01Principles and purposeThe professional or clinical skill and the decisions it supports.
Competent procedural practice is a controlled sequence rather than manual dexterity alone. Define the clinical question and likely benefit, consider a less invasive alternative, and identify patient-specific hazards. Explain the procedure, material risks, alternatives and what happens if it is not performed, adapting communication to the patient. Consent remains an ongoing dialogue. Lack of capacity requires the appropriate legal and best-interests process; urgency changes what can wait, not the need to document reasoning.
Preparation prevents rescue. Review identity, site and laterality, anatomy, previous imaging, infection risk, allergies, anticoagulants, platelet or coagulation information when relevant, and physiological stability. Select equipment before positioning the patient. Decide monitoring, analgesia, local anaesthesia, assistant, ultrasound or senior support and the plan for bleeding, vasovagal reaction, pneumothorax or other procedure-specific harm. If the operator cannot recognise and manage likely complications, supervision is required.
Aseptic technique protects susceptible sites. Perform hand hygiene, prepare a clean work area, use appropriate personal protective equipment, disinfect skin where required, and identify key parts such as sterile connection ends and key sites such as puncture points. Once prepared, do not touch them. A glove is not a substitute for hand hygiene and becomes contaminated when it touches a non-sterile surface. A breach requires stopping and replacing the contaminated component or rebuilding the field.
A standard sequence can be shared across venepuncture, cannulation, arterial sampling, catheterisation, aspiration and drains: prepare; pause; position; identify anatomy; perform the minimum safe attempts; obtain the intended endpoint; secure or dress; reassess. Procedure-specific technique belongs to an authorised local protocol and supervised skills training. Blind persistence after repeated failure increases haematoma, infection and patient distress and can make later expert attempts harder.
Verification depends on purpose. A cannula needs patency, absence of swelling and secure fixation; a catheter needs urine flow without traction and a continuing indication; a specimen needs identity, correct container and timely transport. Some devices require imaging or pressure confirmation before use. Record operator, indication, consent, site, technique, device, attempts, specimens, immediate outcome, complications and aftercare. Tell the patient what symptoms to report and hand over a removal or review date.
Key points
- Before any procedure confirm indication, alternatives, consent or valid authority, patient identity, site, allergies, anticoagulation, relevant results and your competence.
- Use the local standard operating procedure and supervision threshold; the same named procedure can require different equipment, imaging or expertise in different patients.
- Create an aseptic field, identify key parts and key sites, perform hand hygiene and protect them from contact according to national infection-prevention policy.
- Use a deliberate pause immediately before an invasive step to reconfirm patient, procedure, site, position, equipment, monitoring and rescue plan.
- Stop when anatomy is uncertain, resistance or unexpected pain occurs, physiology deteriorates, sterility is breached or the result conflicts with expectation.
- Label specimens at the bedside with correct identifiers, source, side, time and requested analyses, then verify dispatch and result ownership.
- A procedure ends only after haemostasis, device security, physiological reassessment, complication surveillance, documentation and patient-facing aftercare.
02Situations and prioritiesThe context, relevant information and actions that matter most.
Missing consent, unclear indication, absent rescue equipment, unreviewed anticoagulation or lack of supervision are reasons to pause before touching the patient.
Contact with a key part or key site, torn glove, contaminated field or uncertain sterility requires correction before continuing.
Poor landmarks, variant anatomy, obesity, oedema, previous surgery or unexpected resistance should lower the threshold for imaging or expert help.
Syncope, hypoxia, hypotension, severe pain, arrhythmia or new neurological symptoms require stopping, ABCDE assessment and escalation.
No expected fluid, no blood return, swelling on flushing, persistent bleeding or discordant specimen appearance means success has not been verified.
Pain, erythema, leakage, blockage, dislodgement and loss of ongoing indication prompt immediate review and possible removal or replacement.
03Assessment and interpretationHow to gather information, assess the situation and recognise uncertainty.
Consider the information, its meaning and its limitations before deciding what follows.
- 01
Pre-procedure assessment - Why
- Confirm indication, capacity and consent, identity, site, allergies, relevant medicines and investigations.
- Interpretation and limitations
- Proceed only when anticipated benefit, operator competence, equipment and complication plan are adequate for this patient.
- 02
Team stop check - Why
- Immediately before the invasive step, verbalise patient, procedure, site, position and critical concerns with the assistant.
- Interpretation and limitations
- A shared pause detects mismatches created during preparation and creates permission for any team member to stop.
- 03
Aseptic field check - Why
- Identify and protect key parts and key sites throughout the procedure.
- Interpretation and limitations
- Any breach is corrected before contact with the susceptible site; unrecognised contamination invalidates the protection.
- 04
Endpoint verification - Why
- Confirm the intended physiological or technical result before declaring completion.
- Interpretation and limitations
- A device that is present but not patent, correctly positioned or clinically effective is not a successful procedure.
- 05
Specimen chain - Why
- Label in the patient’s presence and confirm source, time, container, request and dispatch.
- Interpretation and limitations
- Wrong-patient or wrong-site specimens can create plausible but dangerous results and require immediate incident management.
- 06
Post-procedure review - Why
- Assess observations, site, pain, bleeding and procedure-specific complications at planned times.
- Interpretation and limitations
- Document outcome, restrictions, red flags, result ownership and device review or removal date.
04Worked approachesCases with ordered reasoning, an action and a check of the outcome.
01Worked caseRepeated failed cannulationA dehydrated adult needs time-critical intravenous treatment. Two peripheral cannulation attempts have failed and a haematoma is developing.+
- 1Stop further blind attempts, reassess urgency, circulation, available routes and the local attempt limit; explain the situation and obtain help rather than normalising repeated trauma.
- 2Review anatomy, previous access, infection and bleeding risks, then select an appropriately skilled operator and ultrasound or alternative access according to the local pathway.
- 3Repeat the identity, indication, equipment and aseptic stop check; protect key parts and sites and stop again if anatomy or patient tolerance becomes unsafe.
- 4Verify patency and absence of swelling before use, secure and label the device, reassess the haematoma, document every attempt and hand over site surveillance and removal criteria.
02Safety processBedside specimen collectionPleural fluid from the right side is required for several analyses during an aspiration.+
- 1Agree and document the requested tests, containers, minimum volumes and priority before the sterile procedure begins.
- 2At the bedside, label each container with patient identifiers, right pleural source, date and time, matching it to the request.
- 3Verify haemostasis and respiratory status while an assistant checks packaging and dispatch requirements.
- 4Record the specimen and nominate who will review urgent, preliminary and final results, including after team transfer.
03Applied approachDevice review on the ward roundA urinary catheter inserted for accurate output during shock remains three days after recovery.+
- 1Confirm the original indication and whether current monitoring still requires an indwelling device.
- 2Assess urine, drainage, fixation, discomfort, infection features and alternative ways to meet the care need.
- 3Remove promptly through the local protocol if there is no continuing indication, or document why it remains and set a new review date.
- 4Verify voiding and retention risk after removal and communicate the outcome at handover.
05Feedback, follow-up and evidenceReview outcomes, seek feedback and identify what to improve.
- Inspect every invasive device each shift or review for indication, function, site complication, fixation and earliest safe removal.
- After a procedure, repeat observations and targeted examination at an interval determined by the possible early complication.
- Track specimens through collection, transport, reporting and action, with explicit ownership of preliminary and final results.
- Document failed attempts and complications because they alter the safest strategy for the next operator.
- Audit breaches, wrong-site near misses and device infections through local safety systems to improve the work process.
- Verify that the patient understands restrictions, wound or device care and symptoms that require immediate help.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
The stop point is active
A pause works only when the team checks current information and anyone can halt the procedure; reciting a completed form has little protective value.
Competence includes stopping
Knowing when anatomy, physiology, equipment or supervision is inadequate is part of procedural skill, not evidence of failure.
Gloves can contaminate
Sterile gloves do not preserve asepsis after contact with curtains, phones, packaging edges or other non-sterile surfaces.
Device days accumulate harm
Infection and mechanical risk continue while a device remains; a daily indication review is a preventive intervention.
Specimen identity is clinical care
Correct sampling without correct bedside labelling and result ownership is an incomplete and unsafe procedure.
Assessment transfer
In MRCS or CPSA stations, verbalise indication, consent, preparation, stop checks, complication plan and aftercare even when technical performance is simulated.
Analgesia enables safety
Pain control and positioning improve cooperation and reduce movement; plan them rather than treating distress as a technical obstacle.
Failed attempts are data
Site, depth, resistance and patient response should be communicated to the next operator to avoid repeating an unsafe approach.
07Common pitfallsFrequent interpretation and management errors.
- 01
Beginning before confirming indication, consent, laterality, relevant medicines and rescue plan.
- 02
Exceeding competence or attempt limits without calling an appropriately skilled operator.
- 03
Touching a key part with contaminated gloves and continuing because the breach appears small.
- 04
Forcing through unexpected resistance or pain instead of stopping and reassessing anatomy.
- 05
Labelling specimens away from the bedside or omitting anatomical source and side.
- 06
Leaving a device, result or complication without a review time and named owner.