Does the Use of a Pulmonary Artery Catheter Make a Difference During or After Cardiac Surgery?

The Use of Pulmonary Artery Catheters and Echocardiography in the Cardiac Surgery Setting: A Nationwide Italian Survey

OBJECTIVE

Wide variations exist in the use of pulmonary artery catheters (PACs) and echocardiography in the field of cardiac surgery.

DESIGN

A national survey promoted by the Italian Association of Cardio-Thoracic Anesthesiologists and Intensive Care was conducted.

SETTING

The study occurred in Italian cardiac surgery centers (n = 71).

PARTICIPANTS

Anesthesiologists-intensivists were enrolled.

INTERVENTIONS

Anonymous questionnaires were used to investigate the use of PACs and echocardiography in the operating room (OR) and intensive care unit (ICU).

MEASUREMENTS AND MAIN RESULTS

A total of 257 respondents (32.2% response rate) from 59 centers (83.1% response rate) participated. Use of PACs seems less common in ORs (median insertion in 20% [5-70] of patients), with slightly higher use in ICUs; in about half of cases, it was the continuous cardiac output monitoring system of choice. Almost two-thirds of respondents recently inserted at least one PAC within a few hours of ICU admission, despite its need being largely preoperatively predictable. Protocols regulating PAC insertion were reported by 25.3% and 28% of respondents (OR and ICU, respectively). Transesophageal echocardiography (TEE) was performed intraoperatively in >75% of patients by 86.4% of respondents; only 23.7% stated that intraoperative TEE relied on anesthesiologists. Tissue Doppler and/or 3D imaging were widely available (87.4% and 82%, respectively), but only 37.8% and 24.3% of respondents self-declared skills in these modalities, respectively; 77.1% of respondents had no echocardiography certification, nor were pursuing certification (various reasons); 40.9% had not attended recent echocardiography courses. Lower PAC use was associated with university hospitals (OR: p = 0.014, ICU: p = 0.032) and with lower interventions/year (OR: p = 0.023). Higher independence in performing TEE was reported in university hospitals (OR: p < 0.001; ICU: p = 0.006), centers with higher interventions/year (OR: p = 0.019), and by respondents with less experience in cardiology (ICU: p = 0.046).

CONCLUSION

Variability in the use of PACs and echocardiography was found. Protocols regulating the use of PACs seem infrequent. University centers use PACs less and have greater skills in TEE. Training and certifications in echocardiography should be encouraged.

Pulmonary artery catheter receipt among cardiac surgery patients from the national inpatient sample (1999-2019): Prevalence, predictors and hospitalization charges

Despite limited evidence to support its efficacy, use of pulmonary artery catheter (PAC), a relatively expensive medical device, for monitoring clinical status and guiding therapeutic interventions, has become standard of care in many settings, and especially during and after cardiac surgery. We examined the prevalence and predictors of PAC use and its association with hospitalization charges among cardiac surgery patients generally and for each selected subgroup of high-risk or complex surgical procedures. We conducted an analysis on 1,442,528 records from the National Inpatient Sample (1999-2019) that included cardiac surgery patients ≥18 years of age. Subgroups were categorized based on the presence of specific disorders like tricuspid or mitral valve disease, pulmonary hypertension, heart failure, or cardiac surgery combinations. Multivariable regression models were constructed to assess predictors of PAC use as well as PAC use as a predictor of loge hospitalization charges controlling for patient and hospital characteristics. Based on International Classification of Diseases procedure codes, PAC use was prevalent among 7.15 % of cardiac surgery hospitalizations, and hospitalization charges were estimated at $191,345, with no differences according to PAC use. Overall, being female, having Charlson comorbidity index (CCI) > 0, and non-payer (versus Medicare) status were independently associated with PAC use. Among the subgroup with the selected conditions, being female, having CCI>0, and being a Medicaid (versus Medicare) recipient were independently associated with PAC use, whereas elective admission was inversely related to PAC use. Among the subgroup without the selected conditions, having a CCI >0, elective admission, and non-payer (vs. Medicare) status were independently associated with PAC use. PAC use was not independently related to hospitalization charges overall or among subgroups. In conclusion, approximately 7 % of cardiac surgery hospitalizations received a PAC, with no differences in charges according to PAC use and disparities in PAC use driven by sex, elective admission, CCI and health insurance status. Large randomized trials are required to characterize the safety, efficacy, and cost-effectiveness of PAC use among distinct groups of patients undergoing cardiac surgery.

A critical review of the perioperative fluid therapy and hemodynamic monitoring recommendations of the Enhanced Recovery of the Adult Pathway (RICA): A position statement of the fluid therapy and hemodynamic monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section (SHTF) of the Spanish Society of Anesthesiology and Critical Care (SEDAR)

In an effort to standardize perioperative management and improve postoperative outcomes of adult patients undergoing surgery, the Ministry of Health, through the Spanish Multimodal Rehabilitation Group (GERM), and the Aragonese Institute of Health Sciences, in collaboration with multiple Spanish scientific societies and based on the available evidence, published in 2021 the Spanish Intensified Adult Recovery (RICA) guideline. This document includes 12 perioperative measures related to fluid therapy and hemodynamic monitoring. Fluid administration and hemodynamic monitoring are not straightforward but are directly related to postoperative patient outcomes. The Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section (SHTF) of the Spanish Society of Anesthesiology and Critical Care (SEDAR) has reviewed these recommendations and concluded that they should be revised as they do not follow an adequate methodology.

Development and Validation of a Prediction Score for Low-Cardiac-Output Syndrome After Adult Cardiac Surgery

OBJECTIVES

The authors aimed to develop a simple prediction score to help identify patients at high risk of low-cardiac-output syndrome after adult cardiac surgery.

DESIGN

A single-center, retrospective, observational study.

SETTING

At a tertiary hospital.

PARTICIPANTS

Adult patients who underwent on-pump cardiac surgery between April 2016 and March 2021.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

Among the 2,806 patients retained for final analyses, 355 (12.7%) developed low-cardiac-output syndrome. Using a stepwise backward variable selection procedure applied to a multivariate logistic regression, a prediction model, including 8 risk factors, could be identified-preoperative left ventricular ejection fraction, glomerular filtration rate <60 mL/min according to the Cockcroft formula or preoperative dialysis, combined surgery, nonelective surgery, mitral valve surgery for mitral valve regurgitation, history of extracardiac arteriopathy, preoperative hemoglobin <13 g/dL, and New York Heart Association functional class III or IV. A clinical prediction score was derived from the regression coefficients. The model had a good discriminative ability, with an area under the receiver operating characteristics curve of 0.8 (95% CI: 077-0.84). Using a threshold value of 5, the score had a 68% sensitivity, 79% specificity, a positive-predictive value of 33%, and a negative-predictive value of 94%. These results were validated on a validation sample using the bootstrap resampling technique.

CONCLUSIONS

The authors developed a clinical score to facilitate the prediction of low- cardiac-output syndrome after adult cardiac surgery. This could help tailor patient management by contributing to the early identification of those at high risk of postoperative low cardiac output.

New Developments in Continuous Hemodynamic Monitoring of the Critically Ill Patient

Hemodynamic monitoring is a cornerstone in the assessment of patients with circulatory shock. Timely recognition of hemodynamic compromise and proper optimisation is essential to ensure adequate tissue perfusion and maintain renal, hepatic, abdominal, and cerebral functions. Hemodynamic monitoring has significantly evolved since the first inception of the pulmonary artery catheter more than 50 years ago. Bedside echocardiography, when combined with noninvasive and minimally invasive technologies, provides tools to monitor and quantify the cardiac output to promptly react and improve hemodynamic management in an acute care setting. Commonly used technologies include noninvasive pulse-wave analysis, pulse-wave transit time, thoracic bioimpedance and bioreactance, esophageal Doppler, minimally invasive pulse-wave analysis, transpulmonary thermodilution, and pulmonary artery catheter. These monitoring strategies are reviewed here, along with detailed analysis of their operating mode, particularities, and limitations. The use of artificial intelligence to enhance performance and effectiveness of hemodynamic monitoring is reviewed to apprehend future possibilities.

Prediction of low cardiac output syndrome in patients following cardiac surgery using machine learning

Background

This study aimed to develop machine learning models to predict Low Cardiac Output Syndrome (LCOS) in patients following cardiac surgery using machine learning algorithms.

Methods

The clinical data of cardiac surgery patients in Nanjing First Hospital between June 2019 and November 2020 were retrospectively extracted from the electronic medical records. Six conventional machine learning algorithms, including logistic regression, support vector machine, decision tree, random forest, extreme gradient boosting and light gradient boosting machine, were employed to construct the LCOS predictive models with all predictive features (full models) and selected predictive features (reduced models). The discrimination of these models was evaluated by the area under the receiver operating characteristic curve (AUC) and the calibration of the models was assessed by the calibration curve. Shapley Additive explanation (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME) were used to interpret the predictive models.

Results

Data from 1,585 patients [982 (62.0%) were male, aged 18 to 88, 212 (13.4%) with LCOS] were employed to train and validate the LCOS models. Among the full models, the RF model (AUC: 0.909, 95% CI: 0.875–0.943; Sensitivity: 0.849, 95% CI: 0.724–0.933; Specificity: 0.835, 95% CI: 0.796–0.869) and the XGB model (AUC: 0.897, 95% CI: 0.859–0.935; Sensitivity: 0.830, 95% CI: 0.702–0.919; Specificity: 0.809, 95% CI: 0.768–0.845) exhibited well predictive power for LCOS. Eleven predictive features including left ventricular ejection fraction (LVEF), first post-operative blood lactate (Lac), left ventricular diastolic diameter (LVDd), cumulative time of mean artery blood pressure (MABP) lower than 65 mmHg (MABP &lt; 65 time), hypertension history, platelets level (PLT), age, blood creatinine (Cr), total area under curve above threshold central venous pressure (CVP) 12 mmHg and 16 mmHg, and blood loss during operation were used to build the reduced models. Among the reduced models, RF model (AUC: 0.895, 95% CI: 0.857–0.933; Sensitivity: 0.830, 95% CI: 0.702–0.919; Specificity: 0.806, 95% CI: 0.765–0.843) revealed the best performance. SHAP and LIME plot showed that LVEF, Lac, LVDd and MABP &lt; 65 time significantly contributed to the prediction model.

Conclusion

In this study, we successfully developed several machine learning models to predict LCOS after surgery, which may avail to risk stratification, early detection and management of LCOS after cardiac surgery.

New developments in the understanding of right ventricular function in acute care

PURPOSE OF REVIEW

Right ventricular dysfunction has an important impact on the perioperative course of cardiac surgery patients. Recent advances in the detection and monitoring of perioperative right ventricular dysfunction will be reviewed here.

RECENT FINDINGS

The incidence of right ventricular dysfunction in cardiac surgery has been associated with unfavorable outcomes. New evidence supports the use of a pulmonary artery catheter in cardiogenic shock. The possibility to directly measure right ventricular pressure by transducing the pacing port has expanded its use to track changes in right ventricular function and to detect right ventricular outflow tract obstruction. The potential role of myocardial deformation imaging has been raised to detect patients at risk of postoperative complications.

SUMMARY

Perioperative right ventricular function monitoring is based on echocardiographic and extra-cardiac flow evaluation. In addition to imaging modalities, hemodynamic evaluation using various types of pulmonary artery catheters can be achieved to track changes rapidly and quantitatively in right ventricular function perioperatively. These monitoring techniques can be applied during and after surgery to increase the detection rate of right ventricular dysfunction. All this to improve the treatment of patients presenting early signs of right ventricular dysfunction before systemic organ dysfunction ensue.

Pulmonary Artery Catheter in Patients with Severe Acute Pancreatitis: A Single-Center Retrospective Study

OBJECTIVE

It is still uncertain what effects pulmonary artery catheter (PAC)-guided resuscitation has on outcomes for patients with severe acute pancreatitis (SAP). Therefore, we aimed to investigate the effect of PAC on hospital mortality in patients with SAP.

METHODS

We collected the data of patients with a diagnosis of SAP from January 10, 2017, to July 30, 2019. Patients were divided into a PAC group and a control group. The primary outcome measured was the day-28 mortality. Secondary outcomes included day-90 mortality, duration of ICU and hospital stay, ventilation days, usage of renal support and vasoactive agents, incidences of acute abdominal compartment syndrome, infusion volumes, and fluid balance and hemodynamic characteristics measured by the PAC. Kaplan-Meier analysis was applied to estimate survival outcomes. Complications related to PAC were also analyzed.

RESULTS

There was no significant difference between the PAC group and the control group for day-28 mortality (22.7% vs. 30%, odds ratio, 0.69; 95% CI 0.31-1.52; P = 0.35). The duration of ICU stay in the PAC group was shorter (P = 0.00), and the rate of dependence on renal support treatment was lower in the PAC group than in the control group (P = 0.03). There was no difference in other secondary outcomes and no significant difference in the survival curve between the two groups (log-rank P = 0.72, X² = 0.13). However, SAP patients inserted PAC within 24 h ICU admission showed that duration of renal support therapy in PAC patients within 24 h ICU admission (mean days, 1.60; standard deviation, 0.14) was shorter than those with 24-72 h ICU admission (mean days, 2.94; standard deviation, 0.73; P = 0.03). The organ failure rates (1 organ, 2 organs and 3 organs) were all lower in PAC patients within 24 h ICU admission than with 24-72 h ICU admission (P = 0.02, P = 0.02, P = 0.048, respectively).

CONCLUSION

In patients with severe acute pancreatitis, PAC-guided fluid resuscitation shortened the duration of ICU stay, and patients in the PAC group had a lower rate of dependence on renal support, while no benefit in terms of mortality was observed. However, SAP patients inserted PAC within 24 h ICU admission showed shorter duration of renal support therapy and lower organ failure rates than those with 24-72 h ICU admission, indicating that early use of PAC, especially within 24 h, might be better for SAP patients.

PRO: The pulmonary artery catheter has a paramount role in current clinical practice

Ever since its clinical introduction, the utilization of the pulmonary artery catheter (PAC) has been surrounded by multiple controversies, mostly related to imprecise clinical indications and the complications derived from its placement. Currently, one of the most important criticisms of the PAC is the ambiguity in the interpretation of its hemodynamic measurements and therefore, in the translation of this data into specific therapeutic interventions. The popularity of the PAC stems from the fact that it provides hemodynamic data that cannot be obtained from clinical examination. The assumption is that this information would allow better understanding of the individual's hemodynamic profile which would trigger therapeutic interventions that improve patient outcomes. Nevertheless, even with the current diversity of hemodynamic devices available, the PAC remains a valuable tool in a wide variety of clinical settings. The authors present a review exposing the benefits of the PAC, current clinical recommendations for its use, mortality and survival profile, its role in goal-directed therapy, and other applications of the PAC beyond cardiac surgery and the intensive care unit.

Is There a Need for a Pulmonary Artery Catheter in Cardiac Surgery Today?

Pulmonary artery catheters are a useful tool for hemodynamic monitoring in high-risk patients during surgery and while in intensive care. However, there are major risks inherent to the device, and with modern day technology, their routine use has decreased. We discuss the need for routine insertion of pulmonary artery catheters in cardiac surgery. We also present a case of a left ventricular assist device implantation complicated by serious pulmonary hemorrhage due to pulmonary artery catheter insertion, highlighting the potentially life-threatening risks involved.

Analysis of difficulty in placement of pulmonary artery catheter through the left internal jugular vein

Purpose

The left internal jugular vein may be an alternative route for the placement of a pulmonary artery catheter when the right jugular vein is not available. Although the placement through the left internal jugular vein is expected to be more difficult, little has been written regarding difficulties in achieving proper placement of the catheter through the left internal jugular vein.

Methods

This prospective and observational study includes patients undergoing cardiac surgery with the catheter placement by monitoring the pressure waveform for 2 years. We measured the time required for the catheter to pass through the tricuspid and pulmonary valves, respectively. The data were analyzed by Mann-Whitney. P < 0.05 was considered significant.

Results

The catheter placement through the right and left internal jugular vein was done in 285 (group R) and 10 patients (group L), respectively. The time duration through the tricuspid valve in group L was significantly longer than that in group P (8 [5–14] s vs 70 [19.8–138] s, median [range], P < 0.01), whereas the time duration through the pulmonary valve was comparable between the two groups (15 [10–27.75] s vs 15 [10.25–19] s, median [range], P = 0.62).

Conclusion

These results indicate that the difficulty in the catheter placement through the left jugular vein may be to pass through the tricuspid valve, not the pulmonary valve.

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.

Perforation of the left ventricle wall due to the insertion of a pulmonary artery catheter. A case report

Despite the widespread and frequent use in our setting of pulmonary artery catheters for haemodynamic management in critically ill patients, particularly after heart surgery, some experts continue to question the need for these devices. Clinicians need to weigh up the risks and benefits of pulmonary artery catheters placement and bear in mind the potential complications which, though rare, can be potentially fatal. We present a pulmonary artery catheters-related complication not hitherto described in the literature, involving perforation of the interventricular septum and left ventricular free wall caused by a kink in the pulmonary artery catheters that was not suspected, and only diagnosed by direct vision of the heart after pericardial opening. In the interest of patient safety, we must consider the impact of adverse events; improving our situational awareness and our understanding of the mechanisms behind such events can help reduce the likelihood of repetitions in the future.

Reliability of three-dimensional color flow Doppler and two-dimensional pulse wave Doppler transthoracic echocardiography for estimating cardiac output after cardiac surgery

BACKGROUND

Three-dimensional color flow Doppler (3DCF) is a new convenient technique for cardiac output (CO) measurement. However, to date, no one has evaluated the accuracy of 3DCF echocardiography for CO measurement after cardiac surgery. Therefore, this single-center, prospective study was designed to evaluate the reliability of three-dimensional color flow and two-dimensional pulse wave Doppler (2D-PWD) transthoracic echocardiography for estimating cardiac output after cardiac surgery.

METHODS

Post-cardiac surgical patients with a good acoustic window and a low dose or no dose of vasoactive drugs (norepinephrine < 0.05 μg/kg/min) were enrolled for CO estimation. Three different methods (third generation FloTrac/Vigileo™ [FT/V] system as the reference method, 3DCF, and 2D-PWD) were used to estimate CO before and after interventions (baseline, after volume expansion, and after a dobutamine test).

RESULTS

A total of 20 patients were enrolled in this study, and 59 pairs of CO measurements were collected (one pair was not included because of increasing drainage after the dobutamine test). Pearson's coefficients were 0.260 between the CO-FT/V and CO-PWD measurements and 0.729 between the CO-FT/V and CO-3DCF measurements. Bland-Altman analysis showed the bias between the absolute values of CO-FT/V and CO-PWD measurements was - 0.6 L/min with limits of agreement between - 3.3 L/min and 2.2 L/min, with a percentage error (PE) of 61.3%. The bias between CO-FT/V and CO-3DCF was - 0.14 L/min with limits of agreement between - 1.42 L /min and 1.14 L/min, with a PE of 29.9%. Four-quadrant plot analysis showed the concordance rate between ΔCO-PWD and ΔCO-3FT/V was 93.3%.

CONCLUSIONS

In a comparison with the FT/V system, 3DCF transthoracic echocardiography could accurately estimate CO in post-cardiac surgical patients, and the two methods could be considered interchangeable. Although 2D-PWD echocardiography was not as accurate as the 3D technique, its ability to track directional changes was reliable.