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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.
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Urinary catheterisation and nasogastric tube safety

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Synopsis

Insert, confirm, secure, maintain and remove urinary catheters and nasogastric tubes safely, preventing urethral trauma, infection and catastrophic respiratory placement.

  • Use an invasive tube only for a clear indication, document it and review daily; alternatives may meet the goal with less harm.
  • Urinary catheterisation uses aseptic technique, single-use lubricant, the smallest gauge that permits drainage and a sterile closed system.
  • Never inflate a urinary balloon until urine flows and the catheter is advanced appropriately into the bladder; pain or resistance is a stop signal.

Key red flags

Possible urethral injury

Meatal blood, pelvic trauma or perineal bruising requires urological assessment before blind catheterisation.

Balloon in urethra

Pain during balloon inflation, failure to drain or new bleeding requires immediate stopping, complete balloon deflation and senior review before any further catheter manipulation.

Respiratory NG placement

Cough, cyanosis, breathlessness, voice change or falling saturation during insertion requires immediate withdrawal.

Feeding aspiration

Acute cough, desaturation, fever or respiratory distress during feeding requires stopping feed and urgent assessment.

Reasoning priorities

01
Bladder scan when appropriate

Confirm retention and guide whether catheterisation is needed.

Device and timing limitations apply; severe symptoms or acute renal risk may still require urgent action.

Worked reasoning

Worked case: no NG aspirateNothing down an unconfirmed tube

A newly inserted NG tube yields no aspirate and the patient needs time-critical medication.

  1. Do not flush, medicate or feed; reassess patient, respiratory symptoms, external length, fixation and insertion events.
  2. Reason that absence of distress or a plausible tube length cannot confirm gastric position and that flushing could deliver fluid into lung.
  3. Use manoeuvres allowed by local policy to obtain aspirate, then arrange an appropriate placement X-ray if pH confirmation remains unavailable; use an alternative medicine route meanwhile.
  4. Verify trained X-ray interpretation and documented authorisation, record external length and communicate confirmation before first use.
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Sources and review status7 sources · checked 7 Sept 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 7 Sept 2026; clinical approval remains outstanding.

Authoring stateRapid draftClinical stateAwaiting reviewJurisdictionUnited Kingdom