In this post hoc analysis of 45 patients with septic shock with persistent tachycardia, we characterised features of haemodynamic response focusing on SDPdifference, classifying patients according to variations in arterial dP/dtmax after 4 h of esmolol administration to maintain HR <95 beats min-1. A cut-off value of 0.9 mm Hg ms-1 was used for group allocation.
After reducing HR, arterial dP/dtmax remained above the cut-off in 23 patients, whereas it decreased below the cut-off in 22 patients (from 0.99 [0.37] to 0.63 [0.16] mm Hg ms-1; mean [SD], P<0.001). At baseline, patients with decreased dP/dtmax after esmolol had lower SDPdifference than those with higher dP/dtmax (40 [19] vs 53 [16] mm Hg, respectively; P=0.01). The SDPdifference remained unchanged after esmolol in the higher dP/dtmax group (49 [16] mm Hg), whereas it decreased significantly in patients with lower dP/dtmax (29 [11] mm Hg; P<0.001). In the latter, the HR reduction resulted in a significant cardiac output reduction with unchanged SV, whereas in patients with higher dP/dtmax SV increased (from 48 [12] to 67 [14] ml; P<0.001) with maintained cardiac output.
A decrease in SDPdifference could discriminate between compensatory and non-compensatory tachycardia, revealing a covert loss of myocardial contractility not detected by conventional echocardiographic parameters and deteriorating after HR reduction with esmolol.
NCT02188888.