E5. Lung ultrasound and echocardiography for peripartum haemodynamic monitoring of patients with severe preeclampsia

Abstract

Introduction: The ability to judge intravascular volume is fundamental in the management of patients with severe preeclampsia. Insufficient intravascular volume can result in decreased oxygen delivery to tissues and exacerbates organ dysfunction. On the other hand, fluid excesses can lead to fluid extravasation and pulmonary edema. Outside of pregnancy, transthoracic echocardiography and lung ultrasonography have become important diagnostic and monitoring tools in critically ill patients. Only few studies to date, however, examined the utility of echocardiography in combination with lung ultrasonography for guiding fluid therapy in patients with severe preeclampsia. The objective of our study was to evaluate the correlation between myocardial function, assessed by echocardiography, and extravascular lung water (EVLW) sonographic measurements in patients with severe preeclampsia before delivery as well as in the first days postpartum.Methods: The study population consisted of patients consecutively admitted at a single level III referral institution with the diagnosis of preeclampsia with severe features between April, 2015 and February, 2016. Severe features of preeclampsia were defined using the American College of Obstetricians and Gynecologist Task Force on Hypertension in Pregnancy recommendations. All subjects were studied by standard two-dimensional and Doppler transthoracic echocardiography. Patients were studied at rest in the left lateral decubitus position and data were acquired at end expiration from standard parasternal/apical/subcostal views. Left ventricular systolic function was assessed by the left ventricular ejection fraction (LV EF) using the Teicholz method from the parasternal long axis view. E/E’ ratio was used as a marker of diastolic function (E wave representing the early diastolic mitral inflow velocity assessed by pulse wave Doppler and E’ representing the early diastolic mitral annulus displacement velocity assessed by tissue Doppler). Preload assessment involved measurement of inferior vena cava (IVC) diameter and its response to respiration (% of decrease in IVC diameter with spontaneous inspiration). Lung ultrasound was performed according to a systematic protocol in supine patients. The Echo Comet Score (ECS) was obtained by the 28-rib interspaces technique dividing the chest wall in 12 areas on the left (from the second to the fourth intercostal space) and 16 areas on the right (from the second to the fifth intercostal space) anterior and lateral hemithorax. Statistical comparison between ECS, LV EF, E/E0 ratio, expiratory IVC diameter, and IVC diameter decrease with inspiration before delivery versus within 24 h post-delivery versus 4 days postdelivery was performed using repeated measures ANOVA. Spearman’s correlation analysis was used to determine whether ECS correlated with measures of systolic function, diastolic function or preload. A p values of < 0.05 was considered significant.Results: Seventeen women with preeclampsia with severe features were included. Echo Comet Score was significantly higher measured before delivery versus 24 h postdelivery, versus 4 days postdelivery (p = 0.03). Left ventricular EF and E/E’ ratio did not differ significantly before delivery versus within 24 h post-delivery versus 4 days post-delivery (p = 0.11 and p = 0.66, respectively). Expiratory IVC diameter and IVC diameter decrease during inspiration were significantly lower before delivery versus post-partum (p = 0.01 and p = 0.04, respectively). No statistically significant correlation was found between ECS and the LV EF, E/E’ ratio, expiratory IVC diameter, decrease in IVC during inspiration (p40.05 regardless of timing of measurement, i.e. before delivery versus within 24 h post-delivery versus 4 days post-delivery).Conclusions: The increased EVLW in preeclamptic patients decreases rapidly following delivery and it seems to be associated primarily with increased vascular permeability or “capillary leak” syndrome, rather than systolic or diastolic myocardial dysfunction. Rapid increase in expiratory inferior vena cava diameter immediately after delivery suggests limited accuracy of this sonographic parameter to assess preload in pregnancy probably due to decreased venous return caused by to the gravid uterus.