Cardiac Index Values Research Articles

Calciotropic and Phosphaturic Hormones in End-Stage Heart Failure Patients Supported by a Left-Ventricular Assist Device.

BackgroundCalcium and phosphate are central for myocardial contractility and energy metabolism, and low levels of the calciotropic hormone 1,25-dihydroxyvitamin D (1,25(OH)2D), as well as high levels of the phosphaturic hormone fibroblast growth factor (FGF)-23, are independently associated with poor clinical outcome in heart failure (HF) patients. We therefore aimed to investigate the postoperative time course of the aforementioned hormones in HF patients supported with a left-ventricular assist device (LVAD) implant.MethodsFor the present study, stored biobank plasma samples of 69 patients, collected before LVAD implantation (t0) and 12 days (t1), 30 days (t2), 83 days (t3), and 300 days (t4) post-intervention, were used to measure circulating FGF-23, parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), 1,25(OH)2D, and kidney function.ResultsMost patients were male and had baseline INTERMACS levels and cardiac index values ≤ 3 and ≤ 2.7 L/min/m2, respectively. There were significant time effects on estimated glomerular filtration rate (eGFR), FGF-23 and 1,25(OH)2D, but not on PTH or 25OHD. Notably, eGFR values increased and FGF-23 levels decreased only transiently, whereas 1,25(OH)2D increased continuously until t4. The rise in 1,25(OH)2D was largely influenced by those patients who survived the first post-implant year, and was not seen in non-survivors. Variations in 1,25(OH)2D levels could only partly be explained by eGFR values or FGF-23, 25OHD, and PTH levels (multiple R2 = 0.305;P<0.001).ConclusionsThe present study indicates that LVAD implantation has only transient effects on circulating FGF-23 levels, but is associated with a continuous increase in circulating 1,25(OH)2D levels, especially in survivors.

Cardiac index by thermodilution or transthoracic echocardiography in dogs at different hemodynamic states

ABSTRACT: Proper monitoring of cardiac index (CI) in critically ill patients requires accurate and minimally invasive methods. The aim of this study was to compare the CI values obtained by thermodilution or echocardiography using different methods in dogs in different hemodynamic states. Nine dogs weighing 19.6±1.3kg were anesthetized with isoflurane at 1.4V% (Baseline) and subjected to mechanical ventilation (MV),a hypodynamic state (Hypo) with isoflurane at 3.5V% and hyperdynamic state (hyper) with dobutamine infusion at 5μgkg-1min-1. CI analysis was performed by thermodilution (TD) and using the modified Simpson's method, aortic velocity-time integral (A-VTI) method and pulmonary VTI (P-VTI) method. We performed Pearson's correlation and Bland-Altman analysis. The CI values (Lm-2min-1) of the animals in the Baseline, MV, Hypo and Hyper states were 4.3±1, 3.6±0.7, 2.9±0.66 and 6.1±2, for TD; 2.8±0.7, 2.4±0.3, 1.7±0.7 and 4.4±1.2, for Simpson's method; 3.4±0.9, 3.1±0.7, 2.6±3.4, 6.1±1.8 for A-VTI; and 3.6±0.8, 3.6±0.8, 2.7±0.6 and 6.2±1.5, for P-VTI. The CI values using Simpson's method were lower than those obtained by TD in all states, and it was observed a significant correlation in the Hypo (r=0.89) and Hyper (r=0.76) groups. In addition,the percent error in the Hypo group using Simpson's method was 26% relative to TD, which allowed for the identification of the different hemodynamic states. With respect to the other methods and states, there was no agreement or correlation between the methods and TD. We concluded that none of the tested echocardiography methods exhibited acceptable agreement with thermodilution at different hemodynamic states.

D2. Screening of preeclampsia (PE) in the first trimester: high total vascular resistance (TVR) with a reduced fat mass increase the risk in normo BMI patients

Introduction: Abnormalities of cardiac output, TVR and water body distribution are connected with PE and foetal growth restriction (FGR).Targets: To identify patients at risk of PE in the first trimester through USCOM system, bioimpedance and combined screening (maternal history, biophysical and biochemical markers). We enrolled 150 healthy nulliparous women with normal BMI.Results: The patients were divided into two groups: Group A (TVR <1200 dynes sec cm−5), Group B (TVR41200 dynes sec cm−5). Lower values of the Cardiac Output (CO), Cardiac index (CI), Inotropy index (INO), Heart rate (HR) and higher values of Flow Time correct (TFC) have been highlighted in the group B (p < 0.01) compared to group A. 8% of study population developed PE or PE + FGR. In this group 75% of the patients presented high TVR values and 50% is at high risk on the basis of combined screening. We found lower Fat Mass in complicated pregnancies with high TVR values compared to uncomplicated pregnancies with high TVR (Table 1).Conclusions: High TVR and lower Fat Mass in the first trimester may be an early marker of PE more than the combined screening. Moreover, lower fat mass increases the positive predictive value of isolated high TVR from 18% to 50% (Figure 1).Figure 1. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) of high Total Vascular Resistence (TVR), Combined first trimester screening (maternal history + mean artery pressure + pulsatility index of uterine artery Doppler + PAPP-A + PlGF) and high TVR + Fat Mass <20%.

Cardiac index assessment by the pressure recording analytical method in infants after paediatric cardiac surgery: a pilot retrospective study.

Our aim was to verify whether the cardiac index (CI) estimated by the pressure recoding analytical method (PRAM) was associated with clinical metabolic indexes of tissue perfusion and mechanical ventilation duration in paediatric patients undergoing cardiac surgery on cardiopulmonary bypass (CPB) for congenital heart disease and whether it could therefore be considered a clinically reliable monitoring method. A retrospective study was conducted in a paediatric cardiac intensive care unit (PCICU), applying PRAM, a minimally invasive advanced haemodynamic monitoring system (MostCare®, Vygon, Vytech), for the first 24 postoperative hours. Haemodynamic and clinical average values were analysed as time-weighted average values at four postoperative time points (during the first 2 h from PCICU admission, from the 3rd to the 6th, from the 7th to the 12th and from the 13th to the 24th postoperative hours) and correlated with respective variables recorded and averaged at the same time points. Forty consecutive patients were enrolled. Median (interquartile range) age, CPB time and Aristotle score were 85 (47-200) days, 157 (112-185) minutes and 8.9 (7.5-10), respectively. CI values at the four time points were 2.89 (2.67-3.19), 2.94 (2.60-3.17), 2.84 (2.64-3.26) and 2.93 (2.58-3.46) l/min/m2, respectively. CI values correlated with lactate levels (r: -0.2; P = 0.01), systolic pressure (r: 0.34, P = 0.0001), heart rate (r: -0.4; P = 0.0001), vasoactive inotropic score (r: -0.3; P = 0.0001) and diuretic dose (r: -0.2; P = 0.01). In patients with low cardiac output syndrome (diagnosed according to clinical metabolic indexes), CI values estimated by PRAM were significantly lower than those of patients without signs of low cardiac output syndrome (P = 0.0001): 3.0 vs 2.8 (95% CI of difference -0.05 to 0.67), 3.1 vs 2.7 (95% CI of difference 0.13-0.85), 3.2 vs 2.7 (95% CI of difference 0.11-0.83) and 3.2 vs 2.7 (95% CI of difference 0.08-0.81) l/min/m2, respectively. Patients with a CI equal to or above 3 l/min/m2, compared with others, showed a significantly lower increase in creatinine levels from PCICU arrival to postoperative day 1: 0.07 (-0.1 to 0.2) vs 0.21 (0.05-0.3) mg/dl (P = 0.0016). Prediction of mechanical ventilation duration was independently associated only with CI (b: -3.4; r: -0.39; P = 0.04) in a multivariable model after adjustment for Aristotle score, vasoactive inotrope score, cross-clamp time, creatinine levels at PCICU admission and patient's age. CI estimated by PRAM after paediatric cardiac surgery was reliably associated with clinical indicators of tissue perfusion, with vasoactive and diuretic drug requirements, and predicted longer mechanical ventilation duration.

Methylene blue compared to norepinephrine in the management of vasoplegic syndrome in pediatric patients after cardiopulmonary bypass: a randomized controlled study

Background and aimVasoplegic syndrome (VS) is a frequent complication following cardiopulmonary bypass (CPB) requiring escalating dose of vasopressor support. The guanylate cyclase inhibitor methylene blue (MB) could be an attractive alternative treatment in such cases. This study examines the efficacy and safety of using MB compared to the commonly used norepinephrine in VS in pediatric population following CPB.MethodsForty patients of pediatric age group who developed VS following CPB for elective corrective cardiac surgeries received 0.5 μg/kg/min norepinephrine intravenous infusion for 5 min without improvement (Time 1). Patients were randomly assigned to two equal groups. Group MB received 1.5 mg/kg methylene blue by intravenous infusion over 20 min. Group N did not receive MB. Norepinephrine infusion was continued in both groups and titrated according to the response of patients with a maximum dose of 2 μg/kg/min (Time 2). Heart rate, mean arterial pressure (MAP), central venous pressure (CVP), cardiac output (CO), cardiac index (CI), mean pulmonary artery pressure (MPAP), systemic vascular resistance (SVR) and systemic vascular resistance index (SVRI) were calculated in both groups. Side effects related to the study drug were recorded.ResultsTime 2 values of norepinephrine dose were significantly lower in MB group compared to N group. Time 2 values of MAP were significantly higher in MB group compared to N group with a significant decrease in HR in MB group compared to N group. No change in the rhythm was detected in the two groups. Time 2 values of CVP were higher in MB group compared to N group. Time 2 values of CO and CI were significantly lower in MB group compared to N group and SVR and SVRI were significantly higher in MB group compared to N group. Time 2 values of MPAP were comparable in both groups and showed no significant change. No side effects from using MB were recorded as pulmonary edema and respiratory distress.ConclusionIn this study, MB showed superior efficacy and safety in managing VS in pediatrics following CPB compared to the conventionally used norepinephrine.

Prevalence of Coronary Artery to Pulmonary Artery Collaterals in Patients with Chronic Thromboembolic Pulmonary Hypertension: Retrospective Analysis from a Single Center.

Our aim was to determine the prevalence of coronary artery - pulmonary artery collaterals in patients with chronic thromboembolic pulmonary hypertension (CTEPH) by retrospectively evaluating coronary angiograms of eligible consecutive patients who had undergone pulmonary endarterectomy (PEA). We also aimed to evaluate predictors and potential clinical associates of these collaterals. Coronary angiograms of 83 consecutive CTEPH patients who had undergone coronary angiography before PEA operation between January 1, 2012 and June 1, 2015 were retrospectively evaluated for presence of coronary artery - pulmonary artery collaterals. Medical records of all patients were also retrospectively reviewed for demographic information, cardiovascular risk factors, preoperative right heart catheterization reports, operation reports, and follow-up data. Data of CTEPH patients with coronary artery - pulmonary artery collaterals were compared with data of CTEPH patients without such collaterals. There were 15 patients (18.1%) with definite and 4 patients (4.8%) with probable coronary artery - pulmonary artery collaterals among the study population. CTEPH patients with collaterals had higher preoperative pulmonary artery pressures, higher pulmonary vascular resistance (PVR) and lower cardiac index values compared with CTEPH patients without collaterals. However, CTEPH patients with collaterals displayed higher amount of reduction in PVR after PEA compared with patients without collaterals. There were no significant differences between groups regarding incidence of reperfusion injury or mortality. Prevalence of coronary artery - pulmonary artery collaterals seems to be increased in our CTEPH patients compared with the general population. The presence of coronary artery - pulmonary artery collaterals is often combined with proximal disease with the possibility of increased reduction of PVR after PEA operation.

Diagnostic value of non-invasive cardiac output parameters in premature infants with patent ductus arteriosus

Objective To investigate the diagnostic value of non-invasive cardiac output parameters: cardiac index (CI) and minute distance (MD), in premature infants with patent ductus arteriosus (PDA) and determine the cut-off value. Methods Clinical data of 98 premature infants admitted to the neonatal intensive care unit from January 2015 to June 2015 were collected. These premature infants were divided into the treated PDA group (n=30), the untreated PDA group (n=28) and the normal premature group (n=40) based on the results of echocardiogram in the first three days after birth and the use of drugs. Non-invasive cardiac output parameters were measured in the first three days after birth. The data were analyzed by t test, analysis of variance and SNK-q test. The diagnostic value of CI and MD for PDA was analyzed by the receiver operating characteristic curve. Results By preliminary analysis of the ROC curve, CI and MD were the most representative parameters for the diagnosis of PDA which need to be treated clinically, we thus chose CI and MD in this study. The aortic and pulmonary arterial CI and MD in the treated PDA group were significantly higher than in the untreated PDA group and the normal premature group (all P 0.05). The cut-off value of the aortic CI and MD was 2.95 L/(min·m2) and 21.50 m/min, respectively, while that of the pulmonary arterial CI and MD was 4.55 L/(min·m2) and 26.50 m/min, respectively. The sensitivity and specificity of the combined aortic CI and MD for the treated PDA group were 0.90 and 0.82, and those of combined pulmonary arterial CI and MD were 0.87 and 0.82; and those of combined aortic and pulmonary arterial CI and MD were 0.80 and 0.88, respectively. Conclusions The non-invasive cardiac output parameters CI and MD have good diagnostic value for the PDA needing clinical treatment, and the combined use of the two parameters can improve specificity, and help formulate the early treatment strategy for premature infants with PDA. When aortic CI was ≥2.95 L/(min·m2) and MD was ≥ 21.50 m/min, a preliminary diagnosis of the PDA needing clinical treatment, can be made, and simultaneously when the pulmonary arterial CI was ≥ 4.55 L/(min·m2) and MD was ≥ 26.50 m/min, the arterial duct should be closed timely. Key words: hemodynamics; premature infants; PDA; non-invasive cardiac output parameters

Cardiac sympathetic index identifies patients with Parkinson's disease and REM behavior disorder

ObjectiveTo compare circadian autonomic fluctuations in patients with Parkinson's Disease (PD) with or without REM sleep behavior disorder (RBD) by using heart rate variability (HRV) analysis. MethodsThis is a case-control study including 20 PD patients with RBD (PD-RBD) and 20 PD patients without RBD (PD). In all patients, we measured the components of HRV in the frequency domain during 24-h with daytime and night time recordings. Selected variables considered were low-frequency (LF) influenced by the sympathetic system and high-frequency (HF) influenced by the parasympathetic system. Moreover, we calculated night-to-day ratio for both LF (cardiac sympathetic index) and HF (cardiac parasympathetic index) spectral components. Video-polysomnography was performed in all patients to diagnose RBD. ResultsBoth nocturnal LF and HF spectral power values were significantly higher in PD-RBD patients than in PD patients (P < 0.001 and P = 0.004 respectively). Moreover, in PD-RBD patients LF and HF values were higher at night than during the day while no difference between night time and daytime values was observed in patients with PD. Cardiac sympathetic index value was significantly higher in PD-RBD patients (median 1.83, range 1.65–3.66) than in PD patients (median 0.93, range 0.44–1.3) without overlap of individual values between groups (accuracy 100%). By contrast, cardiac parasympathetic index had sensitivity of 45% and specificity of 100% for differentiating between PD groups. ConclusionsCardiac sympathetic index distinguishes PD-RBD patients from those with PD on an individual basis, thus representing a valid help in everyday clinical practice for screening of RBD in PD patients.

Comparing maximum autonomic activity of psychogenic non-epileptic seizures and epileptic seizures using heart rate variability

PurposeThe semiology of psychogenic non-epileptic seizures (PNES) can resemble epileptic seizures, and differentiation between epileptic seizures with no EEG-correlate and PNES can be challenging even for trained experts. Therefore, there has been a search for a quantitative measure, other than EEG and semiology that could distinguish PNES from epileptic seizures. We used ECG to measure heart rate variability (HRV) in order to compare maximum autonomic activity of epileptic seizures and PNES. These comparisons could potentially serve as biomarkers for distinguishing these types of clinical episodes. MethodForty-nine epileptic seizures from 17 patients and 24 PNES from 7 patients with analyzable ECG were recorded during long-term video-EEG monitoring. Moving windows of 100 R–R intervals throughout each seizure were used to find maximum values of Cardiac Sympathetic Index (CSI) (sympathetic tonus) and minimum values of Cardiac Vagal Index (CVI), Root-Mean-Square-of-Successive-Differences (RMSSD) and HF-power (parasympathetic tonus). In addition, non-seizure recordings of each patient were used to compare HRV-parameters between the groups. ResultsThe maximum CSI for epilepsy seizures were higher than PNES (P=0.015). The minimum CVI, minimum RMSSD and HF-power did not show significant difference between epileptic seizures and PNES (P=0.762; P=0.152; P=0.818). There were no statistical difference of non-seizure HRV-parameters between the PNES and epilepsy patients. ConclusionWe found the maximum sympathetic activity accompanying the epileptic seizures to be higher, than that during the PNES. However, the great variation of autonomic response within both groups makes it difficult to use these HRV-measures as a sole measurement in distinguishing epileptic seizures from PNES.

Exhaled CO2 Parameters as a Tool to Assess Ventilation-Perfusion Mismatching during Neonatal Resuscitation in a Swine Model of Neonatal Asphyxia.

BackgroundEnd-tidal CO2 (ETCO2), partial pressure of exhaled CO2 (PECO2), and volume of expired CO2 (VCO2) can be continuously monitored non-invasively to reflect pulmonary ventilation and perfusion status. Although ETCO2 ≥14mmHg has been shown to be associated with return of an adequate heart rate in neonatal resuscitation and quantifying the PECO2 has the potential to serve as an indicator of resuscitation quality, there is little information regarding capnometric measurement of PECO2 and ETCO2 in detecting return of spontaneous circulation (ROSC) and survivability in asphyxiated neonates receiving cardiopulmonary resuscitation (CPR).MethodsSeventeen newborn piglets were anesthetized, intubated, instrumented, and exposed to 45-minute normocapnic hypoxia followed by apnea to induce asphyxia. Protocolized resuscitation was initiated when heart rate decreased to 25% of baseline. Respiratory and hemodynamic parameters including ETCO2, PECO2, VCO2, heart rate, cardiac output, and carotid artery flow were continuously measured and analyzed.ResultsThere were no differences in respiratory and hemodynamic parameters between surviving and non-surviving piglets prior to CPR. Surviving piglets had significantly higher ETCO2, PECO2, VCO2, cardiac index, and carotid artery flow values during CPR compared to non-surviving piglets.ConclusionSurviving piglets had significantly better respiratory and hemodynamic parameters during resuscitation compared to non-surviving piglets. In addition to optimizing resuscitation efforts, capnometry can assist by predicting outcomes of newborns requiring chest compressions.

Hemodynamic Consequences of Two Different Surgical and Anesthetic Techniques for the Treatment of Aortic Valve Stenosis - A Randomized Comparison

There are two substantially different methods of doing aortic valve replacement in elderly patients with severe aortic valve stenosis: The trans-apical aortic valve replacement (TAVI) and the standard surgical aortic valve replacement (SAVR). The impact of surgery as well as anesthesia has great influence on perioperative hemodynamics. We compared the perioperative hemodynamic variables in comparable groups of patients going through either of these procedures. Methods: The present study is a subset of the STACATO trial, which was a multicenter trial with the objective of comparing the two treatment methods in patients with significant valvular aortic stenosis who were eligible for either procedure. This study analyses hemodynamic data as well as arterial blood gases and s-creatinine from the 58 randomized patients in our institution. Results: Patients in the SAVR group had lower values of cardiac index (CI) and stroke volume index (SVI) than the TAVI group at all times (p<0.001). At the end of surgery the SAVR group had a higher pO2 (p<0.0001), a higher s-lactate (p=0,003) and a lower hematocrit (p=0,045) than the TAVI group and in the postoperative period the pH was closer to normal in the TAVI group. The perioperative fluid balance was higher in the SAVR group (p<0.0001). A more pronounced increase in s-creatinine (p=0.034) was seen in the TAVI group. There were no differences in the perioperative use of inotropes, vasoconstrictors or vasodilators. Conclusions: The main finding in the present study was that the surgical and anesthesiological management of TAVI resulted in more stable hemodynamics both per- and postoperatively compared to SAVR patients.

Abstract 12070: Long-term Prognostic Value of Cardiac Power Index in Patients Admitted With Acute Decompensated Heart Failure

Backgrounds: Cardiac power is the rate of hydraulic work done by the heart. It has recently been shown that cardiac power index (CPI) provided prognostic independent and incremental prediction in adverse outcomes beyond traditional hemodynamic parameters in ambulatory patients with advanced heart failure. However, there is little information available on the long-term prognostic value of CPI in patients with acute decompensated heart failure (ADHF). Methods and Results: We studied 209 patients admitted for ADHF, who underwent right heart catheterization at the admission and were discharged with survival. CPI was calculated by: CPI W/m 2 = ([mean arterial pressure(mmHg) - [right arterial pressure(mm Hg)] x cardiac output [L/min] x K)/ (BSA m 2 ) where K = 0.0022. During a mean follow-up period of 4.4±3.3 yrs, 50 patients had cardiovascular death (CVD). CPI was significantly lower in patients with than without CVD (0.407±0.138 vs 0.550±0.258 W/m 2 , p=0.0002). Multivariate Cox regression analysis revealed that CPI (hazard ratio 0.092 [95%CI 0.017-0.497], p=0.005) was significantly associated with CVD, independently of body mass index, BUN and serum sodium levels, after adjustment for age, systolic blood pressure, pulmonary vascular resistance, and serum creatinine, albumin, and hemoglobin levels. Patients with low CPI (lowest tertile&lt;0.395 W/m 2 ) had a significantly higher CVD risk than those with middle CPI(0.395-0.565 W/m 2 ) and high CPI (highest tertile: &gt;0.565 W/m 2 ) (41%(28/69) vs 22%(15/70) vs 10%(10/70), p&lt;0.0001, respectively). The adjusted hazard ratio in patients with low CPI was 3.40 (95%CI 1.46-7.92). Conclusions: CPI could provide the long-term prognostic information in patients admitted with ADHF.

Comparison of pulmonary artery and transpulmonary thermodilution cardiac output measurements in unsedated newborn calves

ObjectiveTo compare the agreement, repeatability and trending ability of transpulmonary thermodilution (TPTD) and pulmonary artery thermodilution (PATD) cardiac output ( Q˙t) measurements in unsedated newborn calves. Study designProspective experimental trial. AnimalsEight newborn calves weighing a median (range) of 53 (46–59) kg. MethodsPulmonary and femoral artery thermodilution catheters were placed under local anaesthesia. A total of 382 PATD and TPTD Q˙t measurements were performed simultaneously. Cardiac output was influenced by intravenous doxapram and theophylline in a randomized crossover fashion. Bland–Altman analysis for multiple comparisons, concordance and polar plots were used to assess TPTD against PATD. ResultsMedian (range) cardiac index values measured with PATD and TPTD were 197 mL kg−1 minute−1 (74–335 mL kg−1 minute−1) and 196 mL kg−1 minute−1 (59–395 mL kg−1 minute−1), respec-tively. A small mean bias of -3 mL kg−1 minute−1 with limits of agreement (LOA) of -64 to 58 mL kg−1 minute−1 and a percentage error of 31% were found. Eighty-two mean values were calculated. This reduced the LOA to -50 to 41 mL kg−1 minute−1 with a similar small bias and a percentage error of 23%. Mean TPTD tracked changes in Q˙t compared with mean PATD with 90% concordance, a mean polar angle of 6° and radial LOA of 43°, indicating marginal trending ability. Keeping the femoral artery catheter patent and obtaining acceptable measurements were very challenging because the calves were not used to being restrained. Calf movement had less influence on PATD. Conclusions and clinical relevanceWe recommend that PATD remains the reference method to measure Q˙t in unsedated newborn calves. However, the robust results of the evaluation of the less invasive TPTD technique warrants further evaluation taking into account the difficulties reported in this study.

To morphological description of cardiovascular system in pinnipeds (Pinnipedia)

Morphometric parameters of the heart, the absolute and relative caliber of the aortic arch and the major arterial trunks are determined for northern fur seal Callorhinus ursinus , Steller sea lion Eumetopias jubatus , spotted seal Phoca largha , harbor seal Phoca vitulina stejnegeri , and ribbon seal Histriophoca fasciata . The value of cardiac index, the thickness of ventricular wall, and the relative diameter of arterial trunks correlate well with energy expenditures of the entire body of mammals or their certain organs during the life cycle. The hypothesis is confirmed on seals’ adaptation to asphyxia by pronounced dilatation of the aorta ascending that ensures constant blood pressure and supports perfusion of brain and cardiac tissue.

Indexation of cardiac output to biometric parameters in critically ill patients: A systematic analysis of a transpulmonary thermodilution–derived database

PurposeCardiac output (CO) (liters per minute) is usually normalized (ie, indexed) to the patient's body surface area (BSA) resulting in the hemodynamic variable cardiac index (CI) (liters per minute per square meter). We aimed (1) to evaluate the impact of different body weight–based CO indexations on the resulting CI values and (2) to identify biometric parameters independently associated with CO in critically ill patients. Materials and methodsThe study is an analysis of a database containing transpulmonary thermodilution–derived hemodynamic variables of 234 medical intensive care unit patients. ResultsCardiac index indexed to actual BSA was statistically significantly lower compared with CI indexed to predicted BSA in the totality of patients and in the subgroups of patients with body mass index greater than or equal to 25 kg/m2 but less than 30 kg/m2 and body mass index greater than or equal to 30 kg/m2 (with a statistically significant difference in the proportion of low and high CI measurements).Multivariate analysis of the first CO measurement of each patient demonstrated that CO was independently associated with age (P < .001), height (P = .001), and actual body weight (BWact) (P = .030).Multivariate analysis of the mean of the patients' CO measurements confirmed age (P < .001), height (P = .001), and BWact (P < .001) as biometric factors independently associated with CO. Age was identified as the most important factor with each year of age decreasing CO by 66 mL/min (95% confidence interval, 47-86 mL/min). ConclusionsThe indexation of CO to BSA is highly dependent on the body weight estimation formula used to calculate BSA. Cardiac output is independently associated with the biometric factors age, height, and BWact. These factors might be considered for indexation of CO.

The effects of differential injection sites of cold saline on transpulmonary thermodilution parameter values.

AimTo investigate the effects of differential sites for cold saline injection on transpulmonary thermodilution parameter values.MethodsThis was a prospective study. Twelve patients were recruited for the following examinations: control condition (injection site at proximal injection end of the Swan-Ganz catheter), proximal end condition (injection site at sheath of the Swan-Ganz catheter), and distal end condition (injection site at PA end of the Swan-Ganz catheter). Sixty measurements were performed for each condition. The cardiac index, global end diastolic volume index (GEDI), and extravascular lung water index for the three different injection sites were recorded from each patient. In addition, the mean transmission time (MTt), downslope time, and area under the curve obtained from PiCCO-VoLEF-Win software were compared among different groups.ResultsThere were no differences in cardiac index and extravascular lung water index values among the three conditions (P>0.05). There were no differences in GEDI between the proximal end condition and control condition (P>0.05), while the GEDI was significantly lower for the distal end condition (493.33±254.65 mL/m2) than for the control condition (645.53±234.46 mL/m2) (P<0.05) and proximal end condition (717.96±321.63 mL/m2) (P<0.01). There were no differences in downslope time and area under the curve among the three conditions (P>0.05). There were no differences in MTt between the proximal end condition and control condition (P>0.05), while the MTt was significantly lower for distal end condition (40.22±16.37 seconds) than for the control condition (42.91±17.93 seconds) (P<0.05) and proximal end condition (47.16±16.64 seconds) (P<0.01).ConclusionThe differential sites for cold saline injection impacted transpulmonary thermodilution parameter values.

Echocardiographic detection of transpulmonary bubble transit during acute respiratory distress syndrome.

BackgroundTranspulmonary bubble transit (TPBT) detected with contrast echocardiography is reported as a sign of intrapulmonary shunt during cirrhosis or exercise in healthy humans. However, its physiological meaning is not clear during acute respiratory distress syndrome (ARDS). Our aim was to determine the prevalence, significance, and prognosis of TPBT detection during ARDS.MethodsThis was a prospective observational study in an academic medical intensive care unit in France. Two hundred and sixteen consecutive patients with moderate-to-severe ARDS underwent transesophageal echocardiography with modified gelatine contrast. Moderate-to-large TPBT was defined as right-to-left passage of at least ten bubbles through a pulmonary vein more than three cardiac cycles after complete opacification of the right atrium. Patients with intra-cardiac shunt through patent foramen ovale were excluded.ResultsThe prevalence of moderate-to-large TPBT was 26% (including 42 patients with moderate and 15 with large TPBT). Patients with moderate-to-large TPBT had higher values of cardiac index and heart rate as compared to those without TPBT. There was no significant difference in PaO2/FIO2 ratio between groups, and TPBT was not influenced by end-expiratory positive pressure level in 93% of tested patients. Prevalence of septic shock was higher in the group with moderate-to-large TPBT. Patients with moderate-to-large TPBT had fewer ventilator-free days and intensive care unit-free days within the first 28 days, and higher in-hospital mortality as compared to others.ConclusionsModerate-to-large TPBT was detected with contrast echocardiography in 26% of patients with ARDS. This finding was associated with a hyperdynamic and septic state, but did not influence oxygenation.

Multisite Near Infrared Spectroscopy During Cardiopulmonary Bypass in Pediatric Patients

Multisite near infrared spectroscopy (NIRS) monitoring during pediatric cardiopulmonary bypass (CPB) has not been extensively validated. Although it might be rational to explore regional tissue saturation at different body sites (namely brain, kidney, upper body, lower body), conflicting results are currently provided by experience in children. The aim of our study was to evaluate absolute values of multisite NIRS saturation during CPB in a cohort of infants undergoing pediatric cardiac surgery to describe average differences between cerebral, renal, upper body (arm), and lower body (thigh) regional saturation. Furthermore, the correlation between cerebral NIRS and cardiac index (CI) at CPB weaning was evaluated. Twenty-five infants were enrolled: their median weight, age, and body surface area were 3.9 (3.3-6) kg, 111 (47-203) days, and 0.24 (0.22-0.33) m(2) , respectively. Median Aristotle score was 8 (6-10), and vasoactive inotropic score at CPB weaning was 16 (14-25). A total of 17 430 data points were recorded by each sensor: two-way ANOVA showed that time (P < 0.0001) and site (P = 0.0001) significantly affected variations of NIRS values: however, if cerebral NIRS values are excluded, sensor site is no more significant (P = 0.184 in the no circulatory arrest [noCA] group and P = 0.42 in the circulatory arrest [CA] group). Analysis of NIRS saturation changes over time showed that, at all sites, average NIRS values increased after CPB start, even if the increase of cerebral saturation was less intense than other sites (P < 0.0001). Detailed analysis of interaction between site of NIRS measurement and time point showed that cerebral NIRS (ranging from 65 to 75%) was always significantly lower than that of other channels (P < 0.0001) that tended to be in the range of oversaturation (80-90%), especially during the CPB phase. Average cerebral NIRS values of patients who did not undergo circulatory arrest (CA) during CPB, 10 min after CPB weaning, were associated with average CI values with a significant correlation (r = 0.7, P = 0.003). In conclusion, during CPB, cerebral NIRS values are expected to remain constantly lower than somatic sensors, which instead tend to show similar elevated saturations, regardless of their position. Based on these results, positioning of noncerebral NIRS sensors during CPB without CA may be questioned.

Comparison of pulse contour analysis by Pulsioflex and Vigileo to measure and track changes of cardiac output in critically ill patients

We compared the new Pulsioflex and the Vigileo devices to measure cardiac index (CI) in critically ill patients. Both devices measure CI by pulse-contour analysis. The Pulsioflex device also allows an auto-calibration (not based on thermodilution). Patients were included if we administered fluids (20 patients), reduced (20 patients), or increased (20 patients) the dose of norepinephrine. Before and after interventions, we measured CI provided by the Vigileo (CIVig) and Pulsioflex (CIPfx) devices before and after its auto-calibration. CI measured by transpulmonary thermodilution (CIthermo) was used as the reference. Considering absolute values of CI (n=120), the percentage error was 59% for CIVig vs CIthermo and 40% for CIthermo vs CIPfx. Auto-calibrating CIPfx after interventions did not improve the percentage error between CIPfx and CIthermo (39%). Considering the fluid-induced changes in CI, the coefficient of correlation with changes in CIthermo was 0.50 for CIVig, and 0.73 for CIPfx (P=0.27). It was not significantly improved if CIPfx was auto-calibrated (r=0.64). Considering the norepinephrine-induced changes in CI, the coefficient of correlation with changes in CIthermo was 0.41 for CIVig. It tended to be better for CIPfx (r=0.71, P=0.07). It was not significantly improved by auto-calibration (r=0.53). The Pulsioflex did not reliably estimate the absolute values of CI. For tracking fluid-induced changes in CI, the Pulsioflex was reliable, and also the Vigileo. For tracking norepinephrine-induced changes in CI, it was also reliable and tended to be better than the Vigileo. Auto-calibration allowed by the system did not improve its reliability.

Sepsis survivors present with higher values of cardiac index and velocity time integral in the emergency department

Myocardial depression is common among septic patients [1]. The aim of this study was to assess whether the values of cardiac index (CI) and velocity-time integral (VTI) calculated by echocardiography differ between survivors and nonsurvivors of sepsis.