DISCUSSION
“The Practical Guidelines for Safe Central Venous Catheter (CVC)
Placement and Management” issued by the Japanese Society of
Anesthesiologists (JSA, 2017) recommend zone B, an area around the
junction of the left and right innominate veins and the upper superior
vena cava (SVC), as the optimal position of catheter tip following
insertion;7, 8 these guidelines pertain to all central
venous catheters and do not particularly focus on adequate positions of
PICC tips. The European Society for Clinical Nutrition and Metabolism
(ESPEN) guidelines (2009) also pertain to all CVC, presumably also
including PICCs, and accordingly, the adequate site for catheter
placement is when “the tip is in the lower third of the SVC, at the
atrio-caval junction (CAJ), or in the upper portion of the
RA.”9 Similar recommendations are presented in “Safe
Vascular Access (2016)” (UK) where the lower SVC or the upper RA
position is considered optimal;10 however, some
American authors exclude the upper RA and limit the optimal position of
the catheter tip to the lower SVC and vicinity of the
CAJ.11 Hence, adequate placement of the catheter
recommended in the JSA guidelines is slightly
shorter;3 those guidelines, however, have been
established with the goal of reducing frequency of CVC-related
complications (vessel or myocardium perforation, thrombosis, occlusion,
catheter-related infections, pneumothorax, arrhythmias, etc.) and have
been based on reported data where CVC tip positions were confirmed
either with X-ray fluoroscopy or portable chest radiography.
With technological advancements of magnetic tracking and intra-cavity
ECG, PICCs have been recently inserted at the bedside without X-ray
fluoroscopy or post-insertional chest radiography. PICCs placed with the
Sherlock 3CG™ TCS, where tip position at the CAJ is
considered correct accordingly with the observed inversion of the
electrocardiographic P-wave (NICE Medical Technology Guidance), tend to
be inserted too far into the RA. Malposition of the catheter tip with
the Sherlock 3CG™ does occur and reach proportions of
56.1% or 20.5%, depending on the definition of the adequate tip
position (low SVC/CAJ or mid SVC/low SVC/CAJ/high RA,
respectively).12 According to Johnston et al.malposition might be due to specific characteristics of the
3CG™ technology (targeting the CAJ, which is sometimes
impossible to achieve in clinical settings), difficulty in defining the
CAJ position on chest radiographs and/or inconsistent CVC placement
guidelines.12 Thus, even if the catheter is inserted
and fixed in a suitable position, complications might still occur.
Arrhythmias related to PICCs are rare. In three reported
cases,5, 6 nonsustained VT occurred in awake patients
upon change in their body position (usually from supine to lateral
decubitus) following PICC placement and confirmation of the tip position
in the lower SVC by fluoroscopy or chest radiography. In our case, PICC
was inserted with the Sherlock 3CG™ TCS one day before
surgery and arrhythmia did not occur until the patient was positioned
for operation under general anesthesia. Movements of the catheter tip
(caudally up to 5.3 cm [or 2.2 rib spaces])13, 14due to shoulder adduction have been reported, but only rarely do they
induce ventricular tachyarrhythmias. The catheter tips constantly moving
accordingly with the blood/injection fluid flow changes in the vicinity
of the CAJ (lower risk of thrombosis12) or upper RA
might occasionally contact the atrioventricular (AV) node/right
ventricular wall; however, if this contact is only momentary, arrhythmia
will presumably not occur. This might change in lateral decubitus or
prone position when the contact with the AV node/ right ventricular
wall6 would last longer and, thus, induce VT that is
not observed immediately after PICC insertion (usually in supine
position). A minor change in body position might terminate the
arrhythmia (in our case, further adduction of the shoulder ) but
respiration- and blood flow-related movements would not cease (Fig. 3).
In an awake patient, arrhythmia might produce symptoms like dyspnea,
chest pain, or palpitations and, thus, provoke a timely
response5, 6 contrary to that in patients being under
general anesthesia, in whom suspicion and vigilant observation of the
ECG tracing during changes in body position remain the only means of
early recognition and treatment of PICC-induced arrhythmias. Simulation
of the intraoperative position immediately after PICC insertion might
allow detection of positional change-induced arrythmias and prompt early
correction of the catheter position (usually pulling back the catheter);
however, it is not always possible in clinical settings.