Ultrasonography in Acute Kidney Injury

Abstract

Advances in the use of ultrasonography can enhance our ability to better characterize acute kidney injury (AKI). AKI is a clinical syndrome characterized by a rapid decrease in kidney excretory function with the accumulation of products of nitrogen metabolism and other clinically unmeasured waste products, and may proceed to include clinical manifestations including decreased urine output, development of metabolic acidosis, and electrolyte abnormalities [1]. The Kidney Disease Improving Global Outcomes (KDIGO) criteria defines AKI (Table 1). Staging severity of AKI guides the physician in respect to medical management and prognosis. The overall incidence of AKI is around 20% of patients hospitalized worldwide, and around 50% in intensive care unit (ICU) patients [2, 3]. AKI has been found to have increasing morbidity and mortality, no matter the cause of admission, as well as an in-hospital mortality of close to 50% [4]. In a large study of 8 ICUs over 8 years, Kellum et al. found that AKI was associated with increasing mortality rate with worsening AKI stage. A decrease in urine output alone, without an increase in serum creatinine, was associated with decreased 1-year survival [5]. Recurrent AKI has also been associated with increased mortality, further demonstrating the importance of detecting, monitoring, and diagnosing AKI [6].

Correlation Analysis of Ultrasonography Kidney Morphological Profiles and the Classification of Persistent and Transient Acute Kidney Injury (Aki) in Children During the Pandemic Period at the Dr. Soetomo General Teaching Hospital

“…Moses and Fernandes stated that the thickness of the kidney parenchyma can serve as a differentiator between Acute Kidney Injury (AKI) and Chronic Kidney Disease (CKD), where in CKD, the kidney parenchyma gradually narrows with the decrease in glomerular filtration rate (Moses and Fernandez 2022). Conversely, in AKI, an increase in parenchymal thickness is found, especially in cases with intrinsic etiology.…”

“…The alterations observed in the renal parenchyma are intricately linked to processes such as Acute Tubular Injury, Acute Tubular Necrosis, and Interstitial Nephritis. These pathological mechanisms underlie changes in renal parenchymal echogenicity observed in AKI conditions stemming from Intrinsic Renal etiologies, a scenario that might manifest in MIS-C (Gaut and Liapis 2021;Moses and Fernandez 2022). While the presence of renal echogenicity doesn't necessarily distinguish between the various causes of renal disease, it can serve as an indicator of the extent of glomerular sclerosis/crescent formation, tubular atrophy, and interstitial inflammation/fibrosis (Kelahan et al 2019).…”

Sound waves and solutions: Point-of-care ultrasonography for acute kidney injury in cirrhosis

“…Obstructive or post-renal AKI arises from an obstruction downstream of the renal collecting system, commonly due to urinary retention, benign prostatic hyperplasia, nephrolithiasis, malignancy or even an obstructed Foley catheter. Upon ultrasonographic examination, hydronephrosis and dilation of the pelvicalyceal system in suggestive of obstruction, and promptly relieving obstruction is warranted[ 33 ]. Tension ascites should also be considered, as IAH (defined as ≥ 12 mmHg) and ACS (defined as ≥ 20 mmHg and signs of organ dysfunction) reduce renal perfusion pressure and lead to AKI[ 34 ].…”

PoCUS in nephrology: a new tool to improve our diagnostic skills

“…Renal colic is a common presentation in nephrology which involves a significant amount of resource use, including advanced imaging as well as direct and indirect costs related to patient care and lost work time. Hydronephrosis is presented as a black branching structure in the renal sinus with US but we can also find the cause of the obstruction as a stone in the renal pelvis as a high brightness structure with an acoustic shadow [ 68 ]. Even if we do not visualize the stone during the examination, the presence of hydronephrosis suggests ureteral obstruction.…”