Measurement of inotropy and systemic oxygen delivery in term, low- and very-low-birth-weight neonates using the Ultrasonic Cardiac Output Monitor (USCOM)

Hypertensive disorders and maternal hemodynamic changes in pregnancy: monitoring by USCOM® device

Hypertensive disorders are quite common, complicating about 10% of pregnancies, while preeclampsia occurs in 2-8% of cases. The most recognized etiopathogenetic factor for the development of preeclampsia is deficient remodeling of the spiral arteries during trophoblastic invasion. Recently, some authors speculated about the "cardiovascular origin of preeclampsia"; in particular, they postulate that placental dysfunction is not the primum movens of preeclampsia, but it could be caused by a failure of the maternal cardiovascular system to adapt to the pregnancy itself. Moreover, several studies have also shown that developing preeclampsia in pregnancy is associated with an increased risk of cardiovascular disease later in life. Due to the importance of this pathology, it would be crucial to have an effective screening in order to implement a prophylaxis; for this purpose, it could be useful to have an accurate and noninvasive device for the assessment of maternal hemodynamic variables. USCOM^® (Ultrasonic Cardiac Output Monitor) is a noninvasive Doppler ultrasonic technology which combines accuracy, reproducibility, noninvasiveness, and a fast learning curve. Maternal hemodynamic evaluation is important in order to monitor the changes that the maternal organism encounters, in particular a reduction in blood pressure, a decrease in total peripheral resistances, and an increase in cardiac output, resulting in a hyperdynamic circle. These hemodynamic modifications are lacking in pregnancies complicated by preeclampsia. For these reasons, it is crucial to have a tool that allows these parameters to be easily evaluated in order to identify those women at higher risk of hypertensive complications and more severe outcomes.

The clinical value of ultrasonic cardiac output monitor in very-low birth-weight and extremely-low-birth-weight infants undergoing PDA ligation

BACKGROUND

Cardiorespiratory instability occurs very often in very-low-birth-weight (VLBW) and extremely-low-birth-weight (ELBW) infants undergoing patent ductus arteriosus (PDA) ligation during the early postoperative period. This study aimed to investigate ultrasonic cardiac output monitor (USCOM) as a bedside tool by evaluating the hemodynamic changes in preterm infants following PDA ligation and assessing factors that may influence these changes.

METHODS

This was a single-center prospective observational study at a third-level neonatal intensive care unit. A total of 33 infants, including 21 VLBW and 12 ELBW infants, were involved. Hemodynamic measurements were performed in these infants using a USCOM preoperatively as well as 0-1 h, 8-10 h, and 24 h postoperatively.

RESULTS

The PDA ligation was associated with reductions of the left ventricular cardiac output (LVCO) (P < 0.001), cardiac index (P < 0.001), flow time corrected (FTC) (P < 0.001), Smith-Madigan inotropy index (SMII) (P < 0.001), oxygen delivery (DO₂) (P < 0.001), and oxygen delivery index (DO₂I) (P < 0.001) and an increase of the systemic vascular resistance index (SVRI) (P < 0.001) at 0-1 h, 8-10 h, and 24 h post-ligation compared with the respective preoperative values. Compared with the respective values at 0-1 h post-ligation, there was no significant difference in the CI, SMII, or FTC at 8-10 h and 24 h post-ligation. However, the SVRI decreased at 8-10 h and 24 h post-ligation. Moreover, the DO₂I increased at 8-10 h and 24 h post-ligation, and the LVCO and DO₂ increased at 24 h post-ligation.

CONCLUSION

Our study confirmed that the hemodynamic changes measured by the USCOM were similar to those measured by echocardiography in previous reports. Thus, USCOM is a useful and convenient bedside tool for assessing hemodynamic changes to guide the use of fluids, inotropic agents, and vasopressors and help modify the post-ligation course, and they may be a surrogate for repeated echocardiography during the early post-ligation period in preterm infants or a preliminary screening method.

Reduced Echocardiographic Inotropy Index after Cardiopulmonary Bypass Is Associated With Complications After Cardiac Surgery: An Institutional Outcomes Study

OBJECTIVE

Despite advances in echocardiography and hemodynamic monitoring, limited progress has been made to effectively quantify left ventricular function during cardiac surgery. Traditional measures, including left ventricular ejection fraction (LVEF) and cardiac index, remain dependent on loading conditions; more complex measures remain impractical in a dynamic surgical setting. However, the Smith-Madigan Inotropy Index (SMII) and potential-to-kinetic energy ratio (PKR) offer promise as measures calculable during cardiac surgery and potentially predictive of outcomes. Using echocardiographic and hemodynamic monitoring data, the authors aimed to calculate SMII and PKR values after cardiopulmonary bypass and understand associations with postoperative outcomes, adjusting for previously identified risk factors.

DESIGN

Observational cohort study.

SETTING

Tertiary care academic hospital.

PATIENTS

The study comprised 189 elective adult cardiac surgical procedures from 2015-2016.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was postoperative mortality or organ system complication (stroke, prolonged ventilation, reintubation, cardiac arrest, acute kidney injury, new-onset atrial fibrillation). After adjustment, SMII <0.83 W/m² independently predicted the primary outcome (adjusted odds ratio 2.19, 95% confidence interval 1.08-4.42); whereas PKR, LVEF, and cardiac index demonstrated no associations. When SMII and PKR were incorporated into a EuroSCORE II risk model, predictive performance improved (net reclassification index improvement 0.457; p = 0.001); whereas a model incorporating LVEF and cardiac index demonstrated no improvement (0.130; p = 0.318).

CONCLUSION

The present study demonstrated that SMII, but not PKR, as a measure of cardiac function was associated with major complications. The study's data may guide investigations of more suitable perioperative goal-directed therapies to reduce complications after cardiac surgery.