Current use of the pulmonary artery catheter

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.

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.

Agreement of Cardiac Output Measurements between Bioreactance and Transthoracic Echocardiography in Preterm Infants during the Transitional Phase: A Single-Centre, Prospective Study

INTRODUCTION

Bioreactance cardiac output (CO) monitors are able to non-invasively and continuously monitor CO. However, as a novel tool to measure CO, it must be proven to be accurate and precise.

OBJECTIVE

To determine the agreement between CO measured with a bioreactance monitor and transthoracic echocardiography-derived left ventricular output parameters in preterm infants.

METHODS

This is a prospective observational study in 63 preterm neonates with non-invasive respiratory support, not requiring inotrope support. The infants underwent continuous bioreactance monitoring of CO and stroke volume (SV) and simultaneous transthoracic echocardiography every 6 h until 72 h of life.

RESULTS

The agreement between bioreactance and transthoracic echocardiography, for both SV and CO, was poor. The percentage error was 67.5% for SV and 71.6% for CO. The mean error was 60.4% for SV and 69.8% for CO. Bias was affected by numerous variables. After correcting for time, CO and SV bias were significantly affected by the presence of an open patent ductus arteriosus and the level of CO.

CONCLUSION

Bioreactance cannot be considered interchangeable with transthoracic echocardiography to measure CO in preterm infants during the transition phase. Agreement between bioreactance and other CO metrics should be assessed before concluding its accuracy or inaccuracy in neonates.

Impact of processes of care aimed at complication reduction on the cost of complex cancer surgery

BACKGROUND AND OBJECTIVES

Health care providers add multiple processes to the care of complex cancer patients, believing they prevent and/or ameliorate complications. However, the relationship between these processes, complication remediation, and expenditures is unknown.

METHODS

Data for patients with cancer diagnoses undergoing colectomy, rectal resection, pulmonary lobectomy, pneumonectomy, esophagectomy, and pancreatic resection were obtained from hospital and inpatient physician Medicare claims for the years 2005-2009. Risk-adjusted regression analyses measured the association between hospitalization costs and processes presumed to prevent and/or remedy complications common to high-risk procedures.

RESULTS

After controlling for comorbidities, analysis identified associations between increased costs and use of multiple processes, including arterial lines (4-12% higher; P < 0.001) and pulmonary artery catheters (23-33% higher; P < 0.001). Epidural analgesia was not associated with higher costs. Consultations were associated with 24-44% (P < 0.001) higher costs, and total parenteral nutrition was associated with 13-31% higher costs (P < 0.001).

CONCLUSIONS

Many frequently utilized processes and services presumed to avoid and/or ameliorate complications are associated with increased surgical oncology costs. This suggests that the patient-centered value of each process should be measured on a procedure-specific basis. Likewise, further attention should be focused on defining the efficacy of each of these costly, but frequently unproven, additions to perioperative care.

Effect of transplantation of bone marrow stem cells on myocardial infarction size in a rabbit model

BACKGROUND

Intravenous transplantation has been regarded as a most safe method in stem cell therapies. There is evidence showing the homing of bone marrow stem cells (BMSCs) into the injured sites, and thus these cells can be used in the treatment of acute myocardial infarction (MI). This study aimed to investigate the effect of intravenous and epicardial transplantion of BMSCs on myocardial infarction size in a rabbit model.

METHODS

A total of 60 New Zealand rabbits were randomly divided into three groups: control group, epicardium group (group I) and ear vein group (group II). The BMSCs were collected from the tibial plateau in group I and group II, cultured and labeled. In the three groups, rabbits underwent thoracotomy and ligation of the middle left anterior descending artery. The elevation of ST segment >0.2 mV lasting for 30 minutes on the lead II and III of electrocardiogram suggested successful introduction of myocardial infarction. Two weeks after myocardial infarction, rabbits in group I were treated with autogenous BMSCs at the infarct region and those in group II received intravenous transplantation of BMSCs. In the control group, rabbits were treated with PBS following thoracotomy. Four weeks after myocardial infarction, the heart was collected from all rabbits and the infarct size was calculated. The heart was cut into sections followed by HE staining and calculation of infarct size with an image system.

RESULTS

In groups I and II, the infarct size was significantly reduced after transplantation with BMSCs when compared with the control group (P<0.05). However, there was no significant difference in the infarct size between groups I and II (P>0.05).

CONCLUSION

Transplantation of BMSCs has therapeutic effect on MI. Moreover, epicardial and intravenous transplantation of BMSCs has comparable therapeutic efficacy on myocardial infarction.

Increasing use of less-invasive hemodynamic monitoring in 3 specialty surgical intensive care units: a 5-year experience at a tertiary medical center

INTRODUCTION

Less-invasive hemodynamic monitoring (eg, esophageal doppler monitoring [EDM] and arterial pressure contour analysis, FloTrac) is increasingly used as an alternative to pulmonary artery catheters (PACs) in critically ill intensive care unit (ICU).

HYPOTHESIS

The decrease in use of PACs is not associated with increased mortality.

METHODS

Five-year retrospective review of 1894 hemodynamically monitored patients admitted to 3 surgical ICUs in a university-affiliate, tertiary care urban hospital. Data included the number of admissions, diagnosis-related group discharge case mix, length of stay, insertion of monitoring devices (PAC, EDM, and FloTrac probes), administered intravenous vasoactive agents (β-predominant agonists--dobutamine, epinephrine, and dopamine; vasopressors--norepinephrine and phenylephrine), and mortality. Data from hospital administrative databases were compiled to create patient characteristic and monitoring variables across a 5-year time period, 2005 to 2009 inclusive. Chi-square for independent proportions, 1-way analysis of variance, and Kruskal-Wallis tests were used; tests for trend were conducted. An α level of .05 was considered significant. Statistical Package for the Social Sciences v14 was used for all statistical testing.

RESULTS

There was a significant change in the type of hemodynamic monitors inserted in 2 of the 3 surgical ICUs (in the general surgery and neurointensive care but not in the cardiac ICU) from PACs to less-invasive devices (FloTrac or EDM) during the 5-year study period (P < .001). There was no change in mortality rate over the time period (P = .492). There was an overall increase in the proportion of monitored patients who received intravenous vasoactive agents (P < .001) with a progressive shift from β-agonists to vasopressors (P < .002). Multivariate analyses indicated that age, case mix, and use of vasoactive agents were all independent predictors of inhospital mortality (P = .001) but that type of monitoring was not (P = .638).

CONCLUSIONS

In a 5-year period, the decreased insertions of PACs were replaced by increased utilization of less-invasive hemodynamic monitoring devices. This change in practice did not adversely impact mortality.

Transesophageal echocardiography in noncardiac thoracic surgery

In high-risk surgeries with medically complicated patients, transesophageal echocardiography (TEE) adds an additional level of monitoring with which few can disagree. This article presents multiple applications of TEE that can assist both the anesthesiologist and the surgeon through major noncardiac thoracic surgery. It highlights how TEE can be used as an adjuvant to lung resection surgery; TEE as a monitor during lung transplantation; TEE to assess patients for extracorporeal membrane oxygenation; TEE for thoracic aortic surgery; and TEE in the assessment of patients with acute pulmonary hypertension undergoing noncardiac thoracic surgery.

Pulmonary artery catheters for adult patients in intensive care

BACKGROUND

Since pulmonary artery balloon flotation catheterization was first introduced in 1970, by HJ Swan and W Ganz, it has been widely disseminated as a diagnostic tool without rigorous evaluation of its clinical utility and effectiveness in critically ill patients. A pulmonary artery catheter (PAC) is inserted through a central venous access into the right side of the heart and floated into the pulmonary artery. PAC is used to measure stroke volume, cardiac output, mixed venous oxygen saturation and intracardiac pressures with a variety of additional calculated variables to guide diagnosis and treatment. Complications of the procedure are mainly related to line insertion. Relatively uncommon complications include cardiac arrhythmias, pulmonary haemorrhage and infarct, and associated mortality from balloon tip rupture.

OBJECTIVES

To provide an up-to-date assessment of the effectiveness of a PAC on mortality, length of stay (LOS) in intensive care unit (ICU) and hospital and cost of care in adult intensive care patients.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 12); MEDLINE (1954 to January 2012); EMBASE (1980 to January 2012); CINAHL (1982 to January 2012), and reference lists of articles. We contacted researchers in the field. We did a grey literature search for articles published until January 2012.

SELECTION CRITERIA

We included all randomized controlled trials conducted in adults ICUs, comparing management with and without a PAC.

DATA COLLECTION AND ANALYSIS

We screened the titles and abstracts and then the full text reports identified from our electronic search. Two authors (SR and MG) independently reviewed the titles, abstracts and then the full text reports for inclusion. We determined the final list of included studies by discussion among the group members (SR, ND, MG, AK and SC) with consensus agreement. We included all the studies that were in the original review. We assessed seven domains of potential risk of bias for the included studies. We examined the clinical, methodological and statistical heterogeneity and used random-effects model for meta-analysis. We calculated risk ratio for mortality across studies and mean days for LOS.

MAIN RESULTS

We included 13 studies (5686 patients). We judged blinding of participants and personnel and blinding of outcome assessment to be at high risk in about 50% of the included studies and at low risk in 25% to 30% of the studies. Regardless of the high risk of performance bias these studies were included based on the low weight the studies had in the meta-analysis. We rated 75% of the studies as low risk for selection, attrition and reporting bias. All 13 studies reported some type of hospital mortality (28-day, 30-day, 60-day or ICU mortality). We considered studies of high-risk surgery patients (eight studies) and general intensive care patients (five studies) separately as subgroups for meta-analysis. The pooled risk ratio (RR) for mortality for the studies of general intensive care patients was 1.02 (95% confidence interval (CI) 0.96 to 1.09) and for the studies of high-risk surgery patients the RR was 0.98 (95% CI 0.74 to 1.29). Of the eight studies of high-risk surgery patients, five evaluated the effectiveness of pre-operative optimization but there was no difference in mortality when these studies were examined separately. PAC did not affect general ICU LOS (reported by four studies) or hospital LOS (reported by nine studies). Four studies, conducted in the United States (US), reported costs based on hospital charges billed, which on average were higher in the PAC groups. Two of these studies qualified for analysis and did not show a statistically significant hospital cost difference (mean difference USD 900, 95% CI -2620 to 4420, P = 0.62).

AUTHORS' CONCLUSIONS

PAC is a diagnostic and haemodynamic monitoring tool but not a therapeutic intervention. Our review concluded that use of a PAC did not alter the mortality, general ICU or hospital LOS, or cost for adult patients in intensive care. The quality of evidence was high for mortality and LOS but low for cost analysis. Efficacy studies are needed to determine if there are optimal PAC-guided management protocols, which when applied to specific patient groups in ICUs could result in benefits such as shock reversal, improved organ function and less vasopressor use. Newer, less-invasive haemodynamic monitoring tools need to be validated against PAC prior to clinical use in critically ill patients.

The damage control sequence in the elderly: Strategy, complexities, and outcomes

Traditional management in cases of exsanguinating abdominal trauma led to poor outcomes in critically injured patients. Because prolonged operations were not well tolerated due to the severe physiologic derangements, an abbreviated laparotomy began to be used. Patients were then resuscitated in the intensive care unit and brought back to the operating room once their physiology had been normalised. This approach has been termed the damage control sequence. Elderly trauma patients are susceptible to significant injury that may mandate a damage control sequence. For myriad reasons, including pre-existing medical conditions, decreased physiologic reserve, and the emergent nature of their injuries, the application of this management approach in the elderly is fraught with challenges. The purpose of this review is to enumerate the damage control sequence, describe the complexities of its use in the elderly, and discuss associated outcomes in this challenging patient population.

Perioperative haemodynamic therapy

PURPOSE OF REVIEW

To discuss the perioperative monitoring tools and targets for haemodynamic optimization and to assess the influence of goal-directed therapy (GDT) on organ function, complications and outcome in different categories of surgical patients.

RECENT FINDINGS

The choice of perioperative haemodynamic monitoring for GDT depends on the surgery-related and the patient-related risk. Conventional monitoring and minimally invasive approaches can be used for perioperative optimization of low-risk to moderate-risk patients. Thermodilution methods and continuous cardiac output/oxygen transport monitoring are the most reliable techniques for major surgery and high-risk/unstable patients. An important goal of perioperative haemodynamic therapy is to maintain cardiac function and organ perfusion, optimizing the balance between oxygen delivery and consumption. Several studies, using different monitoring tools and end-points, have shown that GDT provides optimal haemodynamic performance, improves organ function, reduces the number of complications and time to ICU and hospital discharge and decreases the mortality rate in high-risk surgical patients.

SUMMARY

GDT provides a number of benefits in major surgery. Based on adequate monitoring, the goal-directed algorithms facilitate early detection of pathophysiological changes and influence the perioperative haemodynamic therapy that can improve the clinical outcome. The perioperative GDT should be early, adequate and individualized for every patient.

Cardiopulmonary effects of matching positive end-expiratory pressure to abdominal pressure in concomitant abdominal hypertension and acute lung injury

BACKGROUND

To evaluate the cardiopulmonary effects of positive end-expiratory pressure (PEEP) equalization to intra-abdominal pressure (IAP) in an experimental model of intra-abdominal hypertension (IAH) and acute lung injury (ALI).

METHODS

Eight anesthetized pigs were submitted to IAH of 20 mm Hg with a carbon dioxide insufflator for 30 minutes and then submitted to lung lavage with saline and Tween (2.5%). Pressure x volume curves of the respiratory system were performed by a low flow method during IAH and ALI, and PEEP was subsequently adjusted to 27 cm . H2O for 30 minutes.

RESULTS

IAH decreases pulmonary and respiratory system static compliances and increases airway resistance, alveolar-arterial oxygen gradient, and respiratory dead space. The presence of concomitant ALI exacerbates these findings. PEEP identical to AP moderately improved oxygenation and respiratory mechanics; however, an important decline in stroke index and right ventricle ejection fraction was observed.

CONCLUSIONS

Simultaneous IAH and ALI produce important impairments in the respiratory physiology. PEEP equalization to AP may improve the respiratory performance, nevertheless with a secondary hemodynamic derangement.

Use of echocardiography and modalities of patient monitoring of trauma patients

PURPOSE OF REVIEW

Trauma patients require evaluation of the anatomic structure as well as the hemodynamic profile of the heart to improve effectiveness of resuscitation. They are prone to hemodynamic instability and must be monitored with various modalities to detect deterioration early. Newer, less invasive ultrasound technologies are replacing familiar 'gold standard' modalities of the past. This article reviews the indications, roles, imaging approaches, and limitations of modern echocardiography. A brief review of other ICU monitoring modalities is also presented.

RECENT FINDINGS

Echocardiography has emerged as a first-line diagnostic tool for assessment of trauma patients, especially those with hemodynamic compromise. It yields crucial information about structural damage as well as the hemodynamic profile and can be performed through either the transesophageal or transthoracic route. Quick and systematic use of echocardiography for diagnosis and management of critically injured patients may lead to improved outcomes.

SUMMARY

Echocardiography plays an important role in the trauma bay for diagnosis of thoracic injury and at the bedside in the ICU for evaluation of the hemodynamic profile.

History of right heart catheterization: 100 years of experimentation and methodology development

The development of right heart catheterization has provided the clinician the ability to diagnose patients with congenital and acquired right heart disease, and to monitor patients in the intensive care unit with significant cardiovascular illnesses. The development of bedside pulmonary artery catheterization has become a standard of care for the critically ill patient since its introduction into the intensive care unit almost 40 years ago. However, adoption of this procedure into the mainstream of clinical practice occurred without prior evaluation or demonstration of its clinical or cost-effectiveness. Moreover, current randomized, controlled trials provide little evidence in support of the clinical utility of pulmonary artery catheterization in the management of critically ill patients. Nevertheless, the right heart catheter is an important diagnostic tool to assist the clinician in the diagnosis of congenital heart disease and acquired right heart disease, and moreover, when catheter placement is proximal to the right auricle (atria), this catheter provides an important and safe route for administration of fluids, medications, and parenteral nutrition. The purpose of this manuscript is to review the development of right heart catheterization that led to the ability to conduct physiologic studies in cardiovascular dynamics in normal individuals and in patients with cardiovascular diseases, and to review current controversies of the extension of the right heart catheter, the pulmonary artery catheter.

The Current Role of the Pulmonary Artery Catheter in Critical Care: A Case Report and Review of the Literature

The clinical use of the pulmonary artery catheter (PAC) has changed the modern practice of intensive care medicine. However, the effect of invasive haemodynamic monitoring on patient outcome remains uncertain. We report an unusual case of malposition of a PAC in the left internal mammary vein and we discuss the role of this monitor in the intensive care setting. Overall, the literature does not suggest a positive effect of PAC use on patient outcome. It has been suggested that PAC insertion may be of little benefit unless linked to specific therapies which may alter outcome. It is essential to understand the capabilities and limitations of the PAC in order to minimise potential complications and maximise benefits.