Correlation between maternal haemodynamic profile and lung interstitial oedema in postpartum patients with severe preeclampsia

Objective. To assess potential correlation between maternal haemodynamic profile and lung interstitial oedema in post­partum patients with severe preeclampsia.
Materials and Methods. We included 21 patients with severe features of preeclampsia at four days postpartum. Two main parameters, which differentiate haemodynamic profile of pre­eclampsia, i.e. cardiac output (CO) and peripheral vascular resistance (PVR), were assessed by echocardiography. Cardiac output was calculated by multiplying stroke volume by heart rate. Stroke volume was obtained by using pulse-wave Dop­pler method and calculated as the product of left-ventricular outflow tract area and left-ventricular outflow tract veloci­ty-time integral. Peripheral vascular resistance was calculated by dividing mean arterial blood pressure by CO. Lung ultra­sound Echo Comet Score (ECS) was used as a marker of lung interstitial fluid. It was obtained using the 28-rib interspaces technique. Any correlation between ECS and CO or PVR was assessed by Kendall’s tau (p < 0.05 significant).
Results. Cardiac output ranged from 3.2 to 7.1 L/min (median 4.6 L/min), PVR from 1,178.0 to 2,734.0 dynes × sec/cm5 (me­dian 1,834.0 dynes × sec/cm5), and ECS from 0 to 40 (median 7). There was a significant inverse correlation between CO and ECS (Kendall’s tau = -0.334, p = 0.04). Moreover, higher PVR was significantly associated with higher ECS (Kendall’s tau = 0.340, p = 0.03).
Conclusions. Increased lung interstitial fluid in early postpar­tum period in preeclampsia is associated with low CO and high PVR. These results indicate that patients with severe pre­eclampsia who present with a low CO/high PVR haemody­namic profile are at higher risk of postpartum lung oedema.