Pulmonary Artery Catheter Use During Cardiac Surgery in the United States, 2010 to 2014

Pulmonary artery catheter use and in-hospital outcomes in cardiac surgery: a systematic review and meta-analysis

OBJECTIVES

To determine the association of intraoperative pulmonary artery catheter (PAC) use with in-hospital outcomes in cardiac surgical patients.

METHODS

MEDLINE, Embase, and Cochrane Library (Wiley) databases were screened for studies that compared cardiac surgical patients receiving intraoperative PAC with controls and reporting in-hospital mortality. Secondary outcomes included intensive care unit length of stay, cost of hospitalization, fluid volume administered, intubation time, inotropes use, acute kidney injury (AKI), stroke, myocardial infarction (MI), and infections.

RESULTS

Seven studies (25 853 patients, 88.6% undergoing coronary artery bypass graft surgery) were included. In-hospital mortality was significantly increased with PAC use [odds ratio (OR) 1.57; 95% confidence interval (CI) 1.12-2.20, P = 0.04]; PAC use was also associated with greater intraoperative inotrope use (OR 2.61; 95% CI 1.54-4.41) and costs [standardized mean difference (SMD) = 0.20; 95% CI 0.16-0.23], longer intensive care unit stay (SMD = 0.29; 95% CI 0.25-0.33), and longer intubation time (SMD = 0.44; 95% CI 0.12-0.76).

CONCLUSIONS

PAC use is associated with significantly increased odds of in-hospital mortality, but the amount and quality of the available evidence is limited. Prospective randomized trials testing the effect of PAC on the outcomes of cardiac surgical patients are urgently needed.

Point-of-Care Bedside Brain Magnetic Resonance Imaging Is Safe in Extracorporeal Membrane Oxygenation Patients With Swan Ganz Catheters: A Phantom Experiment and Single Center Experience

INTRODUCTION

More than 1.2 million pulmonary artery catheters (PACs) are used in cardiac patients per annum within the United States. However, it is contraindicated in traditional 1.5 and 3T magnetic resonance imaging (MRI) scans. We aimed to test preclinical and clinical safety of using this imaging modality given the potential utility of needing it in the clinical setting.

METHODS

We conducted two phantom experiments to ensure that the electromagnetic field power deposition associated with bare and jacketed PACs was safe and within the acceptable limit established by the Food and Drug Administration. The primary end points were the safety and feasibility of performing Point-of-Care (POC) MRI without imaging-related adverse events. We performed a preclinical computational electromagnetic simulation and evaluated these findings in nine patients with PACs on veno-arterial extracorporeal membrane oxygenation.

RESULTS

The phantom experiments showed that the baseline point specific absorption rate through the head averaged 0.4 W/kg. In both the bare and jacketed catheters, the highest net specific absorption rates were at the neck entry point and tip but were negligible and unlikely to cause any heat-related tissue or catheter damage. In nine patients (median age 66, interquartile range 42-72 y) with veno-arterial extracorporeal membrane oxygenation due to cardiogenic shock and PACs placed for close hemodynamic monitoring, POC MRI was safe and feasible with good diagnostic imaging quality.

CONCLUSIONS

Adult ECMO patients with PACs can safely undergo point-of-care low-field (64 mT) brain MRI within a reasonable timeframe in an intensive care unit setting to assess for acute brain injury that might otherwise be missed with conventional head computed tomography.

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.

Characteristics of pulmonary artery catheter use in multicenter ICUs in Japan and the association with mortality: a multicenter cohort study using the Japanese Intensive care PAtient Database

BACKGROUND

It has been 50 years since the pulmonary artery catheter was introduced, but the actual use of pulmonary artery catheters in recent years is unknown. Some randomized controlled trials have reported no causality with mortality, but some observational studies have been published showing an association with mortality for patients with cardiogenic shock, and the association with a pulmonary artery catheter and mortality is unknown. The aim of this study was to investigate the utilization of pulmonary artery catheters (PACs) in the intensive care unit (ICU) and to examine their association with mortality, taking into account differences between hospitals.

METHODS

This is a retrospective analysis using the Japanese Intensive care PAtient Database, a multicenter, prospective, observational registry in Japanese ICUs. We included patients aged 16 years or older who were admitted to the ICU for reasons other than procedures. We excluded patients who were discharged within 24 h or had missing values. We compared the prognosis of patients with and without PAC. The primary outcome was hospital mortality. We performed propensity score analysis to adjust for baseline characteristics and hospital characteristics.

RESULTS

Among 184,705 patients in this registry from April 2015 to December 2020, 59,922 patients were included in the analysis. Most patients (94.0%) with a PAC in place had cardiovascular disease. There was a wide variation in the frequency of PAC use between hospitals, from 0 to 60.3% (median 14.4%, interquartile range 2.2-28.6%). Hospital mortality was not significantly different between the PAC use group and the non-PAC use group in patients after adjustment for propensity score analysis (3.9% vs 4.3%; difference, - 0.4%; 95% CI - 1.1 to 0.3; p = 0.32). Among patients with cardiac disease, those with post-open-heart surgery and those in shock, hospital mortality was also not significantly different between the two groups (3.4% vs 3.7%, p = 0.45, 1.7% vs 1.7%, p = 0.93, 4.8% vs 4.9%, p = 0.87).

CONCLUSIONS

The frequency of PAC use varied among hospitals. PAC use for ICU patients was not associated with lower hospital mortality after adjusting for differences between hospitals.

Unrecognized Pulmonary Hypertension in Non-Cardiac Surgical Patients: At-Risk Populations, Preoperative Evaluation, Intraoperative Management and Postoperative Complications

Pulmonary hypertension is a well-established independent risk factor for perioperative complications after elective non-cardiac surgery. Patients undergoing cardiac surgery are routinely evaluated for the presence of pulmonary hypertension in the preoperative period. Better monitoring in the postoperative critical care setting leads to more efficient management of potential complications. Data among patients with pulmonary hypertension undergoing elective non-cardiac surgery are scant. Moreover, the condition may be unidentified at the time of surgery. Also, monitoring after non-cardiac surgery can be very limited in the PACU setting, as opposed to the critical care setting. All these factors can result in a higher postoperative complication rate and poor outcomes.

Association of pulmonary artery catheter with in-hospital outcomes after cardiac surgery in the United States: National Inpatient Sample 1999-2019

To examine associations of pulmonary artery catheter (PAC) use with in-hospital death and hospital length of stay (days) overall and within subgroups of hospitalized cardiac surgery patients. Secondary analyses of 1999-2019 National Inpatient Sample data were performed using 969,034 records (68% male, mean age: 65 years) representing adult cardiac surgery patients in the United States. A subgroup of 323,929 records corresponded to patients with congestive heart failure, pulmonary hypertension, mitral/tricuspid valve disease and/or combined surgeries. We evaluated PAC in relation to clinical outcomes using regression and targeted maximum likelihood estimation (TMLE). Hospitalized cardiac surgery patients experienced more in-hospital deaths and longer stays if they had ≥ 1 subgroup characteristics. For risk-adjusted models, in-hospital deaths were similar among recipients and non-recipients of PAC (odds ratio [OR] 1.04, 95% confidence interval [CI] 0.96, 1.12), although PAC was associated with more in-hospital deaths among the subgroup with congestive heart failure (OR 1.14, 95% CI 1.03, 1.26). PAC recipients experienced shorter stays than non-recipients (β =  - 0.40, 95% CI - 0.64, - 0.15), with variations by subgroup. We obtained comparable results using TMLE. In this retrospective cohort study, PAC was associated with shorter stays and similar in-hospital death rates among cardiac surgery patients. Worse clinical outcomes associated with PAC were observed only among patients with congestive heart failure. Prospective cohort studies and randomized controlled trials are needed to confirm and extend these preliminary findings.

Mastering the Best Practices: A Comprehensive Look at the European Guidelines for Cardiopulmonary Bypass in Adult Cardiac Surgery

The successful outcome of a cardiac surgery procedure is significantly dependent on the management of cardiopulmonary bypass (CPB). Even if a cardiac operation is technically well-conducted, a patient may suffer CPB-related complications that could result in severe comorbidities, reduced quality of life, or even death. However, the role of clinical perfusionists in perioperative patient care, which is critical, is often overlooked. Therefore, the European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Cardiothoracic Anaesthesiology (EACTA), and the European Board of Cardiovascular Perfusion (EBCP) have agreed to develop joint clinical practice guidelines (CPGs) for CPB due to its significant impact on patient care and significant variations in practice patterns between countries. The European guidelines, based on the EACTS standardized framework for the development of CPGs, cover the entire spectrum of CPB management in adult cardiac surgery. This includes training and education of clinical perfusionists, machine hardware, disposables, preparation for initiation of CPB, a complete set of procedures during CPB to help maintain end-organ function and anticoagulation, weaning from CPB, and the gaps in evidence and future research directions. This comprehensive coverage ensures that all aspects of CPB management are addressed, providing clinicians with a standardized approach to CPB management based on the latest evidence and best practices. To ensure better integration of these evidence-based recommendations into daily practice, this review aims to provide a general understanding of guideline development and an overview of essential treatment recommendations for CPB management.

QSM Throughout the Body

Magnetic materials in tissue, such as iron, calcium, or collagen, can be studied using quantitative susceptibility mapping (QSM). To date, QSM has been overwhelmingly applied in the brain, but is increasingly utilized outside the brain. QSM relies on the effect of tissue magnetic susceptibility sources on the MR signal phase obtained with gradient echo sequence. However, in the body, the chemical shift of fat present within the region of interest contributes to the MR signal phase as well. Therefore, correcting for the chemical shift effect by means of water-fat separation is essential for body QSM. By employing techniques to compensate for cardiac and respiratory motion artifacts, body QSM has been applied to study liver iron and fibrosis, heart chamber blood and placenta oxygenation, myocardial hemorrhage, atherosclerotic plaque, cartilage, bone, prostate, breast calcification, and kidney stone.

Malposition of a pulmonary artery catheter in the left ventricle: a case report

BACKGROUND

Placement of pulmonary artery catheters may be associated with a variety of complications. We present a case where a pulmonary artery catheter was accidentally advanced into the left ventricle by perforating the intraventricular septum.

CASE PRESENTATION

A 73-year-old woman underwent mitral valve dysfunction. A pulmonary artery catheter could not pass the tricuspid valve under general anesthesia, which was manually advanced via the right ventricle during surgery. After valve replacement, systolic pulmonary artery pressure was higher than radial arterial blood pressure. Transesophageal echocardiography (TEE) revealed the tip of the catheter in the left ventricle. The catheter was withdrawn and then advanced to the pulmonary artery under monitoring of TEE. Transseptal shunt flow gradually decreased and finally disappeared. The surgery was completed without additional procedures.

CONCLUSIONS

Although ventricular septal perforation is rare, it should be recognized as a potential complication of pulmonary artery catheter insertion.

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.

2021: Perioperative and Critical Care Year in Review for the Cardiothoracic Surgery Team

For yet another year, our lives have been dominated by a pandemic. This year in review, we feature an expert panel opinion regarding extracorporeal support in the context of COVID-19, challenging previously held standards. We also feature survey results assessing the impact of the pandemic on cardiac surgical volume. Furthermore, we focus on a single center experience that evaluated the use of pulmonary artery catheters and the comparison of transfusion strategies in the Restrictive and Liberal Transfusion Strategies in Patients With Acute Myocardial Infarction (REALITY) trial. Additionally, we address the impact of acute kidney injury on cardiac surgery and highlight the controversy regarding the choice of fluid resuscitation. We close with an evaluation of dysphagia in cardiac surgery and the impact of prehabilitation to optimize surgical outcomes.

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.

The Pulmonary Artery Catheter in the Perioperative Setting: Should It Still Be Used?

The pulmonary artery catheter (PAC) was introduced into clinical practice in the 1970s and was initially used to monitor patients with acute myocardial infarctions. The indications for using the PAC quickly expanded to critically ill patients in the intensive care unit as well as in the perioperative setting in patients undergoing major cardiac and noncardiac surgery. The utilization of the PAC is surrounded by multiple controversies, with literature claiming its benefits in the perioperative setting, and other publications showing no benefit. The right interpretation of the hemodynamic parameters measured by the PAC and its clinical implications are of the utmost essence in order to guide a specific therapy. Even though clinical trials have not shown a reduction in mortality with the use of the PAC, it still remains a valuable tool in a wide variety of clinical settings. In general, the right selection of the patient population (high-risk patients with or without hemodynamic instability undergoing high-risk procedures) as well as the right clinical setting (centers with experience and expertise) are essential in order for the patient to benefit most from PAC use.

Perioperative approach to precapillary pulmonary hypertension in non-cardiac non-obstetric surgery

Pulmonary hypertension (PH) confers a significant challenge in perioperative care. It is associated with substantial morbidity and mortality. A considerable amount of information about management of patients with PH has emerged over the past decade. However, there is still a paucity of information to guide perioperative evaluation and management of these patients. Yet, a satisfactory outcome is feasible by focusing on elaborate disease-adapted anaesthetic management of this complex disease with a multidisciplinary approach. The cornerstone of the peri-anaesthetic management of patients with PH is preservation of right ventricular (RV) function with attention on maintaining RV preload, contractility and limiting increase in RV afterload at each stage of the patient's perioperative care. Pre-anaesthetic evaluation, choice of anaesthetic agents, proper fluid management, appropriate ventilation, correction of hypoxia, hypercarbia, acid-base balance and pain control are paramount in this regard. Essentially, the perioperative management of PH patients is intricate and multifaceted. Unfortunately, a comprehensive evidence-based guideline is lacking to navigate us through this complex process. We conducted a literature review on patients with PH with a focus on the perioperative evaluation and suggest management algorithms for these patients during non-cardiac, non-obstetric surgery.

Short and Mid-Term Economic Impact of Pulmonary Artery Catheter Use in Adult Cardiac Surgery: A Hospital and Integrated Health System Perspective

Objective

A monitoring pulmonary artery catheter (PAC) is utilized in approximately 34% of the US cardiac surgical procedures. Increased use of PAC has been reported to have an association with complication rates: significant decreases in new-onset heart failure (HF) and respiratory failure (RF), but increases in bacteremia and urinary tract infections. We assessed the impact of increasing PAC adoption on hospital costs among cardiac surgery patients for US-based healthcare systems.

Methods

An Excel-based economic model calculated annualized savings for a US hospital with various cardiac surgical volumes and PAC adoption rates. A second model, for an integrated payer-provider health system, analyzed outcomes/costs resulting from the cardiac surgical admission and for the treatment of persistent HF and RF complications in the year following surgery. Model inputs were extracted from published literature, and one-way and probabilistic sensitivity analyses were performed.

Results

For an acute care hospital with 500 procedures/year and 34% PAC adoption, annualized savings equalled $61,806 vs no PAC utilization. An increase in PAC adoption rate led to increased savings of $134,751 for 75% and $170,685 for 95% adoption. Savings ranged from $12,361 to $185,418 at volumes of 100 and 1500 procedures/year, respectively. For an integrated payer-provider health system with the base-case scenario of 3845 procedures/year and 34% PAC adoption, estimated savings were $596,637 for the combined surgical index admission and treatment for related complications over the following year.

Conclusion

PAC utilization in adult cardiac surgery patients results in reduced costs for both acute care hospitals and payer-provider integrated health systems.

The impact of pulmonary artery catheter use in cardiac surgery

OBJECTIVE

Pulmonary artery catheterization provides continuous monitoring of hemodynamic parameters that may aid in the perioperative management of patients undergoing cardiac surgery. However, prior data suggest that pulmonary artery catheterization has limited benefit in intensive care and surgical settings. Thus, this study sought to determine the impact of pulmonary artery catheter insertion on short-term postoperative outcomes in a large, contemporaneous cohort of patients undergoing open cardiac surgery compared with standard central venous pressure monitoring.

METHODS

This was an observational study of open cardiac surgeries from 2010 to 2018. Patients with pulmonary artery catheter insertion were identified and matched against patients without pulmonary artery catheter insertion via 1:1 nearest neighbor propensity matching. Multivariable analysis was performed to assess the impact of pulmonary artery catheterization on operative mortality in the overall cohort, as well as recent heart failure, mitral valve disease, and tricuspid insufficiency subgroups.

RESULTS

Of the 11,820 patients undergoing (Society of Thoracic Surgeons indexed) coronary or valvular surgery, 4605 (39.0%) had pulmonary artery catheter insertion. Propensity score matching yielded 3519 evenly balanced pairs. Compared with central venous pressure monitoring, pulmonary artery catheter use was not associated with improved operative mortality in the overall cohort or in the recent heart failure, mitral valve disease, or tricuspid insufficiency subgroups. Intensive care unit length of stay was longer (P < .001), and there were more packed red blood cell transfusions in the pulmonary artery catheterization group (P < .001); however, postoperative outcomes were otherwise similar, including stroke, sepsis, and new renal failure (P > .05).

CONCLUSIONS

These findings suggest that pulmonary artery catheterization may have limited benefit in cardiac surgery.

CON: Pulmonary artery catheter use should be forgone in modern clinical practice

The pulmonary artery catheter (PAC) and its role in the practice of modern medicine remains to be questioned and has experienced a substantial decline in its use in the most recent decades. The complications associated to its use, the lack of consistency of the interpretation provided by the PAC among clinicians, the development of new hemodynamic methods, and the deleterious cost profile associated to the PAC are some of the reasons behind the decrease in its use. Since its introduction into clinical practice, the PAC and the data obtained from its use became paramount in the management of critically ill patients as well as for the high-risk/invasive procedures. Initially, many clinicians were under the impression that regardless the clinical setting, acquiring the information provided by the PAC justified its use, until a growing body of evidence demonstrated its lack of mortality and morbidity improvement, as well as several reports of the presence of difficulties—some of them fatal—during its insertion. The authors present an updated review discussing the futility of the PAC in current clinical practice, the complications associated to its insertion, the lack of mortality benefit in critically ill patients and cardiac surgery, as well as present alternative hemodynamic methods to the PAC.

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.

To Swan or Not to Swan: Indications, Alternatives, and Future Directions

The pulmonary artery catheter (PAC) has revolutionized bedside assessment of preload, afterload, and contractility using measured pulmonary capillary wedge pressure, calculated systemic vascular resistance, and estimated cardiac output. It is placed percutaneously by a flow-directed balloon-tipped technique through the venous system and the right heart to the pulmonary artery. Interest in the hemodynamic variables obtained from PACs paved the way for the development of numerous less-invasive hemodynamic monitors over the past 3 decades. These devices estimate cardiac output using concepts such as pulse contour and pressure analysis, transpulmonary thermodilution, carbon dioxide rebreathing, impedance plethysmography, Doppler ultrasonography, and echocardiography. Herein, the authors review the conception, technologic advancements, and modern use of PACs, as well as the criticisms regarding the clinical utility, reliability, and safety of PACs. The authors comment on the current understanding of the benefits and limitations of alternative hemodynamic monitors, which is important for providers caring for critically ill patients. The authors also briefly discuss the use of hemodynamic monitoring in goal-directed fluid therapy algorithms in Enhanced Recovery After Surgery programs.

Trends in Central Venous Catheter Insertions by Anesthesia Providers: An Analysis of the Medicare Physician Supplier Procedure Summary From 2007 to 2016

BACKGROUND

Central line insertion is a core skill for anesthesiologists. Although recent technical advances have increased the safety of central line insertion and reduced the risk of central line-associated infection, noninvasive hemodynamic monitoring and improved intravenous access techniques have also reduced the need for perioperative central venous access. We hypothesized that the number of central lines inserted by anesthesiologists has decreased over the past decade. To test our hypothesis, we reviewed the Medicare Physician Supplier Procedure Summary (PSPS) database from 2007 to 2016.

METHODS

Claims for central venous catheter placement were identified in the Medicare PSPS database for nontunneled and tunneled central lines. Pulmonary artery catheter insertion was included as a nontunneled line claim. We stratified line insertion claims by specialty for Anesthesiology (including Certified Registered Nurse Anesthetists and Anesthesiology Assistants), Surgery, Radiology, Pulmonary/Critical Care, Emergency Physicians, Internal Medicine, and practitioners who were not anesthesia providers such as Advanced Practice Nurses (APNs) and Physician Assistants (PAs). Utilization rates per 10,000 Medicare beneficiaries were then calculated by specialty and year. Time-based trends were analyzed using Joinpoint linear regression, and the Average Annual Percent Change (AAPC) was calculated.

RESULTS

Between 2007 and 2016, total claims for central venous catheter insertions of all types decreased from 440.9 to 325.3 claims/10,000 beneficiaries (AAPC = -3.4, 95% confidence interval [CI], -3.6 to -3.2: P < .001). When analyzed by provider specialty and year, the number of nontunneled line insertion claims fell from 43.1 to 15.9 claims/10,000 (AAPC = -7.1; -7.3 to -7.0: P < .001) for surgeons, from 21.3 to 18.5 claims/10,000 (AAPC = -2.5; -2.8 to -2.1: P < .001) for radiologists, and from 117.4 to 72.7 claims/10,000 (AAPC = -5.2; 95% CI, -6.3 to -4.0: P < .001) for anesthesia providers. In contrast, line insertions increased from 18.2 to 26.0 claims/10,000 (AAPC = 3.2; 2.3-4.2: P < .001) for Emergency Physicians and from 3.2 to 9.3 claims/10,000 (AAPC = 6.0; 5.1-6.9: P < .001) for PAs and APNs who were not anesthesia providers. Among anesthesia providers, the share of line claims made by nurse anesthetists increased by 14.5% over the time period.

CONCLUSIONS

We observed a 38.3% decrease in claims for nontunneled central lines placed by anesthesiologists from 2007 to 2016. These findings have implications for anesthesiology resident training and maintenance of competence among practicing clinicians. Further research is needed to clarify the effect of decreasing line insertion numbers on line insertion competence among anesthesiologists.

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.

The Reduction in Right Ventricular Longitudinal Contraction Parameters Is Not Accompanied by a Reduction in General Right Ventricular Performance During Aortic Valve Replacement: An Explorative Study

OBJECTIVE

The aim of the present study was to identify whether the decrease of longitudinal parameters after cardiothoracic surgery (ie, tricuspid annular systolic plane excursion [TAPSE] and systolic excursion velocity [S']) is accompanied by a reduction in global right ventricular (RV) performance.

DESIGN

Prospective, observational study.

SETTING

Single-center explorative study in a tertiary teaching hospital.

PARTICIPANTS

The study comprised 20 patients who underwent aortic valve replacement with or without coronary artery bypass grafting.

INTERVENTIONS

During cardiac surgery, simultaneous measurements of RV function were performed with a pulmonary artery catheter and transesophageal echocardiography.

MEASUREMENTS AND MAIN RESULTS

TAPSE and S' were reduced significantly directly after surgery compared with the time before surgery (TAPSE from 20.8 [16.6-23.4] mm to 9.1 [5.6-15.5] mm; p < 0.001 and S' from 8.7 [7.9-10.7] cm/s to 7.2 [5.7-8.6] cm/s; p = 0.041). However, the reduction in TAPSE and S' was not accompanied by a reduction in RV performance, as assessed with the TEE-derived myocardial performance index (MPI) and pulmonary artery catheter-derived RV ejection fraction (RVEF). Both remained statistically unaltered before and after the procedure (MPI from 0.52 [0.43-0.58] to 0.50 [0.42-0.88]; p = 0.278 and RVEF from 27% [22%-32%] to 26% [22%-28%]; p = 0.294).

CONCLUSIONS

In the direct postoperative phase, the reduction of echocardiographic parameters of longitudinal RV contractility (TAPSE and S') were not accompanied by a reduction in global RV performance, expressed as MPI and RVEF. Solely relying on a single RV parameter as a marker for global RV performance may not be adequate to assess the complex adaptation of the right ventricle to aortic valve replacement.

Free breathing three-dimensional cardiac quantitative susceptibility mapping for differential cardiac chamber blood oxygenation - initial validation in patients with cardiovascular disease inclusive of direct comparison to invasive catheterization

BACKGROUND

Differential blood oxygenation between left (LV) and right ventricles (RV; ΔSaO2) is a key index of cardiac performance; LV dysfunction yields increased RV blood pool deoxygenation. Deoxyhemoglobin increases blood magnetic susceptibility, which can be measured using an emerging cardiovascular magnetic resonance (CMR) technique, Quantitative Susceptibility Mapping (QSM) - a concept previously demonstrated in healthy subjects using a breath-hold 2D imaging approach (2DBHQSM). This study tested utility of a novel 3D free-breathing QSM approach (3DNAVQSM) in normative controls, and validated 3DNAVQSM for non-invasive ΔSaO2 quantification in patients undergoing invasive cardiac catheterization (cath).

METHODS

Initial control (n = 10) testing compared 2DBHQSM (ECG-triggered 2D gradient echo acquired at end-expiration) and 3DNAVQSM (ECG-triggered navigator gated gradient echo acquired in free breathing using a phase-ordered automatic window selection algorithm to partition data based on diaphragm position). Clinical testing was subsequently performed in patients being considered for cath, including 3DNAVQSM comparison to cine-CMR quantified LV function (n = 39), and invasive-cath quantified ΔSaO2 (n = 15). QSM was acquired using 3 T scanners; analysis was blinded to comparator tests (cine-CMR, cath).

RESULTS

3DNAVQSM generated interpretable QSM in all controls; 2DBHQSM was successful in 6/10. Among controls in whom both pulse sequences were successful, RV/LV susceptibility difference (and ΔSaO2) were not significantly different between 3DNAVQSM and 2DBHQSM (252 ± 39 ppb [17.5 ± 3.1%] vs. 211 ± 29 ppb [14.7 ± 2.0%]; p = 0.39). Acquisition times were 30% lower with 3DNAVQSM (4.7 ± 0.9 vs. 6.7 ± 0.5 min, p = 0.002), paralleling a trend towards lower LV mis-registration on 3DNAVQSM (p = 0.14). Among cardiac patients (63 ± 10y, 56% CAD) 3DNAVQSM was successful in 87% (34/39) and yielded higher ΔSaO2 (24.9 ± 6.1%) than in controls (p < 0.001). QSM-calculated ΔSaO2 was higher among patients with LV dysfunction as measured on cine-CMR based on left ventricular ejection fraction (29.4 ± 5.9% vs. 20.9 ± 5.7%, p < 0.001) or stroke volume (27.9 ± 7.5% vs. 22.4 ± 5.5%, p = 0.013). Cath measurements (n = 15) obtained within a mean interval of 4 ± 3 days from CMR demonstrated 3DNAVQSM to yield high correlation (r = 0.87, p < 0.001), small bias (- 0.1%), and good limits of agreement (±8.6%) with invasively measured ΔSaO2.

CONCLUSION

3DNAVQSM provides a novel means of assessing cardiac performance. Differential susceptibility between the LV and RV is increased in patients with cine-CMR evidence of LV systolic dysfunction; QSM-quantified ΔSaO2 yields high correlation and good agreement with the reference of invasively-quantified ΔSaO2.

Controversies in the Postoperative Management of the Critically Ill Heart Transplant Patient

Heart transplant recipients are susceptible to a number of complications in the immediate postoperative period. Despite advances in surgical techniques, mechanical circulatory support (MCS), and immunosuppression, evidence supporting optimal management strategies of the critically ill transplant patient is lacking on many fronts. This review identifies some of these controversies with the aim of stimulating further discussion and development into these gray areas.

Hemodynamic early goal-directed therapy: Explaining the fine print

The management of patients after cardiothoracic surgery can be very complex. Variabilities exist in hemodynamic status after cardiac surgery and the use of cardiopulmonary bypass – all of which can have a significant impact on myocardial Frank–Starling curves. Typically, invasive monitoring with pulmonary artery catheters is used to assess the complex physiology that these patients experience in the perioperative setting. However, the use of invasive monitoring is not without risk, and the broader benefits are poorly defined. Furthermore, there is growing evidence to support the use of hemodynamic early goal-directed therapy to optimize outcomes in critically ill patients. The purpose of this editorial statement is the review of some of the current literature with regards to the utility of goal-directed therapy as applied to the postoperative cardiac surgical patient.

Impaired right ventricular ejection fraction after cardiac surgery is associated with a complicated ICU stay

Background

Right ventricular (RV) dysfunction is a known risk factor for increased mortality in cardiac surgery. However, the association between RV performance and ICU morbidity is largely unknown.

Methods

We performed a single-centre, retrospective study including cardiac surgery patients equipped with a pulmonary artery catheter, enabling continuous right ventricular ejection fraction (RVEF) measurements. Primary endpoint of our study was ICU morbidity (as determined by ICU length of stay, duration of mechanical ventilation, usage of inotropic drugs and fluids, and kidney dysfunction) in relation to RVEF. Patients were divided into three groups according to their RVEF; < 20%, 20-30%, and > 30%.

Results

We included 1109 patients. Patients with a RVEF < 20% had a significantly longer stay in ICU, a longer duration of mechanical ventilation, higher fluid balance, a higher incidence of inotropic drug usage, and more increase in postoperative creatinine levels in comparison to the other subgroups. In a multivariate analysis, RVEF was independently associated with increased ICU length of stay (OR 0.934 CI 0.908-0.961, p < 0.001), prolonged duration of mechanical ventilation (OR 0.969, CI 0.942-0.998, p = 0.033), usage of inotropic drugs (OR 0.944, CI 0.917-0.971, p < 0.001), and increase in creatinine (OR 0.962, CI 0.934-0.991, p = 0.011).

Conclusions

A decreased RVEF is independently associated with a complicated ICU stay.

Pulmonary artery catheter use in adult patients undergoing cardiac surgery: a retrospective, cohort study

Background

The utility of pulmonary artery catheters (PACs) and their measurements depend on a variety of factors including data interpretation and personnel training. This US multi-center, retrospective electronic health record (EHR) database analysis was performed to identify associations between PAC use in adult cardiac surgeries and effects on subsequent clinical outcomes.

Methods

This cohort analysis utilized the Cerner Health Facts database to examine patients undergoing isolated coronary artery bypass graft (CABG), isolated valve surgery, aortic surgery, other complex non-valvular and multi-cardiac procedures, and/or heart transplant from January 1, 2011, to June 30, 2015. A total of 6844 adults in two cohorts, each with 3422 patients who underwent a qualifying cardiac procedure with or without the use of a PAC for monitoring purposes, were included. Patients were matched 1:1 using a propensity score based upon the date and type of surgery, hospital demographics, modified European System for Cardiac Operative Risk Evaluation (EuroSCORE II), and patient characteristics. Primary outcomes of 30-day in-hospital mortality, length of stay, cardiopulmonary morbidity, and infectious morbidity were analyzed after risk adjustment for acute physiology score.

Results

There was no difference in the 30-day in-hospital mortality rate between treatment groups (OR, 1.17; 95% CI, 0.65-2.10; p = 0.516). PAC use was associated with a decreased length of stay (9.39 days without a PAC vs. 8.56 days with PAC; p < 0.001), a decreased cardiopulmonary morbidity (OR, 0.87; 95% CI, 0.79-0.96; p < 0.001), and an increased infectious morbidity (OR, 1.28; 95% CI, 1.10-1.49; p < 0.001).

Conclusions

Use of a PAC during adult cardiac surgery is associated with decreased length of stay, reduced cardiopulmonary morbidity, and increased infectious morbidity but no increase in the 30-day in-hospital mortality. This suggests an overall potential benefit associated with PAC-based monitoring in this population.

Trial registration

The study was registered at clinicaltrials.gov (NCT02964026) on November 15, 2016.

The Septic Heart: Current Understanding of Molecular Mechanisms and Clinical Implications

Septic cardiomyopathy is a key feature of sepsis-associated cardiovascular failure. Despite the lack of consistent diagnostic criteria, patients typically exhibit ventricular dilatation, reduced ventricular contractility, and/or both right and left ventricular dysfunction with a reduced response to volume infusion. Although there is solid evidence that the presence of septic cardiomyopathy is a relevant contributor to organ dysfunction and an important factor in the already complicated therapeutic management of patients with sepsis, there are still several questions to be asked: Which factors/mechanisms cause a cardiac dysfunction associated with sepsis? How do we diagnose septic cardiomyopathy? How do we treat septic cardiomyopathy? How does septic cardiomyopathy influence the long-term outcome of the patient? Each of these questions is interrelated, and the answers require a profound understanding of the underlying pathophysiology that involves a complex mix of systemic factors and molecular, metabolic, and structural changes of the cardiomyocyte. The afterload-related cardiac performance, together with speckle-tracking echocardiography, could provide methods to improve the diagnostic accuracy and guide therapeutic strategies in patients with septic cardiomyopathy. Because there are no specific/causal therapeutics for the treatment of septic cardiomyopathy, the current guidelines for the treatment of septic shock represent the cornerstone of septic cardiomyopathy therapy. This review provides an up-to-date overview of the current understanding of the pathophysiology, summarizes the evidence of currently available diagnostic tools and treatment options, and highlights the importance of further urgently needed studies aimed at improving diagnosis and investigating novel therapeutic targets for septic cardiomyopathy.

Pulmonary Artery Catheter Placement Aided by Transesophageal Echocardiography versus Pressure Waveform Transduction

OBJECTIVE

To compare pulmonary artery catheter (PAC) placement by transesophageal echocardiography combined with pressure waveform transduction versus the traditional technique of pressure waveform transduction alone.

DESIGN

A prospective, randomized trial.

SETTING

Single university hospital.

PARTICIPANTS

Forty-eight patients with chronic thromboembolic pulmonary hypertension (CTEPH) scheduled for pulmonary thromboendarterectomy.

INTERVENTIONS

PACs were placed in 48 patients with CTEPH scheduled for pulmonary thromboendarterectomy by either a combined approach (eg, transesophageal echocardiography [TEE] and pressure waveform transduction) or by pressure waveform transduction alone.

MEASUREMENTS AND MAIN RESULTS

Successful placement of the PAC via a combined technique or pressure waveform transduction alone was timed, number of attempts recorded, and final location noted. The final location of the pressure waveform-guided catheters was the proximal right pulmonary artery in 6 of 24 cases (25%), whereas the combined method resulted in successful placement in the proximal right pulmonary artery in 24 of 24 cases (100%). The pressure waveform technique resulted in a mean time to placement and mean number of attempts of 74 seconds and 1.70 attempts, respectively. The combined approach resulted in a mean time to placement and mean number of attempts of 89 seconds and 1.79 attempts, respectively. The combined method resulted in placement in the proximal right pulmonary artery significantly more often than the pressure-only method but did not reduce significantly the number of attempts or time required to place the catheter successfully. Additionally, among those cases that required more than 1 attempt or manipulation, there was no difference in the time to successful placement or the number of attempts required for successful placement.

CONCLUSION

TEE guidance during PAC insertion was hypothesized to result in a higher success rate, precise placement, and shorter times to placement. One hundred percent of the PACs inserted with TEE guidance were positioned successfully in the proximal right pulmonary artery, which is the institutional preference. Although the combined technique resulted in greater precision, the clinical significance of this is unknown. The time to placement benefit was not confirmed by this study.

Fluids and Organ Dysfunction: A Narrative Review of the Literature and Discussion of 5 Controversial Topics

Evidence-based clinical decision making is at the forefront of modern cardiothoracic anesthesia practice. Therefore, as a field, cardiac anesthesiologist should strive to ensure that the available evidence is of the highest possible quality. In this narrative review, 5 important topics that the authors believe require additional investigation in cardiothoracic anesthesia and critical care related to fluid therapy and organ dysfunction are outlined briefly. In particular, the authors believe that the areas of pulmonary artery catheter use, restrictive versus liberal transfusion strategies, cardiopulmonary bypass prime composition, colloid use in resuscitation and its effects on acute kidney injury, and management of acute kidney injury after cardiac surgery hold many unanswered questions and opportunities for continued improvement in the specialty of cardiac anesthesia. This article accompanies a presentation at the 46th Association of Cardiac Anesthesiologists Annual Meeting on October 22, 2017.

Variation in Frequency of Intraoperative Arterial, Central Venous and Pulmonary Artery Catheter Placement During Kidney Transplantation: An Analysis of Invasive Monitoring Trends

The rapidly increasing number of kidney transplantations warrants assessment of anesthesia care in this patient population. We explored the frequency of arterial catheter (AC), central venous catheter (CVC) and pulmonary artery catheter (PAC) placement during kidney transplantation in the USA using data from the National Anesthesia Clinical Outcomes Registry (NACOR) and assessed the between-facility variation in the frequency of catheter placement. We defined cases of kidney transplantation using Agency for Healthcare Research and Quality Clinical Classification Software. Placement of AC, CVC and PAC was defined by respective Current Procedural Terminology codes. The frequency of vascular catheter placement across facility types was compared using Pearson χ2 test. We identified 10,580 cases of kidney transplantation performed in 100 facilities from January 1, 2010 to December 31, 2014. Placement of an AC was reported in 1700 (16.1%), CVC in 2580 (24.4%) and PAC in 50 (0.5%) of cases. The frequency of placement of specific types of catheters was statistically different across facility types (p < 0.001). Within individual facilities that reported at least 50 cases of kidney transplantation, the percentages of cases performed with AC, CVC and PAC ranged from 0% to 86%, 0% to 90% and 0% to 3%, respectively. Considerable between-facility variation in the frequency of AC, CVC and PAC placement during kidney transplantation raises concerns about the need for better practice standardization. Excess invasive monitoring may represent a safety risk as well as unnecessary additional cost. If kidney transplantation can be safely performed without an AC, CVC or PAC in most patients, facilities with above-average catheter placement rates may have an opportunity for measurable reduction in catheter-related perioperative complications. Optimizing perioperative monitoring is an important component of ensuring high functioning, high-value medical systems.

Utilizing transesophageal echocardiography for placement of pulmonary artery catheters

OBJECTIVE

Pulmonary artery catheters (PACs) have routinely been positioned by wedging into the pulmonary artery before pulling back 1-2 centimeters or advancing the PAC several centimeters after achieving a pulmonary artery waveform. A rare, major complication is pulmonary artery rupture. This study presents transesophageal echocardiography (TEE) for PAC placement by leaving the catheter tip at the one o'clock position, upper window short-axis view of the ascending aorta at the bifurcation of the pulmonary artery (TEE distance).

DESIGN

Prospective observational cohort study.

SETTING

Large urban academic medical center.

PARTICIPANTS

30 males and 30 females undergoing cardiac surgery requiring cardiopulmonary bypass.

INTERVENTION

TEE was utilized to obtain an upper esophageal short-axis view of the aorta with long-axis view of the main and right pulmonary arteries.

MEASUREMENTS AND RESULTS

The distance between TEE position and wedge position was recorded along with patients' gender, height, and weight. A correlation was found between TEE and wedge distances (P < .0001). There were significant gender differences in TEE distance, with a mean of 43.6 cm in females and 46.5 cm in males (P = .0004). The mean wedge distance was 47.5 cm in females and 51.9 cm in males (P < .0001). The differences between distances of wedge and TEE positions (5.39 cm, males; 3.93 cm, females) were also significant (P < .0001).

CONCLUSIONS

By securing the PAC at the one o'clock TEE position, physicians are assured of a safety margin of several centimeters. This direct visualization method for PAC placement may decrease the risk for accidental wedging intraoperatively.