Edema in Renal Diseases – Current View on Pathogenesis

Management and outcomes of acute post-streptococcal glomerulonephritis in children

Acute post-streptococcal glomerulonephritis (APSGN) is the major cause of acute glomerulonephritis among children, especially in low- and middle-income countries. APSGN commonly occurs following pharyngitis due to the activation of antibodies and complements proteins against streptococcal antigens through the immune-complex-mediated mechanism. APSGN can be presented as acute nephritic syndrome, nephrotic syndrome, and rapidly progressive glomerulonephritis, or it may be subclinical. The management of APSGN is mainly supportive in nature with fluid restriction, anti-hypertensives, diuretics, and renal replacement therapy with dialysis, when necessary, as the disease is self-limiting. Congestive heart failure, pulmonary edema, and severe hypertension-induced encephalopathy might occur during the acute phase of APSGN due to hypervolemia. APSGN generally has a favorable prognosis with only a small percentage of patients with persistent urinary abnormalities, persistent hypertension, and chronic kidney disease after the acute episode of APSGN. Decreased complement levels, increased C-reactive protein, and hypoalbuminemia are associated with disease severity. Crescent formations on renal biopsy and renal insufficiency on presentation may be the predictors of disease severity and poor outcomes in APSGN in children.

Prognostic Risk Factors for the Development of Compartment Syndrome in Acute Lower Limb Ischemia Patients Treated with Catheter-Directed Thrombolysis

OBJECTIVE

To determine predisposing factors that may lead to the development of compartment syndrome (CS) in patients with acute lower limb ischemia (ALLI) managed with intra-arterial catheter-directed thrombolysis (CDT).

METHODS

This is a retrospective study of patients admitted between 01/2002 and 12/2015 to three university hospitals in Tampere, Turku, and Oulu, Finland, with acute or acute-on-chronic lower limb ischemia (Rutherford I-IIb). Patients managed with CDT and aspiration thrombectomies (AT) as an adjunct to CDT were included in the study. Multivariable binary logistic regression models were used to detect possible risk factors for the development of CS and its impact on the limb salvage and survival. Amputation-free survival (AFS) rates of CS and non-CS patients were compared using Kaplan-Meier survival analysis. The length of hospitalization was calculated and compared between the CS and non-CS groups.

RESULTS

A total of 292 CDTs with or without ATs were performed on patients with a mean age of 71 years (standard deviation 13 years), 151 (51.7%) being male. Altogether, 12/292 (4.1%) treatment-related CS cases were registered. Renal insufficiency (odds ratio [OR] 4.27, P = .07) was associated with an increased risk of CS. All CS cases were managed with fasciotomies. Treatment with fasciotomy was associated with a prolonged hospitalization of a median of 7 days versus the 4 days for non-CS patients, P < .001. During the median follow-up of 51 months (interquartile range 72 months), 152/292 (52.1%) patients died and 51/292 (17.5%) underwent major amputations. CS was not associated with an increased risk of mortality, but it was associated with a higher risk of major amputation (OR 3.87, P = .027). The AFS rates of patients with or without CS did not significantly differ from each other in the long term.

CONCLUSION

CS after CDT for the treatment of ALLI is uncommon. Renal insufficiency is associated with an increased risk of CS. Fasciotomy prolongs the hospitalization. Patients with CS are exposed to an increased risk of major amputation.

Prior fluid and electrolyte imbalance is associated with COVID-19 mortality

Background

The COVID-19 pandemic represents a major public health threat. Risk of death from the infection is associated with age and pre-existing comorbidities such as diabetes, dementia, cancer, and impairment of immunological, hepatic or renal function. It remains incompletely understood why some patients survive the disease, while others do not. As such, we sought to identify novel prognostic factors for COVID-19 mortality.

Methods

We performed an unbiased, observational retrospective analysis of real world data. Our multivariable and univariable analyses make use of U.S. electronic health records from 122,250 COVID-19 patients in the early stages of the pandemic.

Results

Here we show that a priori diagnoses of fluid, pH and electrolyte imbalance during the year preceding the infection are associated with an increased risk of death independently of age and prior renal comorbidities.

Conclusions

We propose that future interventional studies should investigate whether the risk of death can be alleviated by diligent and personalized management of the fluid and electrolyte balance of at-risk individuals during and before COVID-19.

Chronic Kidney Disease as a Predictor of Postoperative Choroidal Effusions After Glaucoma Surgery

PRCIS

Patients with chronic kidney disease (CKD) are at increased risk for choroidal effusion development following glaucoma surgery.

PURPOSE

Choroidal effusion is a postoperative complication of glaucoma surgery that results from a transudative fluid collection in the suprachoroidal space. Kidney disease alters bodily fluid dynamics through a variety of mechanisms. The relationship between CKD and choroidal effusion following glaucoma surgery has not previously been studied. The purpose of this study was to determine the relationship between CKD and choroidal effusion development after glaucoma surgery.

PATIENTS AND METHODS

This retrospective cohort study consisted of 86 eyes from 86 patients who received glaucoma filtering surgery or transscleral cyclophotocoagulation within the study timeframe. Forty-three patients had CKD, and 43 patients did not have kidney disease. The main outcome of this study was the development of choroidal effusion measured by the Pearson χ2 test and multivariate analysis using a binomial regression with a log link.

RESULTS

Ten patients (23.3%) in the CKD group developed choroidal effusion, while 2 patients (4.7%) in the no-kidney disease group developed choroidal effusion (relative risk, 5.0; 95% confidence interval: 1.16-21.5; P=0.013). The association between CKD and choroidal effusion showed mixed results in the multivariate analysis, with some analyses showing a significant association and others showing no significant association.

CONCLUSIONS

In both the univariate and multivariate analyses, CKD was found to be significantly associated with choroidal effusion after glaucoma surgery.

The predominance and diagnostic value of neutrophils in differentiating transudates and exudates in dogs

BACKGROUND

There is disagreement in the literature about the proportion of neutrophils expected in canine transudates. A cutoff of <30% neutrophils has been recommended for distinguishing transudates from exudates, but its validity has not been established.

OBJECTIVE

The aim of this study was to evaluate differential cell counts in canine effusions and analyze the percentage and number of neutrophils in transudates and exudates.

METHODS

Effusion data were obtained retrospectively from 263 dogs with pleural or peritoneal effusion. Low-protein transudates, high-protein transudates, and exudates were classified using the total protein (TP) concentration and total nucleated cell count (TNCC). Differential percentages and absolute neutrophil counts were compared by the effusion type and underlying etiology.

RESULTS

Low-protein transudates (n = 63), high-protein transudates (n = 84), and exudates (n = 77) had a median (range) of 35% (0%-100%), 59% (0%-100%), and 90% (50%-98%) neutrophils (P < .0001). All effusions with <50% neutrophils were transudates, but 53% of transudates had ≥50% neutrophils, and 69% had ≥30%. Median neutrophil counts were 62/µL (0-892/µL), 538/µL (0-4550/µL), and 45 590/µL (5400-496 800/µL) in low-protein transudates, high-protein transudates, and exudates, respectively (P < .0001). Neutrophil counts correlated with TNCC (r²  = 0.99), such that using neutrophil cutoffs did not affect effusion classifications in most cases. Neutrophil percentages and counts were higher in effusions from dogs with uroabdomen and sepsis (P < .01); neutrophil counts were lower in dogs with hepatic insufficiency (P < .0001). Uroabdomen usually caused low-protein, high-neutrophil exudates.

CONCLUSIONS

Although effusions with <50% neutrophils are transudates, most transudates and exudates have ≥50% neutrophils, limiting the diagnostic usefulness of % neutrophils for classifying effusions. Absolute neutrophil cutoffs did not notably improve effusion classification but could warrant future studies.