Pulmonary Artery Catheter Measurements Research Articles

Hemodynamic Determinants of Cardiac Surgery-Associated Acute Kidney Injury.

Examine the: 1) relative role of hemodynamic determinants of acute kidney injury (AKI) obtained in the immediate postcardiac surgery setting compared with established risk factors, 2) their predictive value, and 3) extent mediation via central venous pressure (CVP) and mean arterial pressure (MAP). Retrospective observational study. The main outcome of the study was moderate to severe AKI, per kidney disease: improving global outcomes, within 14 days of surgery. U.S. academic medical center. Adult patients undergoing cardiac surgery between January 2000 and December 2019 (n = 40,426) in a single U.S.-based medical center. Pulmonary artery catheter measurements were performed at a median of 102 minutes (11, 132) following cardiopulmonary bypass discontinuation. None. The median age of the cohort was 67 years (58, 75), and 33% were female; 70% had chronic hypertension, 29% had congestive heart failure, and 3% had chronic kidney disease. In a multivariable model, which included comorbidities and traditional intraoperative risk factors, CVP (p < 0.0001), heart rate (p < 0.0001), cardiac index (p < 0.0001), and MAP (p < 0.0001), were strong predictors of AKI, and superseded factors such as surgery type and cardiopulmonary bypass duration. The cardiac index had a significant interaction with heart rate (p = 0.026); a faster heart rate had a differentiating effect on the relationship of cardiac index with AKI, where a higher heart rate heightened the risk of AKI primarily in patients with low cardiac output. There was also significant interaction observed between CVP and MAP (p = 0.009); where the combination of elevated CVP and low MAP had a synergistic effect on AKI incidence. Hemodynamic factors measured within a few hours of surgery showed a strong association with AKI. Furthermore, determinants of kidney perfusion, namely CVP and arterial pressure are interdependent; as are constituents of stroke volume, that is, cardiac output and heart rate.

Effect of prehospital high-dose glucocorticoid on hemodynamics in patients resuscitated from out-of-hospital cardiac arrest: a sub-study of the STEROHCA trial

BackgroundFollowing resuscitated out-of-hospital cardiac arrest (OHCA), inflammatory markers are significantly elevated and associated with hemodynamic instability and organ dysfunction. Vasopressor support is recommended to maintain a mean arterial pressure (MAP) above 65 mmHg. Glucocorticoids have anti-inflammatory effects and may lower the need for vasopressors. This study aimed to assess the hemodynamic effects of prehospital high-dose glucocorticoid treatment in resuscitated comatose OHCA patients.MethodsThe STEROHCA trial was a randomized, placebo-controlled, phase 2 trial comparing one prehospital injection of methylprednisolone 250 mg with placebo immediately after resuscitated OHCA. In this sub-study, we included patients who remained comatose at admission and survived until intensive care unit (ICU) admission. The primary outcome was cumulated norepinephrine use from ICU admission until 48 h reported as mcg/kg/min. Secondary outcomes included hemodynamic status characterized by MAP, heart rate, vasoactive-inotropic score (VIS), and the VIS/MAP-ratio as well as cardiac function assessed by pulmonary artery catheter measurements. Linear mixed-model analyses were performed to evaluate mean differences between treatment groups at all follow-up times.ResultsA total of 114 comatose OHCA patients were included (glucocorticoid: n = 56, placebo: n = 58) in the sub-study. There were no differences in outcomes at ICU admission. From the time of ICU admission up to 48 h post-admission, patients in the glucocorticoid group cumulated a lower norepinephrine use (mean difference − 0.04 mcg/kg/min, 95% CI − 0.07 to − 0.01, p = 0.02). Moreover, after 12–24 h post-admission, the glucocorticoid group demonstrated a higher MAP with mean differences ranging from 6 to 7 mmHg (95% CIs from 1 to 12), a lower VIS (mean differences from − 4.2 to − 3.8, 95% CIs from − 8.1 to 0.3), and a lower VIS/MAP ratio (mean differences from − 0.10 to − 0.07, 95% CIs from − 0.16 to − 0.01), while there were no major differences in heart rate (mean differences from − 4 to − 3, 95% CIs from − 11 to 3). These treatment differences between groups were also present 30–48 h post-admission but to a smaller extent and with increased statistical uncertainty. No differences were found in pulmonary artery catheter measurements between groups.ConclusionsPrehospital treatment with high-dose glucocorticoid was associated with reduced norepinephrine use in resuscitated OHCA patients.Trial registration: EudraCT number: 2020-000855-11; submitted March 30, 2020. URL: https://www.clinicaltrials.gov; Unique Identifier: NCT04624776.Graphic

Uso del catéter de arteria pulmonar en las primeras horas posoperatorias de cirugía cardiovascular de alto riesgo

IntroductionInformation on physiological phenomena in the postoperative period of cardiac surgery, pulmonary artery catheter (PAC) use, and medical behaviors derived from its measurement, is limited. ObjectiveTo describe the patterns of PAC use and therapeutic behaviors derived from it in the first postoperative hours of high-risk cardiovascular surgery. Materials and methodsRetrospective cohort study of high-risk cardiovascular surgery patients, managed with PAC in the intensive care unit of the Hospital Universitario San Ignacio in Bogotá D.C. (Colombia). The therapeutic interventions derived from the hemodynamic evaluation with this catheter were evaluated, taking into account the patterns of use and therapeutic behaviors according to the postoperative moment. ResultsForty-two patients were included. Median age 65 years, 59.5% men, 57.1% with EuroSCORE≥6. Median time of PAC use was 63 h (RIC 45–80). The number of PAC measurements per 12 h decreased from 2.16±0.53 in the first 12 h to 1.30±0.82 after 48 h (p: 0.0003). The number of behaviors taken from each measurement decreased from 1.48±0.45 to 0.71±0.51 (p: 0.0001) in the same period. There was significant reduction in number of behaviors associated with fluid, vasoactive, and vasodilator administration over time. ConclusionsOur data suggest that with the passage of hours the number of PAC measurements is decreasing, as well as the number of behaviors taken based on these measurements. These data suggest that many of the patients who maintained the pulmonary artery catheter for up to 48–72 h no longer required it. Further studies will be needed to clarify which patients benefit from pulmonary artery catheterization beyond 48 h.

The Story of the Pulmonary Artery Catheter: Five Decades in Critical Care Medicine.

The Story of the Pulmonary Artery Catheter: Five Decades in Critical Care Medicine.

Hemodynamic effects of COVID-19 vaccination in hospitalized patients awaiting heart transplantation

BackgroundThe hemodynamic effects of pre-transplant vaccination against COVID-19 among heart transplant candidates hospitalized for advanced heart failure remains unknown. MethodsA retrospective chart review was conducted at a high-volume transplant center from January through December 2021. 22 COVID-19 vaccination events occurred among patients hospitalized for decompensated heart failure while awaiting transplantation. Primary outcomes included inotrope and vasopressor dosages. Secondary outcomes included vital signs, pulmonary artery catheter measurements, diuretic dosages, and renal function. Data were extracted 24 h before through 72 h after vaccination. ResultsOne of 22 vaccination events was associated with hemodynamic changes requiring increased inotropic and vasopressor support post-vaccination. In all other cases, transient hemodynamic changes occurred without need for escalated therapy. ConclusionsCOVID-19 vaccination can be administered safely to most critically ill patients with advanced heart failure including those awaiting transplantation. All patients should be monitored closely as some may be susceptible to significant hemodynamic changes.

Inferior Vena Cava Diameter Measurement Provides Distinct and Complementary Information to Right Atrial Pressure in Acute Decompensated Heart Failure

Inferior vena cava (IVC) measurements correlate only modestly with right atrial pressure (RAP). Part of this inaccuracy is due to the high compliance of the venous system, where a large change in blood volume may result in only a small change in pressure. As such, the information provided by the IVC may be different rather than redundant. We analyzed patients in the ESCAPE (Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness) trial who had both pulmonary artery catheter and IVC measurements at baseline (n = 108). There was only a modest correlation between baseline RAP and IVC diameter (r = 0.41; P < 0.001). Hemoconcentration, defined as an increase in hemoglobin levels between admission and discharge, was correlated with decrease in IVC diameter (r = 0.35; P = 0.02) but not with a decrease in RAP (r = 0.01; P = 0.95). When patients had both IVC and RAP measurements that were below the median, survival rates were superior to the rates of those who had only 1 measurement below the median, and when both rates were above the median, patients fared the worst (P = 0.002). IVC and RAP have limited correlation with each another, and changes in intravascular volume appear to correlate better with IVC diameter rather than with RAP. Furthermore, complementary information is provided by pressure and volume assessments in acute decompensated heart failure.

Venous Congestion, Not Cardiac Index is Associated with Diuretic Resistance

Background Diuretic resistance is associated with worse outcomes in acute decompensated heart failure (ADHF). Traditional dogma has held that low cardiac index (CI) is a driver of diuretic resistance by reducing renal perfusion. Recently, accumulating evidence has shown that venous congestion has a more potent effect on cardiorenal interactions than low CI. However, venous congestion also likely identifies patients with increased volume overload and the potential for a greater diuretic response. Hypothesis Right atrial pressure (RAP) will be associated with diuretic response while CI will have little to no association. Methods We analyzed a subset of patients from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) dataset (n=190). Diuretic efficiency (DE) was defined as daily urine output (UOP) per doubling of loop diuretic dose, and compared with baseline, final (day of pulmonary artery catheter (PAC) removal) and change in PAC variables. Daily UOP was additionally examined with time-matched PAC measurements. Results DE was weakly positively correlated with baseline RAP (r=0.16, p=0.03) but negatively correlated with final RAP (r=-0.21, p=0.009) and change in RAP from baseline (r=-0.27, p=0.001). There was no correlation between DE and the remaining PAC variables, including CI. In high vs. low DE groups dichotomized by median value, the low DE group had significantly higher final RAPs (9.0, IQR 6.0-15.5 mmHg vs. 8.0, IQR 4.8-12.0 mmHg, p=0.04) and smaller reductions in RAP (-2.0 mmHg, IQR-5.0-2.0 mmHg vs. -5.0, IQR=-10.0-0.0 mmHg, p=0.03). There were no DE group differences for baseline CI (p=0.78), final CI (p=0.42), or change in CI (p=0.92). There were no significant differences in DE in subjects with CI 2.2 L/min/m2 (p=0.95). Time-matched PAC and UOP data showed a weak positive correlation between RAP and UOP adjusted for diuretic dose (r=0.13, p=0.03), but no correlation between UOP and CI (p=0.18). Conclusions We were unable to identify any association between CI and DE. Higher baseline RAP predicted better DE, but later in the hospital course higher RAP predicted worse DE, likely indicating that elevated RAP is a marker rather than a mediator of diuretic response. Overall, these results suggest that PACs provide limited value in the workup of diuretic resistance.

Marked reduction in right ventricular longitudinal contraction after cardiopulmonary bypass in patients with preserved right ventricular output

Introduction Assessment of right ventricular (RV) function is crucial since RV failure with a reduced cardiac output is associated with compromised outcome in cardiac surgery. Echocardiographic evaluation of RV function is commonly used, and a reduction in tricuspid annular plane systolic excursion (TAPSE) and tricuspid annulus tissue Doppler imaging (S’) have been observed independently of clinical signs of RV failure. This has led to uncertainty of these variables’ ability to reflect RV function in cardiac surgery [1]. The objective of this study was to describe changes in transoesophageal echocardiographic (TEE) measurements of TAPSE and S’ during coronary artery bypass graft (CABG) surgery with detailed haemodynamic monitoring using pulmonary artery catheter (PAC) assessment of RV output in patients undergoing uncomplicated CABG without RV impairment. Methods We prospectively studied 30 patients with concomitant PAC and TEE measurements at four time-points, namely after: anaesthesia induction, sternotomy, cardiopulmonary bypass (CPB) and upon arrival in the intensive care unit (ICU). Results TAPSE and S’ were significantly reduced by 43% (p Discussion TAPSE and S’ were both reduced after CPB despite maintained cardiac output. RVFAC, RVEF and RV-GLS remained stable, however, these measures were unable to detect minor changes in SV. 3D-echocardiography showed a strong correlation with SV measured by thermodilution, but with a consistent underestimation of approximately 10%. Our results suggest that 3D echocardiography is better at tracking RV output than other echocardiographic modalities, however, the clinician should be aware that 3D echocardiography underestimates SV compared to thermodilution.

Accuracy and Trending Ability of the Fourth-Generation FloTrac/EV1000 System in Patients With Severe Aortic Valve Stenosis Before and After Surgical Valve Replacement

Evaluate the accuracy and trending ability of the fourth-generation FloTrac/EV1000 (Edwards Lifesciences, Irvine, CA) system in patients with severe aortic valve stenosis by comparing FloTrac/EV1000-derived cardiac output (CCO-FT) with continuous thermodilution pulmonary artery catheter (CCO-PAC) measurements before and after surgical valve replacement. Prospective clinical study. Anesthesia for cardiac surgery, operating room, single-center university hospital. Twenty-five patients were included. After exclusion, 20 patients undergoing elective aortic valve replacement were analyzed. After induction of general anesthesia, CCO-FT and CCO-PAC values were recorded every 30 seconds before and after aortic valve replacement with a bioprosthesis under cardiopulmonary bypass (CPB). Data were analyzed separately from skin incision to last suture and before and after CPB. Regression analyses, Bland-Altman analyses, and trending analyses (4-quadrant plot, polar plot) were performed. The percentage errors of the FloTrac/EV1000 were 69.7% and 59.3% before and after CPB, respectively. The concordance rates (CRs) and angular CRs of the FloTrac/EV1000 were 50.9% and 57.1%, and 48.7% and 61.9% before and after CPB, respectively. This study revealed a low level of agreement and poor trending ability of the FloTrac/EV1000 system compared to continuous thermodilution pulmonary artery catheter in patients with severe aortic stenosis. Although there was a slight improvement after surgical valve replacement and CPB, the results were not within acceptable limits to replace CCO-PAC in this patient population.

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

36th International Symposium on Intensive Care and Emergency Medicine : Brussels, Belgium. 15-18 March 2016.

Abstract 11924: Phenotypes of Heart Failure Identified via Cluster Analysis Do Not Recapitulate Hemodynamic Profiles: Insights From the ESCAPE Trial

Background: Heart failure (HF) classification criteria do not adequately describe disease state. We used cluster analysis to identify distinct phenotypes of patients in the pulmonary artery catheter (PAC) arm of the ESCAPE trial, and examine association of clusters with hemodynamic profiles. Methods: Cluster analysis was performed on baseline clinical variables and PAC measurements in a cohort of 172 subjects from the ESCAPE trial, a randomized study examining PAC versus usual care in advanced systolic HF patients. ANOVA examined association between patient clusters and clinically determined hemodynamic profiles (warm/cold/wet/dry); association with clinical outcomes was assessed using Cox proportional hazards models. Results: Four HF clusters were identified with the following general characteristics: Cluster 1(n=75): Male Caucasians with ischemic cardiomyopathy, multiple comorbidities, lowest BNP levels; Cluster 2 (n=33): Females with non-ischemic cardiomyopathy, few comorbidities, most favorable hemodynamics; Cluster 3 (n=29): Young African American males with non-ischemic cardiomyopathy, most adverse hemodynamics and advanced disease; Cluster 4 (n=25): Older Caucasians with ischemic cardiomyopathy, concomitant renal insufficiency, and highest BNP levels. We noted no association between hemodynamic profiles and clusters (P=0.70). Cluster 4 patients had the highest risk of all adverse clinical outcomes, whereas cluster 2 had the lowest. Compared to patients in cluster 4, patients in other clusters had 45-70% lower risk of all-cause mortality. Conclusions: Using a novel approach that clusters patients according to similar clinical variables and PAC measures, we identified 4 clinically relevant phenotypes of HF patients, with no discernable relationship to hemodynamic profiles. Our analysis suggests that HF classification can be enhanced by simultaneous considerations of etiology, comorbid conditions, and biomarker levels.

Echocardiographic estimation of mean pulmonary artery pressure in critically ill patients.

BackgroundIndirect assessment of mean pulmonary arterial pressure (MPAP) may assist management of critically ill patients with pulmonary hypertension and right heart dysfunction. MPAP can be estimated as the sum of echocardiographically derived mean right ventricular to right atrial systolic pressure gradient and right atrial pressure; however, this has not been validated in critically ill patients.MethodsThis prospective validation study was conducted in patients undergoing pulmonary artery catheterisation during intensive care admission. Pulmonary artery catheter (PAC) measurements of MPAP were contemporaneously compared to MPAP estimated utilising transthoracic echocardiography (TTE)-derived mean right ventricular to right atrial systolic pressure gradient added to invasively measured right atrial pressure.ResultsOf 53 patients assessed, 23 had estimable MPAP using TTE. The mean difference between TTE- and PAC-derived MPAP was 1.9 mmHg (SD 5.0), with upper and lower limits of agreement of 11.6 and −7.9 mmHg, respectively. The median absolute percentage difference between TTE- and PAC-derived MPAP was 7.5%. Inter-rater reliability assessment was performed for 15 patients, giving an intra-class correlation coefficient of 0.96 (95% confidence intervals, 0.89 to 0.99).ConclusionsThis echocardiographic method of estimating MPAP in critically ill patients was not equivalent to invasively measured MPAP, based on our predefined clinically acceptable range (±5 mmHg). The accuracy of this method in critically ill patients was similar to the results obtained in ambulatory patients and compared favourably with regard to the accuracy with echocardiographic estimation of systolic pulmonary arterial pressure. The utility of this technique is limited by frequent inability to obtain an adequate tricuspid regurgitant time-velocity integral in critically ill patients.

A Randomized Open-Label Phase I Pilot Study of the Safety and Efficacy of Total Intravenous Anesthesia With Fospropofol for Coronary Artery Bypass Graft Surgery

To determine safety and efficacy of the water-soluble prodrug fospropofol for anesthesia in cardiac surgery and to compare the pharmacodynamic profiles of fospropofol and propofol. Pilot study and a prospective, phase I, open-label, single-center, randomized clinical trial. University hospital; single institution. Sixteen patients undergoing elective first-time coronary artery bypass surgery. Patients were randomized to receive total intravenous anesthesia with fospropofol (n = 8) or propofol (n = 8) combined with alfentanil as total intravenous anesthesia. Bispectral index, arterial blood pressure, and heart rate were recorded continuously, and pulmonary artery catheter measurements were obtained. Plasma concentrations of formate, phosphate, and Ca(2+) were monitored closely. Safety and tolerability were assessed by adverse events, neurologic examinations, clinical laboratory tests, and vital signs. The total doses of fospropofol and propofol during anesthesia were 11.3±2.5 and 4.4±1.0 mg/kg/h, respectively. According to the achieved bispectral index (BIS) values, fospropofol was as effective as propofol in providing general anesthesia and sedation. There were no clinical signs of formate toxicity in the fospropofol group. The only treatment-related adverse event after administration of fospropofol was a transient burning sensation in the perineal and perianal region during induction of sedation or anesthesia. Fospropofol could be used to provide general anesthesia in patients undergoing coronary artery bypass graft surgery. Further larger studies are needed to prove the safety of fospropofol when given to provide general anesthesia for major cardiac surgical procedures.

Uso da monitorização hemodinâmica contínua não invasiva na insuficiência cardíaca descompensada

The clinical and hemodynamic assessment at the bedside and the use of pulmonary artery catheter for the estimation of hemodynamic data have been used in decompensated heart failure. However, there are no data on the use of continuous noninvasive hemodynamic monitoring. To compare the data obtained through noninvasive hemodynamic monitoring with invasive ones in patients with decompensated heart failure and refractory to treatment. The non-invasive hemodynamic measurements were obtained through continuous monitoring of systemic blood pressure by the pulse wave model (Modelflow) and compared with measurements obtained by the passage of a pulmonary artery catheter, simultaneously. A total of 56 measurements were performed in 14 patients studied on different days and time periods. The correlation index between systolic blood pressure measurements was r = 0.26 (95% CI = 0.00 to 0.49, p = 0.0492) and diastolic ones, r = 0.50 (95% CI = 0.27 to 0.67, p <0.0001). The correlation was r = 0.55 (95% CI = 0.34 to 0.71, p <0.0001) for cardiac index and r = 0.32 (95% CI = 0.06 to 0 53, p = 0.0178) for systemic vascular resistance. There was a correlation between the hemodynamic measurements when compared to noninvasive pulmonary artery catheter measurements. The continuous noninvasive hemodynamic monitoring may be useful for hospitalized patients with decompensated heart failure.

Comparison of hemodynamic measurements from invasive and noninvasive monitoring during early resuscitation

Measurements obtained from the insertion of a pulmonary artery catheter (PAC) in critically ill and/or injured patients have traditionally assisted with resuscitation efforts. However, with the recent utilization of ultrasound in the intensive care unit setting, transthoracic echocardiography (TTE) has gained popularity. The purpose of this study is to compare serial PAC and TTE measurements and document levels of serum biomarkers during resuscitation. Over a 25-month period, critically ill and/or injured patients admitted to a Level I adult trauma center were enrolled in this 48-hour intensive care unit study. Serial PAC and TTE measurements were obtained every 12 hours (total = 5 points/patient). Serial levels of lactate, Δ base, troponin-1, and B-type natriuretic peptide were obtained. Pearson correlation coefficient and intraclass correlation (ICC) assessed relationship and agreement, respectively, between PAC and TTE measures of cardiac output (CO) and stroke volume (SV). Analysis of variance with post hoc pairwise determined differences over time. Of the 29 patients, 69% were male, with a mean age of 47.4 years ± 19.5 years and 79.3% survival. Of these, 25 of 29 were trauma with a mean Injury Severity Score of 23.5 ± 10.7. CO from PAC and TTE was significantly related (Pearson correlations, 0.57-0.64) and agreed with moderate strength (ICC, 0.66-0.70). SV from PAC and TTE was significantly related (Pearson correlations, 0.40-0.58) and agreed at a weaker level (ICC, 0.41-0.62). Tricuspid regurgitation was noted in 80% and mitral regurgitation in 50% to 60% of patients. Measurements of CO and SV were moderately strong in correlation and agreement which may suggest PAC measurements overestimate actual values. The significance of tricuspid regurgitation and mitral regurgitation during early resuscitation is unknown.

Agreement between cardiac outputs by four-dimensional echocardiography and thermodilution method is poor

The objective of the study was to determine the agreement of cardiac output (CO) measured by four-dimensional echocardiography (4D echo) to simultaneously obtain CO from pulmonary artery catheter (PAC) using thermodilution technique. Sixty-three comparable readings from 27 patients scheduled for elective coronary artery bypass were included. All echocardiographic measurements were obtained by one experienced echocardiographer. All echo images were analyzed independently and blinded from PAC-obtained measurements. Analysis was primarily done by Bland and Altman plot. The collected data were further controlled for interobserver bias and image quality. Differences in CO measurements increased with higher CO, hence values were logarithmically transformed. On the logaritmic scale, the 4D echo underestimated CO by 0.37 l/min compared with PAC, indicating that PAC measurements were 1.45 times higher than the 4D echo (95% confidence interval 1.32-1.52) and limits of agreement 0.97-2.14). The interobserver bias of 4D echo measurement analysis was 0.29 l/min (95% confidence interval 0.16-0.42) and limits of agreement -0.8-1.38). No difference was seen in image quality between comparisons with good agreement compared with comparisons with poor agreement. The agreement between COs by 4D echo and standard PAC thermodilution technique was poor. 4D echo underestimates CO as compared with PAC. This is most likely caused by the analysis software or low frame rate inherent to the technique.

Pulmonary Artery Catheter (PAC) Accuracy and Efficacy Compared with Flow Probe and Transcutaneous Doppler (USCOM): An Ovine Cardiac Output Validation

Background. The pulmonary artery catheter (PAC) is an accepted clinical method of measuring cardiac output (CO) despite no prior validation. The ultrasonic cardiac output monitor (USCOM) is a noninvasive alternative to PAC using Doppler ultrasound (CW). We compared PAC and USCOM CO measurements against a gold standard, the aortic flow probe (FP), in sheep at varying outputs. Methods. Ten conscious sheep, with implanted FPs, had measurements of CO by FP, USCOM, and PAC, at rest and during intervention with inotropes and vasopressors. Results. CO measurements by FP, PAC, and USCOM were 4.0 ± 1.2 L/min, 4.8 ± 1.5 L/min, and 4.0 ± 1.4 L/min, respectively, (n = 280, range 1.9 L/min to 11.7 L/min). Percentage bias and precision between FP and PAC, and FP and USCOM was −17 and 47%, and 1 and 36%, respectively. PAC under-measured Dobutamine-induced CO changes by 20% (relative 66%) compared with FP, while USCOM measures varied from FP by 3% (relative 10%). PAC reliably detected −30% but not +40% CO changes, as measured by receiver operating characteristic area under the curve (AUC), while USCOM reliably detected ±5% changes in CO (AUC > 0.70). Conclusions. PAC demonstrated poor accuracy and sensitivity as a measure of CO. USCOM provided equivalent measurements to FP across a sixfold range of outputs, reliably detecting ±5% changes.

HeartSmart&reg; for routine optimization of blood flow and facilitation of early goal-directed therapy

HeartSmart&reg; for routine optimization of blood flow and facilitation of early goal-directed therapy Kenneth Warring-Davies1, Martin Bland21The Intensive Care Unit, Bradford Royal Infirmary, Bradford, West Yorkshire, UK; 2Department of Health Sciences, University of York, York, North Yorkshire, UKAbstract: The empirical physiological formulae of the new continuous cardiac dynamic &shy;monitoring HeartSmart&reg; technology, which involves the use of a new inverse square rule of the heart, were investigated with pulmonary artery catheter (PAC) thermodilution in the &shy;estimation of CI in diverse patients. Clinical trial data collected from 268 adult surgery or intensive care patients requiring PAC placement were obtained from 7 NHS Trust hospitals, providing 2720 paired sets of CI estimations for comparison between HeartSmart&reg; and PAC thermodilution. For 95% of pairs of measurements, HeartSmart&reg; values were between 57% and 164% of PAC measurements; additionally, the larger limit of agreement between HeartSmart&reg; and PAC thermodilution (1.26 L min-1&bull;m-2) suggests that HeartSmart&reg; agrees with PAC thermodilution as closely as PAC thermodilution agrees with itself. HeartSmart&reg; can also estimate CI in the extreme circumstances of shock/sepsis, as indicated by PAC thermodilution CI values that were hypo- or hyperdynamic based on systemic inflammatory response syndrome criteria. In CI measurements for hypo- or hyperdynamic values that were matched between HeartSmart&reg; and PAC thermodilution, the difference in total volumes and average CI measurements between the two methods was less than 5%. For unmatched hypo- or hyperdynamic values, the difference between total volumes and average CI measurements was less than 33% &ndash; an acceptable percentage of difference or error even for normal values of CI. HeartSmart&reg; tracked PAC thermodilution CI hypodynamic values 98.2% of the time and hyperdynamic values 97.6% of the time. These findings show that CI estimations provided by the HeartSmart&reg; empirical physiological formulae are comparable to those obtained using PAC thermodilution. HeartSmart&reg; removes many of the technical barriers that prevent the routine adoption and practice of early goal-directed therapy, and represents a simple, reliable method of estimating CI and other hemodynamic variables at the bedside or in departments other than the Intensive Care Unit.Keywords: cardiac index, early goal-directed therapy, HeartSmart&reg;, cardiodynamics, blood flow

Simultaneous Pulmonary Artery Catheter and Pulse Contour Measurements in a Patient With an LVAD

Although pulmonary artery catheters are highly effective for hemodynamic profiling, they are indwelling invasive devices with inherent risks and are recommended only in a select group of critically ill patients. The Flotrac sensor is a new device that measures continuous cardiac output (CO) via a peripheral arterial line. This article reports the first case of simultaneous measurement of CO from pulse contour analysis using a continuous CO monitor (Flotrac), the thermodilution method from a pulmonary artery catheter, and a surgically implanted left ventricular assist device (LVAD; HeartMate XVE). Six data points were obtained from each modality over 15 hours. Mean COs for the LVAD, pulmonary artery catheter, and sensor were 6.9 ± 0.4 L/min (range, 6.2-7.5 L/min), 7.8 ± 1.1 L/min (range, 5.9-8.8 L/min), and 7.2 ± 0.7 L/min (range, 6.3-8.2 L/min), respectively. There was some agreement between the 3 devices used to measure CO as assessed by Bland-Altman analysis, but the small sample size limited statistical significance. The sensor system is an intriguing semi-invasive method to monitor CO via arterial flow in a patient with LVAD, but more rigorous diagnostic studies are needed to evaluate the validity of pulse contour devices prior to widespread use in this critically ill population.

Noninvasive Doppler ultrasonography for assessing cardiac function: can it replace the Swan-Ganz catheter?

Background Cardiac function, including cardiac index (CI), traditionally has been measured by a pulmonary artery catheter (PAC). A noninvasive alternative for measuring cardiac function would offer obvious advantages. Methods A prospective study of trauma and nontrauma patients was performed in a surgical intensive care unit over a 3-month period. CI was determined using both a standard PAC and a continuous-wave Doppler ultrasound (UTS). The study had 2 phases: phase I was nonblinded and phase II was blinded; the correlation between UTS- and PAC-derived CI was assessed. Results A total of 120 paired measurements of CI were observed in 31 patients. The UTS-derived CI measurements showed agreement with PAC measurements in both phase I and phase II of the study with a bias of .06 L/min/m 2 ± .4 L/min/m 2. Paired measurements correlated well in both phase I ( r = .97, R2 = .95, P < .0001) and phase II ( r = .93, R2 = .86, P < .0001) of the study. Conclusions Doppler UTS correlates well with PAC measurements of CI. This noninvasive modality is an accurate and safe alternative to PAC.