Value of early diagnosis of sepsis complicated with acute kidney injury by renal contrast-enhanced ultrasound

The REPERFUSE study protocol: The effects of vasopressor therapy on renal perfusion in patients with septic shock-A mechanistically focused randomised control trial

INTRODUCTION

Acute kidney injury (AKI) is a common complication of septic shock and together these conditions carry a high mortality risk. In septic patients who develop severe AKI, renal cortical perfusion is deficient despite normal macrovascular organ blood flow. This intra-renal perfusion abnormality may be amenable to pharmacological manipulation, which may offer mechanistic insight into the pathophysiology of septic AKI. The aim of the current study is to investigate the effects of vasopressin and angiotensin II on renal microcirculatory perfusion in a cohort of patients with septic shock.

METHODS AND ANALYSIS

In this single centre, mechanistically focussed, randomised controlled study, 45 patients with septic shock will be randomly allocated to either of the study vasopressors (vasopressin or angiotensin II) or standard therapy (norepinephrine). Infusions will be titrated to maintain a mean arterial pressure (MAP) target set by the attending clinician. Renal microcirculatory assessment will be performed for the cortex and medulla using contrast-enhanced ultrasound (CEUS) and urinary oxygen tension (pO2), respectively. Renal macrovascular flow will be assessed via renal artery ultrasound. Measurement of systemic macrovascular flow will be performed through transthoracic echocardiography (TTE) and microvascular flow via sublingual incident dark field (IDF) video microscopy. Measures will be taken at baseline, +1 and +24hrs following infusion of the study drug commencing. Blood and urine samples will also be collected at the measurement time points. Longitudinal data will be compared between groups and over time.

DISCUSSION

Vasopressors are integral to the management of patients with septic shock. This study aims to further understanding of the relationship between this therapy, renal perfusion and the development of AKI. In addition, using CEUS and urinary pO2, we hope to build a more complete picture of renal perfusion in septic shock by interrogation of the constituent parts of the kidney. Results will be published in peer-reviewed journals and presented at academic meetings.

TRIAL REGISTRATION

The REPERFUSE study was registered on Clinical Trials.gov (NCT06234592) on the 30th Jan 24.

Effect of early stepwise cardiopulmonary rehabilitation on function and quality of life in sepsis patients

BACKGROUND

Sepsis, as a non-limiting host infection disease, can be accompanied by serious complications such as organ failure, which seriously threatens patient quality of life.

AIM

To investigate the effect of early stepwise cardiopulmonary rehabilitation on cardiopulmonary function and quality of life in patients evacuated from mechanical ventilation with sepsis.

METHODS

A total of 80 patients with sepsis who were hospitalized in our hospital from January 2021 to January 2022 were selected and divided into the observation group (n = 40) and the control group (n = 40) according to the random number table method. The observation group was treated with early stepwise cardiopulmonary rehabilitation, and the control group was treated with a conventional treatment regimen. Cardiac function indexes (central venous pressure, cardiac troponin I, B-type brain natriuretic peptide), lung function indicators (diaphragmatic mobility, changes in central venous oxygen saturation, oxygenation index), and quality of life (Quality of Life Evaluation Scale) were compared between the two groups after treatment.

RESULTS

After treatment, the central venous pressure, diaphragm mobility, central venous oxygen saturation, oxygenation index, and Quality of Life Evaluation Scale scores in the observation group were higher than those in the control group, and the differences were statistically significant (P < 0.05). The observation group was less than that of the control group for other parameters, and the differences were statistically significant (P < 0.05).

CONCLUSION

Early stepwise cardiopulmonary rehabilitation can effectively enhance cardiac and pulmonary function and improve the quality of life in patients evacuated from mechanical ventilation with sepsis.

Contrast-Enhanced Ultrasonography for Acute Kidney Injury: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of the work described here was to provide an evidence-based evaluation of contrast-enhanced ultrasonography (CEUS) in acute kidney injury (AKI) and assess variations in renal microperfusion with CEUS quantitative parameters in patients at a high risk of developing AKI.

METHODS

A meta-analysis and systematic review were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the Embase, MEDLINE, Web of Science and the Cochrane Library databases were used to search the relevant articles systematically (2000-2022). Studies using CEUS to assess renal cortical microcirculation in AKI were included.

RESULTS

Six prospective studies (374 patients) were included. The overall quality of included studies was moderate to high. CEUS measures, maximum intensity (standard mean difference [SMD]: -1.37, 95% confidence interval [CI]: -1.64 to -1.09) and wash-in rate (SMD: -0.77, 95% CI: -1.09 to -0.45) were lower in the AKI+ group than in the AKI- group, and mean transit time (SMD: 0.76, 95% CI: 0.11-1.40) and time to peak (SMD: 1.63, 95% CI: 0.99-2.27) were higher in the AKI+ group. Moreover, maximum intensity and wash-in rate values changed before creatinine changed in the AKI+ group.

CONCLUSION

Patients with AKI had reduced microcirculatory perfusion, prolonged perfusion time and a reduced rising slope in the renal cortex, which occurred before serum creatinine changes. And they could be measured using CEUS, indicating that CEUS could help in the diagnosis of AKI.

Evaluating renal microcirculation in patients with acute kidney injury by contrast-enhanced ultrasonography: a protocol for an observational cohort study

BACKGROUND

Acute kidney injury (AKI) in critically ill patients has poor renal outcome with high mortality. Changes in intra-renal microcirculation and tissue oxygenation are currently considered essential pathophysiological mechanisms to the development and progression of AKI. This study aims to investigate the characteristics of contrast-enhanced ultrasonography (CEUS) derived parameters in biopsy-proven AKI patients, and examine the predictive value of these markers for renal outcome.

METHODS AND DESIGN

This prospective observational study will enroll AKI patients who are diagnosed and staging following KDIGO (Kidney Disease: Improving Global Outcomes) criteria. All patients undergo a kidney biopsy and pathological tubulointerstitial nephropathy is confirmed. The CEUS examination will be performed at 0, 4 and 12 weeks after biopsy to monitor renal microcirculation. The percentage decrease of serum creatinine, 4-week and 12-week eGFR (estimated glomerular filtration rate) will also be reviewed as renal prognosis. The relationship of CEUS parameters with clinical and pathological markers will be analyzed. We perform a lassologit procedure to select potential affecting variables, including clinical, laboratory indexes and CEUS markers, to be included in the logistic regression model, and examine their predictive performance to AKI outcomes.

DISCUSSION

If we are able to show that CEUS derived parameters contribute to diagnosis and prognosis of AKI, the quality of life of patients will be improved while healthcare costs will be reduced.

TRIAL REGISTRATION

This study is retrospectively registered on the Chinese Medical Research Registration information System( https://61.49.19.26/login ) on December 31, 2021: MR-11-22-003,503. This study has been approved by the Ethics and Scientific Research Department of Peking University First Hospital.

Predictive Value of the Transthoracic Echocardiography Index for Acute Kidney Injury after Cardiac Valve Surgery

Background: We aimed to demonstrate whether the preoperative transthoracic echocardiography index (TTEI) could improve the predictive value of clinical parameters for cardiac valve surgery-associated acute kidney injury (CVS−AKI). Methods: A total of 213 patients who underwent surgical CVS at Renmin Hospital of Wuhan University were consecutively recruited in this retrospective study. TTE assessments were performed within 7 days before surgery and logistic regression was used to determine TTEI. A nomogram was constructed by integrating TTEI and clinical features, and the net reclassification index (NRI) and integrated discrimination improvement (IDI) were applied to evaluate the improvement in TTEI for CVS−AKI. Results: Among them, 66 patients (30.9%) developed CVS−AKI. The TTEI was calculated as follows: −6.579 + 0.068 × pulmonary artery systolic pressure (mmHg) −0.742 × LVEF (>55%, yes or no) + 0.346 × left ventricle posterior wall thickness (mm). The nomogram based on the TEEI and other clinical factors possessed excellent performance (C-index = 0.880), had great calibration and discrimination, and was clinically useful. Furthermore, NRI (0.07, 95% confidence interval, 95%CI, 0.01−0.12, p = 0.02) and IDI (0.08, 95%CI, 0.01−0.20, p = 0.02) indicated that TTEI could significantly improve the predictive value of clinical features for CVS−AKI. Conclusions: As a simple access and cost-effective parameter, the preoperative TTEI may be a reliable and useful factor for CVS−AKI.

Decreased renal cortical perfusion, independent of changes in renal blood flow and sublingual microcirculatory impairment, is associated with the severity of acute kidney injury in patients with septic shock

Background

Reduced renal perfusion has been implicated in the development of septic AKI. However, the relative contributions of macro- and microcirculatory blood flow and the extent to which impaired perfusion is an intrinsic renal phenomenon or part of a wider systemic shock state remains unclear.

Methods

Single-centre prospective longitudinal observational study was carried out. Assessments were made at Day 0, 1, 2 and 4 after ICU admission of renal cortical perfusion in 50 patients with septic shock and ten healthy volunteers using contrast-enhanced ultrasound (CEUS). Contemporaneous measurements were made using transthoracic echocardiography of cardiac output. Renal artery blood flow was calculated using velocity time integral and vessel diameter. Assessment of the sublingual microcirculation was made using handheld video microscopy. Patients were classified based on the degree of AKI: severe = KDIGO 3 v non-severe = KDIGO 0–2.

Results

At study enrolment, patients with severe AKI (37/50) had prolonged CEUS mean transit time (mTT) (10.2 vs. 5.5 s, p < 0.05), and reduced wash-in rate (WiR) (409 vs. 1203 au, p < 0.05) and perfusion index (PI) (485 vs. 1758 au, p < 0.05); differences persisted throughout the entire study. Conversely, there were no differences in either cardiac index, renal blood flow or renal resistive index. Sublingual microcirculatory variables were not significantly different between groups at study enrolment or at any subsequent time point. Although lactate was higher in the severe AKI group at study enrolment, these differences did not persist, and there were no differences in either ScvO2 or ScvCO2-SaCO2 between groups. Patients with severe AKI received higher doses of noradrenaline (0.34 vs. 0.21mcg/kg/min, p < 0.05). Linear regression analysis showed no correlation between mTT and cardiac index (R-0.18) or microcirculatory flow index (R-0.16).

Conclusion

Renal cortical hypoperfusion is a persistent feature in critically ill septic patients who develop AKI and does not appear to be caused by reductions in macrovascular renal blood flow or cardiac output. Cortical hypoperfusion appears not be associated with changes in the sublingual microcirculation, raising the possibility of a specific renal pathogenesis that may be amenable to therapeutic intervention.

Trial Registration Clinical Trials.gov NCT03713307, 19 Oct 2018.

Ultrasonic Image Features under the Intelligent Algorithm in the Diagnosis of Severe Sepsis Complicated with Renal Injury

This research was aimed at analyzing the diagnosis of severe sepsis complicated with acute kidney injury (AKI) by ultrasonic image information based on the artificial intelligence pulse-coupled neural network (PCNN) algorithm and at improving the diagnostic accuracy and efficiency of clinical severe sepsis complicated with AKI. In this research, 50 patients with sepsis complicated with AKI were collected as the observation group and 50 patients with sepsis as the control group. All patients underwent ultrasound examination. The clinical data of the two groups were collected, and the scores of acute physiology and chronic health assessment (APACHE II) and sequential organ failure assessment (SOFA) were compared. The ultrasonic image information enhancement algorithm based on artificial intelligence PCNN is constructed and simulated and is compared with the maximum between-class variance (OSTU) algorithm and the maximum entropy algorithm. The results showed that the PCNN algorithm was superior to the OSTU algorithm and maximum entropy algorithm in the segmentation results of severe sepsis combined with AKI in terms of regional consistency (UM), regional contrast (CM), and shape measure (SM). The acute physiology and chronic health evaluation (APACHE II) and sequential organ failure assessment (SOFA) scores in the observation group were substantially higher than those in the control group (P < 0.05). The interlobular artery resistance index (RI) in the observation group was substantially higher than that in the control group (P < 0.05). Moreover, the mean transit time (mTT) in the observation group was significantly higher than that in the control group (4.85 ± 1.27 vs. 3.42 ± 1.04), and the perfusion index (PI) was significantly lower than that in the control group (134.46 ± 17.29 vs. 168.37 ± 19.28), with statistical significance (P < 0.05). In summary, it can substantially increase ultrasonic image information based on the artificial intelligence PCNN algorithm. The RI, mTT, and PI of the renal interlobular artery level in ultrasound images can be used as indexes for the diagnosis of severe sepsis complicated with AKI.

The predict value of serum/urocystatin C on acute kidney injury in elderly patients with sepsis

OBJECTIVE

To evaluate the predict value of serum/urocystatin C in acute kidney injury (AKI) in elderly patients with sepsis.

METHODS

A retrospective study was performed and 80 senile patients with sepsis in ** hospital of China was included. According to the diagnosis of AKI, all patients were divided into non-AKI group and AKI group. The clinical characteristics, laboratory and physiological indicators of the two groups were compared. The receiver operating characteristic curve (ROC) was used to analyze the accuracy of the variables, including serum cystatin C, urocystatin C, and serum creatinine, to predict the occurrence of AKI in patients with sepsis.

RESULTS

Of the 80 elderly patients with sepsis in China, 29 patients had AKI. Compared with the non-AKI group, patients in the AKI group had higher APACHE II scores, higher SOFA scores, higher procalcitonin, and lower mean arterial pressure (P < 0.05). The levels of serum cystatin C, urocystatin C, and serum creatinine in the AKI group were significantly higher than those in the non-AKI group (P < 0.05), while the difference in intensive care unit (ICU) mortality rate between the two groups was not significantly different (P > 0.05). The ROC curve showed that the area under the curve of serum cystatin C was 0.893, the area under the curve of urocystatin C was 0.898, and the area under the curve of serum creatinine was 0.652.

CONCLUSION

Serum cystatin and urocystatin could be used to predict the occurrence of AKI in elderly patients with sepsis.

Application of dynamic contrast enhanced ultrasound in the assessment of kidney diseases

PURPOSE OF REVIEW

Many forms of acute and chronic disease are linked to changes in renal blood flow, perfusion, vascular density and hypoxia, but there are no readily available methods to assess these parameters in clinical practice. Dynamic contrast enhanced ultrasound (DCE-US) is a method that provides quantitative assessments of organ perfusion without ionising radiation or risk of nephrotoxicity. It can be performed at the bedside and is suitable for repeated measurements. The purpose of this review is to provide updates from recent publications on the utility of DCE-US in the diagnosis or assessment of renal disease, excluding the evaluation of benign or malignant renal masses.

RECENT FINDINGS

DCE-US has been applied in clinical studies of acute kidney injury (AKI), renal transplantation, chronic kidney disease (CKD), diabetic kidney disease and to determine acute effects of pharmacological agents on renal haemodynamics. DCE-US can detect changes in renal perfusion across these clinical scenarios and can differentiate healthy controls from those with CKD. In sepsis, reduced DCE-US measures of perfusion may indicate those at increased risk of developing AKI, but this requires confirmation in larger studies as there can be wide individual variation in perfusion measures in acutely unwell patients. Recent studies in transplantation have not provided robust evidence to show that DCE-US can differentiate between different causes of graft dysfunction, although it may show more promise as a prognostic indicator of graft function 1 year after transplant. DCE-US can detect acute haemodynamic changes in response to medication that correlate with changes in renal plasma flow as measured by para-aminohippurate clearance.

SUMMARY

DCE-US shows promise and has a number of advantages that make it suitable for the assessment of patients with various forms of kidney disease. However, further research is required to evidence its reproducibility and utility before clinical use can be advocated.