Predictors of the accuracy of pulse-contour cardiac index and suggestion of a calibration-index: a prospective evaluation and validation study

BMC Anesthesiology

Research Article

Bernd Saugel¹  Jonas Koenig¹  Roland M Schmid¹  Veit Phillip¹  Philipp Thies¹  Matthias Treiber¹  Josef Hoellthaler¹  Henrik Einwächter¹  Sebastian Mair¹  Caroline Schultheiss¹  Wolfgang Huber¹  Ulrich Mayr¹  Tibor Schuster²  Florian Eyer³ 

[1] II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, D-81675, Munich, Germany;Institut für Medizinische Statistik und Epidemiologie, Klinikum Rechts der Isar; Technische Universität München, Ismaninger Strasse 22, D-81675, Munich, Germany;Toxikologische Abteilung, II. Medizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, D-81675, Munich, Germany;

关键词: Hemodynamic monitoring;    Pulse contour analysis;    Cardiac output;    Cardiac index;    Calibration;    Transpulmonary thermodilution;    Accuracy;    Precision;   

DOI  :  10.1186/s12871-015-0024-x

 received in 2014-03-26, accepted in 2015-03-19,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundCardiac Index (CI) is a key-parameter of hemodynamic monitoring. Indicator-dilution is considered as gold standard and can be obtained by pulmonary arterial catheter or transpulmonary thermodilution (TPTD; CItd). Furthermore, CI can be estimated by Pulse-Contour-Analysis (PCA) using arterial wave-form analysis (CIpc). Obviously, adjustment of CIpc to CItd initially improves the accuracy of CIpc. Despite uncertainty after which time accuracy of CIpc might be inappropriate, recalibration by TPTD is suggested after a maximum of 8 h.We hypothesized that accuracy of CIpc might not only depend on time to last TPTD, but also on changes of the arterial wave curve detectable by PCA itself. Therefore, we tried to prospectively characterize predictors of accuracy and precision of CIpc (primary outcome). In addition to “time to last TPTD” we evaluated potential predictors detectable solely by pulse-contour-analysis.Finally, the study aimed to develop a pulse-contour-derived “calibration-index” suggesting recalibration and to validate these results in an independent collective.MethodsIn 28 intensive-care-patients with PiCCO-monitoring (Pulsion Medical-Systems, Germany) 56 datasets were recorded. CIpc-values at baseline and after intervals of 1 h, 2 h, 4 h, 6 h and 8 h were compared to CItd derived from immediately subsequent TPTD. Results from this evaluation-collective were validated in an independent validation-collective (49 patients, 67 datasets).ResultsMean bias values CItd-CIpc after different intervals ranged between -0.248 and 0.112 L/min/m2. Percentage-error after different intervals to last TPTD ranged between 18.6% (evaluation, 2 h-interval) and 40.3% (validation, 6 h-interval). In the merged data, percentage-error was below 30% after 1 h, 2 h, 4 h and 8 h, and exceeded 30% only after 6 h. “Time to last calibration” was neither associated to accuracy nor to precision of CIpc in any uni- or multivariate analysis.By contrast, the height of CIpc and particularly changes in CIpc compared to last thermodilution-derived CItd(base) univariately and independently predicted the bias CItd-CIpc in both collectives.Relative changes of CIpc compared to CItd(base) exceeding thresholds derived from the evaluation-collective (-11.6% < CIpc-CItd(base)/CItd(base) < 7.4%) were confirmed as significant predictors of a bias |CItd-CIpc| ≥ 20% in the validation-collective.ConclusionRecalibration triggered by changes of CIpc compared to CItd(base) derived from last calibration should be preferred to fixed intervals.

【 授权许可】

CC BY   
© Huber et al.; licensee BioMed Central. 2015