Cardiac Preload in Children With CV Dysfunction or Dilated CM
Cardiac Preload in Children With CV Dysfunction or Dilated CM
A total of 890 different TPTD assessments performed in 99 pediatric patients equipped with a femoral arterial and a central venous catheter were recorded. From the 99 patients, only 75 (598 TPTD assessments) who fulfilled the criteria for normal cardiovascular status, cardiovascular dysfunction, or dilated cardiomyopathy were included into the analysis. Table 1 shows the characteristics of the patients and Table 2 the hemodynamic variables of every group. Of the 61 patients with cardiovascular dysfunction, 22 had sepsis at admission and 59 fulfilled the criteria for septic shock or had shock associated with SIRS during at least one TPTD assessment throughout their PICU admission, two had burn shock, and one had shock associated with Kawasaki disease. In order to test the patient's fluid responsiveness at distinct preload levels, SVI, CI, and GEDVI were measured in 33 patients with cardiovascular dysfunction and in seven with dilated cardiomyopathy, respectively, before and after 53 (normal saline [NS] 14, albumin 5% [Ab5%] 4, fresh frozen plasma [FFP] 10, packed RBCs [PRBCs] 14, platelets 8, other colloids 3) and 13 (NS 1, hypertonic saline 3% [HS3%] 4, Ab5% 4, PRBCs 4) fluid challenge and fluid loading events. Clinical decisions concerning fluid challenge and fluid loading were made by the PICU physician in charge according to the patient's clinical needs. The median infusion time for the fluid loading and fluid challenge was 33 minutes (interquartile range [IQR], 16–90 min) in the cardiovascular dysfunction and 30 minutes (IQR, 20–30 min) in the dilated cardiomyopathy group. Figure 1 shows the total volume infused at every preload level in the two groups of patients.
(Enlarge Image)
Figure 1.
Fluid responsiveness observations. A, Stroke volume index (SVI) versus global end-diastolic volume index (GEDVI)/normal global end-diastolic volume index (GEDVIN) before and after fluid loading and fluid challenge in patients with cardiovascular dysfunction (black circles) and dilated cardiomyopathy (white circles). B, Boxplot graphs show the percent of SVI and GEDVI change after volume loading according to patients' preinfusion GEDVI/GEDVIN. The boundary of the box closest to zero indicates the 25th percentile, a line within the box marks the median, and the boundary of the box farthest from zero indicates the 75th percentile. Error bars above and below the box indicate the 90th and 10th percentiles. The black little circles are the outlying points. Area under the receiver-operating characteristic curve (AUC) represents the probability that a subject with a defined preinfusion cardiac preload status will exhibit a higher SVI after a volume loading and fluid challenge: minimum AUC = 0.5. GEDVI/GEDVIN = normalized GEDVI, N = number of patients (number of fluid loading and fluid challenge), VI = volume infused in mL/kg, ΔGEDVI = % GEDVI change after volume loading and fluid challenge, ΔSVI = % SVI change after volume loading and fluid challenge, ΔSVI > 15% = % patients with a SVI increase > 15% after fluid loading and fluid challenge. Data (in A) are (25th percentile, median, 75th percentile).
GEDV versus PBSA exhibited a power-law relationship: GEDV = 488.8·PBSA (SD = 97.4 mL; R = 0.93; p < 0.0001; mean square residual = 0.46). Therefore, "normal" GEDVI (GEDVIN) = 488.8·PBSA. The limits of the four levels of cardiac preload, ≤ 0.67, > 0.67 ≤ 1.33, > 1.33 ≤ 1.51, and > 1.51 times GEDVIN (Fig. 2), were set according to 90% and upper 99% GEDVIN CIs, respectively, and were associated with distinct degrees of cardiac preload responsiveness (Figs. 1 and 3): presence of preload responsiveness below 1.33 times GEDVIN, with the highest expected preload responsiveness below 0.67 times GEDVIN; decreased preload responsiveness above 1.33 times GEDVIN, with the maximum efficacy of the Frank-Starling response between > 1.33 and ≤ 1.51 times GEDVIN; and absence of preload responsiveness with maximum expected lung edema above 1.51 times GEDVIN.
(Enlarge Image)
Figure 2.
" Normal" global end-diastolic volume index (GEDVI) values in children. GEDVI versus predicted body surface area (PBSA) "normal" GEDVI (GEDVIN) line was calculated from GEDVIN = 488.8·PBSA. The lines corresponding to 0.67, 1.33, and 1.51 times GEDVIN were set according to 90% and upper 99% GEDVIN CIs, respectively, and define four levels of GEDVI-based cardiac preload.
The relationships of GEDVI/GEDVIN with SVI, CI, and EVLWI are shown in Figure 3. The SVI responses to fluid infusion at the different levels of preinfusion GEDVI/GEDVIN are presented in Figure 1.
(Enlarge Image)
Figure 3.
Normalized cardiac preload (global end-diastolic volume index [GEDVI]/normal global end-diastolic volume index [GEDVIN]) versus stroke volume index (SVI), cardiac index (CI), and extravascular lung water index (EVLWI) in patients with cardiovascular dysfunction (black circles) and dilated cardiomyopathy (white circles). Data are geometric mean with error bars corresponding to 95% CIs. Secondorder polynomial curves were used to fit data points. SVI and CI graphs emulate Frank-Starling curves with their steep and plateau phases. The highest EVLWI values are linked with the plateau phase. Area under the receiver-operating characteristic curve (AUC) represents the probability that a randomly selected subject with a defined cardiac preload status (GEDVI/GEDVIN) will exhibit a different hemodynamic response (higher SVI, CI, or EVLWI) than a randomly selected subject with a lower preload status; minimum AUC = 0.5. GEDVI/GEDVIN = normalized GEDVI, ΔCI = % CI change, ΔEVLWI = % EVLWI change, ΔSVI = % SVI change.
There were no statistically significant differences on SBP between the cardiac preload levels (p = 1): "≤ 0.67 times GEDVIN" 94 (85–104) mm Hg (geometric mean [95% CI]), "> 0.67 ≤ 1.33 times GEDVIN" 98 (95–102) mm Hg, "> 1.33 ≤ 1.51 times GEDVIN" 96 (90–102) mm Hg, and "> 1.51 times GEDVIN" 97 (92–102) mm Hg.
Results
A total of 890 different TPTD assessments performed in 99 pediatric patients equipped with a femoral arterial and a central venous catheter were recorded. From the 99 patients, only 75 (598 TPTD assessments) who fulfilled the criteria for normal cardiovascular status, cardiovascular dysfunction, or dilated cardiomyopathy were included into the analysis. Table 1 shows the characteristics of the patients and Table 2 the hemodynamic variables of every group. Of the 61 patients with cardiovascular dysfunction, 22 had sepsis at admission and 59 fulfilled the criteria for septic shock or had shock associated with SIRS during at least one TPTD assessment throughout their PICU admission, two had burn shock, and one had shock associated with Kawasaki disease. In order to test the patient's fluid responsiveness at distinct preload levels, SVI, CI, and GEDVI were measured in 33 patients with cardiovascular dysfunction and in seven with dilated cardiomyopathy, respectively, before and after 53 (normal saline [NS] 14, albumin 5% [Ab5%] 4, fresh frozen plasma [FFP] 10, packed RBCs [PRBCs] 14, platelets 8, other colloids 3) and 13 (NS 1, hypertonic saline 3% [HS3%] 4, Ab5% 4, PRBCs 4) fluid challenge and fluid loading events. Clinical decisions concerning fluid challenge and fluid loading were made by the PICU physician in charge according to the patient's clinical needs. The median infusion time for the fluid loading and fluid challenge was 33 minutes (interquartile range [IQR], 16–90 min) in the cardiovascular dysfunction and 30 minutes (IQR, 20–30 min) in the dilated cardiomyopathy group. Figure 1 shows the total volume infused at every preload level in the two groups of patients.
(Enlarge Image)
Figure 1.
Fluid responsiveness observations. A, Stroke volume index (SVI) versus global end-diastolic volume index (GEDVI)/normal global end-diastolic volume index (GEDVIN) before and after fluid loading and fluid challenge in patients with cardiovascular dysfunction (black circles) and dilated cardiomyopathy (white circles). B, Boxplot graphs show the percent of SVI and GEDVI change after volume loading according to patients' preinfusion GEDVI/GEDVIN. The boundary of the box closest to zero indicates the 25th percentile, a line within the box marks the median, and the boundary of the box farthest from zero indicates the 75th percentile. Error bars above and below the box indicate the 90th and 10th percentiles. The black little circles are the outlying points. Area under the receiver-operating characteristic curve (AUC) represents the probability that a subject with a defined preinfusion cardiac preload status will exhibit a higher SVI after a volume loading and fluid challenge: minimum AUC = 0.5. GEDVI/GEDVIN = normalized GEDVI, N = number of patients (number of fluid loading and fluid challenge), VI = volume infused in mL/kg, ΔGEDVI = % GEDVI change after volume loading and fluid challenge, ΔSVI = % SVI change after volume loading and fluid challenge, ΔSVI > 15% = % patients with a SVI increase > 15% after fluid loading and fluid challenge. Data (in A) are (25th percentile, median, 75th percentile).
GEDV versus PBSA exhibited a power-law relationship: GEDV = 488.8·PBSA (SD = 97.4 mL; R = 0.93; p < 0.0001; mean square residual = 0.46). Therefore, "normal" GEDVI (GEDVIN) = 488.8·PBSA. The limits of the four levels of cardiac preload, ≤ 0.67, > 0.67 ≤ 1.33, > 1.33 ≤ 1.51, and > 1.51 times GEDVIN (Fig. 2), were set according to 90% and upper 99% GEDVIN CIs, respectively, and were associated with distinct degrees of cardiac preload responsiveness (Figs. 1 and 3): presence of preload responsiveness below 1.33 times GEDVIN, with the highest expected preload responsiveness below 0.67 times GEDVIN; decreased preload responsiveness above 1.33 times GEDVIN, with the maximum efficacy of the Frank-Starling response between > 1.33 and ≤ 1.51 times GEDVIN; and absence of preload responsiveness with maximum expected lung edema above 1.51 times GEDVIN.
(Enlarge Image)
Figure 2.
" Normal" global end-diastolic volume index (GEDVI) values in children. GEDVI versus predicted body surface area (PBSA) "normal" GEDVI (GEDVIN) line was calculated from GEDVIN = 488.8·PBSA. The lines corresponding to 0.67, 1.33, and 1.51 times GEDVIN were set according to 90% and upper 99% GEDVIN CIs, respectively, and define four levels of GEDVI-based cardiac preload.
The relationships of GEDVI/GEDVIN with SVI, CI, and EVLWI are shown in Figure 3. The SVI responses to fluid infusion at the different levels of preinfusion GEDVI/GEDVIN are presented in Figure 1.
(Enlarge Image)
Figure 3.
Normalized cardiac preload (global end-diastolic volume index [GEDVI]/normal global end-diastolic volume index [GEDVIN]) versus stroke volume index (SVI), cardiac index (CI), and extravascular lung water index (EVLWI) in patients with cardiovascular dysfunction (black circles) and dilated cardiomyopathy (white circles). Data are geometric mean with error bars corresponding to 95% CIs. Secondorder polynomial curves were used to fit data points. SVI and CI graphs emulate Frank-Starling curves with their steep and plateau phases. The highest EVLWI values are linked with the plateau phase. Area under the receiver-operating characteristic curve (AUC) represents the probability that a randomly selected subject with a defined cardiac preload status (GEDVI/GEDVIN) will exhibit a different hemodynamic response (higher SVI, CI, or EVLWI) than a randomly selected subject with a lower preload status; minimum AUC = 0.5. GEDVI/GEDVIN = normalized GEDVI, ΔCI = % CI change, ΔEVLWI = % EVLWI change, ΔSVI = % SVI change.
There were no statistically significant differences on SBP between the cardiac preload levels (p = 1): "≤ 0.67 times GEDVIN" 94 (85–104) mm Hg (geometric mean [95% CI]), "> 0.67 ≤ 1.33 times GEDVIN" 98 (95–102) mm Hg, "> 1.33 ≤ 1.51 times GEDVIN" 96 (90–102) mm Hg, and "> 1.51 times GEDVIN" 97 (92–102) mm Hg.
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