Comparison between capnodynamic and thermodilution method for cardiac output monitoring during major abdominal surgery

Abstract

BACKGROUND Cardiac output ( CO ) monitoring is the basis of goal-directed treatment for major abdominal surgery. A capnodynamic method estimating cardiac output ( CO EPBF ) by continuously calculating nonshunted pulmonary blood flow has previously shown good agreement and trending ability when evaluated in mechanically ventilated pigs. OBJECTIVES To compare the performance of the capnodynamic method of CO monitoring with transpulmonary thermodilution ( CO TPTD ) in patients undergoing major abdominal surgery. DESIGN Prospective, observational, method comparison study. Simultaneous measurements of CO EPBF and CO TPTD were performed before incision at baseline and before and after increased (+10 cmH 2 O) positive end-expiratory pressure (PEEP), activation of epidural anaesthesia and intra-operative events of hypovolemia and low CO . The first 25 patients were ventilated with PEEP 5 cmH 2 O (PEEP 5 ), while in the last 10 patients, lung recruitment followed by individual PEEP adjustment (PEEP adj ) was performed before protocol start. SETTING Karolinska University Hospital, Stockholm, Sweden. PATIENTS In total, 35 patients (>18 years) scheduled for major abdominal surgery with advanced hemodynamic monitoring were included in the study. MAIN OUTCOME MEASURES AND ANALYSIS Agreement and trending ability between CO EPBF and CO TPTD at different clinical moments were analysed with Bland--Altman and four quadrant plots. RESULTS In total, 322 paired values, 227 in PEEP 5 and 95 in PEEP adj were analysed. Respectively, the mean CO EPBF and CO TPTD were 4.5 ± 1.0 and 4.8 ± 1.1 in the PEEP 5 group and 4.9 ± 1.2 and 5.0 ± 1.0 l min −1 in the PEEP adj group. Mean bias (levels of agreement) and percentage error (PE) were −0.2 (−2.2 to 1.7) l min −1 and 41% for the PEEP 5 group and −0.1 (−1.7 to 1.5) l min −1 and 31% in the PEEP adj group. Concordance rates during changes in CO EPBF and CO TPTD were 92% in the PEEP 5 group and 90% in the PEEP ad...

Standardized blood volume changes monitored by capnodynamic hemodynamic variables: An experimental comparative study in pigs

“…The ability of CO EPBF to adequately detect CO changes caused by alterations in intravascular volume status (preload) is in line with the results in two recently published clinical studies 11,26 . In anesthetized children CO EPBF detected the reduction in CO caused by increased PEEP ahead of, and more reliable, than non‐invasive blood pressure monitoring 11 .…”

“…In anesthetized children CO EPBF detected the reduction in CO caused by increased PEEP ahead of, and more reliable, than non‐invasive blood pressure monitoring 11 . In adults undergoing major abdominal surgery CO EPBF was observed to decrease rapidly, and in parallel with MAP, during a major surgical bleeding (>15% of the blood volume) which in contrast CO PCA , did not 26 …”

Capnodynamic monitoring of lung volume and blood flow in response to increased positive end-expiratory pressure in moderate to severe COVID-19 pneumonia: an observational study

“…Data were exported to a laptop running dedicated software (MATLAB®, Mathworks, Natick, MA, USA) to obtain real-time measurements of and EPBF (see below, Calculations ). The validity of EPBF [ 13 , 16 ] and [ 11 , 14 ] against standard methods to monitor cardiac output and functional residual capacity have been reported in clinical studies. After 20 min of baseline PEEP (PEEP low ) recording, an arterial blood gas was obtained and analysed immediately (GEM Premier 5000, Artarmon, New South Wales, Australia).…”

“…These techniques require both specialised equipment and procedural expertise. In contrast, capnodynamic monitoring of lung volume and perfusion may be integrated with standard ventilators at the bedside and provides continuous measurements without special respiratory manoeuvres or interruptions [11][12][13][14]. This study aimed to assess the feasibility of capnodynamic monitoring of the responses to increased PEEP on gas exchange in mechanically ventilated patients with moderate to severe C-ARDS.…”

Monitoring Expired CO2 Kinetics to Individualize Lung-Protective Ventilation in Patients With the Acute Respiratory Distress Syndrome

“…The method has been submitted to extensive experimental validation in challenging pulmonary and circulatory conditions (Sander et al, 2014(Sander et al, , 2015. Recently, the first validations of EPBFCO 2 in patients on general anesthesia (Sigmundsson et al, 2021) and of EELVCO 2 (Öhman et al, 2020) have been published. Both performed well in good agreement with clinical reference methods and excellent trending abilities.…”