M ATERIEL ET METHODES
4 – V ARIABLES RECUEILLIES
4.3 Etude de l’hémodynamique systémique et rénale
Le débit cardiaque était mesuré en continu par le moniteur VolumeView/EV 1000™ System (Edwards Lifesciences, Irvine CA, USA), permettant d’obtenir en continu les valeurs de débit et d’index cardiaque grâce à un algorithme ainsi que des données volumétriques grâce à une technique de thermodilution transpulmonaire (VESi Volume d’éjection systolique indexé, VVE Variation du volume d’éjection, RVSi Résistances vasculaires systémiques indexées).
Les données de pressions artérielles systoliques, diastoliques, moyennes, étaient mesurées en continu par un cathéter artériel invasif fémoral et la fréquence cardiaque grâce à un électrocardioscope. Etaient également analysés en continu la température centrale, les valeurs d’EtCO2 et la pression veineuse centrale (PVC), mesurée à l’aide d’une voie veineuse centrale
3 lumières positionnée en territoire cave supérieur.
Seules les données obtenues en échographie étaient colligées de façon discontinue : une échographie cardiaque trans-thoracique et un doppler rénal étaient réalisés de façon répétée lors de l’inclusion, à l’initiation et à la fin de chaque phase de traitement. Les données étaient recueillies sur l’appareil CompactXtreme Ultrasound system CX 50™, Philips Healthcare, associant l’utilisation d’une sonde sectorielle S5-1 (1 à 5 MHz) pour l’échographie cardiaque et une sonde convexe C5-1 (1 à 5 MHz) pour l’échographie rénale.
L’échographie cardiaque trans-thoracique colligeait pour chaque patient, et à chaque étape de traitement, une mesure du débit cardiaque. Cette dernière était évaluée par l’intégrale temps- vitesse sous aortique (en coupe apicale 5 cavités) pendant la systole, de la surface de la chambre de chasse du ventricule gauche sous aortique (en coupe parasternale grand axe) et de la fréquence cardiaque. Etaient également relevées la fonction contractile du ventricule
4.3 Etude de l’hémodynamique systémique et rénale
Le débit cardiaque était mesuré en continu par le moniteur VolumeView/EV 1000™ System (Edwards Lifesciences, Irvine CA, USA), permettant d’obtenir en continu les valeurs de débit et d’index cardiaque grâce à un algorithme ainsi que des données volumétriques grâce à une technique de thermodilution transpulmonaire (VESi Volume d’éjection systolique indexé, VVE Variation du volume d’éjection, RVSi Résistances vasculaires systémiques indexées).
Les données de pressions artérielles systoliques, diastoliques, moyennes, étaient mesurées en continu par un cathéter artériel invasif fémoral et la fréquence cardiaque grâce à un électrocardioscope. Etaient également analysés en continu la température centrale, les valeurs d’EtCO2 et la pression veineuse centrale (PVC), mesurée à l’aide d’une voie veineuse centrale
3 lumières positionnée en territoire cave supérieur.
Seules les données obtenues en échographie étaient colligées de façon discontinue : une échographie cardiaque trans-thoracique et un doppler rénal étaient réalisés de façon répétée lors de l’inclusion, à l’initiation et à la fin de chaque phase de traitement. Les données étaient recueillies sur l’appareil CompactXtreme Ultrasound system CX 50™, Philips Healthcare, associant l’utilisation d’une sonde sectorielle S5-1 (1 à 5 MHz) pour l’échographie cardiaque et une sonde convexe C5-1 (1 à 5 MHz) pour l’échographie rénale.
L’échographie cardiaque trans-thoracique colligeait pour chaque patient, et à chaque étape de traitement, une mesure du débit cardiaque. Cette dernière était évaluée par l’intégrale temps- vitesse sous aortique (en coupe apicale 5 cavités) pendant la systole, de la surface de la chambre de chasse du ventricule gauche sous aortique (en coupe parasternale grand axe) et de la fréquence cardiaque. Etaient également relevées la fonction contractile du ventricule
gauche et sa fraction d’éjection (FeVG) évaluée visuellement sur les différentes incidences ainsi que selon la formule de Teicholz en coupe parasternale grand axe, en l’absence de contre-indication à son emploi [94-96]. Enfin, l’examen comprenait la recherche d’une valvulopathie ou d’une cardiopathie éventuelle.
L’évaluation rénale associait une mesure doppler des vitesses systoliques, moyennes et diastoliques d’une artère interlobaire ou arquée, associée aux index de pulsatilité (IP) et de résistivité (IR) rénaux, telles que décrites par Schnell et al. et présentées dans la figure 33 [59].
gauche et sa fraction d’éjection (FeVG) évaluée visuellement sur les différentes incidences ainsi que selon la formule de Teicholz en coupe parasternale grand axe, en l’absence de contre-indication à son emploi [94-96]. Enfin, l’examen comprenait la recherche d’une valvulopathie ou d’une cardiopathie éventuelle.
L’évaluation rénale associait une mesure doppler des vitesses systoliques, moyennes et diastoliques d’une artère interlobaire ou arquée, associée aux index de pulsatilité (IP) et de résistivité (IR) rénaux, telles que décrites par Schnell et al. et présentées dans la figure 33 [59].
dependent. Thus, RI values greater than 0.70 have been described in healthy children younger than 4 years of age [20], and in individuals older than 60 years who had normal renal function [21]. When the RI is measured for both kidneys, the side-to-side difference is usually less than 5 % [22].
Since RI depends in part on the minimum dia- stolic shift, it may be influenced by the heart rate [23]. According to observations performed by Mostbeck et al. [23] regarding RI changes as a consequence of heart rate variations a formula was developed to correct the RI value for heart rate: ½Corrected RI ¼ observed RI # 0:0026$ 80 # heart rateð Þ': However, the influence of heart rate per se on RI remains unclear, and this formula which has not been validated is usually not used in clin- ical practice [24, 25]. Arrhythmias and especially atrial fibrillation may impact renal RI measurement and
interpretation. This issue has, however, never been stud- ied to our knowledge and most of the studies excluded patients with atrial fibrillation or arrhythmia.
Fig. 1 Vasculature of the kidney. (Adapted by permission from Macmillan Publishers Ltd: Nature Reviews Nephrology; Mimura and Nangaku 2010 [81])
Table 2 Ten-step process to measure Doppler-based renal resistive index (RI)
Step 1 Use (if available) a convex transducer dedicated to abdominal exploration
Step 2 Obtain a B-mode kidney longitudinal scan in a postero- lateral approach
Step 3 Identify intra-renal vessels using colour-Doppler (Fig.2a) Step 4 Localize an interlobar or arcuate artery (Fig.2b) Step 5 Set pulsed wave Doppler as follows:
Smallest Doppler gate (2–5 mm)
Lowest pulse repetition frequency without aliasing Highest gain without background noise
Step 6 Obtain 3–5 consecutive similar-appearing waveforms (Fig.2b)
Step 7 Measure peak systolic and minimum diastolic velocities Step 8 Compute RI for each waveforms
Step 9 Average 3–5 measures to obtain definitive RI value Step 10 Check the controlateral kidney
Fig. 2 Results of a renal colour-Doppler ultrasonography showing renal vascularisation (a). RI measurement using pulsed wave Doppler (b)
1753
Fig. 33 Réalisation du doppler rénal en réanimation. D’après Schnell et al. [59]
dependent. Thus, RI values greater than 0.70 have been described in healthy children younger than 4 years of age [20], and in individuals older than 60 years who had normal renal function [21]. When the RI is measured for both kidneys, the side-to-side difference is usually less than 5 % [22].
Since RI depends in part on the minimum dia- stolic shift, it may be influenced by the heart rate [23]. According to observations performed by Mostbeck et al. [23] regarding RI changes as a consequence of heart rate variations a formula was developed to correct the RI value for heart rate: ½Corrected RI ¼ observed RI # 0:0026$ 80 # heart rateð Þ': However, the influence of heart rate per se on RI remains unclear, and this formula which has not been validated is usually not used in clin- ical practice [24, 25]. Arrhythmias and especially atrial fibrillation may impact renal RI measurement and
interpretation. This issue has, however, never been stud- ied to our knowledge and most of the studies excluded patients with atrial fibrillation or arrhythmia.
Fig. 1 Vasculature of the kidney. (Adapted by permission from Macmillan Publishers Ltd: Nature Reviews Nephrology; Mimura and Nangaku 2010 [81])
Table 2 Ten-step process to measure Doppler-based renal resistive index (RI)
Step 1 Use (if available) a convex transducer dedicated to abdominal exploration
Step 2 Obtain a B-mode kidney longitudinal scan in a postero- lateral approach
Step 3 Identify intra-renal vessels using colour-Doppler (Fig.2a) Step 4 Localize an interlobar or arcuate artery (Fig.2b) Step 5 Set pulsed wave Doppler as follows:
Smallest Doppler gate (2–5 mm)
Lowest pulse repetition frequency without aliasing Highest gain without background noise
Step 6 Obtain 3–5 consecutive similar-appearing waveforms (Fig.2b)
Step 7 Measure peak systolic and minimum diastolic velocities Step 8 Compute RI for each waveforms
Step 9 Average 3–5 measures to obtain definitive RI value Step 10 Check the controlateral kidney
Fig. 2 Results of a renal colour-Doppler ultrasonography showing renal vascularisation (a). RI measurement using pulsed wave Doppler (b)
1753
dependent. Thus, RI values greater than 0.70 have been described in healthy children younger than 4 years of age [20], and in individuals older than 60 years who had normal renal function [21]. When the RI is measured for both kidneys, the side-to-side difference is usually less than 5 % [22].
Since RI depends in part on the minimum dia- stolic shift, it may be influenced by the heart rate [23]. According to observations performed by Mostbeck et al. [23] regarding RI changes as a consequence of heart rate variations a formula was developed to correct the
RI value for heart rate: ½Corrected RI ¼ observed RI #
0:0026$ 80 # heart rateð Þ': However, the influence of
heart rate per se on RI remains unclear, and this formula which has not been validated is usually not used in clin-
ical practice [24, 25]. Arrhythmias and especially atrial
fibrillation may impact renal RI measurement and
interpretation. This issue has, however, never been stud- ied to our knowledge and most of the studies excluded patients with atrial fibrillation or arrhythmia.
Fig. 1 Vasculature of the kidney. (Adapted by permission from Macmillan Publishers Ltd: Nature Reviews Nephrology; Mimura and Nangaku 2010 [81])
Table 2 Ten-step process to measure Doppler-based renal resistive index (RI)
Step 1 Use (if available) a convex transducer dedicated to abdominal exploration
Step 2 Obtain a B-mode kidney longitudinal scan in a postero- lateral approach
Step 3 Identify intra-renal vessels using colour-Doppler (Fig.2a) Step 4 Localize an interlobar or arcuate artery (Fig.2b) Step 5 Set pulsed wave Doppler as follows:
Smallest Doppler gate (2–5 mm)
Lowest pulse repetition frequency without aliasing Highest gain without background noise
Step 6 Obtain 3–5 consecutive similar-appearing waveforms (Fig.2b)
Step 7 Measure peak systolic and minimum diastolic velocities Step 8 Compute RI for each waveforms
Step 9 Average 3–5 measures to obtain definitive RI value Step 10 Check the controlateral kidney
Fig. 2 Results of a renal colour-Doppler ultrasonography showing renal vascularisation (a). RI measurement using pulsed wave Doppler (b)
1753
dependent. Thus, RI values greater than 0.70 have been described in healthy children younger than 4 years of age [20], and in individuals older than 60 years who had normal renal function [21]. When the RI is measured for both kidneys, the side-to-side difference is usually less than 5 % [22].
Since RI depends in part on the minimum dia- stolic shift, it may be influenced by the heart rate [23]. According to observations performed by Mostbeck et al. [23] regarding RI changes as a consequence of heart rate variations a formula was developed to correct the RI value for heart rate: ½Corrected RI ¼ observed RI # 0:0026$ 80 # heart rateð Þ': However, the influence of heart rate per se on RI remains unclear, and this formula which has not been validated is usually not used in clin- ical practice [24, 25]. Arrhythmias and especially atrial fibrillation may impact renal RI measurement and
interpretation. This issue has, however, never been stud- ied to our knowledge and most of the studies excluded patients with atrial fibrillation or arrhythmia.
Fig. 1 Vasculature of the kidney. (Adapted by permission from Macmillan Publishers Ltd: Nature Reviews Nephrology; Mimura and Nangaku 2010 [81])
Table 2 Ten-step process to measure Doppler-based renal resistive index (RI)
Step 1 Use (if available) a convex transducer dedicated to abdominal exploration
Step 2 Obtain a B-mode kidney longitudinal scan in a postero- lateral approach
Step 3 Identify intra-renal vessels using colour-Doppler (Fig.2a) Step 4 Localize an interlobar or arcuate artery (Fig.2b) Step 5 Set pulsed wave Doppler as follows:
Smallest Doppler gate (2–5 mm)
Lowest pulse repetition frequency without aliasing Highest gain without background noise
Step 6 Obtain 3–5 consecutive similar-appearing waveforms (Fig.2b)
Step 7 Measure peak systolic and minimum diastolic velocities Step 8 Compute RI for each waveforms
Step 9 Average 3–5 measures to obtain definitive RI value Step 10 Check the controlateral kidney
Fig. 2 Results of a renal colour-Doppler ultrasonography showing renal vascularisation (a). RI measurement using pulsed wave Doppler (b)
1753
Fig. 33 Réalisation du doppler rénal en réanimation. D’après Schnell et al. [59]
dependent. Thus, RI values greater than 0.70 have been described in healthy children younger than 4 years of age [20], and in individuals older than 60 years who had normal renal function [21]. When the RI is measured for both kidneys, the side-to-side difference is usually less than 5 % [22].
Since RI depends in part on the minimum dia- stolic shift, it may be influenced by the heart rate [23]. According to observations performed by Mostbeck et al. [23] regarding RI changes as a consequence of heart rate variations a formula was developed to correct the RI value for heart rate: ½Corrected RI ¼ observed RI # 0:0026$ 80 # heart rateð Þ': However, the influence of heart rate per se on RI remains unclear, and this formula which has not been validated is usually not used in clin- ical practice [24, 25]. Arrhythmias and especially atrial fibrillation may impact renal RI measurement and
interpretation. This issue has, however, never been stud- ied to our knowledge and most of the studies excluded patients with atrial fibrillation or arrhythmia.
Fig. 1 Vasculature of the kidney. (Adapted by permission from Macmillan Publishers Ltd: Nature Reviews Nephrology; Mimura and Nangaku 2010 [81])
Table 2 Ten-step process to measure Doppler-based renal resistive index (RI)
Step 1 Use (if available) a convex transducer dedicated to abdominal exploration
Step 2 Obtain a B-mode kidney longitudinal scan in a postero- lateral approach
Step 3 Identify intra-renal vessels using colour-Doppler (Fig.2a) Step 4 Localize an interlobar or arcuate artery (Fig.2b) Step 5 Set pulsed wave Doppler as follows:
Smallest Doppler gate (2–5 mm)
Lowest pulse repetition frequency without aliasing Highest gain without background noise
Step 6 Obtain 3–5 consecutive similar-appearing waveforms (Fig.2b)
Step 7 Measure peak systolic and minimum diastolic velocities Step 8 Compute RI for each waveforms
Step 9 Average 3–5 measures to obtain definitive RI value Step 10 Check the controlateral kidney
Fig. 2 Results of a renal colour-Doppler ultrasonography showing renal vascularisation (a). RI measurement using pulsed wave Doppler (b)
1753
dependent. Thus, RI values greater than 0.70 have been described in healthy children younger than 4 years of age [20], and in individuals older than 60 years who had normal renal function [21]. When the RI is measured for both kidneys, the side-to-side difference is usually less than 5 % [22].
Since RI depends in part on the minimum dia- stolic shift, it may be influenced by the heart rate [23]. According to observations performed by Mostbeck et al. [23] regarding RI changes as a consequence of heart rate variations a formula was developed to correct the
RI value for heart rate: ½Corrected RI ¼ observed RI #
0:0026$ 80 # heart rateð Þ': However, the influence of
heart rate per se on RI remains unclear, and this formula which has not been validated is usually not used in clin-
ical practice [24, 25]. Arrhythmias and especially atrial
fibrillation may impact renal RI measurement and
interpretation. This issue has, however, never been stud- ied to our knowledge and most of the studies excluded patients with atrial fibrillation or arrhythmia.
Fig. 1 Vasculature of the kidney. (Adapted by permission from Macmillan Publishers Ltd: Nature Reviews Nephrology; Mimura and Nangaku 2010 [81])
Table 2 Ten-step process to measure Doppler-based renal resistive index (RI)
Step 1 Use (if available) a convex transducer dedicated to abdominal exploration
Step 2 Obtain a B-mode kidney longitudinal scan in a postero- lateral approach
Step 3 Identify intra-renal vessels using colour-Doppler (Fig.2a) Step 4 Localize an interlobar or arcuate artery (Fig.2b) Step 5 Set pulsed wave Doppler as follows:
Smallest Doppler gate (2–5 mm)
Lowest pulse repetition frequency without aliasing Highest gain without background noise
Step 6 Obtain 3–5 consecutive similar-appearing waveforms (Fig.2b)
Step 7 Measure peak systolic and minimum diastolic velocities Step 8 Compute RI for each waveforms
Step 9 Average 3–5 measures to obtain definitive RI value Step 10 Check the controlateral kidney
Fig. 2 Results of a renal colour-Doppler ultrasonography showing renal vascularisation (a). RI measurement using pulsed wave Doppler (b)