Clinical Queries: Nephrology最新文献

Objective

To evaluate the accuracy of velocity parameters and to define optimum threshold values of these parameters in detection of >60% renal artery stenosis in patients with end to side arterial anastomosis.

Methods

The study group composed of 17 patients of transplant renal artery stenosis confirmed by CT angiography; and 25 control patients with normal Doppler study. Doppler parameters like PSV in main transplanted renal artery, PSV in interlobar artery, PSV in iliac artery, acceleration time, and resistive index were evaluated. Pre-PSV ratio and Post-PSV ratio were calculated. Patients were divided into group A (>60% stenosis) and B (<60% stenosis) according to CT angiography reports. Control group assigned as group C. Difference between Doppler parameters were evaluated by individual t test. Receiver operating curve was performed to determine optimal parameter for diagnosis of >60% stenosis.

Results

Considering better sensitivity and specificity for diagnosis of >60% stenosis the best threshold for Intrarenal RI, acceleration time, PSV, Pre-PSV ratio and Post-PSV ratio were determined to be 0.058, 0.071 s, 3.1 m/s, 2 and 10 respectively. P value of acceleration time between group B and C; and P value of PSV in main renal artery, Pre-PSV ratio and Intrarenal RI between group A and B is >0.05.

Conclusion

Post-PSV ratio is the best parameter for diagnosis of significant stenosis and its optimum threshold value is 10.

The presacral space is the site of a group of heterogeneous and rare tumors that are often indolent and produce nonspecific symptoms. Here we report a case of large multiloculated cystic mass in 53-year-old male presented with right-sided low backache. Provisional diagnosis of presacral schwannoma was made with the help computed tomography (CT) study and diagnosis was confirmed by histopathology.

Sjogren's syndrome is a systemic autoimmune disorder characterized by chronic inflammation of the exocrine glands with extra-glandular manifestations. Renal involvement occurs in 18–67% of cases, with chronic tubulo-interstitial nephritis being the most frequent pathology which can lead to distal renal tubular acidosis characterized by normal anion gap acidosis with hypokalemia and alkaline urinary pH. Hypokalemic periodic paralysis can be primary or secondary to potassium deficiency which can arise from several causes. Primary Sjogren's syndrome is a rare cause which can lead to renal involvement producing distal renal tubular acidosis with hypokalemic paralysis.

A poor, uneducated male patient from a remote rural place had undergone Right open pyelolithotomy with Double J (D.J. stent) stenting for obstructive uropathy 15 years ago. He presented with the following prevailing conditions: right flank pain, interrupted urinary stream and burning micturition. Ultrasound showed Gross Hydronephrosis with multiple calculi and D.J. stent in the right kidney.

Urinary bladder also showed presence of D.J. stent with encrustment around the tip of the stent.

The mid part of D.J. stent was not visualized. Later, on X-ray, broken parts of the stent with encrustment were seen in the right renal pelvis and bladder, which were removed, and cystolithotomy was done. Imaging plays a pivotal role in detection of such broken or forgotten stents and can direct early and prompt management to prevent complications.

Tubular ectasia of rete testis is a rare benign condition often confused with testicular neoplasm. Though not thought of clinically, it is usually an incidental finding on ultrasound. Here, we report a case of bilateral rete testis associated with multiple epididymal cysts in otherwise normal patients.

Sepsis often leads to widespread injury causing multiple organ dysfunction and the development of AKI in sepsis often portends poor prognosis. The pathophysiology of sepsis induced AKI is complex and multifactorial. Initially it was thought that hypotension causing hypoperfusion of kidneys as the major cause of AKI in sepsis. Recent work has been shown that rather than hypoperfusion, microvascular dysfunction with release of inflammatory mediators, cytokines, microparticles with adaptation of tubular cells as the major contributor of sepsis induced AKI. The aim of this review is to focus on the recent advances in pathophysiology of sepsis induced AKI and understanding these complex mechanisms which may pave the way for newer treatments in the future which are directed against the specific pathophysiological mechanisms.

Malaria is a mosquito-borne infectious disease with active transmission in the tropics. Malaria is becoming a global threat with the increasing number of cases of ‘imported malaria’. According to the World Health Organization, half of the world's population is at the risk of malaria. Severe malaria is associated with high mortality. There has been a change in the spectrum of manifestations of severe malaria over the past two decades. Acute kidney injury (AKI) in malaria is being frequently reported. AKI is commonly caused by Plasmodium falciparum. However, Plasmodium vivax and Plasmodium knowlesi are also shown to cause AKI. A combination of hemorheological, inflammatory and humoral responses has been implicated in the pathogenesis. AKI in malaria is frequently oliguric and hyper-catabolic. Cerebral malaria and jaundice are often associated with acute kidney injury and portend a poor prognosis. The KDIGO criteria enable earlier detection of acute kidney injury in malaria. Acute tubular necrosis is the most consistent histological feature. A lot of uncertainty surrounds fluid management in severe malaria. A conservative approach to fluid replacement is recommended. Artesunate is the recommended first choice antimalarial for the treatment of severe malaria. Prompt recognition and early institution of renal replacement therapy reduces the mortality.

Pregnancy-related acute kidney injury (P-AKI) incidence has reduced over the recent years with better accessibility and advances in health care. It is still a concern in developing countries where septic abortions and puerperal sepsis persist due to lack of health facilities. Recent advances have helped in a better understanding of pathogenesis of disorders like pre-eclampsia, acute fatty liver of pregnancy, and thrombotic microangiopathy which has helped the physicians to solve the enigma in both diagnosis and management of these conditions. Diagnosis of P-AKI is challenging due to normal maternal physiological changes. Usual definitions of AKI are not very accurate in pregnancy and newer markers for diagnosis of AKI are not well studied in pregnancy. Early identification of the cause of P-AKI and its prompt treatment holds the key in the management of P-AKI. It is of utmost importance to maintain the hemodynamics and acid base balance for ensuring proper utero-placental blood flow and fetal well being in P-AKI. There is neither particular modality of RRT which is better than other nor a preset dialysis prescription for P-AKI, and renal replacement therapy should be individualized to provide optimal care.

Acute kidney injury and multiorgan dysfunction due to sepsis and septic shock increase the morbidity and mortality among critically ill patients. It remains an important challenge in critically ill patients. In this review, management of septic AKI in terms of prevention, medical therapies, and extracorporeal therapies is discussed. Stabilizing the hemodynamic parameters by fluid resuscitation and inotropic support are important strategies to prevent acute kidney injury in the initial stages. Controversies exist in the timing of initiating renal replacement therapy although some studies showed improved outcomes with early initiation. The recommended dose of renal replacement therapy (25 ml/kg/hr) had not shown to be associated with improved survival in randomized studies. The clinical benefit of other therapies, like hemoadsorption, and alkaline phosphatase use is still uncertain. Mesenchymal stem cell therapies are in phase I trials.