A peripherally inserted central catheter (PICC) is a central venous access device (CVAD) which by definition has the distal tip of the catheter located within the central veins. The Infusion Nurses Society suggests that, ideally, a central venous catheter should have its tip situated in the lower third of the superior vena cava at or near the cavoatrial junction (Gorski et al, 2016).
Computed tomography (CT) power-injectable PICCs are now commonly used for CT power-contrast injection, especially for patients with difficult venous access; using these lines for power injection is feasible and safe, as long as precautions are taken (Plumb and Murphy, 2011). However, studies have shown that there is a risk of PICC malposition following CT contrast injection (Lozano, 2012; Lim, 2013; Morden, 2014). The mechanism behind this is thought to obey Newton's third law of motion, that every action has an equal and opposite reaction. It is proposed that increased torque from contrast extrusion results in propulsion of the catheter tip along the vessel wall. Once the stored kinetic energy in a bent catheter is released, the tip travels in the direction of least resistance, which may be upstream and into another vein (Lim, 2013). The occurrence of catheter misplacement after contrast injection has been previously estimated to be between 8% and 15% (Lee and Ricketts, 2017).
The aim of this review was to study appropriately positioned pre-scan PICCs that malposition following injection of CT contrast media and evaluate whether tip location or right or left insertion plays a part in the displacement of PICCs following CT scan. According to one study (Lozano, 2012), initial catheter tip position relative to the tracheobronchial angle was significantly associated with an increased risk of displacement after power injection of contrast (62.5% became displaced if proximal to the tracheobronchial angle compared with 10.14% if distal to the tracheobronchial angle, P<0.006).
Most particularly, the authors wanted to establish whether PICCs can self-correct without intervention as studies previously mentioned have suggested that PICCs need to be replaced if malpositioned. Replacing a catheter that would right itself may mean that a patient has to undergo an unnecessary procedure.
Background
The vascular access team at the authors' trust is managed by the lead vascular access nurse and one clinical nurse specialist. Placement of PICCs is done at the bedside in the wards or at an outpatient clinic. The tip position is confirmed with a chest X-ray after insertion. Once a PICC is confirmed by the vascular access team as safe to use, this information is forwarded via a pro forma to the team at CT scanning, who use this to determine that the PICC tip position has been recorded as safe to use and also record the number of CT power injections performed so that the maximum number recommended by the manufacturer is not breached. The vascular access team worked closely with CT scanning staff before the introduction of CT injectable PICCs, to educate them in the correct use of these devices including aseptic non-touch technique, saline flush before and after, as well as developing a standard operating procedure. This ensured that every patient had a pre- and post-scout view (a preliminary image obtained before performing the major portion of a particular study) undertaken, and reviewed by a radiologist to ensure there was no misplacement following the CT scan.
Aim
The aim of this study was to review PICC insertions at one facility to gain information on the occurrence of iatrogenic misplaced PICCs following injections of contrast media during CT scans. To determine whether PICCs can self-correct and whether left or right arm approach along with tip position at insertion plays a part in misplacement following CT injection.
Method
Information on misplaced PICCs following CT injection was collected in retrospect by reviewing the vascular access team database. The database contains over 6000 entries of patient data, including demographics and information on when the catheter was placed, insertor, type of catheter, length, site of insertion, tip position, and complications.
The use of CT injectable PICCs in this facility was started in 2011 with the use of a 5 French (Fr) PowerPICC. Power injectable 4 Fr and 5 Fr PICCs that were inserted between 1 January 2015 and 30 April 2020 were included in this review. This initial dataset was narrowed to PICCs that were confirmed to be OK for use with confirmation of tip position. This equated to 2045 PICCs.
Based on the comments on the database, entries with ‘CT’ together with words such as ‘misplaced’ or ‘coiled/curled/loop/flipped’ were gathered. These incidences are reported to the vascular access team by CT radiographers if they observe changes in the tip position in the scout views following contrast injection. This information was double-checked with online chest radiograph images to confirm evidence of malposition following CT scan using contrast media.
Inclusion Criteria
Evaluation of Data
The following power-injectable PICCs were used in this facility during the study period:
The brands used were changed during the 5 years under evaluation, so the percentages were also noted:
A total of 21 PICCs (1%) were reported to have misplaced following contrast injection between 2015 and 2020. The number of PICCs inserted on the right arm veins was 1325 (54%) versus 720 PICCs (46%) on the left. The insertion sites were as follows: 14 (67%) in the right basilic vein, 4 (19%) in the left basilic vein, 2 (10%) on the left brachial vein, and 1 (5%) on the right brachial vein. Misplaced PICCs were more common on the right-sided approach than on the left-side, 16 (76%) versus 5 (24%).
The tip locations at the time of insertion of these PICCs are shown in Table 1. On review of the chest X-ray, 19 (90%) correlated with being below the tracheobronchial angle, and 2 (10%) above it.
| Location | Number | % |
|---|---|---|
| Upper SVC | 6 | 30% |
| Mid SVC | 1 | 5% |
| Lower SVC | 6 | 30% |
| SVC/RA | 4 | 20% |
| RA | 4 | 15% |
RA=right atrium; SVC=superior vena cava
After contrast CT injection, the tip misplaced to the locations shown in Figure 1, seven in the right internal jugular, six in the left and four in the right brachiocephalic veins, two in the right subclavian vein, one in the left internal jugular and one coiled in the superior vena cava.
This study could not endorse the suggestion (Lozano et al, 2012) that PICC tip position above the tracheobronchial angle on insertion and before CT scan was significantly associated with an increased risk of displacement following power-contrast injection.
A review of post-contrast injection CT radiology reports showed that out of the 21 PICCs that were misplaced only 12 (57%) had clear written documentation of where the tip was located, was while 9 reports did not mention anything about the tip location.
Repeat X-rays were reviewed and 19 PICCs (90%) showed evidence of self-correction (Figure 2). A total of 8 PICCs demonstrated self-correction on a repeat chest X-ray at 24 hours and 11(52%) at more than 24 hours (mean=64.4 hours).
The longest time for a repeat X-ray from the first time it was observed to have coiled was about 168 hours (7 days). The long time before repeat chest X-ray was for the cases of two chemotherapy patients who were on an alternating-week treatment schedule. It was agreed that the patients would require repeat X-ray before their next treatment; these PICCs were among those that successfully self-corrected.
Manual power flush of around 20 millilitres of 0.9% sodium chloride was documented on three occasions at least 24 hours before repeat chest X-ray. Of these, two PICCs self-corrected at 24 hours and one at 96 hours, leading the authors to hypothesise that a power flush can assist with re-direction.
The two PICCs that were not observed to self-correct at 48 and 144 hours had to be replaced using the guide wire exchange method.
Discussion
The authors would like to note the relevance of this review to the various stakeholders.
Implications for Registered Nurses and Midwives
The registered nurse/midwife directly provides PICC care to patients, and their role in ensuring the safe use of the PICC is important especially in the administration of medications. In the authors' institution, PICC tip position is confirmed by radiography before use. This review supports previous studies of the possibility of misplacement of PICCs following the power injection of contrast. The authors would like staff to be aware of this phenomenon so that possible misplacement of PICC tip following CT is recognised. There may be no immediate symptoms of a misplaced PICC because the catheter generally functions the same.
Furthermore, the study suggests that self-correction of the PICC tip is possible, usually within 24 hours. This can be communicated to the patient while explaining that the PICC cannot be used until it has corrected, and alternative access may be needed for a short while, usually 24 hours.
Implications for PICC Inserter
PICC inserters are the institution's resource for advice on these types of incidences. Although misplacement of PICCs following the power injection of contrast is a possible occurrence, this study supports evidence of self-correction in around 24 hours. This will offer the PICC inserter options on deciding whether to replace the line. It would involve a careful clinical evaluation of the patient's condition on the appropriateness for immediate PICC replacement. For one thing, PICC insertions are not without risks. The need to preserve the health of the vessels is also taken into account. There is also the cost of the procedure and the goal of maximising the lifespan of these devices. An alternative temporary venous access may be considered depending on the patient's need, while waiting for the tip position to self-correct. How long to wait for the tip to self-correct will be a decision that will depend on the immediacy of the need for a PICC and may vary depending on the patient's medical condition.
Implications for Radiology Staff
A protocol is in place within the authors' institution for routinely checking the PICC tip position after contrast injection CT. However, the review found that documentation of the tip location is not clearly written each time.
There are instances where misdirection is reported in general. However, the authors suggest that any changes in tip position should be appropriately documented on the radiology reporting systems for proper communication, and appropriate advice also documented to repeat the X-ray in 24 hours.
The authors recommend waiting a minimum of 24 hours, because in one case found in the review a repeat chest X-ray was carried out after only 20 minutes and the PICC did not self-correct, but on being left for 24 hours self-correction occurred.
If PICCs have malpositioned following CT contrast injection, caution should be observed in giving advice such as immediate removal of the device, especially in patients with difficult access. PICC inserters are conscious that vessel health must be preserved, so saving the line and considering removal as the last option would be beneficial to this aim.
Implications for Patients
Patients being told that their device is not in the right place may worry that they would have to undergo another procedure, but knowing that their PICC can potentially self-correct after 24 hours will be reassuring.
Conclusions
From the review of database records the nurse specialists found that the majority of PICCs that malposition following CT contrast injection self-correct within 24 hours. However, in some cases, it can take up to 72 hours for the PICC to self-correct. The data from this study did not seem to show a link between tip position ahead of CT and the likelihood of misplacement.
There is a need to check the PICC tip position following CT contrast injection because there is a risk of malposition. It should not be assumed that every PICC will be suitable for use after injection of CT contrast and the authors recommend appropriate documentation of the PICC tip following CT contrast injection. If misplacement has occurred, relevant parties must be informed so that a repeat X-ray can be arranged at 24 hours to check for self-correction.
The authors caution against advising immediate removal, re-siting or replacement of the catheter. The study presented here cannot fully exclude other complications brought about by malpositioned PICCs following CT contrast injection. However, as long as it is not used, there is no apparent risk in allowing time for the PICC to self-correct unless there is an urgent need for it to be used.
Power flush of PICCs with saline may have contributed to the PICCs self-correcting, although this would need to be determined by a larger study. Factors relating to the catheter material or patient mobility were not taken into account but these factors, together with gravity or blood flow, may affect the rate of self-correction. Further studies on complications arising from PICCs that do not self-correct and larger sample sizes may be beneficial.