PICC Lines and Midlines

You may well be asked to take blood from a PICC line or be called to see a patient because their PICC line is not working. In this article we will take you through the basics of PICC lines, why they are needed, how to use them and some common pitfalls.

Please note that procedures vary from trust to trust and you should check there are no specific differences before attempting a procedure.


PICC line

A Peripherally inserted central catheter (PICC), is a type of central venous line. The line is inserted from a peripheral site, the upper arm, and the tip lies in the central venous system. Making it 50 -60 cm in length. A PICC line can have either one or two lumens.


So what is the difference between a PICC line and a Midline? 

The answer is clearly demonstrated in the image below. The midline is much shorter, so though it is inserted at the same site as a PICC line, the tip lies more distally, just under the axilla. 

Midlines are generally used for periods up to one month, therefore are less long-lasting than a PICC line. 

image 3
Image from: https://lavascular.com/picc-line-midline-catheter/


So why do we need PICC lines?

There are a few reasons you might consider a PICC line for your patient.

  1. Difficulty gaining peripheral access – be it for bloods or for cannulas.
  2. Medium-term intra-venous access is required. From a few weeks to 6 months. For longer-term access tunnelled catheters may be more appropriate.
  3. The need to administer drugs that can be irritant in a small peripheral vein. For example, chemotherapy.
  4. For total parenteral nutrition.


There are occasions where a PICC line may not be possible, a few things to consider are as follows;

  1. Cellulitis at the site of insertion
  2. DVT in the same arm
  3. Ipsilateral to a radical mastectomy or dialysis grafts.

Also, think carefully about if the line is really needed if you only need access for less than 1 week.


A PICC line is usually inserted by an anaesthetist or by interventional radiology and it can be done on the ward.

The line is inserted either through the basilic or the cephalic vein, using ultrasound guidance. Initially, a guidewire is advanced into the vein, over which the catheter is threaded.

image 4
Image from: https://www.careandwear.com/blogs/community/what-is-a-picc-line

The tip of the catheter lies in the superior vena cava. And the final location is confirmed with an x-ray.

The X-ray is also important to make sure there is no pneumothorax post-insertion.

image 5
Image from radiopedia.com

Using the PICC Line

The PICC line can be used both for administering medications and for taking blood samples.

Medications that go down the PICC line should be prescribed as intravenous. The nursing team take care of the administration side of things, but you may be asked to take the blood samples.

The following is a step by step guide, but please note that guidance may differ by trust and you should always check before attempting any procedures.

  • sterile gloves
  • apron
  • dressing pack
  • normal saline 10mls – check the expiry date.
  • 3x10ml syringes
  • Chlorhexidine wipes
  • Required blood bottles. Note that if you are taking blood cultures, you will need to take a paired sample from a peripheral site as well.

Taking blood from a PICC line can be a lot easier than trying to bleed a patient who has very poor vascular access, but there are two key things to remember, firstly keep it sterile and secondly flush the line after use!

  1. Prepare your equipment. 
    1. Open the dressing pack in a sterile manner, to create a sterile field.
    2. Open the rest of your equipment into the sterile field.
    3. Fill one 10ml syringe with 0.9% saline.
  2. Make sure all the ports are clamped.
  3. Note that the key parts in this procedure are the port and the syringe tip.
  4. Clean the port that you intend to use, thoroughly and leave for 30 seconds to dry.
  5. Unclamp the port, attach one syringe to it. Aspirate 10mls of blood and discard. Make sure you actually discard this sample so you do not get mixed up.
  6. clamp the port whenever you remove the syringe from the port.
  7. Then draw enough blood for your sample.
  8. Finally, flush the line with the 10mls of saline.
  9. Clamp the port and thoroughly clean it.

Remembering to flush the line is key to avoiding the line becoming blocked.


Another reason why you may interact with a PICC line is when there is a complication, or if it stops working.  When assessing any patient, use an A-E framework – checking the line will come nearer the end of that assessment, but should not be forgotten! 

When assessing the line:

  • Look: is there any swelling, redness, or tenderness? Is it warm to touch, is there any discharge?
  • Check the external length of the line, there should be documentation from the time of insertion regarding how long it should be.

Complications that you should be aware of are:

  1. Infection – with any line there is a risk of infection and the PICC line is no exception. The most common organisms are:
    1. coagulase-negative staphylococci
    2. Staphylococcus aureus
    3. Enterococci
    4. Candida

If an infection is suspected, remember to take cultures from the line and peripherally. The line will likely need removal and the tip should also be sent for culture. Patients with a line infection may present very acutely, so make sure to call for help early. 

  1. Occlusion – the line may become blocked for a variety of reasons, it could be mechanical, or a thrombus or due to drug precipitate.
    1. For mechanical occlusions try repositioning the patient.
    2. Avoiding drug precipitants is key, so always flush after accessing a PICC line.
    3. A thrombus is one of the most common causes of occlusions. They can occur either in the SVC or in the catheter itself. Sometimes this can be solved by an infusion of alteplase into the line, this should be done with senior involvement and according to local guidelines.
  2. Air embolus – this is extremely rare and a medical emergency! The key is to prevent it from happening. So make sure ports are always clamped if they are not connected to anything. 
  3. Dislodged PICC line – Check the external length of the PICC line against the one documented in the insertion notes. If there is a discrepancy make sure to check with a senior.

Removing the PICC Line

Though the PICC line insertion is usually done by trained professionals you may be asked to remove a PICC line on the wards. This is a fairly straightforward procedure. However, if you experience any abnormal resistance when removing the line then seek help. 

  • Sterile gloves
  • Chlorhexidine wipes
  • Scissors (to remove the dressing)
  • Suture cutter
  1. Check the patient’s most recent coagulation screen.
  2. Get your equipment ready.
  3. Clean the skin around the area and the ports with 2% chlorhexidine. Leave to dry for 30 seconds.
  4. Remove the dressing, try not to tug on the catheter in this step. Sometimes you might need some scissors.
  5. Carefully cut any sutures that are securing the catheter to the skin.
  6. Slowly pull the catheter out, parallel to the vein.
  7. Cover the exit site with a dressing.
  8. Examine the PICC line to make sure that it is intact. If there is anything missing, make sure to alert a senior. 

If you have removed it due to suspicion of infection then send the tip for micro sampling.


  1. Percutaneous Central Catheter – StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK459338/#_NBK459338_pubdet_.

Written by Dr Ranjana Venkateswaran (FY2) & was reviewed by Dr Nalini Malarkkan (Anaesthetic Consultant)

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