Jinlong Wang
BACKGROUND
Intensive Care Med. 2013;39:420–8.
BACKGROUND
Intensive Care Med. 2013;39:420–8.
BACKGROUND
Renal perfusion at the microvascular level
renal hypoperfusion
renal blood flow overloading
CEUS
■Renal contrast-enhanced ultrasound (CEUS) ■During CEUS, the use of intravenous contrast product increases blood echogenicity and enhances the visualization of microcirculatory renal perfusion when using ultrasonography.
■Good correlation has been demonstrated between CEUS measurements of renal perfusion and gold standard renal blood flow measurements.
Hypertens Res 2002;25:77–83.
RESEARCH GAP
Lack of clinical data on renal microcirculatory perfusion during septic shock
AIM OF THIS STUDY
METHODS
Patients(Septic shock Group,n=20)Inclusion criteria Exclusion criteria Adult ICU patients Pregnancy
Diagnosis of septic shock with SIRS criteria
Left ventricular ejection fraction <30%
Systolic pulmonary arterial pressure > 90 mmHg recent ischemic heart disease (within < 7 days) chronic hemodialysis.
METHODS
Patients(Control Group,n=10)Inclusion criteria Exclusion criteria Adult ICU patients Pregnancy
Traumatic brain injury or stroke
Left ventricular ejection fraction <30%
Without septic shock Systolic pulmonary arterial pressure > 90 mmHg recent ischemic heart disease (within < 7 days) chronic hemodialysis.
METHODS
CEUS measurements ■Measuring time:D0(0-24h),D1(24-48h),D3(after 72h)■Contrast ultrasound agent:The Sonovue(Bracco, Milano,
Italy)■Agent infusion:infused through central venous catheter
with at a rate of 1 mL.min■Ultrasonic measurement:The left kidney was visualized in B
mode in its long axis view with an abdominal convex probe. After 2 min of contrast ultrasound agent administration, three consecutive sequences (15s) were acquired.
METHODS
CEUS sequences analysis ■Renal perfusion was analyzed using VueBox v4.3
software■mTT (mean transit time, seconds) is the time needed
after contrast agent destruction to reach 50% of the maximal intensity signal
■rBV (renal blood volume, a.u.) is a measure of the maximal intensity
■PI (perfusion index) is calculated by dividing rBV by mTT
METHODS
Statistical analysis ■Comparisons of characteristics between septic shock group
and CL group:t test or the Mann Whitney test■Comparison of proportions:Chi-squared test ■Comparisons of CEUS parameters over time in septic shock
group:one factor ANOVA and post hoc analysis■Comparisons of CEUS parameters over time between the
septic shock group and CL or AKI and no AKI in patients with septic shock or ICU survivors and ICU non survivors in patients with septic shock:two way ANOVA analysis
METHODS
Statistical analysis ■Variables discriminate patients according to the
occurrence of severe AKI:ROC curve
■Missing data: Attributing the same value as the previous measure
RESULTS
RESULTS
RESULTS
RESULTS
RESULTS
RESULTS
DISCUSSION
Finding■The first finding was the highly variable cortical renal
perfusion in patients with septic shock, which was high, intermediate or low despite satisfactory macrocirculatory hemodynamics.
■Perfusion of the renal cortex is significantly reduced in patients with septic shock developing severe AKI.
■A gradual improvement in renal cortical perfusion was observed over the first 72 h in patients with septic shock.
DISCUSSION
CEUS parameters
■mTT: a renal refill time
■PI: more variable than mTT
■rBV:multiple factors affect rBV
DISCUSSION
Limitations■There was a heterogeneity in the renal CEUS parameters ■Only measured cortical perfusion and without medullary
perfusion ■This is a single-center study including surgical patients■This study began before the new definitions of septic shock■Patients with septic shock with AKI were older and had worse
baseline renal function than those without AKI. ■Sample size is small
CONCLUSIONS
■though hemodynamic macrovascular parameters were restored, the cortical renal perfusion can be decreased, normal or even increased during septic shock
■There is an average decrease in cortical renal perfusion in patients with septic shock compared to patients without septic shock.
■The decrease in cortical renal perfusion was associated with occurrence of severe AKI.