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.