Background: The haemodynamic monitor PiCCO System, based on transpulmonary arterial thermodilution, has been used with a brachial-axillary access instead of the femoral arterial access during abdominal aortic aneurysm surgical repair. Accuracy and limitations of pulse contour continuous cardiac output (PCCO) were evaluated on the basis of arterial thermodilution cardiac output. The patterns of cardiac index, preload, afterload and cardiac function parameters were also studied in the different phases of the surgical procedure.
Methods: Twenty consecutive patients were studied. Mean differences (bias) between PCCO and arterial thermodilution cardiac output were calculated by the Bland-Altman test. Analysis of variance with multiple comparison test of haemodynamic variables in the different phases were performed. The correlation coefficients between cardiac index and the volumetric preload variables were also obtained.
Results: Brachial artery catheterization was achieved without any major complication. Pulse contour continuous cardiac index (CI) and arterial thermodilution CI values showed overall mean differences (bias) of -0.04 Lámin-1. m-2 (SD 0.8) but after aortic cross-clamping and aortic unclamping they were 0.64 Lámin-1. m-2 (SD 0.57) e -0.57 Lámin-1. m-2 (SD 0.85), respectively (p<0.05). CI, global end-diastolic volume (GEDV) and intrathoracic blood volume (ITBVI) were significantly lower during aortic cross-clamping. CI was not correlated to central venous pressure (r=0.18) but instead, to GEDV (r=0.57) and ITBVI (r=0.65).
Conclusions: PiCCO System with brachial-axillary arterial access was suitable for haemodynamic monitoring of the abdominal aortic aneurysm surgical repair procedures. PCCO must be recalibrated with arterial thermodilution after aortic cross-clamping and unclamping to avoid an over-estimation and an under-estimation respectively. During aortic cross-clamping GEDV and ITBVI indicated a decreased preload. Other haemodynamic variables were less valuable but EVLWI showed an interesting steady increase during the whole procedure.