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Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.

Urodynamics and specialist investigation

Obstetrics and gynaecology · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

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Acute retention or infection around testing

Urodynamics is elective. Fever, rigors, flank pain, sepsis, inability to void, severe suprapubic pain or gross haematuria before or after catheter testing requires prompt clinical assessment rather than reassurance that transient stinging is expected.

Action: Check observations, urine output, abdomen and residual volume, obtain urinalysis, culture and renal tests as indicated, treat sepsis or acute retention through the appropriate pathway, and notify the testing service so elective interpretation or further instrumentation is deferred safely.

Synopsis

Choose urodynamic and related specialist tests only when they answer a management-changing question, understand what the traces represent, and recognise limitations and post-test complications.

  • Urodynamics measures storage and voiding function; it does not replace a detailed history, examination, urinalysis, diary or selective residual assessment.
  • Simple uroflowmetry records voided volume and flow pattern; interpret it with post-void residual and whether the bladder was comfortably full.
  • Multichannel cystometry subtracts abdominal pressure from bladder pressure to estimate detrusor pressure during filling and voiding.
  • Do not perform multichannel filling and voiding cystometry before primary stress-incontinence surgery when history and examination show stress or stress-predominant mixed incontinence and stress leakage is demonstrated.
  • Perform it before stress-incontinence surgery when symptoms are urge-predominant or unclear, suggest voiding dysfunction, coexist with anterior or apical prolapse, or follow previous stress-incontinence surgery.
  • For refractory OAB being considered for invasive treatment, offer urodynamics to determine whether detrusor overactivity is present and use the result in counselling.
  • Catheters, artificial filling, position, anxiety and failure to reproduce symptoms limit ecological validity; label artefact and relate the trace to the person's ordinary pattern.
  • Explain discomfort, transient dysuria, UTI and retention risk, preserve dignity and consent, and give written advice on post-test red flags.

Key red flags

Symptomatic UTI or systemic illness before the appointment should be assessed and usually treated before elective invasive urodynamics.

Inability to void, painful bladder distension, fever, rigors or worsening haematuria after testing needs urgent review for retention, infection or trauma.

New saddle sensory loss, leg weakness or bowel dysfunction with urinary change requires emergency neurological assessment, not routine urodynamics.

Visible haematuria, persistent bladder pain, suspected fistula or a pelvic mass needs its own specialist diagnostic pathway.

A technically implausible trace or failure to reproduce the usual symptom should not drive irreversible treatment without clinical reconciliation.

Investigation priorities

01
Free uroflowmetry with residualFirst step

Assess an uninstrumented flow pattern and emptying before invasive filling when voiding dysfunction is relevant.

Management branches

Test selectionWrite the management question first

Specialist testing is being considered after clinical assessment.

  1. Summarise symptom phenotype, demonstrated findings, diary, residual, prolapse, previous surgery and treatments already tried.
  2. Apply NICE preoperative and refractory-OAB indications, stating which plausible urodynamic result would change counselling or intervention.
  3. Do not test routine uncomplicated demonstrable stress incontinence before primary surgery, and use structural tests only for their separate indications.
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Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • NICE NG123 urodynamic testing recommendations
  • Cambridge University Hospitals urodynamic investigation
  • NHS urinary incontinence diagnosis and urodynamic tests
  • North Bristol NHS Trust urodynamics service

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom