Arterial dP/dtmax accurately reflects left ventricular contractility during shock when adequate vascular filling is achieved
1 Medical Intensive Care Unit, University Hospital of Liège, Liège, Belgium
2 Faculty of Sciences, University of Liège, Liège, Belgium
3 Emergency Department, University Hospital of Liège, Liège, Belgium
4 Mechanical Engineering Department, University of Canterbury, Christchurch, New Zealand
BMC Cardiovascular Disorders 2012, 12:13 doi:10.1186/1471-2261-12-13Published: 1 March 2012
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.
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.
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).
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.