Evidence-based review of the use of the pulmonary artery catheter: impact data and complications

A recommendation for the use of electrical biosensing technology in neonatology

Non-invasive cardiac output monitoring, via electrical biosensing technology (EBT), provides continuous, multi-parameter hemodynamic variable monitoring which may allow for timely identification of hemodynamic instability in some neonates, providing an opportunity for early intervention that may improve neonatal outcomes. EBT encompasses thoracic (TEBT) and whole body (WBEBT) methods. Despite the lack of relative accuracy of these technologies, as compared to transthoracic echocardiography, the use of these technologies in neonatology, both in the research and clinical arena, have increased dramatically over the last 30 years. The European Society of Pediatric Research Special Interest Group in Non-Invasive Cardiac Output Monitoring, a group of experienced neonatologists in the field of EBT, deemed it appropriate to provide recommendations for the use of TEBT and WBEBT in the field of neonatology. Although TEBT is not an accurate determinant of cardiac output or stroke volume, it may be useful for monitoring longitudinal changes of hemodynamic parameters. Few recommendations can be made for the use of TEBT in common neonatal clinical conditions. It is recommended not to use WBEBT to monitor cardiac output. The differences in technologies, study methodologies and data reporting should be addressed in ongoing research prior to introducing EBT into routine practice. IMPACT STATEMENT: TEBT is not recommended as an accurate determinant of cardiac output (CO) (or stroke volume (SV)). TEBT may be useful for monitoring longitudinal changes from baseline of hemodynamic parameters on an individual patient basis. TEBT-derived thoracic fluid content (TFC) longitudinal changes from baseline may be useful in monitoring progress in respiratory disorders and circulatory conditions affecting intrathoracic fluid volume. Currently there is insufficient evidence to make any recommendations regarding the use of WBEBT for CO monitoring in neonates. Further research is required in all areas prior to the implementation of these monitors into routine clinical practice.

Venous excess ultrasonography (VExUS) captures dynamic changes in volume status surrounding hemodialysis: A multicenter prospective observational study

Background

The evaluation of volume status is essential to clinical decision-making, yet multiple studies have shown that physical exam does not reliably estimate a patient's intravascular volume. Venous excess ultrasound score (VExUS) is an emerging volume assessment tool that utilizes inferior vena cava (IVC) diameter and pulse-wave Doppler waveforms of the portal, hepatic and renal veins to evaluate venous congestion. A point-of-care ultrasound exam initially developed by Beaubein-Souligny et al., VExUS represents a reproducible, non-invasive and accurate means of assessing intravascular congestion. VExUS has recently been validated against RHC-the gold-standard of hemodynamic evaluation for volume assessment. While VExUS scores were shown to correlate with elevated cardiac filling pressures (i.e., right atrial pressure (RAP) and pulmonary capillary wedge pressure (PCWP)) at a static point in time, the ability of VExUS to capture dynamic changes in volume status has yet to be elucidated. We hypothesized that paired VExUS examinations performed before and after hemodialysis (HD) would reflect changes in venous congestion in a diverse patient population.

Methods

Inpatients with end-stage renal disease undergoing intermittent HD were evaluated with transabdominal VExUS and lung ultrasonography before and following HD. Paired t-tests were conducted to assess differences between pre-HD and post-HD VExUS scores, B-line scores and dyspnea scores.

Results

Fifty-six patients were screened for inclusion in this study. Ten were excluded due to insufficient image quality or incomplete exams, and forty-six patients (ninety-two paired ultrasound exams) were included in the final analysis. Paired t-test analysis of pre-HD and post-HD VExUS scores revealed a mean VExUS grade change of 0.82 (p<0.001) on a VExUS scale ranging from 0 to 4. The mean difference in B-line score following HD was 0.8 (p=0.001). There was no statistically significant difference in subjective dyspnea score (p=0.41).

Conclusions

Large-volume fluid removal with HD was represented by changes in VExUS score, highlighting the utility of the VExUS exam to capture dynamic shifts in intravascular volume status. Future studies should evaluate change in VExUS grade with intravenous fluid or diuretic administration, with the ultimate goal of evaluating the capacity of a standardized bedside ultrasound protocol to guide inpatient volume optimization.

Protocolised Management of Cardiogenic Shock and Shock Teams: A Narrative Review

Despite advances in therapy, the incidence of cardiogenic shock continues to increase, with significant mortality that has improved minimally over time. Treatment options for cardiogenic shock are complex and time-, resource-, and case volume-dependent, and involve multiple medical specialties. To provide early, more equitable, and standardised access to cardiogenic shock expertise with advanced therapies, cardiogenic shock teams with a protocolised treatment approach have been proposed. These processes have been applied across hospitals into integrated cardiogenic shock networks. This narrative review evaluates the role of cardiogenic shock teams, protocolised and regionalised shock networks, and the main individual components of protocolised shock management approaches.

Clinical impact of pulmonary artery catheter in patients with cardiogenic shock: A systematic review and meta-analysis

BACKGROUND

The clinical utility of the pulmonary artery catheter (PAC) for the management of cardiogenic shock (CS) remains controversial. We performed a systematic review and meta-analysis exploring the association between PAC use and mortality among patients with CS.

METHODS

Published studies of patients with CS treated with or without PAC hemodynamic guidance were retrieved from MEDLINE and PubMed databases from January 1, 2000, to December 31, 2021. The primary outcome was mortality, which was defined as a combination of in-hospital mortality and 30-day mortality. Secondary outcomes assessed 30-day and in-hospital mortality separately. To assess the quality of nonrandomized studies, the Newcastle-Ottawa Scale (NOS), a well-established scoring system was used. We analyzed outcomes for each study using NOS with a threshold value of >6, indicating high quality. We also performed analyses based on the countries of the studies conducted.

RESULTS

Six studies with a total of 930,530 patients with CS were analyzed. Of these, 85,769 patients were in the PAC-treated group, and 844,761 patients did not receive a PAC. PAC use was associated with a significantly lower risk of mortality (PAC: 4.6 % to 41.5 % vs control: 18.8 % to 51.0 %) (OR 0.63, 95 % CI: 0.41-0.97, I2 = 0.96). Subgroup analyses demonstrated no difference in the risk of mortality between NOS ≥ 6 studies and NOS < 6 studies (p-interaction = 0.57), 30-day and in-hospital mortality (p-interaction = 0.83), or the country of origin of studies (p-interaction = 0.08).

CONCLUSIONS

The use of PAC in patients with CS may be associated with decreased mortality. These data support the need for a randomized controlled trial testing the utility of PAC use in CS.

Prevention and management of critical care complications in cardiogenic shock: a narrative review

BACKGROUND

Cardiogenic shock (CS) is a common cause of morbidity and mortality in cardiac intensive care units (CICUs), even in the contemporary era.

MAIN TEXT

Although mechanical circulatory supports have recently become widely available and used in transforming the management of CS, their routine use to improve outcomes has not been established. Transportation to a high-volume center, early reperfusion, tailored mechanical circulatory supports, regionalized systems of care with multidisciplinary CS teams, a dedicated CICU, and a systemic approach, including preventing noncardiogenic complications, are the key components of CS treatment strategies.

CONCLUSIONS

This narrative review aimed to discuss the challenges of preventing patients from developing CS-related complications and provide a comprehensive practical approach for its management.

Monitoring Macro- and Microcirculation in the Critically Ill: A Narrative Review

Circulatory shock is a common and important diagnosis in the critical care environment. Hemodynamic monitoring is quintessential in the management of shock. The currently used hemodynamic monitoring devices not only measure cardiac output but also provide data related to the prediction of fluid responsiveness, extravascular lung water, and also pulmonary vascular permeability. Additionally, these devices are minimally invasive and associated with fewer complications. The area of hemodynamic monitoring is progressively evolving with a trend toward the use of minimally invasive devices in this area. The critical care physician should be well-versed with current hemodynamic monitoring limitations and stay updated with the upcoming advances in this field so that optimal therapy can be delivered to patients in circulatory shock.

Impairment of Mesenteric Perfusion as a Marker of Major Bleeding in Trauma Patients

The majority of potentially preventable mortality in trauma patients is related to bleeding; therefore, early recognition and effective treatment of hemorrhagic shock impose a cardinal challenge for trauma teams worldwide. The reduction in mesenteric perfusion (MP) is among the first compensatory responses to blood loss; however, there is no adequate tool for splanchnic hemodynamic monitoring in emergency patient care. In this narrative review, (i) methods based on flowmetry, CT imaging, video microscopy (VM), measurement of laboratory markers, spectroscopy, and tissue capnometry were critically analyzed with respect to their accessibility, and applicability, sensitivity, and specificity. (ii) Then, we demonstrated that derangement of MP is a promising diagnostic indicator of blood loss. (iii) Finally, we discussed a new diagnostic method for the evaluation of hemorrhage based on exhaled methane (CH₄) measurement. Conclusions: Monitoring the MP is a feasible option for the evaluation of blood loss. There are a wide range of experimentally used methodologies; however, due to their practical limitations, only a fraction of them could be integrated into routine emergency trauma care. According to our comprehensive review, breath analysis, including exhaled CH₄ measurement, would provide the possibility for continuous, non-invasive monitoring of blood loss.

Hemodynamic monitoring in cardiogenic shock

Cardiogenic shock (CS) is a life-threatening condition characterized by acute end-organ hypoperfusion due to inadequate cardiac output that can result in multiorgan failure, which may lead to death. The diminished cardiac output in CS leads to systemic hypoperfusion and maladaptive cycles of ischemia, inflammation, vasoconstriction, and volume overload. Obviously, the optimal management of CS needs to be readjusted in view of the predominant dysfunction, which may be guided by hemodynamic monitoring. Hemodynamic monitoring enables (1) characterization of the type of cardiac dysfunction and the degree of its severity, (2) very early detection of associated vasoplegia, (3) detection and monitoring of organ dysfunction and tissue oxygenation, and (4) guidance of the introduction and optimization of inotropes and vasopressors as well as the timing of mechanical support. It is now well documented that early recognition, classification, and precise phenotyping via early hemodynamic monitoring (e.g., echocardiography, invasive arterial pressure, and the evaluation of organ dysfunction and parameters derived from central venous catheterization) improve patient outcomes. In more severe disease, advanced hemodynamic monitoring with pulmonary artery catheterization and the use of transpulmonary thermodilution devices is useful to facilitate the right timing of the indication, weaning from mechanical cardiac support, and guidance on inotropic treatments, thus helping to reduce mortality. In this review, we detail the different parameters relevant to each monitoring approach and the way they can be used to support optimal management of these patients.

Is There a Correlation Between Left Ventricular Outflow Tract Velocity Time Integral and Stroke Volume Index in Patients Undergoing Cardiac Surgery?

Introduction

Left ventricular outflow tract velocity time integral (LVOT VTI) is a promising surrogate for stroke volume (SV). However, there is controversy in the literature regarding its correlation with thermodilution or newer cardiac output measurement techniques. This study was conducted to determine the correlation between LVOT VTI determined by transesophageal echocardiography (TEE) with stroke volume index (SVI) calculated by thermodilution.

Methods

Consecutive patients older than 17 years undergoing elective cardiac surgery with pulmonary artery catheter (PAC) and TEE monitoring between September 2021 and February 2022 were included in this prospective, descriptive, single-center study. LVOT VTI was measured using TEE after induction of anesthesia but before skin incision and at least four hours after initial LVOT VTI measurement. SVI was simultaneously measured using the continuous thermodilution technique with a PAC. The correlation between LVOT VTI and SVI was determined with Pearson’s correlation index.

Results

Twelve patients were included and 21 paired measurements were compared. Mean SVI was 31.62 ± 10.71 mL/m² and mean LVOT VTI was 14.74 ± 4.79 cm. The Pearson's correlation index for the two measurements was r = 0.257, p = 0.262.

Conclusion

This prospective study demonstrated a weak correlation between LVOT VTI and SVI in patients undergoing cardiac surgery.

Haemodynamic monitoring in acute heart failure - what you need to know

Acute heart failure (AHF) is a sudden, life-threatening condition, defined as a gradual or rapid onset of symptoms and/or signs of HF. AHF requires urgent medical attention, being the most frequent cause of unplanned hospital admission in patients above 65 years of age. AHF is associated with a 4–12% in-hospital mortality rate and a 21–35% 1-year mortality rate post-discharge. Considering the serious prognosis in AHF patients, it is very important to understand the mechanisms and haemodynamic status in an individual AHF patient, thus preventing end-organ failure and death. Haemodynamic monitoring is a serial assessment of cardiovascular function, intended to detect physiologic abnormalities at the earliest stages, determine which interventions could be most effective, and provide the basis for initiating the most appropriate therapy and evaluate its effects. Over the past decades, haemodynamic monitoring techniques have evolved greatly. Nowadays, they range from very invasive to non-invasive, from intermittent to continuous, and in terms of the provided parameters. Invasive techniques contain pulmonary artery catheterization and transpulmonary thermodilution. Minimally invasive techniques include oesophageal Doppler and noncalibrated pulse wave analysis. Non-invasive techniques contain echocardiography, bioimpedance, and bioreactance techniques as well as non-invasive pulse contour methods. Each of these techniques has specific indications and limitations. In this article, we aimed to provide a pathophysiological explanation of the physical terms and parameters used for haemodynamic monitoring in AHF and to summarize the working principles, advantages, and disadvantages of the currently used methods of haemodynamic monitoring.

Pulmonary Artery Catheter Monitoring in Patients with Cardiogenic Shock: Time for a Reappraisal?

Cardiogenic shock represents one of the most dramatic scenarios to deal with in intensive cardiology care and is burdened by substantial short-term mortality. An integrated approach, including timely diagnosis and phenotyping, along with a well-established shock team and management protocol, may improve survival. The use of the Swan-Ganz catheter could play a pivotal role in various phases of cardiogenic shock management, encompassing diagnosis and haemodynamic characterisation to treatment selection, titration and weaning. Moreover, it is essential in the evaluation of patients who might be candidates for long-term heart-replacement strategies. This review provides a historical background on the use of the Swan-Ganz catheter in the intensive care unit and an analysis of the available evidence in terms of potential prognostic implications in this setting.

The Use of Mechanical Circulatory Assist Devices for ACS Patients with Cardiogenic Shock and High-Risk PCI

PURPOSE OF REVIEW

There has been a significant expansion of the use of mechanical circulatory support (MCS) devices for patient with acute coronary syndromes (ACS) with cardiogenic shock (CS) and in patients undergoing high-risk percutaneous interventions (PCI). The purpose of this review is to provide an overview of the indications and outcomes of these devices in high-risk cardiac patients.

RECENT FINDINGS

Early revascularization of the culprit-lesion is the immediate goal in ACS patients with CS and the use of pulmonary artery catheters has been associated with improved outcomes in patients with cardiogenic shock. The MCS devices that are used for myocardial support include the intra-aortic balloon pump (IABP), the left ventricle (LV) to aorta pumps, left atrium (LA) to arterial pumps, and right atrial (RA) to arterial pumps. This review provides an overview on the use of these devices in patients with ACS and CS and those undergoing high-risk PCI. Attention is focused on the IABP, the Impella (LV-aorta pump), the TandemHeart (LA-arterial pump), and veno-arterial extracorporeal membrane oxygenation (RA-arterial pump). The indications, evidence, and complications of each device are reviewed. Each device varies in its physiological effect on native heart function, complexity in insertion, and complications. The use of MCS devices for high-risk PCI and CS has increased in recent years and have demonstrated efficacy in supporting a vulnerable myocardium. Although recommendations can be made for use of each device in certain clinical scenarios, further evidence through registries and clinical trials is necessary to guide appropriate device utilization.

IVC measurement for the noninvasive evaluation of central venous pressure

Central venous pressure (CVP) is one of only a handful of variables that can be used to assess a patient's volume status to attempt to optimize stroke volume. The gold standard method for assessing CVP is though pulmonary artery catheterization, which is invasive and risks severe complications such as pneumothorax and cardiac conduction abnormalities. Current noninvasive methods for estimating CVP such as jugular venous pressure assessment are imperfect with wide inter-examiner variability. The inferior vena cava (IVC) is a highly compliant vessel that uniquely does not constrict in response to hypovolemia, making it an ideal, noninvasive surrogate for the estimation of CVP. A range of IVC indices including minimum and maximum IVC diameter and fraction of IVC collapse with inspiration (known as collapsibility index) have been studied with highly variable results that range from excellent to poor correlation between these values and CVP. Despite this inconsistency in findings, multiple schemes have been proposed to attempt to estimate CVP from IVC measurements, but when prospectively tested, none has been shown to be accurate. Since the most recent 2015 American Society of Echocardiography guidelines, multiple studies have identified unique ways of improving the accuracy of IVC measurement, which could translate into better CVP estimation. The goal of this review is to summarize the many, often conflicting studies that exist in this area, and provide recommendations for future studies based on our findings.

Do pulmonary artery catheters have a role in the 21st century intensive care unit?

Use of pulmonary artery catheters on general intensive care units has declined. Reasons for this decline are explored and the evidence for and against their use is re-examined. We conclude that the growing consensus for a lack of benefit is not justified, and use of pulmonary artery catheters can still be appropriate.

Differential effects of speed and volume on transfusion-associated circulatory overload: A randomized study in rats

BACKGROUND AND OBJECTIVES

Transfusion-associated circulatory overload (TACO) is the primary cause of transfusion-related mortality. Speed and volume of transfusion are major risk factors. The aim of this study was to investigate the interaction of red blood cell (RBC) transfusion speed and volume on the development of TACO.

MATERIALS AND METHODS

A validated model for TACO in anaemic Lewis rats with an acute myocardial infarction was used. The effect on pulmonary hydrostatic pressure of one, two or four units of packed RBCs transfused in either 30 or 60 min was evaluated (3.3-26.6 ml·kg-1 ·hr-1 ). Pulmonary capillary pressure was measured as left ventricular end-diastolic pressure (LVEDP). Cardiac stress biomarkers atrial natriuretic-peptide (ANP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured 1-h post-transfusion.

RESULTS

Thirty animals were included (n = 5 per group). Transfusion of RBCs increased LVEDP in a volume-dependent manner (ΔLVEDP [mmHg]: -0.95, +0.50, +6.26, p < 0.001). Fast transfusion increased overall ΔLVEDP by +3.5 mmHg and up to +11.8 mmHg in the four units' group (p = 0.016). Doubling transfusion speed increased ΔLVEDP more than doubling volume in the larger volume groups. No difference in ANP or NT-proBNP were seen in high transfusion volume or groups.

CONCLUSION

Transfusion volume dose-dependently increased LVEDP, with speed of transfusion rapidly elevating LVEDP at higher transfusion volumes. ANP and NT-proBNP were not impacted by transfusion volume or speed in this model. TACO is seen as purely volume overload, however, this study emphasizes that limiting transfusion speed, as a modifiable risk factor, might aid in preventing TACO.

Perioperative care in open aortic vascular surgery: A Consensus Statement by the Enhanced Recovery after Surgery (ERAS®) Society and Society for Vascular Surgery

The Society for Vascular Surgery and the Enhanced Recovery After Surgery (ERAS®) Society formally collaborated and elected an international, multi-disciplinary panel of experts to review the literature and provide evidence-based recommendations related to all of the health care received in the perioperative period for patients undergoing open abdominal aortic operations (both transabdominal and retroperitoneal approaches, including supraceliac, suprarenal, and infrarenal clamp sites, for aortic aneurysm and aortoiliac occlusive disease). Structured around the ERAS® core elements, 36 recommendations were made and organized into preadmission, preoperative, intraoperative, and postoperative recommendations.

Cardiogenic Shock Management and Research: Past, Present, and Future Outlook

Although great strides have been made in the pathophysiological understanding, diagnosis and management of cardiogenic shock (CS), morbidity and mortality in patients presenting with the condition remain high. Acute MI is the commonest cause of CS; consequently, most existing literature concerns MI-associated CS. However, there are many more phenotypes of patients with acute heart failure. Medical treatment and mechanical circulatory support are well-established therapeutic options, but evidence for many current treatment regimens is limited. The issue is further complicated by the fact that implementing adequately powered, randomized controlled trials are challenging for many reasons. In this review, the authors discuss the history, landmark trials, current topics of medical therapy and mechanical circulatory support regimens, and future perspectives of CS management.

Accuracy and Trending Ability of Electrical Biosensing Technology for Non-invasive Cardiac Output Monitoring in Neonates: A Systematic Qualitative Review

BACKGROUND

Electrical biosensing technology (EBT) is an umbrella term for non-invasive technology utilizing the body's fluctuating resistance to electrical current flow to estimate cardiac output. Monitoring cardiac output in neonates may allow for timely recognition of hemodynamic compromise and allow for prompt therapy, thereby mitigating adverse outcomes. For a new technology to be safely used in the clinical environment for therapeutic decisions, it must be proven to be accurate, precise and be able to track temporal changes. The aim of this systematic review was to identify and analyze studies that describe the accuracy, precision, and trending ability of EBT to non-invasively monitor Left ventricular cardiac output and/or stroke volume in neonates.

METHODS

A qualitative systematic review was performed. Studies were identified from PubMed NCBI, SCOPUS, and EBSCOHost up to November 2021, where EBT technologies were analyzed in neonates, in comparison to a reference technology. Outcome measures were bias, limits of agreement, percentage error for agreement studies and data from 4-quadrant and polar plots for trending studies. Effect direction plots were used to present results.

RESULTS

Fifteen neonatal studies were identified, 14 for agreement and 1 for trending analysis. Only thoracic electrical biosensing technology (TEBT), with transthoracic echocardiography (TTE) as the comparator, studies were available for analyzes. High heterogeneity existed between studies. An equal number of studies showed over- and underestimation of left ventricular output parameters. All studies showed small bias, wide limits of agreement, with most studies having a percentage error >30%. Sub-analyses for respiratory support mode, cardiac anomalies and type of technology showed similar results. The single trending study showed poor concordance, high angular bias, and poor angular concordance.

DISCUSSION

Overall, TEBT shows reasonable accuracy, poor precision, and non-interchangeability with TTE. However, high heterogeneity hampered proper analysis. TEBT should be used with caution in the neonatal population for monitoring and determining therapeutic interventions. The use of TEBT trend monitoring has not been sufficiently studied and requires further evaluation in future trials.

Non-invasive capnodynamic mixed venous oxygen saturation during major changes in oxygen delivery

Mixed venous oxygen saturation (SvO₂) is an important variable in anesthesia and intensive care but currently requires pulmonary artery catheterization. Recently, non-invasive determination of SvO₂ (Capno-SvO₂) using capnodynamics has shown good agreement against CO-oximetry in an animal model of modest hemodynamic changes. The purpose of the current study was to validate Capno-SvO₂ against CO-oximetry during major alterations in oxygen delivery. Furthermore, evaluating fiberoptic SvO₂ for its response to the same challenges. Eleven mechanically ventilated pigs were exposed to oxygen delivery changes: increased inhaled oxygen concentration, hemorrhage, crystalloid and blood transfusion, preload reduction and dobutamine infusion. Capno-SvO₂ and fiberoptic SvO₂ recordings were made in parallel with CO-oximetry. Respiratory quotient, needed for capnodynamic SvO₂, was measured by analysis of mixed expired gases. Agreement of absolute values between CO-oximetry and Capno-SvO₂ and fiberoptic SvO₂ respectively, was assessed using Bland–Altman plots. Ability of Capno- SvO₂ and fiberoptic SvO₂ to detect change compared to CO-oximetry was assessed using concordance analysis. The interventions caused significant hemodynamic variations. Bias between Capno-SvO₂ and CO-oximetry was + 3% points (95% limits of agreements – 7 to + 13). Bias between fiberoptic SvO₂ and CO-oximetry was + 1% point, (95% limits of agreements − 7 to + 9). Concordance rate for Capno-SvO₂ and fiberoptic SvO₂ vs. CO-oximetry was 98% and 93%, respectively. Capno-SvO₂ generates absolute values close to CO-oximetry. The performance of Capno-SvO₂ vs. CO-oximetry was comparable to the performance of fiberoptic SvO₂ vs. CO-oximetry. Capno-SvO₂ appears to be a promising tool for non-invasive SvO₂ monitoring.

Accuracy and precision of continuous non-invasive arterial pressure monitoring in critical care: A systematic review and meta-analysis

OBJECTIVE

To summarize the evidence regarding the accuracy of continuous non-invasive arterial pressure measurements in adult critical care patients.

RESEARCH METHODOLOGY

Medline, EMBASE, and CINAHL were searched for studies that included adult critical care patients reporting the agreement between continuous non-invasive and invasive arterial pressure measurements. The studies were selected and assessed for risk of bias using the Revised Quality Assessment of Diagnostic Accuracy Studies tool by two independent reviewers. The Grading of Recommendations, Assessment, Development and Evaluations approach was used. Pooled estimates of the mean bias and limits of agreement with outer 95% confidence intervals (termed population limits of agreement) were calculated.

RESULTS

Population limits of agreement for systolic blood pressure were wide, spanning from -36.13 mmHg to 28.28 mmHg (18 studies; 785 participants). Accuracy of diastolic blood pressure measurements was highly inconsistent across studies, resulting in imprecise estimates for the population limits of agreement. Population limits of agreement for mean arterial pressure spanned from -39.96 mmHg to 44.36 mmHg (17 studies; 765 participants). The evidence was rated as very low-quality due to very serious concerns about heterogeneity and imprecision.

CONCLUSION

Substantial differences in blood pressure were identified between measurements taken from continuous non-invasive and invasive monitoring devices. Clinicians should consider this broad range of uncertainty if using these devices to inform clinical decision-making in critical care.

Lateral-Apical Approach to Pericardiocentesis for Treatment of Cardiac Tamponade Immediately Post-orthotopic Liver Transplantation

Cardiac tamponade is a rare complication following orthotopic liver transplantation (OLT). The incidence and treatment specific to the immediate postoperative OLT patient have never been reported. Here, we describe a case of OLT complicated by coagulopathy and difficult intraoperative pulmonary artery catheter placement with subsequent postoperative hemopericardium resulting in tamponade. An emergent, ultrasound-guided, lateral-apical pericardiocentesis was successfully performed, suggesting a possible procedural technique for pericardiocentesis in the immediate postoperative period for liver transplant patients.

Energy expenditure and oxygen uptake kinetics in critically ill elderly patients

BACKGROUND

Resting energy expenditure (REE) measurement of critically ill patients is essential for better nutrition management. Younger people increase their oxygen delivery ( D ̇ O 2 ) to meet energy demands, but few reports have investigated oxygen uptake kinetics in elderly patients, which are the main target population in today's intensive care units (ICUs). In this study, we evaluated REE, D ̇ O 2 , and oxygen extraction ratio (O₂ Ext: oxygen consumption [ V ̇ O 2 ]/ D ̇ O 2 ) to clarify appropriate energy needs and consumption in elderly ICU patients.

METHODS

This retrospective observational study included ventilated ICU patients who were divided into elderly participants (age ≥ 65 years) and nonelderly participants (age ≤64 years). V ̇ O 2 , CO₂ production, and cardiac output were measured by indirect calorimetry and noninvasive hemodynamic monitoring for up to 5 days. The initial values of REE, D ̇ O 2 , and O₂ Ext were compared between elderly and nonelderly patients.

RESULTS

This study included 102 patients, of whom 52% (n = 53) were elderly. The absolute deviation of measured REE per ideal body weight (IBW) was significantly higher in elderly than in nonelderly patients (9.3 ± 6.9 vs 6.3 ± 6.6 kcal/kg; P < .01). D ̇ O 2 had a strong negative correlation with age (P < .01). The O₂ Ext value was significantly higher in elderly than in nonelderly patients (37 ± 19% vs 29 ± 13%; P = .03).

CONCLUSIONS

Elderly critically ill patients were characterized by higher deviations in REE, lower D ̇ O 2 , and higher O₂ Ext. In elderly patients, O₂ Ext rather than D ̇ O 2 could be increased to meet energy consumption demands.

The contemporary pulmonary artery catheter. Part 1: placement and waveform analysis

Nowadays, the classical pulmonary artery catheter (PAC) has an almost 50-year-old history of its clinical use for hemodynamic monitoring. In recent years, the PAC evolved from a device that enabled intermittent cardiac output measurements in combination with static pressures to a monitoring tool that provides continuous data on cardiac output, oxygen supply and-demand balance, as well as right ventricular (RV) performance. In this review, which consists of two parts, we will introduce the difference between intermittent pulmonary artery thermodilution using cold bolus injections, and the contemporary PAC enabling continuous measurements by using a thermal filament which at random heats up the blood. In this first part, the insertion techniques, interpretation of waveforms of the PAC, the interaction of waveforms with the respiratory cycle and airway pressure as well as pitfalls in waveform analysis are discussed. The second part will cover the measurements of the contemporary PAC including measurement of continuous cardiac output, RV ejection fraction, end-diastolic volume index, and mixed venous oxygen saturation. Limitations of all of these measurements will be highlighted there as well. We conclude that thorough understanding of measurements obtained from the PAC are the first step in successful application of the PAC in daily clinical practice.

Safety First: An Ambulation Protocol for Patients With Pulmonary Artery Catheters

BACKGROUND

Patients with indwelling pulmonary artery catheters have historically been excluded from participating in early mobility programs because of the concern for catheter-related complications. However, this practice conflicts with the benefits accrued from early mobilization.

OBJECTIVE

The purposes of this quality improvement project were to develop and implement a standardized ambulation protocol for patients with a pulmonary artery catheter in a cardiac surgery intensive care unit and to assess and support safe ambulation practices while preventing adverse events in patients with pulmonary artery catheters.

METHODS

From October 2016 through October 2017, this single-center quality improvement project developed and analyzed the implementation of a safe patient ambulation protocol in the cardiac surgery intensive care unit. Frontline nursing staff and the interdisciplinary team were educated on a standardized protocol that facilitated patient ambulation. Data analyzed included distance of ambulation, catheter migration, presence of cardiac dysrhythmias, and adverse events during ambulation.

RESULTS

During this 1-year project, 41 patients participated in 94 walks for a total distance of 13 676.38 m. There were no reported episodes of cardiac dysrhythmia, accidental occlusion of the pulmonary artery, catheter migration, or pulmonary artery rupture related to ambulation with a pulmonary artery catheter.

CONCLUSIONS

The use of a standardized ambulation protocol can successfully result in safe mobilization of patients with indwelling pulmonary artery catheters.

Removal of a Knotted Pulmonary Artery Catheter Using a Percutaneous Tracheostomy Set

Placement of a pulmonary artery catheter is not a risk-free technique. Related incidents include ventricular arrhythmias, air embolisms, pulmonary artery perforation, infections, or catheter thrombosis. Herein the authors report a rare complication-the intracardiac knotting and its successful extraction using a percutaneous tracheostomy set in a hemodynamically compromised patient after a heart transplant.

Literature and new innovations leading to the rise and fall of the Swan-Ganz catheter

BACKGROUND

In 1970, Harold James Charles Swan and William Ganz published their work on the pulmonary artery catheter (PAC or Swan-Ganz catheter). They described the successful bedside use of a flow-directed catheter to continuously evaluate the heart, and it was used extensively in the years following to care for critically ill patients. In recent decades, clinicians have reevaluated the risks and benefits of the PAC.

AIM

We acknowledge the contributions of Swan and Ganz and discuss literature, including randomized controlled trials, and new technology surrounding the rise and fall in use of the PAC.

METHODS

We performed a literature search of retrospective and prospective studies, including randomized controlled trials, and editorials to understand the history and clinical outcomes of the PAC.

RESULTS

In the 1980s, clinicians began to question the benefits of the PAC. In 1996 and 2003, a large observational study and randomized controlled trial, respectively, showed no clear benefits in outcome. Thereafter, use of PACs began to drop precipitously. New less and noninvasive technology can estimate cardiac output and blood pressure continuously.

CONCLUSIONS

Swan and Ganz contributed to the bedside understanding of the pathophysiology of the heart. The history of the rise and fall in use of the PAC parallels the literature and invention of less-invasive technology. Although the PAC has not been shown to improve clinical outcomes in large randomized controlled trials, it may still be useful in select patients. New less-invasive and noninvasive technology may ultimately replace it if literature supports it.

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.

Management of Cardiogenic Shock in a Cardiac Intensive Care Unit

Cardiogenic shock (CS) is a complex condition characterized by end-organ hypoperfusion and requiring pharmacologic and/or mechanical circulatory support. It is caused by a decline in cardiac output due to a primary cardiac disorder. CS is frequently complicated by multiorgan system dysfunction that requires a multidisciplinary approach in a critical care setting. Appropriate use of diagnostic data using tools available in a modern cardiac intensive care unit should guide optimal management incorporating both pharmacologic and nonpharmacologic therapies to minimize morbidity and mortality.

Accuracy and precision of zero-heat-flux temperature measurements with the 3M™ Bair Hugger™ Temperature Monitoring System: a systematic review and meta-analysis

Zero-heat-flux thermometers provide clinicians with the ability to continuously and non-invasively monitor body temperature. These devices are increasingly being used to substitute for more invasive core temperature measurements during surgery and in critical care. The aim of this review was to determine the accuracy and precision of zero-heat-flux temperature measurements from the 3M™ Bair Hugger™ Temperature Monitoring System. Medline and EMBASE were searched for studies that reported on a measurement of core or peripheral temperature that coincided with a measurement from the zero-heat-flux device. Study selection and quality assessment was performed independently using the Revised Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2). The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to summarize the strength of the evidence. Pooled estimates of the mean bias and limits of agreement with outer 95% confidence intervals (population limits of agreement) were calculated. Sixteen studies were included. The primary meta-analysis of zero-heat-flux versus core temperature consisted of 22 comparisons from 16 individual studies. Data from 952 participants with 314,137 paired measurements were included. The pooled estimate for the mean bias was 0.03 °C. Population limits of agreement, which take into consideration the between-study heterogeneity and sampling error, were wide, spanning from - 0.93 to 0.98 °C. The GRADE evidence quality rating was downgraded to moderate due to concerns about study limitations. Population limits of agreement for the sensitivity analysis restricted to studies rated as having low risk of bias across all the domains of the QUADAS-2 were similar to the primary analysis. The range of uncertainty in the accuracy of a thermometer should be taken into account when using this device to inform clinical decision-making. Clinicians should therefore consider the potential that a temperature measurement from a 3M™ Bair Hugger™ Temperature Monitoring System could be as much as 1 °C higher or lower than core temperature. Use of this device may not be appropriate in situations where a difference in temperature of less than 1 °C is important to detect.

Cardiac output monitoring: Technology and choice

The accurate quantification of cardiac output (CO) is given vital importance in modern medical practice, especially in high-risk surgical and critically ill patients. CO monitoring together with perioperative protocols to guide intravenous fluid therapy and inotropic support with the aim of improving CO and oxygen delivery has shown to improve perioperative outcomes in high-risk surgical patients. Understanding of the underlying principles of CO measuring devices helps in knowing the limitations of their use and allows more effective and safer utilization. At present, no single CO monitoring device can meet all the clinical requirements considering the limitations of diverse CO monitoring techniques. The evidence for the minimally invasive CO monitoring is conflicting; however, different CO monitoring devices may be used during the clinical course of patients as an integrated approach based on their invasiveness and the need for additional hemodynamic data. These devices add numerical trend information for anesthesiologists and intensivists to use in determining the most appropriate management of their patients and at present, do not completely prohibit but do increasingly limit the use of the pulmonary artery catheter.

Value of Hemodynamic Monitoring in Patients With Cardiogenic Shock Undergoing Mechanical Circulatory Support

The recent widespread availability and use of mechanical circulatory support is transforming the management and outcomes of cardiogenic shock (CS). Clinical decision-making regarding the optimization of therapies for patients with CS can be guided effectively by hemodynamic monitoring with a pulmonary artery catheter (PAC). Because several studies regarding the benefit of PACs are ambiguous, the use of PACs is variable among clinicians treating patients with CS. More notable is that PAC use has not been studied as part of a randomized, controlled trial in patients with CS with or without mechanical circulatory support. Standardized approaches to hemodynamic monitoring in these patients can improve decision-making and outcomes. In this review, we summarize the hemodynamics of CS and mechanical circulatory support with PAC-derived measurements, and provide a compelling rationale for the use of PAC monitoring in patients with CS receiving mechanical circulatory support.

Graduating Fellows' Procedural Comfort Level With Pulmonary Critical Care Procedures

BACKGROUND

Graduating fellows from pulmonary and critical care programs are expected to independently perform bronchoscopy and common medical procedures in the intensive care unit. Given variable exposure and learning opportunities at different training programs, little is known about how comfortable graduating fellows are with these procedures.

METHODS

A survey concerning the ACGME required procedures for pulmonary and critical care fellowship was sent to graduating fellows and program directors at all ACGME accredited subspecialty fellowship programs in pulmonary, critical care, and combined pulmonary critical care medicine.

RESULTS

Critical care fellows performed the most intubations, paracenteses, arterial lines, central venous catheter insertions, and cardioversions, but did not perform as many bronchoscopy related procedures as the other subgroups. Pulmonary and combined pulmonary/critical care fellows performed and felt confident in most procedures. Program directors from all specialties agreed with the fellows overall about the procedural confidence gained during training. There also appeared to be a correlation between number of procedures performed and the confidence of the proceduralist. There appears to be a certain threshold number of successful completions to achieve confidence for independent practice for each surveyed procedure.

CONCLUSION

There is a correlation between a fellow's procedural comfort with independent practice and the number of successful attempts by a graduating fellow. There are no universal guidelines that outline the appropriate number of successful attempts needed for independent practice, and our data strongly suggests that there is a threshold for each procedure across these three subspecialties.

Accuracy and precision of cardiac output estimation by an automated, brachial cuff-based oscillometric device in patients with shock

Non-invasive monitoring of cardiac output is a technological and clinical challenge, especially for critically ill, surgically operated, or intensive care unit patients. A brachial cuff-based, automated, oscillometric device used for blood pressure and arterial stiffness ambulatory monitoring (Mobil-O-Graph) provides a non-invasive estimation of cardiac output values simultaneously with regular blood pressure measurement. The aim of the study was to evaluate the feasibility of this apparatus to estimate cardiac output in intensive care unit patients and to compare the non-invasive estimated cardiac output values with the respective gold standard method of thermodilution during pulmonary artery catheterization. Repeated sequential measurements of cardiac output were performed, in random order, by thermodilution (reference) and Mobil-O-Graph (test), in 24 patients hospitalized at intensive care unit. Reproducibility and accuracy of the test device were evaluated by Bland–Altman analysis, intraclass correlation coefficient, and percentage error. Mobil-O-Graph underestimated significantly the cardiac output by −1.12 ± 1.38 L/min ( p < 0.01) compared to thermodilution. However, intraclass correlation coefficient was >0.7 indicating a fair agreement between the test and the reference methods, while percentage error was approximately 39% which is considered to be within the acceptable limits. Cardiac output measurements were reproducible by both Mobil-O-Graph (intraclass correlation coefficient = 0.73 and percentage error = 27.9%) and thermodilution (intraclass correlation coefficient = 0.91 and percentage error = 26.7%). We showed for the first time that cardiac output estimation in intensive care unit patients using a non-invasive, automated, oscillometric, cuff-based apparatus is reproducible (by analyzing two repeated cardiac output measurements), exhibiting similar precision to thermodilution. However, the accuracy of Mobil-O-Graph (error compared to thermodilution) could be considered fairly acceptable. Future studies remain to further examine the reliability of this technology in monitoring cardiac output or stroke volume acute changes which is a more clinically relevant objective.

Volume incompliance and transfusion are essential for transfusion-associated circulatory overload: a novel animal model

BACKGROUND

Transfusion‐associated circulatory overload (TACO) is the predominant complication of transfusion resulting in death. The pathophysiology is poorly understood, but inability to manage volume is associated with TACO, and observational data suggest it is different from simple cardiac overload due to fluids. We developed a two‐hit TACO animal model to assess the role of volume incompliance (“first‐hit”) and studied whether volume overload (“second‐hit”) by red blood cell (RBC) transfusion is different compared to fluids (Ringer's lactate [RL]).

MATERIALS AND METHODS

Male adult Lewis rats were stratified into a control group (no intervention) or a first hit: either myocardial infarction (MI) or acute kidney injury (AKI). Animals were randomized to a second hit of either RBC transfusion or an equal volume of RL. A clinically relevant difference was defined as an increase in left ventricular end‐diastolic pressure (ΔLVEDP) of +4.0 mm Hg between the RBC and RL groups.

RESULTS

In control animals (without first hit) LVEDP was not different between infusion groups (Δ + 1.6 mm Hg). LVEDP increased significantly more after RBCs compared to RL in animals with MI (Δ7.4 mm Hg) and AKI (Δ + 5.4 mm Hg), respectively. Volume‐incompliant rats matched clinical TACO criteria in 92% of transfused versus 25% of RL‐infused animals, with a greater increase in heart rate and significantly higher blood pressure.

CONCLUSION

To our knowledge, this is the first animal model for TACO, showing that a combination of volume incompliance and transfusion is essential for development of circulatory overload. This model allows for further testing of mechanistic factors as well as therapeutic approaches.

Automated echocardiography for measuring and tracking cardiac output after cardiac surgery: a validation study

Echocardiographic measurement of cardiac output with automated software analyses of spectral curves in the left ventricular outflow tract has been introduced. This study aimed to assess the precision and accuracy of cardiac output measurements as well as the ability to track cardiac output changes over time comparing the automated echocardiographic method with the continuous pulmonary artery thermodilution cardiac output technique and the manual echocardiographic method in cardiac surgery patients. Cardiac output was measured simultaneously with all three methods in 50 patients on the morning after cardiac surgery. A second comparison was performed 90-180 min later. Precisions for each method were measured. Bias and limits of agreement (LoA) between methods were assessed and concordance- and polar plots were used for evaluating trending of cardiac output. When comparing the automated echocardiographic method with the thermodilution technique, the mean bias was 0.72 L/min with LoA - 1.89; 3.33 L/min corresponding to a percentage error of 46%. The concordance rate was 47%. The mean bias between the automated- and the manual echocardiographic methods was - 0.06 L/min (95% LoA - 2.33; 2.21 L/min, percentage error 42%). The concordance rate was 79%. The automated echocardiographic method did not meet the criteria for interchangeability with the thermodilution technique or the manual echocardiographic method. Trending ability was poor when compared to the continuous thermodilution technique, but moderate when compared to the manual echocardiographic method.Trial registry number: NCT03372863. Retrospectively registered December 14th 2017.

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.

Stroke Volume Optimization: Utilization of the Newest Cardiac Vital Sign: Considerations in Recovery from Cardiac Surgery

The hemodynamic monitoring landscape is rapidly evolving from pressure-based and static parameters to more blood flow-based and dynamic parameters. Consensus guidelines for cardiac surgery state that the pulmonary artery catheter is neither required nor helpful in most patients. In the meantime, critical care has been searching for the alternatives to the pulmonary artery catheter and protocols for use. Best available evidence for any protocol developed suggests the inclusion of stroke volume optimization to determine fluid responsiveness. Additional strategies to using stroke volume to optimize hemodynamics, including case studies, are discussed.

Retinal oxygen saturation as a non-invasive estimate for mixed venous oxygen saturation and cardiac output

PURPOSE

To investigate the correlation between retinal vessel oxygen saturation and mixed venous oxygen saturation (SvO_2-mixed ) and cardiac output (CO).

METHODS

Retinal arterial (SaO_2-retinal ) and venous (SvO_2-retinal ) oxygen saturation were measured non-invasively with dual-wavelength retinal oximetry in subjects receiving invasive measurements of SvO_2-mixed and CO through right heart catheterization. Correlations were analysed using Spearman's rank correlation coefficients and linear regression models.

RESULTS

Fourteen patients (median age 62.7 years, range: 21-77) were included in the analysis. When adjusted for age, SvO_2-retinal showed a positive correlation with SvO_2-mixed (β = 0.80, p = 0.003). Retinal arteriovenous oxygen saturation difference was significantly correlated with the inverse of CO (Spearman's ρ = 0.59, p = 0.026).

CONCLUSION

This pilot study provides proof of concept for the use of retinal oximetry as a non-invasive tool to assess systemic cardiovascular function.

Pulmonary Hypertension in Intensive Care Units: An Updated Review

Pulmonary hypertension (PH) is a condition associated with high morbidity and mortality. Patients with PH who require critical care usually have severe right ventricular (RV) dysfunction. Although different groups of PH have different etiologies, pulmonary vascular dysfunction is common in these groups. PH can lead to increased pulmonary artery pressure, which can ultimately cause RV failure. Clinicians should be familiar with the presentations of this disease and diagnostic tools. The contributing factors, if present (e.g., sepsis), and coexisting conditions (e.g., arrhythmias) should be identified and addressed accordingly. The preload should be optimized by fluid administration, diuretics, and dialysis, if necessary. On the other hand, the RV afterload should be reduced to improve the RV function with pulmonary vasodilators, such as prostacyclins, inhaled nitric oxide, and phosphodiesterase type 5 inhibitors, especially in group 1 PH. Inotropes are also used to improve RV contractility, and if inadequate, use of ventricular assist devices and extracorporeal life support should be considered in suitable candidates. Moreover, vasopressors should be used to maintain systemic blood pressure, albeit cautiously, as they increase the RV afterload. Measures should be also taken to ensure adequate oxygenation. However, mechanical ventilation is avoided in RV failure. In this study, we reviewed the pathophysiology, manifestations, diagnosis, monitoring, and management strategies of PH, especially in intensive care units.

Hemodynamics of Cardiogenic Shock

Cardiogenic shock (CS) represents an advanced state of morbidity along the pathophysiologic pathway of end-organ hypoperfusion caused by reduced cardiac output and blood pressure. Acute coronary syndromes remain the most common cause of CS. The spectrum of hypoperfusion states caused by low cardiac output ranges from pre-CS to refractory CS and can be characterized by an array of hemodynamic parameters. This review provides the foundation for a hemodynamic understanding of CS including the use of hemodynamic monitoring for diagnosis and treatment, the cardiac and vascular determinants of CS, and a hemodynamic approach to risk stratification and management of CS.

Anesthesia-Associated Relative Hypovolemia: Mechanisms, Monitoring, and Treatment Considerations

Although the utility and benefits of anesthesia and analgesia are irrefutable, their practice is not void of risks. Almost all drugs that produce anesthesia endanger cardiovascular stability by producing dose-dependent impairment of cardiac function, vascular reactivity, and compensatory autoregulatory responses. Whereas anesthesia-related depression of cardiac performance and arterial vasodilation are well recognized adverse effects contributing to anesthetic risk, far less emphasis has been placed on effects impacting venous physiology and venous return. The venous circulation, containing about 65–70% of the total blood volume, is a pivotal contributor to stroke volume and cardiac output. Vasodilation, particularly venodilation, is the primary cause of relative hypovolemia produced by anesthetic drugs and is often associated with increased venous compliance, decreased venous return, and reduced response to vasoactive substances. Depending on factors such as patient status and monitoring, a state of relative hypovolemia may remain clinically undetected, with impending consequences owing to impaired oxygen delivery and tissue perfusion. Concurrent processes related to comorbidities, hypothermia, inflammation, trauma, sepsis, or other causes of hemodynamic or metabolic compromise, may further exacerbate the condition. Despite scientific and technological advances, clinical monitoring and treatment of relative hypovolemia still pose relevant challenges to the anesthesiologist. This short perspective seeks to define relative hypovolemia, describe the venous system’s role in supporting normal cardiovascular function, characterize effects of anesthetic drugs on venous physiology, and address current considerations and challenges for monitoring and treatment of relative hypovolemia, with focus on insights for future therapies.

'Combat' Approach to Cardiogenic Shock

The incidence of cardiogenic shock is rising, patient complexity is increasing and patient survival has plateaued. Mirroring organisational innovations of elite military units, our multidisciplinary medical specialists at the INOVA Heart and Vascular Institute aim to combine the adaptability, agility and cohesion of small teams across our large healthcare system. We advocate for widespread adoption of our 'combat' methodology focused on: increased disease awareness, early multidisciplinary shock team activation, group decision-making, rapid initiation of mechanical circulatory support (as appropriate), haemodynamic-guided management, strict protocol adherence, complete data capture and regular after action reviews, with a goal of ending preventable death from cardiogenic shock.