Comparison of cardiac function index derived from femoral and jugular indicator injection for transpulmonary thermodilution with the PiCCO-device: A prospective observational study

Abstract

IntroductionCardiac function index (CFI) is a trans-pulmonary thermodilution (TPTD)-derived estimate of systolic function. CFI is defined as the ratio of cardiac output divided by global end-diastolic volume GEDV (CFI = CO/GEDV). Several studies demonstrated that the use of femoral venous access results in a marked overestimation of GEDV, while CFI is underestimated. One study suggested a correction formula for femoral venous access that markedly reduced the bias for GEDVI. Therefore, the last PiCCO-algorithm requires information about the CVC-position which suggests a correction of GEDV for femoral access. However, a recent study demonstrated inconsistencies of the last PiCCO algorithm using incorrected GEDV to calculate CFI despite obvious correction of GEDV. Nevertheless, this study was based on mathematical analyses of data displayed in a total of 15 patients equipped with only a femoral, but not with a jugular CVC. Therefore, this study compared CFI derived from the femoral indicator injection TPTD to data derived from jugular indicator injection in 28 patients with both a jugular and a femoral CVC.Methods28 ICU-patients with PiCCO-monitoring were included. Each dataset consisted of three triplicate TPTDs using the jugular venous gold standard access and the femoral access with and without information about the femoral indicator injection to evaluate, if correction for femoral GEDV also pertains to CFI. (CFI_jug: jugular indicator injection; CFI_fem: femoral indicator injection; CFI_fem_cor: femoral indicator injection with correct information about CVC-position; CFI_fem_uncor: femoral indicator injection with uncorrect information about CVC-position; CFI_fem_uncor_form = CFI_fem_uncor * (GEDVI_fem_uncor/GEDVI_fem_cor)).ResultsCFI_fem_uncor was significantly lower than CFI_jug (4.28±1.70 vs. 5.21±1.91 min-1; p<0.001). Similarly, CFI_fem_cor was significantly lower than CFI_jug (4.24±1.62 vs. 5.21±1.91 min-1; p<0.001). This is explained by the finding that CFI_fem_uncor was not different to CFI_fem_cor (4.28±1.70 vs. 4.24±1.62 min-1; p = 0.611). This suggests that correction for femoral CVC does not pertain to CFI. Calculative correction of CFI_fem_uncor by multiplying CFI_fem_uncor by the ratio GEDVI_fem_uncor/GEDVI_jug resulted in CFI_fem_uncor_form which was slightly, but significantly different from the gold standard CFI_jug (5.51±2.00 vs. 5.21±1.91 min-1; p = 0.024). The agreement of measurements classified in the same category of CFI (decreased (<4.5), normal (4.5–6.5) and increased (>6.5 min-1)) was high for CFI_jug and CFI_fem_uncor_form (identical categories in 26 of 28 comparisons; p = 0.49). By contrast, the agreement with CFI_jug was significantly lower for CFI_fem_cor (14 out of 28; p<0.001) and CFI_fem_uncor (15 out of 28; p<0.001).ConclusionsWhile the last PiCCO algorithm obviously corrects GEDVI for femoral indicator injection, this correction is not applied to CFI. Therefore, femoral TPTD indicator injection results in substantially lower values for CFI compared to TPTD using a jugular CVC. N...

Injection Site Matters: A Comparative Analysis of Transpulmonary Thermodilution via Simultaneous Femoral and Jugular Indicator Injections under Veno-Venous Extracorporeal Membrane Oxygenation Therapy

“…Multivariate analyses revealed a significant independent correlation between increased GEDVI, EVLWI, and the femoral injection site [6]. Due to this and further evidence suggesting relevant differences caused by the site of indicator injection [5], we performed measurements of both sites (jugular/femoral) in patients with jugular and femoral access in routine clinical practice and interpreted the results in a clinical context.…”

“…Studies have already shown that TPTD-derived parameters with femoral indicator injections have led to a significant overestimation of the GEDVI compared to jugular indicator injections [5]. Concerning the injection site and investigating TPTD in patients undergoing vv-ECMO therapy, Herner et al not only illustrated how all TPTD-derived parameters changed after the initiation of vv-ECMO therapy, but they also noted that the parameters measured in patients after femoral injections were significantly higher than those after jugular injections.…”

“…The aim of our pilot study was to investigate whether the site of injection-femoral vs. jugular-has a significant influence on the comparability and validity of TPTD-derived measurements. Although there are several publications on the topic of managing advanced hemodynamic monitoring in patients with extracorporeal support systems [5,7,8], this is the first analysis of hemodynamic patterns using the PiCCO ® system at different measurement sites simultaneously in the same patient with ongoing vv-ECMO therapy.…”

Accuracy of non-invasive and minimally invasive hemodynamic monitoring: where do we stand?

“…One limitation of the PiCCO system is its needs of transpulmonary measurement and its invasive nature. Recent studies have shown that when more distant central lines are used, the device is not able to predict the cardiac function reliably (27). Despite its limitations, PiCCO is extremely effective in goal directed therapy of patients in ICU and early fluid resuscitation efforts, thereby, decreasing mortality (28).…”

Cardiac output estimation based on arterial and venous blood gas analysis: proposal of a monitoring method

“…These systems can provide information on the hemodynamic status of critically ill patients and can also be used in the perioperative setting. Although abovementioned devices have made it possible to improve the treatment of critically ill patients and optimize goal-directed therapy, they are expensive, not commonly available, and have shown limitations in providing reliable data in different contexts [ 3 – 5 ].…”