Non-invasive Cardiac Output Monitoring and Assessment of Fluid Responsiveness in Children With Shock in the Emergency Department

Abstract

IntroductionThe assessment of fluid responsiveness is important in the management of shock but conventional methods of assessing fluid responsiveness are often inaccurate. Our study aims to evaluate changes in objective hemodynamic parameters as measured using electrical cardiometry (ICON® monitor) following the fluid bolus in children presenting with shock and to evaluate whether any specific hemodynamic parameter can best predict fluid responsiveness among children with shock.Materials and MethodsWe conducted a prospective observational study in children presenting with shock to our emergency department between June 2020 and March 2021. We collected the parameters such as heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and hemodynamic data such as cardiac output CO), cardiac index (CI), index of contractility (ICON), stroke volume (SV), stroke index (SI), corrected flow time (FTC), systolic time ratio (STR), variation of index of contractility (VIC), stroke volume variation (SVV), systemic vascular resistance (SVR), and thoracic fluid content (TFC) using the ICON monitor before and after fluid bolus (FB). We assessed percent change (Δ) and used paired-sample Student’s t-test to compare pre- and post-hemodynamic data and Mann–Whitney U-test to compare fluid responders and non-responders. P-Values < 0.05 were considered statistically significant.ResultsWe recorded 42 fluid interventions in 40 patients during our study period. The median IQR age was 10.56 (4.8, 14.8) years with male/female ratio (1.2:1). There was a significant decrease in ΔRR [−1.61 (−14.8, 0); p = 0.012], ΔDBP [−5.5 (−14.4, 8); p = 0.027], ΔMAP [−2.2 (−11, 2); p = 0.018], ΔSVR [−5.8 (−20, 5.2); p = 0.025], and ΔSTR [−8.39 (−21, 3); p = 0.001] and significant increase in ΔTFC [6.2 (3.5, 11.4); p = 0.01] following FB. We defined fluid responders by an increase in SV by ≥10% after a single FB of 20 ml/kg crystalloid. Receiver operating curve analysis revealed that among all the parameters, 15% change in ICON had an excellent AUC (0.85) for the fluid responsiveness.ConclusionOur study showed significant changes in objective hemodynamic parameters, such as SVR, STR, and TFC following FB in children presenting with shock. A 15% change in ICON had an excellent predictive performance for the fluid responsiveness among our cohort of pediatric shock.

Assessing Fluid Responsiveness Using Noninvasive Hemodynamic Monitoring in Pediatric Shock: A Review

“…EC has demonstrated both accuracy and efficiency in hemodynamic monitoring in critically ill children; however, very few have investigated FR. 33 65 66 67 Three studies verified the utility of NICOM-derived SVV in predicting FR in the postoperative period. 26 63 68 Interestingly, patients were mechanically ventilated in two of these studies, and spontaneously breathing in one, thus supporting the reliability of NICOM in both clinical situations.…”

“…Awadhare et al investigated a variety of parameters after fluid bolus, including CI, SI, and ∆ICON. 67 While all were good indicators of FR, ∆ICON of 15% demonstrated by NICOM after fluid bolus was most predictive. In the final study, after investigation of PLR in conjunction with CI, Lu et al concluded that at least a 7.5% increase in CI was only predictive in children over 5 years old with 100% sensitivity, which raises uncertainty regarding age limitations for NICOM use.…”

Assessing Passive Leg Raise Test in Pediatric Shock Using Electrical Cardiometry

“…This current endeavor follows a recent study from our institution by Awadhare et al that evaluated a fluid bolus challenge in tandem with the same ICON® monitor. 16 Aside from identifying significant changes in TFC, STR, MAP, and SVR, our prior study concluded that a 15% change in the ICON had strong predictive value in fluid responsiveness. 16 The differing findings in the current study highlight potential incongruences between observed volume expansion provided by the PLR maneuver compared with a physical fluid bolus.…”

“…This determination is known as "fluid responsiveness" and is broadly defined as a 10 to 15% increase in either stroke volume (SV) or cardiac output (CO) following crystalloid fluid bolus. [14][15][16] Passive leg raise (PLR) is a bedside maneuver in which the patient's lower extremities are raised to 45 degrees, to simulate administration of an "auto-bolus." Essentially, this maneuver is thought to facilitate rapid venous return from the lower extremities and augment preload, 17 manifested in both subjective and objective clinical parameters.…”

“…21,22 EC has shown increasing promise in its accuracy and reliability in both critically ill and perioperative populations. [23][24][25] Though previously our team had explored the use of EC in determining hemodynamic changes following fluid bolus in children with shock, 16 we wanted to assess PLR using EC in the pediatric cohort. Thus, our study aimed to assess fluid responsiveness following PLR in children presenting with shock to our emergency department (ED) using EC.…”