Benign prostatic hyperplasia (BPH) is the most common benign neoplasm in aging men, serving as a primary cause of lower urinary tract symptoms (LUTS), bladder outlet obstruction (BOO), and compromised quality of life [1,2]. Histological evidence of BPH increases progressively with age, affecting nearly 50% of men in their sixth decade and up to 80–90% by the ninth decade [3]. While pharmacological therapies (alpha-1 blockers and 5-alpha reductase inhibitors) have reduced surgical intervention rates, operative therapy remains mandatory for patients with recurrent acute urinary retention (AUR), refractory symptoms, recurrent urinary tract infections (UTIs), gross hematuria, bladder calculi, or renal insufficiency [4,5]. Transurethral resection of the prostate (TURP) has historically represented the benchmark surgical modality for symptomatic BOO [6]. Despite the introduction of bipolar TURP (b-TURP) and laser techniques (e.g., HoLEP, ThuLEP), monopolar TURP (m-TURP) remains widely utilized globally—particularly in low- and middle-income healthcare settings—due to lower equipment costs, institutional availability, and durable functional outcomes [7]. However, m-TURP relies on non-conductive, electrolyte-free irrigating fluids—most commonly 1.5% glycine solution—to maintain endoscopic visibility, clear blood, and prevent electrical current dispersion [8]. Systemic absorption of this hypo-osmolar fluid through opened prostatic venous sinuses or capsular breaches can trigger Transurethral Resection (TURP) syndrome [9]. Pathophysiologically, TURP syndrome presents as acute intravascular volume overload, dilutional hyponatremia, plasma hypo-osmolality, and glycine-specific neuro-metabolic toxicity [10,11]. Clinical manifestations range from early nausea, vomiting, restlessness, and bradycardia to severe cerebral edema, seizures, pulmonary edema, cardiac arrhythmias, coma, and death [12,13]. While surgical duration and irrigant volume are recognized exposure factors, pre-operative prostate volume is a central determinant of procedural complexity [14]. Larger prostate glands feature an expanded vascular bed, increased number of exposed venous channels, heavier tissue resection requirements, and prolonged resection times—all facilitating irrigant entry into the circulation [15]. This prospective study evaluated the occurrence of TURP syndrome during m-TURP using 1.5% glycine and defined its specific association with prostate volume alongside key intraoperative variables and serum sodium dynamics [16,17].

2.1 Study Design and Patient Selection A prospective observational study was conducted in the Department of General Surgery at Vilasrao Deshmukh Government Medical College, Latur, Maharashtra, India, over an 18-month period (2023–2026). Approval was obtained from the Institutional Ethics Committee, and written informed consent was secured from all participants. • Inclusion Criteria: Male patients aged >50 years diagnosed clinically and ultrasonographically with BPH, admitted for elective m-TURP using 1.5% glycine irrigation, providing written informed consent. • Exclusion Criteria: Patients aged ≤50 years; suspected/confirmed prostate carcinoma; prior prostatic or urethral surgery; active neurogenic bladder; concomitant urinary bladder/urethral calculi or strictures; pre-existing dyselectrolytemia (baseline Na⁺ <135 mEq/L); severe uncompensated renal or cardiac failure; and procedures abandoned or converted intraoperatively. 2.2 Sample Size Calculation The sample size (n) was calculated using the standard proportional formula for epidemiological studies: Where Z = 1.96 (95% confidence level), p = 0.50 (expected proportion set at 50% for maximum sample size estimation), q = 100 - p = 50, and L = 5% (allowable absolute error). A total of 384 consecutive eligible patients were enrolled. 2.3 Operative Protocol and TURP Syndrome Diagnostic Criteria All procedures were performed under spinal anesthesia using a standard monopolar resectoscope with continuous flow 1.5% glycine solution. Operative duration (minutes), total glycine consumed (Liters), resected tissue weight (grams), capsular perforations, and bleeding severity were documented. Pre- and post-operative serum sodium (Na⁺) and potassium (K⁺) were measured. TURP Syndrome Definition: Diagnosed when acute cardiovascular and/or neurological features occurred during or immediately after m-TURP alongside post-operative hyponatremia or a significant drop in serum sodium from baseline. Severity was graded as Mild (Na⁺ 130–134.9 mEq/L, mild symptoms), Moderate (Na⁺ 125–129.9 mEq/L or fall >10 mEq/L, confusion, bradycardia), or Severe (Na⁺ <125 mEq/L or fall >15 mEq/L, seizures, coma, pulmonary edema). 2.4 Statistical Analysis Data were analyzed using IBM SPSS software. Continuous variables were expressed as Mean ± Standard Deviation (SD) and Median (IQR). Categorical variables were presented as counts and percentages. Pre- and post-operative serum electrolytes were compared using the paired t-test. Categorical comparisons used the Chi-square test or Fisher's exact test. Non-parametric group comparisons (TURP vs. Non-TURP) used the Mann-Whitney U test. A p-value <0.05 was considered statistically significant (p < 0.001 highly significant).

3.1 Demographic and Baseline Clinical Characteristics Among the 384 patients, the mean age was 67.00 ± 6.91 years (range: 51–86 years), with the 61–70 years age group accounting for 50.52% of the cohort. LUTS alone was the main presenting complaint (43.23%), followed by acute urinary retention (20.05%). Comorbidities were present in 71.09% of patients, dominated by hypertension (25.52%) and diabetes mellitus (18.75%). Most patients were classified as ASA II (60.16%). Table 1: Baseline Demographic and Clinical Profile of the Study Cohort (N = 384) Parameter / Variable Value (Mean ± SD / N [%]) Age (years) 67.00 ± 6.91 • 51–60 years 73 (19.01%) • 61–70 years 194 (50.52%) • 71–80 years 102 (26.56%) • >80 years 15 (3.91%) Primary Clinical Presentation • Lower Urinary Tract Symptoms (LUTS) alone 166 (43.23%) • Acute Urinary Retention (AUR) 77 (20.05%) • LUTS + AUR 63 (16.41%) • Recurrent Urinary Tract Infections (UTI) 33 (8.59%) • Failed Medical Management 26 (6.77%) • Hematuria 19 (4.95%) Comorbidity Profile • No Comorbidities 111 (28.91%) • Hypertension (HTN) 98 (25.52%) • Diabetes Mellitus (DM) 72 (18.75%) • HTN + DM 44 (11.46%) • Ischemic Heart Disease (IHD) / Others 59 (15.36%) ASA Physical Status Grade • Grade I 73 (19.01%) • Grade II 231 (60.16%) • Grade III 80 (20.83%) 3.2 Overall Operative Parameters & TURP Syndrome Incidence The mean pre-operative prostate volume was 58.05 ± 14.52 g. Overall mean operative duration was 51.06 ± 12.88 min, resected tissue weight was 24.89 ± 10.55 g, and total glycine volume used was 20.21 ± 3.15 L. The overall incidence of TURP syndrome was 2.34% (9/384 patients), consisting of 3 mild (0.78%), 3 moderate (0.78%), and 3 severe (0.78%) cases. Table 2: Pre-operative and Operative Parameters of the Study Cohort (N = 384) Variable Mean ± SD Median (IQR) Pre-operative Prostate Size (g) 58.05 ± 14.52 58.00 (48.00–66.00) Serum PSA (ng/mL) 4.28 ± 1.36 4.34 (3.33–5.19) P ti H l bi ( /dL) 12 87 ± 1 08 12 80 (12 10 13 60) Prostate Volume and TURP Syndrome Study | GMC Latur 3.3 Risk Factor Analysis: TURP Syndrome vs. Non-TURP Syndrome Patients developing TURP syndrome had significantly larger pre-operative prostate volumes (99.11 ± 13.99 g vs. 57.07 ±13.04 g, p < 0.001). No cases occurred in glands ≤60 g. Incidence reached 42.11% in glands >80 g (p < 0.001). Table 3: Comparative Analysis of Risk Factors Between Study Group Variable Non-TURP (n = 375) TURP Syn (n = 9) p-value Age (years) 66.70 ± 6.68 79.67 ± 3.67 <0.001* Prostate Size (g) 57.07 ± 13.04 99.11 ± 13.99 <0.001* • ≤60 g (n=227) 227 (100%) 0 (0%) <0.001† • 61–80 g (n=138) 137 (99.28%) 1 (0.72%) • >80 g (n=19) 11 (57.89%) 8 (42.11%) Operative Duration (min) 50.27 ± 11.92 83.67 ± 9.08 <0.001* • ≤60 min (n=299) 299 (100%) 0 (0%) <0.001† • >75 min (n=12) 5 (41.67%) 7 (58.33%) Tissue Resected (g) 23.96 ± 8.69 63.44 ± 9.49 <0.001* • >60 g resected (n=6) 0 (0%) 6 (100%) <0.001† Glycine Consumed (L) 19.99 ± 2.80 29.07 ± 4.16 <0.001* • >30 L used (n=4) 0 (0%) 4 (100%) <0.001† Capsular Perforation (n=2) 0 (0%) 2 (100%) <0.001‡ Significant Bleeding (n=3) 0 (0%) 3 (100%) <0.001† Post-op Serum Na⁺ (mEq/L) 137.20 ± 2.79 124.28 ± 5.18 <0.001* Serum Sodium Fall (mEq/L) 2.74 ± 1.40 15.42 ± 4.36 <0.001* * Mann-Whitney U test; † Chi-square test; ‡ Fisher's exact test. 3.4 Perioperative Serum Electrolyte Dynamics Across the cohort, mean serum sodium dropped significantly postoperatively (139.93 ± 2.40 mEq/L pre-op to 136.90 ± 3.47 mEq/L post-op, p < 0.001). Serum potassium showed no significant alteration (4.21 ± 0.34 vs. 4.23 ± 0.37 mEq/L, p = 0.068). Table 4: Perioperative Serum Electrolyte Changes Across the Cohort (N = 384) Electrolyte Pre-operative (mEq/L) Post-operative (mEq/L) Mean Change (mEq/L) p-value (Paired t) Serum Sodium (Na⁺) 139.93 ± 2.40 136.90 ± 3.47 -3.03 ± 2.45 <0.001 Serum Potassium (K⁺) 4.21 ± 0.34 4.23 ± 0.37 +0.02 ± 0.21 0.068 3.5 Individual Profile of the 9 TURP Syndrome Cases Table 5: Clinical, Biochemical, and Management Details of TURP Syndrome Cases Case Age Size Dur. Tissue Glycine Post Na⁺ Na⁺ Fall CV / Neuro Features Grading Management & Outcome #1 74 95 g 83 m 52 g 24.0 L 120.6 18.0 Bradycardia, Seizures Moderate O₂ + FR + Furosemide + EC (Resolved) #2 83 72 g 81 m 66 g 34.3 L 123.1 19.0 Arrhythmia, Confusion Moderate O₂ + FR + Furosemide + EC (Resolved) #3 74 111 g 87 m 69 g 30.1 L 119.4 20.2 Bradycardia, Seizures Severe O₂ + Furo + 3% NaCl + ICU (Resolved) #4 80 114 g 90 m 56 g 22.8 L 133.1 8.9 Bradycardia, Nausea Mild O₂ + Fluid Restriction + Furo (Resolved) #5 84 97 g 96 m 48 g 29.6 L 130.1 11.0 HTN, Restlessness Mild O₂ + Fluid Restriction + Furo (Resolved) #6 83 98 g 75 m 73 g 32.4 L 120.2 19.3 Bradycardia, Seizures Severe O₂ + Furo + 3% NaCl + ICU (Resolved) Prostat e Volu 117 me and 70 TURP S yndrome Study | G MC Latur O Fl id R t i ti F Page 4 of 5 Table 6: Comparative Overview with Published Literature Study Sample Size Irrigant Incidence Key Risk Factors Identified Mebust et al. [6] 3,885 1.5% Glycine 2.0% Resection time >90 min, tissue weight >45 g Rassweiler et al. [7] Review Various 0.5–5.0% Prolonged resection, capsular breach, bleeding Regmi et al. [17] Tertiary Care 1.5% Glycine 3.8% Age >60 yrs, surgery >60 min, heavy resection Present Study (2026) 384 1.5% Glycine 2.34% Prostate size >80 g, duration >75 min, glycine >25 L

In this prospective cohort of 384 patients undergoing m-TURP with 1.5% glycine, the overall incidence of TURP syndrome was 2.34%, which aligns with international reported rates (0.5%–3.8%) [6,17]. The central finding is that pre-operative prostate volume >80 g acts as the primary pathophysiological driver of TURP syndrome. RECOMMENDED CLINICAL PROTOCOL FOR MONOPOLAR TURP 1. Pre-op Stratification: Flag glands >80 g as high-risk; consider staged TURP, bipolar TURP, or laser enucleation (HoLEP) where available. 2. Strict Time Cap: Restrict monopolar resection time strictly to ≤60 minutes (risk spikes significantly after 75 minutes). 3. Glycine Threshold: Limit total glycine volume to <25 Liters; pause resection if capsular perforation or major sinus bleeding occurs. 4. Routine Post-op Na⁺ Checks: Mandate serum electrolyte testing postoperatively for all glands >60 g or resection times >60 min.

Limitations: Single-center design; fluid absorption was estimated via gross glycine consumption rather than direct ethanol tracer measurement; and low absolute event count (n=9) precluded complex multivariate regression modeling. Conclusion: Pre-operative prostate volume >80 g is a critical determinant of TURP syndrome during monopolar resection, driving prolonged operative duration, heavy tissue removal, and excessive glycine absorption. Pre-operative risk stratification, strict adherence to a 60-minute resection limit, and routine post-operative serum sodium monitoring are essential to ensure patient safety.

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