Effects of fluid administration on arterial load in septic shock patients

Manuel Ignacio Monge García (1,2), Pedro Guijo González (1), Manuel Gracia Romero (1), Anselmo Gil Cano (1), Chris Oscier (2), Andrew Rhodes (2), Robert Michael Grounds (2), Maurizio Cecconi (2)

(1)Servicio de Cuidados Intensivos y Urgencias, Hospital SAS de Jerez, Jerez de la Frontera, Spain.

(2)Department of Intensive Care Medicine, St. George’s Healthcare NHS Trust and St George’s University of London, London, United Kingdom.

ELECTRONIC SUPPLEMENTARY MATERIAL

Table 1. Changes in arterial load parameters in preload non-responders (CO increase < 10% after fluid administration) categorized according to their mean arterial pressure increase (pressure responders = mean arterial pressure increase ≥ 10% after fluid administration).
Before fluid expansion / After fluid expansion / p valuea
Ea, mmHg/mL
Pressure responders / 1.21 (1.01 to 1.53) / 1.37 (1.01 to 1.71) / 0.26
Pressure nonresponders / 1.43 (1.01 to 1.96) / 1.38 (1.07 to 1.93)
C, mL/mmHg
Pressure responders / 1.76 (1.37 to 2.05) / 1.69 (1.21 to 1.77) / 0.11
Pressure nonresponders / 1.33 (1.04 to 1.77) / 1.37 (0.92 to 1.73)
SVR, dyn∙s∙cm-5
Pressure responders / 645 (607 to 1256) / 807 (657 to 1342) / 0.09
Pressure nonresponders / 981 (629 to 1636) / 965 (646 to 1744)
Tau, s
Pressure responders / 0.90 (0.80 to 1.18) / 0.96 (0.82 to 1.16) / 0.79
Pressure nonresponders / 0.93 (0.66 to 1.52) / 0.99 (0.64 to 1.49)
Data are expressed as the median(25th to 75th percentile).Ea: effective arterial elastance; C: net arterial compliance;SVR: systemic vascular resistance; Tau: arterial time constant.
a p value refers to group-interaction in repeated ANOVA analysis.
Table 2. Effects of volume expansion on effective arterial elastance (Ea), using mean arterial pressure (MAP) as surrogate for end-systolic pressure.
Before volume expansion / After volume expansion / p value
Preload-responders / 1.33 (0.76 to 1.69) / 1.12 (0.97 to 1.32)*** / / < 0.001b
Pressure-responders / 1.25 (0.71 to 1.55) / 1.12 (0.72 to 1.57)* / / 0.005a
Pressure non-responders / 1.35 (0.79 to 1.81) / 1.13 (0.75 to 1.36)***
Preload-nonresponders / 1.10 (0.77 to 1.54) / 1.03 (0.75 to 1.41)
Pressure-responders / 0.92 (0.77 to 1.30) / 1.03 (0.78 to 1.45) / / 0.264a
Pressure non-responders / 1.11 (0.74 to 1.55) / 1.06 (0.70 to 1.41)
* p < 0.05, ** p < 0.0001 vs. before volume expansion.
p value refers to group-interaction (a: pressure vs pressure non-responders; b: preload vs preload non-responders) in repeated ANOVA analysis (after logarithmic transformation).
Table 3. Relative changes induced by fluid administration in arterial load parameters according to type of fluid administrated.
NORMAL SALINE
(n = 58) / HES
(n=23) / p valuea
ΔMAP, % / 7 (2 to 14) / 4 (2 to 11) / 0.72
ΔEa, % / -3 (-12 to 3) / -7 (-19 to 1) / 0.13
ΔC, % / -1 (-10 to -8) / 2 (-5 to 18) / 0.23
ΔSVR, % / -2 (-10 to 4) / -6 (-17 to 1) / 0.09
ΔTau, % / -1 (-7 to 4) / -5 (-12 to 6) / 0.62
Data are expressed as the median(25th to 75th percentile). ΔC: fluid-induced changes in net arterial compliance; ΔEa: fluid-induced changes in effective arterial elastance; ΔMAP: fluid-induced changes in mean arterial pressure; ΔSVR: fluid-induced changes in systemic vascular resistance;ΔTau: fluid-induced changes in arterial time constant.
a p value refers to normal saline vs HES.
Table 4. Preinfusion values and relative changes induced by fluid administration in arterial load parameters according to presence of vasopressor support.
VASOPRESSOR
(n = 58) / NO VASOPRESSOR
(n = 23) / p valuea
Baseline parameters
Ea, mmHg/mL / 1.70 (1.11 to 2.37) / 1.46 (1.21 to 2.01) / 0.37
C, mL/mmHg / 1.15 (0.76 to 1.48) / 1.38 (1.10 to 1.92) / 0.03
SVR, dyn∙s∙cm-5 / 994 (629 to 1636) / 1035 (778 to 1301) / 1
Tau, s / 0.82 (0.63 to 1.04) / 0.95 (0.82 to 1.41) / 0.02
MAP, mmHg / 74 (60 to 80) / 69 (64 to 76) / 0.30
Changes after VE
ΔMAP (%) / 5 (2 to 14) / 8 (2 to 11) / 0.80
ΔEa (%) / -4 (-15 to 2) / -3 (-13 to 2) / 0.60
ΔC (%) / 0 (-8 to 12) / -1 (-11 to 16) / 0.62
ΔSVR (%) / -5 (-13 to 2) / -2 (-6 to 7) / 0.18
ΔTau (%) / -3 (-11 to 4) / -3 (-7 to 6) / 0.47
Data are expressed as median(25th to 75th percentile). C: net arterial compliance; Ea: effective arterial elastance; MAP: mea arterial pressure; SVR: systemic vascular resistance; Tau: time constant for arterial system; VE: volume expansion; ΔC: fluid-induced changes in net arterial compliance; ΔEa: fluid-induced changes in effective arterial elastance; ΔMAP: fluid-induced changes in mean arterial pressure; ΔSVR: fluid-induced changes in systemic vascular resistance;ΔTau: fluid-induced changes in arterial time constant.
a p value refers to patients with vs without vasopressor support.
Figure 1. Relationship and concordance analysis between stroke volume and arterial pressure changes after volume administration in septic shock patients.
DAP: diastolic arterial pressure; MAP: mean arterial pressure; PP: arterial pulse pressure; SV: stroke volume; SYS: systolic arterial pressure. Concordance: percentage of data in which the direction of change agreed.
Figure 2. Prediction of arterial pressure response by arterial load parameters in preload-responder patients.
Comparison of ROC curves for testing the ability of arterial load parameters to detect a mean arterial pressure (MAP) increase ≥ 10% after volume administration in preload-responder patients. All ROC curves were not significant.
Figure 3. Prediction of arterial pressure response by arterial load parameters in hypotensive patients.
Comparison of ROC curves for testing the ability of arterial load parameters to detect a mean arterial pressure (MAP) increase ≥ 10% after volume administration in preload-responder patients. All ROC curves were not significant.