Prospective longitudinal observational study of the macro and micro haemodynamic responses to septic shock in the renal and systemic circulations: a protocol for the MICROSHOCK – RENAL study

Watchorn, Jim; Huang, Dean Y.; Hopkins, Philip; Bramham, Kate; Hutchings, Sam

doi:10.1136/bmjopen-2018-028364

Cited by 7 publications

(6 citation statements)

References 34 publications

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“…A reduction in variables reflective of blood volume and blood flow was observed in both groups, but with greater variability in patients with sepsis associated AKI. This heterogeneity may be a result of sub-phenotypes of septic AKI, where a variety of changes occur in response to a septic insult and is the subject of ongoing study (11,24). Additionally, the greater urine output observed in the septic group raises the possibility that some of these patients may have been recovering renal function at the time CEUS measurements were performed.…”

Section: Discussionmentioning

confidence: 99%

“…Our group is currently recruiting to an ongoing study, Microshock Renal (Clinicaltrials.gov NCT03713307) which aims to explore the pathogenesis of septic AKI and in particular the contribution of hypoperfusion in patients with septic shock. The protocol for this study has been published elsewhere and uses a relatively new technique, contrast-enhanced ultrasound (CEUS), to visualize perfusion within the renal parenchyma, alongside measures of global renal blood flow and cardiac output (11).…”

Section: Introductionmentioning

confidence: 99%

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Critically Ill COVID-19 Patients With Acute Kidney Injury Have Reduced Renal Blood Flow and Perfusion Despite Preserved Cardiac Function: A Case-Control Study Using Contrast-Enhanced Ultrasound

Watchorn

Huang

Joslin

et al. 2020

Shock

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Background: Acute kidney injury (AKI) is a common complication of COVID-19 critical illness but the pathophysiology is uncertain. Some evidence has indicated that a vascular aetiology may be implicated. We used contrastenhanced ultrasound (CEUS) and echocardiography to study renal perfusion and global blood flow and compared our findings with measurements taken in a group of septic shock patients and healthy volunteers. Methods: Prospective casecontrol study. Renal perfusion variables were assessed with CEUS; macrovascular blood flow was assessed using Doppler analysis of large renal vessels; echocardiography was used to assess right and left heart function and cardiac output. Results: CEUS-derived parameters were reduced in COVID-19 associated AKI compared with healthy controls (perfusion index 3,415 vs. 548 a.u., P ¼ 0Á001; renal blood volume 7,794 vs. 3,338 a.u., P ¼ 0Á04). Renal arterial flow quantified using time averaged peak velocity was also reduced compared with healthy controls (36Á6 cm/s vs. 20Á9 cm/s, P ¼ 0.004) despite cardiac index being similar between groups (2.8 L/min/m 2 vs. 3.7 L/min/m 2 , P ¼ 0.07). There were no differences in CEUSderived or cardiac parameters between COVID-19 and septic shock patients but patients with septic shock had more heterogeneous perfusion variables. Conclusion: Both large and small vessel blood flow is reduced in patients with COVID-19 associated AKI compared with healthy controls, which does not appear to be a consequence of right or left heart dysfunction. A reno-vascular pathogenesis of COVID-19 AKI seems likely.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Critically Ill COVID-19 Patients With Acute Kidney Injury Have Reduced Renal Blood Flow and Perfusion Despite Preserved Cardiac Function: A Case-Control Study Using Contrast-Enhanced Ultrasound

Watchorn

Huang

Joslin

et al. 2020

Shock

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“…Serial assessments were made of the renal and systemic macro-and microcirculatory state using CEUS, transthoracic echocardiography and sublingual video microscopy at 4 time points: Day zero (D0) within 24 h of ICU admission, D0 + 24 h (D1), D0 + 48 h (D2) and D0 + 96 h (D4). The study protocol was published prior to data analysis [11].…”

Section: Methodsmentioning

confidence: 99%

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

et al. 2022

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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.

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“…Most studies have found the involvement of three factors in its pathophysiological process: Inflammation, 4,5 diffuse microcirculation blood flow abnormality, 6 and bioenergy‐adaptive response of cells to injury 7,8 . The changes in renal blood perfusion, including macroscopic (larger blood vessels such as renal artery) and microscopic circulation (smaller vessels typically less than 20 μm in diameter, where cellular substrate delivery occurs), 9 seem to play a vital role in the occurrence of acute renal injury 10 . Prowle et al found that renal blood flow (RBF) decreased in septic kidney injury while studying great vessel blood flow 11 .…”

Section: Introductionmentioning

confidence: 99%

Diagnostic value of ultrasound and contrast‐enhanced ultrasound in septic acute kidney injury

Liu

Ding

Zhang

et al. 2021

J of Clinical Ultrasound

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Purpose This study aimed to explore the clinical value of ultrasonic Doppler examination and contrast‐enhanced ultrasound (US) in the circulation of septic acute kidney injury (AKI). Methods Patients with intensive care unit‐related infection were divided into AKI group and control groups. The AKI group was divided into three subgroups according to the serum creatinine value: stage 1, stage 2, and stage 3. Relevant parameters and blood flow of the renal artery were measured, and further contrast‐enhanced US was performed and time‐intensity curve was analyzed. Results The renal blood flow (RBF) and time‐averaged velocity decreased significantly in the AKI group compared with the control group (p = .021 and p = .001). The peak value decreased and time to peak (TTP) prolonged in the AKI group (p < .001). With the aggravation of the disease, the RBF decreased slightly among subgroups (p = 0.124). However, the peak value gradually decreased and the TTP prolonged (all p < .05). The multiple linear regression model showed that only PI, RI, and TTP were independently and linearly correlated with the serum creatinine value. Conclusions Doppler US and contrast‐enhanced US are of great help in the detection of condition changes and prognosis of patients with sepsis‐induced AKI.

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Prospective longitudinal observational study of the macro and micro haemodynamic responses to septic shock in the renal and systemic circulations: a protocol for the MICROSHOCK – RENAL study

Cited by 7 publications

References 34 publications

Critically Ill COVID-19 Patients With Acute Kidney Injury Have Reduced Renal Blood Flow and Perfusion Despite Preserved Cardiac Function: A Case-Control Study Using Contrast-Enhanced Ultrasound

Critically Ill COVID-19 Patients With Acute Kidney Injury Have Reduced Renal Blood Flow and Perfusion Despite Preserved Cardiac Function: A Case-Control Study Using Contrast-Enhanced Ultrasound

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

Diagnostic value of ultrasound and contrast‐enhanced ultrasound in septic acute kidney injury

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