Nerve catheters: infusions and ward care

Infusion regimes for nerve and fascial plane catheters, a daily check and how to fix common problems on the ward.

A catheter next to a nerve or in a fascial plane keeps a block going for days. This page covers how to run the infusion, what to check each day and how to fix the common problems on the ward. How to insert each catheter is on the block pages, under "Continuous techniques".

When a catheter helps

Pain expected to last longer than a single injection: major joint surgery, amputation, rib fractures, open abdominal or chest surgery.
Painful physiotherapy or repeated procedures such as dressing changes.
Patients who cannot have, or do badly with, opioids.
Improving blood flow after replantation or limb salvage surgery.

Infusion regimes for adults

Catheter	Solution	Background infusion	Patient bolus	Programmed bolus instead
Interscalene, supraclavicular, infraclavicular	Ropivacaine 0.2% or levobupivacaine 0.125%	4–8 mL/h	2–5 mL, lockout 20–30 min	Little evidence in the arm: use a background infusion
Femoral, adductor canal	Ropivacaine 0.2% or levobupivacaine 0.125%	4–8 mL/h (lower rates keep quadriceps strength)	2–5 mL, lockout 30 min	5–10 mL every 1–3 hours
Sciatic (popliteal)	Ropivacaine 0.2% or levobupivacaine 0.125%	4–8 mL/h	2–5 mL, lockout 30 min	5–10 mL every 1–3 hours
Fascial planes: erector spinae, serratus, paravertebral, rectus sheath, TAP, quadratus lumborum	Ropivacaine 0.2% or levobupivacaine 0.125%	8–12 mL/h per side	5 mL, lockout 30–60 min	10–20 mL every 2–6 hours per side: planes need volume to spread

These are typical adult starting points, not a protocol. Follow your hospital's pump programme and prescription chart.
Add up the hourly dose of every catheter, bolus and top-up. Ropivacaine 0.2% at 10 mL/h is 20 mg/h; the product information for continuous peripheral nerve block gives 5–10 mL/h (10–20 mg/h). Reduce in the frail, the elderly, low body weight, and liver or heart failure.
Two catheters (both sides, or two nerves) share one dose limit: halve the rate on each.
Programmed intermittent boluses gave slightly better pain scores than a continuous infusion in a network meta-analysis, mainly for leg and trunk catheters.
Children: use the paediatric dose calculator (0.1–0.3 mg/kg per hour).
Epidural infusions are covered on the lumbar and thoracic epidural pages.

Open the infusion programmerNeed an individual regime? Work out a background rate, programmed bolus and patient bolus that stay within the 24-hour dose limit.

Daily check on the ward

Pain score at rest and on movement, and what the patient can now do (deep breath, cough, physiotherapy).
Sensory and motor block: is the limb weaker or number than expected?
Catheter site: redness, swelling, pus, leak; the depth mark at the skin compared with the mark at insertion.
Pump: the right drug, the right programme, the volume given and the number of boluses asked for.
Symptoms of local anaesthetic toxicity: tingling round the mouth, metallic taste, ringing in the ears, drowsiness, twitching.
Anticoagulant and antiplatelet drugs: time of the last and next dose.
Safety of a numb limb: falls risk, heel and pressure areas, sling or knee brace, hot drinks and heat packs.
Plan: how long the catheter stays, and which tablets take over when it comes out.

Troubleshooting

Problem	Think of	What to do
Pain despite the infusion	Pump stopped or disconnected; catheter moved; pain outside the catheter's territory (for example the back of the knee with an adductor canal catheter).	Check the pump, the line and the depth mark. Give a bolus of 5–10 mL of the infusion solution and reassess in 15–20 minutes. Block returns: increase the rate or add regular boluses. No block: the catheter has moved, so replace it or change to another plan.
Leak at the site	Common, especially with shallow catheters and large volumes. Fluid tracks back along the catheter.	If pain relief is good, reinforce the dressing and carry on. If pain relief has gone, treat it as a displaced catheter.
Dense motor block or a very numb limb	Rate or strength too high. Also think of nerve injury, a tight plaster or compartment syndrome if there is pain out of proportion.	Pause the infusion for 1–2 hours, then restart at a lower rate or weaker strength. Protect the limb. If strength does not return when expected, examine and escalate.
Short of breath with an interscalene or supraclavicular catheter	Phrenic nerve block; pneumothorax; spread to the neck.	Sit the patient up, give oxygen, stop or reduce the infusion and get a chest X-ray or lung ultrasound if it does not settle.
Tingling lips, metallic taste, ringing ears, confusion, fits	Local anaesthetic toxicity: catheter in a vessel, or too much drug.	Stop the infusion, call for help and follow the LAST protocol.
Blood in the catheter or filter	Catheter tip in a vessel.	Stop the infusion. Do not give a bolus. Usually remove the catheter.
Catheter disconnected	The inside of the catheter may be contaminated.	Not witnessed: remove the catheter. Seen as it happened: follow local policy (many units clean, cut the end with sterile scissors and reconnect) or remove.
Red, swollen or oozing site, or fever	Infection. The risk rises the longer the catheter stays in.	Remove the catheter, send the tip and a swab, and review daily. Spreading redness, an abscess or new weakness needs urgent senior review.
Pump alarm: blockage	Kinked catheter under the dressing, closed clamp, blocked filter.	Straighten, unclamp, change the filter. If it will not flush easily, do not force it.
Patient on anticoagulants	Bleeding when the catheter is removed, most important for deep and paravertebral catheters.	Time the removal with the anticoagulation guidelines.
Catheter will not come out	Kink, knot or tight tissue.	Do not pull hard and never cut it. Change the limb position, try again later and ask for senior help.

Taking the catheter out

Remove when pain can be controlled by tablets, usually after 2–5 days, or sooner if there is any sign of infection.
Check the timing of anticoagulants first.
Pull gently and check that the tip is complete. Cover with a dressing.
Tell the patient the numbness will wear off over the next hours, and to start the tablets before it does.
Record the date and time of removal and that the tip was seen intact.

Sources: Ilfeld BM. Continuous peripheral nerve blocks: an update of the published evidence and comparison with novel, alternative analgesic modalities. Anesth Analg 2017;124:308–335. Ilfeld BM. Continuous peripheral nerve blocks: a review of the published evidence. Anesth Analg 2011;113:904–925. Law WZW, Sara RA, Cameron AJD, Lightfoot NJ. Local anaesthetic delivery regimens for peripheral nerve catheters: a systematic review and network meta-analysis. Anaesthesia 2020;75:395–405. Infusion rates are typical ranges from these reviews and UK product information. A guide for trained clinicians only: follow your hospital's policy.