Post-obstructive Diuresis Research Articles

Djenkolism: Acute Kidney Injury Unresponsive to Conservative Therapy - A Case Report

Djenkol beans (Archidendron jiringa), a popular food in Southeast Asia, can cause djenkolism—a condition leading to acute kidney injury due to the presence of djenkol acid. This case report details a 26-year-old male who presented with three days of anuria following the consumption of half a kilogram of djenkol beans. Upon admission, he exhibited severe abdominal pain, costovertebral tenderness, and elevated renal markers, leading to a diagnosis of obstructive uropathy caused by djenkolic acid crystals. Initial conservative treatment was ineffective, prompting the need for emergency ureteroscopy and placement of bilateral JJ stents to relieve the obstruction. Post-procedure, the patient experienced significant improvement, with a marked increase in urine output; post-obstructive diuresis in the first 24 hours, and resolution of abdominal pain, alongside improved renal function. This case underscores the importance of recognizing djenkolism as a potential cause of acute kidney injury, and advocating for timely diagnosis and intervention to mitigate kidney damage. Public awareness regarding the risks associated with djenkol consumption is also essential. Keywords: Djenkolism, Obstructive Uropathy, Post-Obstructive Diuresis, Acute Kidney Injury

Rate of Post Obstructive Diuresis in Rapid Versus Gradual Bladder Decompression in Patients with Chronic Urinary Retention

Background: Post-obstructive diuresis (POD) is a polyuric state in which copious amounts of salt and water are eliminated after the relief of a urinary tract obstruction. POD is a clinical diagnosis based on urine output exceeding 200 mL per hour for two or more consecutives hours or 3L in 24 hours after decompressing an obstructed bladder, bilateral ureteric obstruction or unilateral ureteric obstruction in a solitary kidney. Methodology: This was a prospective, randomized study in which patients with chronic urinary retention were randomized into two groups: A and B. Group A had rapid urinary decompression with 18Fr urethral catheter attached to a urine bag, while group B had gradual decompression using a urethral catheter attached to an intravenous fluid giving set which was then attached to urine bag. Post obstructive diuresis in each group were assessed at designated times. Data Analysis and Result Presentation: Data was analyzed using the Statistical Package for Social Sciences (IBM) SPSS version 21. Data was summarized by descriptive statistics. The two arms were compared for similarities in demographic variables. Continuous and categorical variables were compared using student t- test and Pearsons‘ Chi – square respectively. Significant p value was 0.05. Result: Sixty patients were recruited into the study and randomized into group A (rapid urinary decompression) and B (gradual urinary decompression) with 30 patients in each group. Thirteen patients (43.33%) had post obstructive diuresis in group A compared to 15 patients (50%) in group B. p value of 0.584. Diuresis resolved within 24 hours in 9 patients (30%) in group A and 11 patients (36.7%) in group B. p value of 0.999. The mean reduction in systolic blood pressure was 8.21 ± 2.63mmHg in group A and 7.63 ± 2.14mmHg in group B. p value of 0.583. The mean reduction diastolic blood pressure was 3.84 ± 1.31mmHg in group A and 3.41 ± 1.16mmHg in group B. P value of 0.624. No patient in both groups developed hypotension (BP of <90/60). Conclusion: There was no statistically significant different in post obstructive diuresis. However, over 46.7% of patients had diuresis in both groups without any one developing hypotension. This may be due to routine prophylactic fluid and electrolyte replacement using normal saline.

Post-obstructive diuresis after posterior urethral valve treatment in neonates: a retrospective cohort study.

The management of posterior urethral valve (PUV) in neonates requires close monitoring in the intensive care unit because of the risk of post-obstructive diuresis (POD). Our aim was to describe the incidence and factors associated with POD in newborns treated for PUV. Retrospective analysis of the medical records of all neonates who underwent surgical intervention for PUV in our neonatal intensive care unit between January 2014 and April 2021. Of the 40 patients included, 15 (37.5%) had POD defined by urine output > 6ml.kg-1.h-1 during the first 24h following urinary tract obstruction relief. At prenatal ultrasound examinations, oligohydramnios was more common in the group with POD than in the group without (53.3% vs. 8%, p = 0.002). Preterm birth was more frequent in neonates with POD (66.7% vs. 8%; p < 0.001). Median serum creatinine (212 [137-246] vs. 95 [77-125] µmol.l-1; p < 0.001) and urea (8.5 [5.2-12.2] vs. 4.1 [3.5-4.7] mmol.l-1; p < 0.001) concentrations on the day of obstruction relief were significantly higher in the group with POD than in the group without. After adjustment for prematurity, logistic regression models confirmed correlation between the occurrence of POD and the severity of the consequences of urethral obstruction (i.e., oligohydramnios and serum creatinine levels; ß = 2.90 [0.88; 5.36], p = 0.013 and ß = 0.014 [0.003; 0.031], p = 0.034, respectively). In neonates, POD is common after the relief of PUV-related obstruction. Our findings may help to identify patients at highest risk. A higher resolution version of the Graphical abstract is available as Supplementary information.

Coexistence of acute pancreatitis and an obstructing upper ureteral calculus: does a calculus cause pancreatitis? a case report.

A 36-year-old male patient presented with epigastric, and right loin pain with decreased urine output for 3 days. On physical examination, he had central abdominal and right flank tenderness. An abdominal ultrasound showed mild to moderate ascites, a hyperechoic pancreas, a small (26×77mm) left kidney with increased echogenicity, right renal hypertrophy with moderate hydronephrosis, and a dilated upper ureter due to a 10mm obstructing stone with a perirenal fluid collection. The diagnosis of acute pancreatitis with an obstructing right upper ureteric stone was established. Under spinal anesthesia, an emergency ureteroscopy with laser fragmentation of the stone was performed, and a JJ stent was inserted. He developed postobstructive diuresis and his renal function was improved with a rapid decline of pancreatic enzymes as well. Two theories explain the presentation of acute pancreatitis by ureteral obstruction. First, the obstructed severe hydronephrotic kidney compresses the duodenum and head of the pancreas, obstructing the distal part of the common bile duct and triggering the elevation of pancreatic duct pressure, bile reflux, trypsin activation, and pancreatic autodigestion. The second theory states that acute pancreatitis develops when urine is extravasated from an obstructed kidney into the adjacent tissues, irritating the uncinate process of the pancreas. Although mentioning ureteral obstruction as a cause of pancreatitis is scarce, the clinician should be aware that in each case of ureteral obstruction, the emergence of acute pancreatitis is a possible complication.

Life-Threatening Complications Associated with Bladder Decompression: A Case Report.

The clinical course of patients who present to the emergency department (ED) with urinary retention is usually uneventful. In this case, we explore the life-threatening complications of urinary retention and bladder decompression. We report the case of a 57-year-old man who presented to the ED with difficulty voiding. A urinary catheter was placed. The patient had severe post-obstructive diuresis. He developed hematuria and became hypotensive. After aggressive resuscitation, including blood products, the patient required operative intervention for hemorrhage control. Clinicians should be aware of and be able to manage the rare but life-threatening complications associated with urinary retention.

Abstract #1184936: Pituitary Apoplexy after Post-Obstructive Diuresis in a Patient with Known Pituitary Macroadenoma

Pituitary apoplexy is a clinical syndrome due to abrupt hemorrhage and/or infarction of the pituitary gland, generally within a pituitary adenoma. The most common symptoms are acute onset of headache, visual disturbances or ocular palsy. Diagnosis of pituitary tumor is often not known at the time of apoplexy. Risk factors for pituitary apoplexy include cerebral angiography, head trauma, dynamic endocrine testing, such as insulin tolerance test, surgery (especially cardiac and orthopedic), treatment with GnRH agonists for prostate cancer, and anticoagulation.

PD38-06 TURPUDU TRIAL- A PROSPECTIVE STUDY EVALUATING THE EFFECT OF TRANSURETHRAL RESECTION OF PROSTATE ON URODYNAMIC PARAMETERS IN PATIENTS OF BENIGN ENLARGEMENT OF PROSTATE WITH UPPER URINARY TRACTS DILATATION

You have accessJournal of UrologyCME1 May 2022PD38-06 TURPUDU TRIAL- A PROSPECTIVE STUDY EVALUATING THE EFFECT OF TRANSURETHRAL RESECTION OF PROSTATE ON URODYNAMIC PARAMETERS IN PATIENTS OF BENIGN ENLARGEMENT OF PROSTATE WITH UPPER URINARY TRACTS DILATATION Shantanu Tyagi, Kalpesh Parmar, and Shrawan Singh Shantanu TyagiShantanu Tyagi More articles by this author , Kalpesh ParmarKalpesh Parmar More articles by this author , and Shrawan SinghShrawan Singh More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002596.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Pressure-flow changes after transurethral resection of prostate (TURP) for benign prostatic enlargement (BPE) with lower urinary tract symptoms have been well described in the literature. But, till date no study has evaluated the post-TURP urodynamic changes in patients with BPE with upper urinary tract dilatation (UTD). With this background, we evaluated the urodynamic outcomes of TURP in patients of BPE with UTD and correlate with International Prostate Symptoms Score (IPSS). METHODS: In this prospective study (TURPUDU stands for - TURP for Upper tract Dilatation and Urodynamic changes), patients of BPE with UTD from July 2017 to Jan 2021 were enrolled. Study protocol was registered and cleared with Institutional review board (NK/3880/MS/148). Detailed IPSS score, ultrasonography abdomen, serum creatinine, and serum PSA were recorded. All the patients were catheterised and observed for post-obstructive diuresis. At 4 weeks, repeat ultrasound and serum creatinine were recorded. Urodynamic study (UDS) was performed after ensuring sterile urine culture. Patients underwent TURP as per standard technique. A repeat UDS was performed after 3 months and analyses were done. RESULTS: Ninety-five patients were enrolled of which data of 90 patients were analysed. In the filling phase of the UDS study, there was a significant decrease in detrusor pressure at the end filling phase from 29 cm H2O to 8 cm H2O post-TURP. Maximum cystometric capacity (MCC) [409 ml to 485 ml (p-value <0.001)] and bladder compliance [10 ml/cm of H2O to 33 ml/cm of H2O (p-value <0.001)] significantly improved at 3 months following surgery. In the voiding phase, peak flow rate showed a significant increase [5 ml/sec to 16 ml/sec (p-value <0.001)], post-void residual urine volume significantly decreased [460 ml to 30 ml (p value <0.001)] and peak detrusor pressure marginally decreased following TURP. Detrusor contractility index also improved significantly at 3 months post TURP [53 to 108; (p-value <0.05)]. Among 78 patients with a weak bladder (BCI <100) before surgery, BCI improved in 55% of patients following TURP (n=43). The IPSS score decreased from 21±6 to 4±2 following TURP. CONCLUSIONS: This is the first study evaluating the effect of TURP on urodynamic parameters in patients of BPE with upper tract changes. Changes in the bladder dynamics and resolution of hydroureteronephrosis following TURP reflected in the changes in urodynamic parameters and International prostate symptom score. Source of Funding: None © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e647 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Shantanu Tyagi More articles by this author Kalpesh Parmar More articles by this author Shrawan Singh More articles by this author Expand All Advertisement PDF DownloadLoading ...

Presentation Variables Associated With the Development of Severe Post-obstructive Diuresis in Male Cats Following Relief of Urethral Obstruction.

Background:Diuresis following relief of urethral obstruction is a potentially life-threatening complication of feline urethral obstruction. Evidence regarding the incidence of post-obstructive diuresis (POD) in cats is scarce. Establishing historical, physical examination, and initial clinicopathologic variables associated with risk for developing POD may better enable clinicians to direct treatment for this common feline emergency and to educate clients regarding financial expectations.ObjectivesTo report the incidence of POD in a large group of cats with urethral obstruction and determine whether select presenting physical examination or initial clinicopathologic variables may predict the onset or severity of POD.MethodsThe records of 260 cats that were admitted to the University of California, Davis, Veterinary Medical Teaching Hospital for urethral obstruction were reviewed. Urine output after urethral catherization was categorized into no POD (urine output ≤ 2 mL/kg/h), mild-moderate POD (urine output > 2 but <5 mL/kg/h) and severe POD (urine output ≥ 5 mL/kg/h). Select presentation physical examination, venous acid-base, electrolyte, serum biochemistry, and urinalysis results were compared among the groups.Results67.7% of cats experienced POD, and in 35% of cats it was categorized as severe. Evaluated historical and physical examination variables correlated with development of POD were lower body weight and, for severe POD, hypovolemia. Clinicopathologic variables associated with development of POD included acidemia, azotemia, hyperphosphatemia, hyperkalemia, hyponatremia, hypochloremia, hypocalcemia, hypermagnesemia, and hypoalbuminemia. Cats with severe POD were hospitalized a median of 1 day longer than those without POD.ConclusionsResults of the present study indicate that there are presentation variables associated with onset and severity of POD following relief of feline urethral obstruction.

Predictors of Renal Recovery among Patients of Obstructive Urolithiasis with Renal FailureA Prospective Observational Study

Introduction: Timely intervention in patients of obstructive uropathy secondary to renal and /or ureteric stones can reduce the morbidity and mortality in such patients. Aim: To determine the factors predicting recovery in patients of urinary stones and obstructive uropathy. Materials and Methods: This prospective observational study was conducted at Shri Mahant Inderesh Hospital, Dehradun, Uttrakhand, India, between December 2018 and June 2020. All patients with renal failure (serum creatinine &gt;1.5 mg/dL) secondary to urinary stones presenting to the Emergency Department were included in the study. Baseline demographic data, clinical, haematological, biochemical and microbiological parameters were recorded at presentation and after Double J Stent (DJS) insertion at postintervention day 1, 3 and 7. Total 40 patients were divided into two groups i.e, recovered (n=25) and non recovered (n=15) groups. Receiver Operating Characteristic (ROC) curves was used to obtain optimal threshold duration of illness, the values of serum creatinine, serum urea, haemoglobin and serum potassium, and time to nadir creatinine for predicting renal recovery. The graphs were made using both Microsoft excel and SPSS software. Results: Out of total 40 pateints, 29 were males and 11 were females. The mean duration of symptoms in the recovered and non recovered groups was 4.64 and 15.53 days, respectively (p-value=0.001). Thirteen out of 15 patients (86.6%) in the non recovered group and 10 out of 25 (40%) in the recovered group had pre-existing co-morbidities (p-value=0.004). Postobstructive diuresis was present in 84% patients in the recovered and 46.6% in the non recovered group (p-value=0.016). The nadir serum creatinine level was 1.26 mg/dL in recovered as compared to 6.08 mg/dL in the non recovered patients (p-value=0.001). The ROC curves were plotted for various parameters in order to find the prognostic accuracy in predicting recovery. The best criteria were symptom duration ≤6 days, serum creatinine at presentation ≤6.2 mg/dL, serum potassium ≤5.5 mg/dL, and haemoglobin level &gt;9.4 gm/dL. Conclusion: Short duration of symptoms (≤6 days), lower serum creatinine levels (≤6.2 mg/dL), lower serum potassium levels (≤5.5 mg/dL), and higher haemoglobin level (&gt;9.4 gm/dL) were found to predict a greater chance of recovery. These factors can help in formulating treatment protocols for early intervention leading to a better prognosis in this subgroup of patients.

Pathological post-obstructive diuresis following obstructive uropathy due to constipation in the post-partum period: a case report

BackgroundConstipation during pregnancy is not uncommon. Usually, this does not warrant extensive evaluation and settles with minor interventions or lifestyle modifications. Severe fecal impaction in chronically constipated patients can rarely lead to obstructive uropathy. Relief of obstruction can result in a diuretic phase which may be self-limiting or pathological. However, occurrence of pathological post-obstructive diuresis as a result of severe constipation is an extremely rare complication during pregnancy and puerperium which can even be fatal if not promptly diagnosed and adequately monitored and timely intervened. We describe the management of a pathological post-obstructive diuresis which occurred in the immediate postpartum period after treatment of severe constipation and obstructive uropathy.Case presentationA woman who had undergone an emergency caesarean section due to deep transverse arrest 1 week ago, presented with fecal impaction and anuria. On relief of urinary obstruction which had developed secondary to fecal impaction, she developed pathological post-obstructive diuresis. Careful and timely monitoring with exact fluid replacement, correction of electrolyte imbalances and multidisciplinary care ensured complete recovery of the patient.ConclusionsDespite obstructive uropathy being uncommon in obstetric practice, clinicians need to have a high index of suspicion to monitor and promptly manage the potentially life-threatening condition of post-obstructive diuresis in pregnant and puerperal women undergoing urinary tract decompression. Due to unreliability of laboratory cutoff values in pregnancy and puerperium, a more vigilant and multidisciplinary approach with lower threshold for intervention is more prudent in the management of these patients.

Post Obstruction Diuresis: A Clinical Diagnosis, you don’t have to Miss it

Post-obstructive diuresis (POD) is a specific entity which may occur post catheterization and is a rare but potentially lifethreatening condition if not recognized and managed appropriately. However, prolonged bilateral ureteral obstruction (BUO) can cause severe structural and functional tubular damage. Complications that may arise: volume depletion, hyponatremia/ hypernatremia, hypokalemia, hypomagnesaemia, metabolic acidosis, hypovolemic shock and death.

Effect of Transurethral Resection of the Prostate on Urodynamic Parameters in Patients with Benign Prostatic Enlargement with Upper Urinary Tract Dilatation

Objective: To evaluate the urodynamic outcomes of transurethral resection of the prostate (TURP) in patients of benign prostatic enlargement (BPE) with upper urinary tract dilatation and correlate with International Prostate Symptoms Score (I-PSS). Methods: In this prospective study, patients of BPE with upper urinary tract dilatation from July 2017 to June 2019 were enrolled. At presentation, detailed I-PSS, ultrasonography abdomen, serum creatinine, and serum PSA were recorded. All the patients were catheterized and observed for postobstructive diuresis. At 4 weeks, repeat ultrasound and serum creatinine were recorded. Urodynamic study (UDS) was performed after ensuring sterile urine culture. Patients underwent TURP as per the standard technique. A repeat UDS was performed after 3 months, and analysis was done. Results: Forty-four patients were enrolled of which data of 37 patients were analyzed. In the filling phase of the UDS, there was a significant decrease in detrusor pressure at the end filling phase from 27 to 9.0 cm H2O after TURP. Maximum cystometric capacity and bladder compliance significantly improved at 3 months following surgery. In the voiding phase, peak flow rate showed a significant increase, postvoid residual urine volume significantly decreased, and peak detrusor pressure marginally decreased following TURP. The I-PSS decreased from 20 ± 8 to 5 ± 6 following TURP. Conclusion: High detrusor pressure and reduced compliance is a risk factor for upper urinary tract dilatation. Changes in the bladder dynamics and resolution of hydronephrosis following TURP reflected in the changes in urodynamic parameters and I-PSS.

Clinical characteristics and outcome of high-pressure chronic urinary retention: A systematic review

Background: Although not infrequent, publications on high-pressure chronic urinary retention (HPCR) are limited. Lack of awareness of this condition can lead to delayed diagnosis and suboptimal treatment. This systematic review aimed to describe the clinical characteristics and outcome of HPCR. Methods: Keywords were searched in PubMed, Scopus, EMBASE, LILACS, Cochrane-CENTRAL, APAMED Central and Google Scholar. Relevant articles were added from the list of references of eligible articles. Studies describing any two of the characteristic features related to HPCR were included. Qualitative analysis was performed using the available data. Results: Eight prospective studies with 271 patients ( Mage=66.4 years, range 14–89 years; 263 males) were identified. The commonest presentation was tense painless palpable bladder (99.6%). Late-onset nocturnal enuresis was reported in 68.4%, and resistant hypertension was reported in 41.6%. Elevated levels of serum creatinine were identified in 43–81%. Benign prostatic hyperplasia (64.1%) was the commonest aetiology followed by prostatic malignancy (22.6%). A satisfactory response was seen following the definitive treatment of the underlying aetiology. Initial bladder decompression reversed adverse cardiovascular changes and improved renal function but resulted in post-obstructive diuresis. Heterogeneity of the reported data in available studies was a major limitation. Conclusions: Late-onset nocturnal enuresis, a tense painless and non-tender palpable bladder and treatment-resistant hypertension are important clinical findings which would raise the suspicion of HPCR in the clinical setting. Urinary tract ultrasonography showing upper-tract dilatation and raised serum creatinine support the diagnosis. Definitive treatment targeting the underlying aetiology following careful decompression of the bladder showed satisfactory outcomes. Level of evidence: Level 2a(-).

Post-obstructive diuresis; underlying causes and hospitalization

Objective: This paper aims to estimate the incidence of post-obstructive diuresis (POD) among patients with urinary retention, explore possible underlying causes and identify patients who need hospitalization.Material and methods: This retrospective study includes patients admitted for urinary retention in Zealand University Hospital, Denmark. We collected demographic characteristics, health information and laboratory results from patients’ charts and analyzed data statistically.Results: We assessed 64 patients, and POD occurred in 29.7%. A significant correlation was observed between POD and residual urine, serum creatinine, serum urea and systolic and diastolic blood pressure. We identified increased residual urine volume as an independent predictor of POD by OR 1.21 (95% CI: 1.06–1.40), p = 0.006 per 100 mL and creatinine of >120 umol/L is an independent predictor of POD by OR 7.17 (95% CI; 1.63–31.37), p = 0.009. Patients with residual urine at the time of diagnosis of more than 1150 ml will suffer POD with a probability of area under curve (AUC) 0.874 (p < 0.001) with 84% sensitivity and 78% specificity. Patients with creatinine >120 umol/L will suffer POD with a probability of AUC 0.774 (p < 0.001) with 68% sensitivity and 82% specificity.Conclusion: In this small retrospective study residual urine of more than 1150 mL and elevated creatinine are independent predictors of POD in patients with urinary retention. However, larger prospective studies are needed to confirm these findings.

Post-obstructive Diuresis: A Cautionary Tale

Post-obstructive diuresis (POD) following decompression of urinary tract obstruction is usually a self-limiting phenomenon. However, prolonged bilateral ureteral obstruction (BUO) can cause severe structural and functional tubular damage. We present a case of POD resulting from partial nephrogenic diabetes insipidus and discuss the diagnosis, treatment, and prognosis.

Bilateral ureteral obstruction is rapidly accompanied by ER stress and activation of autophagic degradation of IMCD proteins, including AQP2.

After the release of bilateral ureteral obstruction (BUO), postobstructive diuresis from an impaired urine concentration mechanism is associated with reduced aquaporin 2 (AQP2) abundance in the inner medullary collecting duct (IMCD). However, the underlying molecular mechanism of this AQP2 reduction is incompletely understood. To elucidate the mechanisms responsible for this phenomenon, we studied molecular changes in IMCDs isolated from rats with 4-h BUO or sham operation at the early onset of AQP2 downregulation using mass spectrometry-based proteomic analysis. Two-hundred fifteen proteins had significant changes in abundances, with 65% of them downregulated in the IMCD of 4-h BUO rats compared with sham rats. Bioinformatic analysis revealed that significantly changed proteins were associated with functional Gene Ontology terms, including “cell-cell adhesion,” “cell-cell adherens junction,” “mitochondrial inner membrane,” “endoplasmic reticulum chaperone complex,” and the KEGG pathway of glycolysis/gluconeogenesis. Targeted liquid chromatography-tandem mass spectrometry or immunoblot analysis confirmed the changes in 19 proteins representative of each predominant cluster, including AQP2. Electron microscopy demonstrated disrupted tight junctions, disorganized adherens junctions, swollen mitochondria, enlargement of the endoplasmic reticulum lumen, and numerous autophagosomes/lysosomes in the IMCD of rats with 4-h BUO. AQP2 and seven proteins chosen as representative of the significantly altered clusters had a significant increase in immunofluorescence-based colocalization with autophagosomes/lysosomes. Immunogold electron microscopy confirmed colocalization of AQP2 with the autophagosome marker microtubule-associated protein 1A/1B-light chain 3 and the lysosomal marker cathepsin D in IMCD cells of rats with 4-h BUO. We conclude that enhanced autophagic degradation of AQP2 and other critical proteins, as well as endoplasmic reticulum stress in the IMCD, are initiated shortly after BUO.

Post-obstructive diuresis: a complication of urinary retention.

Post-obstructive diuresis: a complication of urinary retention.

Factors associated with postobstructive diuresis following decompressive surgery with placement of ureteral stents or subcutaneous ureteral bypass systems for treatment of ureteral obstruction in cats: 37 cases (2010-2014).

To describe postobstructive diuresis (POD) in cats undergoing surgical placement of ureteral stents or subcutaneous ureteral bypass systems for treatment of ureteral obstruction in cats and to identify factors associated with duration and maximum severity of POD. Retrospective case series. 37 client-owned cats with ureteral obstruction treated between August 2010 and December 2014. Medical records were reviewed, and data extracted included signalment, history, results from physical examinations and clinical laboratory analyses, treatment, urine output, and outcome. Data were evaluated to identify factors associated with POD duration and maximum severity, alone or in combination. Serum concentrations of creatinine, potassium, phosphorus, and BUN before surgery positively correlated with duration and maximum severity of POD. Absolute changes in serum concentrations of creatinine, potassium, and BUN from before surgery to after surgery positively correlated with POD duration. Cats with anuria before surgery had longer POD than did other cats; however, there was no difference in POD duration or maximum severity with unilateral versus bilateral ureteral obstruction. Thirty-four of 37 (92%) cats survived to hospital discharge, which was not associated with whether ureteral obstruction was unilateral or bilateral. Azotemia resolved in 17 of the 34 (50%) cats that survived to hospital discharge. Results of the present study indicated that several factors were associated with POD duration and maximum severity, alone or in combination, and that with intensive management of fluid and electrolyte derangements, regardless of the extent of the original azotemia, a high percentage of cats survived to hospital discharge.

PT168 - The outcomes of male patients with acute urinary retention with concomitant post-obstructive diuresis

PT168 - The outcomes of male patients with acute urinary retention with concomitant post-obstructive diuresis

Incidence of pathologic postobstructive diuresis after resolution of ureteropelvic junction obstruction with a normal contralateral kidney

Postobstructive diuresis (POD) after unilateral pyeloplasty or percutaneous nephrostomy (PCN) tube insertion for ureteropelvic junction obstruction (UPJO) in patients with a normal contralateral kidney is not well described. The objective of this study was to determine the incidence and characteristics of POD after relief of unilateral UPJO in patients with a normal contralateral kidney. Children who underwent a unilateral pyeloplasty or PCN for UPJO from 2010 to 2017 with a normal contralateral kidney were retrospectively reviewed. Postobstructive diuresis was defined as urine output (UO) of >300% of expected UO. Patients with a solitary kidneyor those who underwent bilateral pyeloplasty or bilateral PCN tube placement were excluded. Out of 396 children meeting inclusion criteria, seven (1.8%) developed POD (4 after pyeloplasty and 3 after PCN tube placement). Median age at intervention was 1.7 years (range 11 days-18 years); median weight was 11.4kg (range 3.7-54.2kg). Postobstructive diuresis was more likely to occur in patients with grade 4 hydronephrosis (3.0%) and larger kidneys and if a PCN tube was placed before pyeloplasty. There was no significant difference in age, gender, kidney laterality, or function between those who developed POD and those who did not. Postobstructive diuresis was managed with additional intravenous fluids and electrolyte monitoring. Median initial postprocedure UOwas 5.9mg/kg/hr (range 3.2-10.0mg/kg/hr). In five children who underwent PCN in whom UOcould be differentiated between kidneys, median initial postprocedure UOwas 6.1mg/kg/hr (range 2.5-9.1mg/kg/hr) from the affected side and 0.8mg/kg/hr (range 0.4-0.9mg/kg/hr) from the unaffected side. The median length of time to resolution of POD was 3 days (range 2-4 days). One patient developed significant acidosis and lethargy that improved with intravenous fluid management. Mild hyponatremia developed in two, hypokalemia in one, hypophosphatemia in one, acidosis in one, and hypoglycemia in 1 patient. A low but clinically significant risk of POD occurring after relief of unilateral UPJO in children with a normal contralateral kidney is described. Limitations include retrospective analysis and small sample size due to the rarity of the condition. Postobstructive diuresis after decompression of UPJO in patients with a normal contralateral kidney is a rare event (1.8%). However, POD does occur, and patients should be carefully monitored after these procedures given the potential for significant dehydration and electrolyte disturbances.