Arterial dP/dtmax accurately reflects left ventricular contractility during shock when adequate vascular filling is
Philippe Morimont1, Bernard Lambermont, Thomas Desaive
1Medical Intensive Care Unit, Emergency Department, University Hospital of Liège, and Faculty of Sciences, University of Liège, Liège, Belgium. ph.morimont@chu.ulg.ac.be
Background:
Peak first derivative of femoral artery pressure (arterial dP/dtmax) derived from fluid-filled catheter remains questionable to assess left ventricular (LV) contractility during shock. The aim of this study was to test if arterial dP/dtmax is reliable for assessing LV contractility during various hemodynamic conditions such as endotoxin-induced shock and catecholamine infusion.
Methods:
Ventricular pressure-volume data obtained with a conductance catheter and invasive arterial pressure obtained with a fluid-filled catheter were continuously recorded in 6 anaesthetized and mechanically ventilated pigs. After a stabilization period, endotoxin was infused to induce shock. Catecholamines were transiently administrated during shock. Arterial dP/dtmax was compared to end-systolic elastance (Ees), the gold standard method for assessing LV contractility.
Results:
Endotoxin-induced shock and catecholamine infusion lead to significant variations in LV contractility. Overall, significant correlation (r=0.51; p<0.001) but low agreement between the two methods were observed. However, a far better correlation with a good agreement were observed when positive-pressure ventilation induced an arterial pulse pressure variation (PPV)≤11% (r=0.77; p<0.001).
Conclusion:
While arterial dP/dtmax and Ees were significantly correlated during various hemodynamic conditions, arterial dP/dtmax was more accurate for assessing LV contractility when adequate vascular filling, defined as PPV≤11%, was achieved.
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