Renal Profile and Outcome of Patients With Post-Obstructive Diuresis at the UST Hospital: A Retrospective Study

Nenuel Angelo B. Luna, Dexter Clifton C. Pe

Oct 2025 DOI 10.35460/2546-1621.2024-0034     Access   

Abstract

Background of the Study: Post-obstructive diuresis (POD) is a common diagnosis among urologic patients that is medically diagnosed and managed. It is defined as urine production exceeding 200 mL per hour for two consecutive hours or producing greater than 3 L of urine in 24 hours. There is limited data on the risk factors of developing POD, but the need to identify such is important to prevent its complications such as dehydration, electrolyte imbalance, acute renal failure and even death.

Objectives: The study aims to identify clinical and renal predictors of developing POD. It also seeks to show the outcome of patients diagnosed with POD and its correlation with medical management.

Method: This is a retrospective study of all patients diagnosed with POD centered in the University of Santo Tomas Hospital from January 2017 to December 2018. Renal parameters such as serum creatinine, sodium, potassium, urea and ionized calcium were analyzed. Urinalysis and arterial blood gases were also noted and correlated.

Results: Among a total of 106 patients with obstruction, 28.32% developed POD after decompression. The mean age is 58.2 ± 13.89, and most are male. Patients with POD have significantly longer days of obstruction (14 days, p = 0.049) compared to non-POD. Overweight patients comprise a significantly larger proportion of patients who had POD (p = <0.001). Those with baseline acute kidney injury (AKI) (elevated serum creatinine at an average of 1.93 and low eGFR at an average of 35.6) have a significantly higher risk of developing POD (p = 0.004). Serum sodium levels were also higher among patients with POD (140, p = 0.008). Renal predictors identified include obstruction from prostate cancer (p = 0.011), longer duration of obstruction (p = 0.042), low eGFR (p = 0.009) and AKI (p = 0.004). Intravenous fluid (IVF) did not differ in the type used and outcomes of POD. Fluid replacement per urine volume also did not alter the disease course (p = 801). Regarding outcome, all discharged patients improved but differed significantly from the non-POD group regarding prolonged hospital stay. There were no significant electrolyte imbalances, postoperatively.

Conclusion: POD occurs more likely among patients with a baseline AKI, low level of eGFR, longer duration of obstructions beyond 14 days and those with prostate cancer. Serum sodium and creatinine were higher among patients with POD. POD is associated with prolonged hospital stay, but obstruction relief leads to renal function improvement.

Keywords: Post-obstructive diuresis, obstructive uropathy

  1. Halbgewachs C, Domes T. Postobstructive diuresis: pay close attention to urinary retention. Can Fam Physician. 2015;61(2):137–42. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4325860/
  2. Leslie DS and Bates DB. Postobstructive diuresis. StatPearls Publishing LLC; 2019. 
  3. Thiel M. Postobstructive polyuria in unilateral hydronephrosis: A case with 58 l/day. Urologe A. 2010;40:133–6.
  4. American Society of Nephrology. Post-obstructive diuresis. 2019. 
  5. Leigie N, Jadoul M, Pirson W, Damas P, Donner E. Post-obstructive diuresis: diagnosis and management. Revue Medicale de1 Liege. 2017;72:529–33
  6. Shah A. A guide for the assessment and management of post-obstructive diuresis. Urology News. 2015;19(3).
  7. Bermeo JH, Junior S, Barros JA, Oliveira AC, Neto RC, Drezner AC. Risk factors for postobstructive diuresis in pediatric patients with ureteropelvic junction obstruction, following open pyeloplasty in three high complexity institutions. Journal of Pediatric Urology. 2018;20(2):e13–7.
  8. Hamdi A, Hajage D, Van Glabeke E, Belenfant X, Vincent F, Gonzalez F, et al. Severe post‐renal acute kidney injury, post‐obstructive diuresis and renal recovery. BJU Int [Internet]. 2012;110(11c). Available from: https://doi.org/10.1111/j.1464-410x.2012.11193.x
  9. Harrison S, Lasri A, Jabbour Y, Slaoui A, Djamal J, Karmouni T, et al. Post-obstructive diuresis: Physiopathology, diagnosis and management after urological treatment of obstructive renal failure. Open J Urol [Internet]. 2018;08(09):267–74. Available from: https://doi.org/10.4236/oju.2018.89030
  10. Limjunyawong K, Choonhaklai V, Chittchang V, Akarasakul D, Pumpaisanchai S, Wongwattanasatien N, et al. Prevalence and risk factors of post obstructive diuresis after percutaneous nephrostomy in obstructive nephropathy patients. The Thai Journal of Urology. 2017;38(2):8–19.
  11. Fröhlich L, Hartmann K, Sautter-Louis C, Dorsch R. Postobstructive diuresis in cats with naturally occurring lower urinary tract obstruction: incidence, severity and association with laboratory parameters on admission. J Feline Med Surg [Internet]. 2016;18(10):809–17. Available from: https://doi.org/10.1177/1098612X15594842
  12. Francis BJ, Wells RJ, Rao S, Hackett TB. Retrospective study to characterize post-obstructive diuresis in cats with urethral obstruction. J Feline Med Surg [Internet]. 2010;12(8):606–8. Available from: https://doi.org/10.1016/j.jfms.2010.03.004
  13. Wilson D. Cross-circulation study of natriuretic factors in post-obstructive diuresis. J Clin Invest. 1976;57(2):380–9.
  14. Quinlan MR, Cronin P, Daly PJ, Watson RWG, Manucha W, Docherty NG, et al. A gender comparison of postobstructive injury in the rat kidney. Kidney Blood Press Res [Internet]. 2010;33(4):266–73. Available from: https://doi.org/10.1159/000317934
  15. Gillenwater JY, Westervelt FB Jr, Vaughan ED Jr, Howards SS. Renal function after release of chronic unilateral hydronephrosis in man. Kidney Int [Internet]. 1975;7(3):179–86. Available from: https://doi.org/10.1038/ki.1975.26
  16. Shankel SW. Massive Post-Obstructive Diuresis. Am J Case Rep [Internet]. 2018;19:57–60. Available from: https://doi.org/10.12659/ajcr.906238
  17. Sakar B. Conducting record review studies in clinical practice. J Clin Diagn Res. 2014;8(9):G01-G4.

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