The incidence of Deep Vein Thrombosis (DVT) in patients with MIDLINE

By Cristiano Antonino Last updated Mar 1, 2021

Deep vein thrombosis (DVT) related to the presence of a venous access has a multicausal aetiology. The MIDLINE is a peripheral venous catheter which is very similar in technology to the PICC (Central Insertion Peripheral Catheter) in both implantation and management.

The MIDLINE differs from the PICC in the position of the catheter tip, in the case of the PICC we are in a large calibre vessel and it is a Central Venous Catheter (CVC) while the MIDLINE is in a small calibre vessel and this makes it a peripheral venous access.

The formation of thrombi in a classic needle cannula that we place in the arm is possible, but they are small in size and often remain localised in the vicinity of the cannula.

Thrombi are clots that have an affinity for the surfaces to which they adhere, which can also be seen in needle cannulas and deflectors if the blood has been flowing for some time, clots are formed that have one or more points where they adhere and remain stationary in the tube.

The blood clots in a complex of reactions called the “coagulation cascade” and is important because it participates in the process of closing a lesion to avoid continuous blood loss.

Deep vein thrombosis (DVT): Is the presence and use of MIDLINE the cause of thrombus formation?

The presence of the MIDLINE in the lumen of the vein is a risk factor because it can act as an obstacle and alter the blood flow favouring the coagulation processes, it can also be further facilitated by varying clinical and congenital conditions of the patient.

These factors are independent of the choices the nurse can make, whether in implantation or management.

It is known that there are some diseases that are more conducive to DVT than others, such as the characteristics of the vascular access itself, the calibre and hardness can increase or decrease the risk of DVT, the larger the calibre the greater the risk.

The use of the vascular device cannot cause a thrombus, because we are in an endoluminal environment where not all the factors of the coagulation cascade are present.

Inside the lumen we can have the formation of an endoluminal clot, due to a reflux of blood inside the catheter, it can also not be seen if the device is not transparent.

MIDLINE and propagation of the filamentous clot

Subsequently with the use of the MIDLINE the filamentous clot may propagate into the adjacent vein and may become an additional trigger.

The reflux of blood within the device causes a clot which has to be taken into account, as it can be more or less frequent depending on the use and the level of autonomy of the patient (which has to be maintained for quality of life).

The cause of venous pressure variations can be related to the patient’s movements by standing up or moving the arm, but also very strong coughing attacks can cause significant venous pressure variations.

The nurse can limit the presence of the endoluminal clot, with a flush to remove debris and with a heparinized lock (agreed with the medical staff).

Heparinisation of the vascular access cannot be a reason for reducing venous catheter-related infections, it never has been because it has no active ingredients against microorganisms, although paradoxically neither is using a lock with antibiotics which are the anti-bacterial par excellence.

Thrombosis in the presence of a MIDLINE can progress and give a DVT, the reason being that the presence of extraluminal thrombi increases the deficits in the circulation and acts as a further stimulus for the coagulation cascade.

How to detect a DVT?

The presence of an altered venous circulation is visible due to an increase in the diameter of the arm, which was either measured during catheter implantation and can therefore be re-measured later or can be compared with the contralateral arm.

The comparison with the contralateral arm in the presence of a DVT is often decisive, looking at the two arms we can observe both the size, the arm with the DVT is also twice the size of the one without the device, then it presents itself with a more compact tissue than the other arm because it is imbibed due to the defect of return circulation.

A number of studies with a focus on continuous improvement detect and report on complications and offer data on the complications of DVT of CVC but also of MIDLINE.

The occurrence of a DVT can be estimated per 1000 catheter days or as a percentage of implanted MIDLINEs.

The figure for 1000 catheter days must be weighed against the use made of it, as one factor that influences it is the frequency of use, if I use it in DH and every 20 days I use it, then there will be a greater number of days than if I use it daily (LINK).

The complication rate is a very useful figure, for example if it is 4%, then every 25 implants you might see a DVT.

Is DVT from MIDLINE dangerous?

DVT is dangerous if left untreated because it can cause embolism and thus put the patient’s life at risk.

The detection of an arm with suspected DVT requires immediate medical evaluation, because the MIDLINE or PICC should not be removed until the arm has been evaluated.

Removal of the vascular access in the presence of a thrombus may lead to embolism, the patient will receive anticoagulation therapy and the problem will be resolved.

The presence of a DVT in a patient can be experienced by doctors and nurses in 3 ways, indifference, blame, continuous improvement.

Indifference means that a DVT does not provoke any discussion in the team.

Guilt leads to ignoring the event and feeling bad and could be a reason for strong changes but not the first time.

Continuous improvement is a challenging approach where each case of complication is analysed and a shared solution is sought to ensure that it does not happen again.