2 Fick equation applied during normal ventilation and 50 seconds of partial rebreathing using additional dead space. We compared the cardiac output measured by the CO2 rebreathing method vs. the thermodilution technique. METHODS: Seven mongrel-dogs (24.6 +/- 0.4 kg) were studied, anesthesia was induced and maintained with a pentobarbital 25 mg/kg IV bolus injection followed by an infusion of 5 mg/kg/h. Mechanical ventilation was accomplished with a Servo 900C ventilator with FiO2 0.6 to maintain normocarbia. A fiberoptic pulmonary artery catheter was introduced via an external jugular vein for continuous monitoring of the cardiac output by the thermodilution method. Also cardiac output was measured by using partial CO2 rebreathing method. A continuous infusion of 0.5% bupivacaine was started at 0.5 mg/kg/min via the venous infusion port of the pulmonary catheter. Bupivacaine was infused continuously until mean arterial pressure decreased to 60 mmHg or less for at least 5 seconds. RESULTS: The total measured cardiac outputs (n = 72) were distributed over the range of 1.03-7.72 L/min by thermodilution method and 1.6-7.3 L/min by CO2 rebreathing. The correlation coefficients between both cardiac outputs was 0.6, the mean difference was 0.27 +/- 0.81 L/min. CONCLUSIONS: The cardiac output measured by CO2 rebreathing method was well correlated with cardiac output by thermodilution method.