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.