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Analysis of the Sherlock II tip location system for inserting peripherally inserted central venous catheters
Clinical Imaging 37 (2013) 917–921
Contents lists available at ScienceDirect
Clinical Imaging journal homepage: http://www.clinicalimaging.org
Analysis of the Sherlock II tip location system for inserting peripherally inserted central venous catheters☆,☆☆,★ Valdis Lelkes, Abhishek Kumar ⁎, Pratik A. Shukla, Sohail Contractor, Thomas Rutan University of Medicine and Dentistry of New Jersey, Newark, NJ 07101, USA
a r t i c l e
i n f o
Article history: Received 25 November 2012 Received in revised form 24 March 2013 Accepted 25 April 2013 Keywords: Chest radiography/x-ray (CXR) Malpositioned catheter Peripherally inserted central catheter (PICC) Sherlock II tip location system Superior vena cava (SVC)/right atrium (RA) junction Bedside PICC
a b s t r a c t Peripherally inserted central catheters (PICCs) are frequently placed at the bedside. The purpose of our study was to evaluate the efficacy of the Sherlock II tip location system (Bard Access Systems, Salt Lake City, UT), which offers electromagnetic detection of the PICC tip to assist the operator in guiding the tip to a desired location. We performed a retrospective review of patients who had a bedside PICC using the Sherlock II tip location system. Three hundred seventy-five of 384 patients (97.7%) had the catheter tip positioned appropriately. Our results suggest that the Sherlock II tip location system is an efficacious system for bedside PICC placement. Published by Elsevier Inc.
1. Introduction Peripherally inserted central venous catheters (PICCs) are used for long-term intravenous access to administer drugs such as antibiotics and chemotherapy, as well as total parental nutrition [1]. Bedside PICC placement is less costly and obviates the need to transport the patient to the angiography suite when compared to PICC placement using fluoroscopic guidance. Difficulties with bedside PICC placement include catheter sizing and optimal tip location in the superior vena cava (SVC). Although catheter sizing is largely subjective and experience based, several bedside maneuvers are used to aid in catheter tip manipulation towards the SVC. These include turning the patient’s head towards the side of insertion, bringing the patient’s chin to their chest, and having the patient perform a Valsalva maneuver at the time of placement to guide the catheter down to the SVC. However, without direct fluoroscopic visualization, malpositioning often occurs [2,3]. The optimal position for a PICC tip is the SVC/right atrium (RA) junction [4]. Postprocedural chest radiographs are obtained after bedside placement to confirm tip location and guide subsequent intervention. This can ☆ Financial support: none. ☆☆ Conflicts of interest: none. ★ Meeting presentation: SIR Annual Scientific Meeting 2012, San Francisco, CA, March 23, 2012. ⁎ Corresponding author. Department of Radiology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, 150 Bergen St. UH CC-318, Newark, NJ 07101, USA. Tel.: +1 973 972 5188; fax: +1 973 972 7429. E-mail address: [email protected] (A. Kumar). 0899-7071/$ – see front matter. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.clinimag.2013.04.009
delay use of the catheter and, in cases of malpositioning, necessitates more procedures. Several catheter tip guidance devices have been developed to decrease the incidence of malpositioning. These include ultrasound [5], electrocardiography [6,7], and electromagnetic devices. Here we evaluate the efficacy of the Sherlock II tip location system that uses an electromagnetic tip and sensor to improve the accuracy of PICC tip placement. 2. Methods 2.1. Experimental design The protocol for this study was reviewed and approved by the Institutional Review Board at our institution. We performed a retrospective review of chest radiographs on the Centricity Enterprise Picture Archiving and Communication Systems (General Electric Healthcare, Piscataway, NJ, USA) at our institution of patients who had a PICC placed at bedside using the Sherlock II tip location system. Demographic data, side of access (right vs. left), and the position of the PICC tip as seen on follow-up chest X-ray were recorded. Accurate tip position was defined as the SVC–RA junction, as defined by catheter tip position within 2 cm proximal or distal to the crossing of the right main stem bronchus (Fig. 1A). 2.2. Study population Our patient database was accessed for all bedside PICCs placed with the Sherlock II tip location system from December 2010 to
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V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921
Fig. 1. Chest x-ray depicting the PICC tip (A) correctly placed at the SVC/RA junction (arrow), (B) malpositioned in the contralateral brachiocephalic vein (arrow), (C) malpositioned in the ipsilateral jugular vein (arrow), and (D) malpositioned in the azygos vein (arrow).
December 2011. Patients with shortened midline catheters (i.e., where the tip of the catheter was in the brachial, axillary, or subclavian veins) were excluded from the study, as these were intentionally sized in such a way at the time of catheter placement and did not reflect a failure of the tip location device. Additionally, PICC exchanges requiring no new access were excluded as they were exchanged over a guide-wire and did not require the Sherlock II tip location system. Catheters placed in the arterial system [2] were also excluded. These three sets of patients were excluded as we wanted to assess the efficacy of the system in performing its intended purpose (i.e., assisting the operator guide the catheter tip towards the SVC). 2.3. Statistical methods Statistical comparison between groups was performed using Fisher’s Exact Test for categorical variables and Student’s t test for continuous variables. Two-tailed tests were performed for each scenario, and significance level was set at Pb.05. All analyses were performed using Microsoft Office Excel 2007 (Microsoft Corp., Redmond, WA, USA).
operator using a ruler provided in the system’s kit. The Sherlock II system is designed to be used with all types of Bard Access Systems' PICCs. We typically use a single-lumen PICC, but double-lumen PICCs can also be used. The electromagnetic sensor was placed on the patient’s chest. This sensor detects the slight magnetic fields generated by the pre-loaded stylet in Bard Access Systems' PICC kits. The catheter was subsequently placed through the sheath, while the operator was able to view the direction of the catheter on a monitor (Fig. 2). The PICC was tested for bidirectional flow by aspirating venous blood and flushing the catheter with saline. A portable chest X-ray was ordered to confirm PICC tip location. If the catheter tip was found to be malpositioned, the patient was brought to the angiography suite where fluoroscopic guidance was used to achieve optimal tip placement. For PICCs that were placed short in the axillary or subclavian veins, no further intervention was performed. Some catheters were erroneously placed in the arterial system [2] and were identified postprocedure by arterial blood gas. These patients had their catheters replaced by an attending radiologist in the angiography suite.
3. Results 2.4. Bedside procedure Informed consent is obtained prior to each procedure. The patient’s arm was prepped and draped in a sterile fashion. Using 1% lidocaine for local anesthesia, the basilic vein was punctured using a 21-gauge needle under ultrasound guidance. After passing a guidewire, an exchange was made for a 4.5-French peel-away introducer. An appropriate-length 4-French single-lumen PowerPICC (Bard Access Systems, Salt Lake City, UT, USA) was measured by the
From December 2010 to December 2011, 424 patients had a PICC placed using the Sherlock II tip location system. Forty patients were excluded from the study (2 PICCs were exchanges; 36 patients with short PICCs in the brachial, axillary, or subclavian veins; and 2 patients with catheters placed in the arterial system). Three hundred seventyfive of 384 (97.7%) patients had the tip of the catheter positioned at or near the SVC/RA junction (Table 1). Only nine (2.3%) patients were found to have malpositioned catheter tips. Malpositioned sites were
V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921
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Fig. 2. Sherlock II tip location system with (A) electromagnetic sensor placed on patient chest (B, C) indicating progression of PICC tip shown (arrows) (D) to the final location of choice (arrows).
as follows: three in the contralateral brachiocephalic vein, two in the ipsilateral internal jugular vein, two coiled/tip pointing upwards in the SVC, one coiled in the ipsilateral subclavian vein, and one in the azygos vein (Table 2, Fig. 1B–D). These patients were brought to the angiography suite where the catheter tip was repositioned. No significant differences with respect to age, sex, or side of access were found between accurate and malpositioned PICCs (Table 3).
bedside PICC placement has certain advantages. These include lack of ionizing radiation; elimination of need to transport critically ill patients for a relatively simple procedure, as well as cost savings that can be as high as $2800 per procedure [8–11]. According to the Infusion Nursing Standards of Practice, the optimal position of the tip should be in the lower one third of the SVC near its junction with the RA [12–15]. At this location, the catheter tip lies parallel to the vein wall and has less contact with the wall because of the vessel’s large diameter. Furthermore, the SVC has a high blood
4. Discussion Bedside PICC placement is a fairly common practice. Although fluoroscopy provides direct visualization for optimal placement,
Table 1 Subgroup analysis of appropriately positioned PICC Location
Number of patients
SVC/RA junction RA Brachiocephalic/ inominate vein Total
324 25 26 384
% of desired location 86.4 6.7 6.9 100
% total 84.4 6.5 6.8 97.7
Table 2 Subgroup analysis of malpositioned PICC Location
Number of patients
% of malpositioned
% total
Contralateral brachiocephalic vein Ipsilateral internal jugular vein Coiled/pointing superiorly in SVC Kinked/coiled in ipislateral subclavian Azygos vein Total
3
33.3
0.78
2
22.2
0.52
2
22.2
0.52
1
11.1
0.26
1 9
11.1 100
0.26 2.3
920
V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921
Table 3 Demographic data analysis
Sex
Male Female Side of access Left Right Average age (range)
Desired location
Malpositioned
P value
194/375 181/375 108/375 267/375 53.1
3/9 6/9 3/9 6/9 52.8
PN.05
(51%) (49%) (29%) (71%) (18–92)
(33.3%) (66.6%) (33.3%) (66.6%) (25–83)
PN.05 PN.05
Demographic data comparing sex, age, and side of access amongst the two groups. Note: no significant differences exist between groups.
flow rate, and at this location, the tip is oriented in the direction of blood flow, which assists in dilution of the infusion [16]. If the tip is placed proximal to the SVC, there is an increased risk of contact between the catheter tip and the wall of the vessel, which can lead to damage to the vessel wall. This vessel wall damage may have significant consequences such as formation of a thrombus or perforation [16,17]. Aberrant positioning of the catheter tip into a small tributary vessel or crossing the midline into a contralateral vessel would position the tip in the opposite direction of blood flow, also increasing the chance of vessel wall injury. On the other hand, catheter tips that are placed distal to the SVC enter the RA. This may lead to cardiac complications such as arrhythmias [18,19]. Bedside maneuvers including turning the chin towards the side of placement, lifting the chin up, and having the patient perform a Valsalva maneuver while advancing the catheter can help place the catheter tip in the SVC. A postprocedural chest radiograph is performed to confirm the position of the catheter tip. Malpositioned catheter tips are generally repositioned, and imaging studies are repeated to reensure optimal tip position [12,13]. This process may delay the use of the catheters. Catheter tip location systems have been developed to aid in placing bedside PICCs and assist the operator in placing the tip at the desired location. These include ultrasound [5], electrocardiography [6,7], and electromagnetic devices [20,21]. The Sherlock II Tip Location System by Bard Access Systems uses magnet tipped catheters that are detected by a portable sensor that is placed on the patient’s upper chest, which senses the tip of the catheter as it passes through the patient’s vasculature towards the SVC/RA junction. The sensor has a visual display that provides the operator real-time information pertaining to the catheter tip’s location, direction, and depth in relation to the sensor. The system locates and displays the PICC tip position accurately within 1 cm and can only be used with Bard catheters that have the magnetic stylet approved for use with this system [22]. Few peer-reviewed studies have been published evaluating the use of magnetic sensors for PICC placement. Gonzalez et al. demonstrated the use of electromagnetic assistance in placing catheters in swine [23]. This study evaluated 44 catheter placements utilizing an experimental sensor. When comparing the position of the tip using the system versus fluoroscopic guidance, there was an average error difference measurement of only 0.4 cm. Buehrle et al. evaluated the Navigator BioNavigation System (CORPAK Med Systems, Buffalo Grove, IL, USA), an electromagnetic tip location system. This study evaluated 300 catheter placements using the device and successfully placed 99% in the SVC and 1% in the RA [20]. The authors concluded that using that electromagnetic guidance could negate the need for a postprocedural chest X-ray. This conclusion was also drawn with other guidance systems [5]. Naylor [21] evaluated malposition rates using the Sherlock II tip location system. The study consisted of 317 catheter placements using the tip location system with a malposition rate of 2.5% with two lines in the internal jugular, one crossing midline to the contralateral side, two coiled in the sublclavian vein or the SVC, and 3 stopping in the brachiocephalic vein. The author reported a 13.4% malposition rate for bedside PICCs placed without the use of a navigation system divided
amongst the malposition sites mentioned. Our study produced a similar rate of 2.3%. There are a few limitations of our study. In the group with accurately positioned catheters, we included 26 PICCs with their tip in the brachiocephalic vein close to the SVC (Table 1). These catheters were considered to be in satisfactory position on the postprocedure radiograph at the time and not replaced. Thus, we included them in our accurately positioned group. These catheters may have been sized inappropriately by the operator and thus cut slightly short of the SVC/RA junction. While they may not be ideally positioned, these PICCs did not evaluate the accuracy of the Sherlock II system as catheter sizing is still subjective and operator dependent. Thus, these catheters can be excluded from our analysis as short PICCs. Excluding these 26 catheters from our analysis, we have a total of 358 PICCS in our study, of which 349 were appropriately placed. This analysis yields a success rate of 97.4% and is not notably different than our reported results. Several reasons may account for this small failure rate of the Sherlock II tip location device. Firstly, PICC placement is still operator dependent. We believe that, with increased operator experience, the rate of malpositioning may be less. According to the manufacturer instructions, the electromagnetic sensor component of the device must be placed completely flat on the patient’s chest with the sensor as close to the neck as possible. We observed that optimal placement of the sensor device in the recommended anatomical position on the chest is often difficult in uncooperative and critically ill patients. This could in turn reduce the accuracy of catheter tip detection by the electromagnetic system. In addition, patient's body habitus may play a role in the accuracy of the electromagnetic detection system. Unfortunately, our procedure notes did not document if the operator had difficulty placing the device on the patient’s chest or experienced lack of cooperation from the patient. It is unclear if this was definitely a contributing factor for failure of the device. However, future studies looking at correlation between patient body habitus and malposition rates may be helpful. A larger study may allow subset analysis of patients in which the device was placed easily over the chest versus patients where the device placement was difficult due to patient condition. The Sherlock II tip location system is an electromagnetic tip detection device that shows the location, direction, and depth of the PICC tip. Our study concludes that this system allows for accurate bedside PICC placement with a 97.7 % success rate. With increased operator experience, success rates may be even higher. Future larger studies may help elucidate the reasons for the small failure rate of the device, some of which may be resolved by operator experience. We believe that the use of electromagnetic tip location devices such as the Sherlock II may eventually eliminate the need for postprocedure chest radiographs, thus saving costs and time associated with bedside PICC placement. References [1] Amerasekera SS, Jones CM, Patel R, Cleasby MJ. Imaging of the complications of peripherally inserted central venous catheters. Clin Radiol 2009;64(8):832–40. [2] Cardella JF, Fox PS, Lawler JB. Interventional radiologic placement of peripherally inserted central catheters. J Vasc Interv Radiol 1993;4(5):653–60. [3] Trerotola SO, Thompson S, Chittams J, Vierregger KS. Analysis of tip malposition and correction in peripherally inserted central catheters placed at bedside by a dedicated nursing team. J Vasc Interv Radiol 2007;18(4):513–8. [4] Sansivero GE. Features and selection of vascular access devices. Semin Oncol Nurs 2010;26(2):88–101. [5] Matsushima K, Frankel HL. Bedside ultrasound can safely eliminate the need for chest radiographs after central venous catheter placement: CVC sono in the surgical ICU (SICU). J Surg Res 2010;163(1):155–61. [6] Pittiruti M, La Greca A, Scoppettuolo G. The electrocardiographic method for positioning the tip of central venous catheters. J Vasc Access 2011;12(4):280–91. [7] Gaard SSP, Erikson M. Improving the Health Literacy of Hospitals; 2010 [Madison, WI] http://www.healthliteracywisconsin.org/. Accessed on July 18, 2012. [8] Royer T. Nurse-driven interventional technology. A cost and benefit perspective. J Infus Nurs 2001;24(5):326–31.
V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921 [9] Hunter MR. Development of a vascular access team in an acute care setting. J Infus Nurs 2003;26(2):86–91. [10] Hornsby S, Matter K, Beets B, Casey S, Kokotis K. Cost losses associated with the "PICC, stick, and run team" concept. J Infus Nurs 2005;28(1): 45–53. [11] Miller DL, Balter S, Dixon RG, et al. Quality improvement guidelines for recording patient radiation dose in the medical record for fluoroscopically guided procedures. J Vasc Interv Radiol 2012;23(1):11–8. [12] Statement. NAoVANP. Tip location of peripherally inserted central catheters. J Vasc Access Device 1998;3:8–10. [13] Infusion nursing standards of practice. J Infus Nurs 2006;29(1Suppl):S1–S92. [14] Kidney DD, Nguyen DT, Deutsch LS. Radiologic evaluation and management of malfunctioning long-term central vein catheters. AJR Am J Roentgenol 1998;171(5): 1251–7. [15] Tan PL, Gibson M. Central venous catheters: the role of radiology. Clin Radiol 2006;61(1):13–22. [16] Racadio JM, Doellman DA, Johnson ND, Bean JA, Jacobs BR. Pediatric peripherally inserted central catheters: complication rates related to catheter tip location. Pediatrics 2001;107(2):E28.
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[17] Kundra P, Chandran BV, Subbarao KS. Unanticipated complication of a malpositioned central venous catheter. J Anesth 2009;23(2):275–7. [18] Elsharkawy H, Lewis BS, Steiger E, Farag E. Post placement positional atrial fibrillation and peripherally inserted central catheters. Minerva Anestesiol 2009;75(7–8):471–4. [19] Orme RM, McSwiney MM, Chamberlain-Webber RF. Fatal cardiac tamponade as a result of a peripherally inserted central venous catheter: a case report and review of the literature. Br J Anaesth 2007;99(3):384–8. [20] Buehrle D. PICC placement in humans using electromagnetic detection. http://www.corpakmedsystems.com/supplement_material/Supplement_PDFs/ Navigator/Buehrle_Article.pdf. Accessed on July 18, 2012. [21] Naylor CL. Reduction of malposition in peripherally inserted central catheters with tip location system. J Assoc Vasc Access 2007;12(1):29–31. [22] BardAccess. Sherlock II tip location system: instructions for use. http://www. bardaccess.com/assets/pdfs/ifus/0715972_Sherlock_II_TLS_IFU_web.pdf. Accessed on July 18, 2012. [23] Gonzales AJ, Pestka C, Silverstein F, Golden RN. Peripherally inserted central catheter placement in swine using magnet detection. J Intraven Nurs 1999;22(3): 144–50.
Contents lists available at ScienceDirect
Clinical Imaging journal homepage: http://www.clinicalimaging.org
Analysis of the Sherlock II tip location system for inserting peripherally inserted central venous catheters☆,☆☆,★ Valdis Lelkes, Abhishek Kumar ⁎, Pratik A. Shukla, Sohail Contractor, Thomas Rutan University of Medicine and Dentistry of New Jersey, Newark, NJ 07101, USA
a r t i c l e
i n f o
Article history: Received 25 November 2012 Received in revised form 24 March 2013 Accepted 25 April 2013 Keywords: Chest radiography/x-ray (CXR) Malpositioned catheter Peripherally inserted central catheter (PICC) Sherlock II tip location system Superior vena cava (SVC)/right atrium (RA) junction Bedside PICC
a b s t r a c t Peripherally inserted central catheters (PICCs) are frequently placed at the bedside. The purpose of our study was to evaluate the efficacy of the Sherlock II tip location system (Bard Access Systems, Salt Lake City, UT), which offers electromagnetic detection of the PICC tip to assist the operator in guiding the tip to a desired location. We performed a retrospective review of patients who had a bedside PICC using the Sherlock II tip location system. Three hundred seventy-five of 384 patients (97.7%) had the catheter tip positioned appropriately. Our results suggest that the Sherlock II tip location system is an efficacious system for bedside PICC placement. Published by Elsevier Inc.
1. Introduction Peripherally inserted central venous catheters (PICCs) are used for long-term intravenous access to administer drugs such as antibiotics and chemotherapy, as well as total parental nutrition [1]. Bedside PICC placement is less costly and obviates the need to transport the patient to the angiography suite when compared to PICC placement using fluoroscopic guidance. Difficulties with bedside PICC placement include catheter sizing and optimal tip location in the superior vena cava (SVC). Although catheter sizing is largely subjective and experience based, several bedside maneuvers are used to aid in catheter tip manipulation towards the SVC. These include turning the patient’s head towards the side of insertion, bringing the patient’s chin to their chest, and having the patient perform a Valsalva maneuver at the time of placement to guide the catheter down to the SVC. However, without direct fluoroscopic visualization, malpositioning often occurs [2,3]. The optimal position for a PICC tip is the SVC/right atrium (RA) junction [4]. Postprocedural chest radiographs are obtained after bedside placement to confirm tip location and guide subsequent intervention. This can ☆ Financial support: none. ☆☆ Conflicts of interest: none. ★ Meeting presentation: SIR Annual Scientific Meeting 2012, San Francisco, CA, March 23, 2012. ⁎ Corresponding author. Department of Radiology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, 150 Bergen St. UH CC-318, Newark, NJ 07101, USA. Tel.: +1 973 972 5188; fax: +1 973 972 7429. E-mail address: [email protected] (A. Kumar). 0899-7071/$ – see front matter. Published by Elsevier Inc. http://dx.doi.org/10.1016/j.clinimag.2013.04.009
delay use of the catheter and, in cases of malpositioning, necessitates more procedures. Several catheter tip guidance devices have been developed to decrease the incidence of malpositioning. These include ultrasound [5], electrocardiography [6,7], and electromagnetic devices. Here we evaluate the efficacy of the Sherlock II tip location system that uses an electromagnetic tip and sensor to improve the accuracy of PICC tip placement. 2. Methods 2.1. Experimental design The protocol for this study was reviewed and approved by the Institutional Review Board at our institution. We performed a retrospective review of chest radiographs on the Centricity Enterprise Picture Archiving and Communication Systems (General Electric Healthcare, Piscataway, NJ, USA) at our institution of patients who had a PICC placed at bedside using the Sherlock II tip location system. Demographic data, side of access (right vs. left), and the position of the PICC tip as seen on follow-up chest X-ray were recorded. Accurate tip position was defined as the SVC–RA junction, as defined by catheter tip position within 2 cm proximal or distal to the crossing of the right main stem bronchus (Fig. 1A). 2.2. Study population Our patient database was accessed for all bedside PICCs placed with the Sherlock II tip location system from December 2010 to
918
V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921
Fig. 1. Chest x-ray depicting the PICC tip (A) correctly placed at the SVC/RA junction (arrow), (B) malpositioned in the contralateral brachiocephalic vein (arrow), (C) malpositioned in the ipsilateral jugular vein (arrow), and (D) malpositioned in the azygos vein (arrow).
December 2011. Patients with shortened midline catheters (i.e., where the tip of the catheter was in the brachial, axillary, or subclavian veins) were excluded from the study, as these were intentionally sized in such a way at the time of catheter placement and did not reflect a failure of the tip location device. Additionally, PICC exchanges requiring no new access were excluded as they were exchanged over a guide-wire and did not require the Sherlock II tip location system. Catheters placed in the arterial system [2] were also excluded. These three sets of patients were excluded as we wanted to assess the efficacy of the system in performing its intended purpose (i.e., assisting the operator guide the catheter tip towards the SVC). 2.3. Statistical methods Statistical comparison between groups was performed using Fisher’s Exact Test for categorical variables and Student’s t test for continuous variables. Two-tailed tests were performed for each scenario, and significance level was set at Pb.05. All analyses were performed using Microsoft Office Excel 2007 (Microsoft Corp., Redmond, WA, USA).
operator using a ruler provided in the system’s kit. The Sherlock II system is designed to be used with all types of Bard Access Systems' PICCs. We typically use a single-lumen PICC, but double-lumen PICCs can also be used. The electromagnetic sensor was placed on the patient’s chest. This sensor detects the slight magnetic fields generated by the pre-loaded stylet in Bard Access Systems' PICC kits. The catheter was subsequently placed through the sheath, while the operator was able to view the direction of the catheter on a monitor (Fig. 2). The PICC was tested for bidirectional flow by aspirating venous blood and flushing the catheter with saline. A portable chest X-ray was ordered to confirm PICC tip location. If the catheter tip was found to be malpositioned, the patient was brought to the angiography suite where fluoroscopic guidance was used to achieve optimal tip placement. For PICCs that were placed short in the axillary or subclavian veins, no further intervention was performed. Some catheters were erroneously placed in the arterial system [2] and were identified postprocedure by arterial blood gas. These patients had their catheters replaced by an attending radiologist in the angiography suite.
3. Results 2.4. Bedside procedure Informed consent is obtained prior to each procedure. The patient’s arm was prepped and draped in a sterile fashion. Using 1% lidocaine for local anesthesia, the basilic vein was punctured using a 21-gauge needle under ultrasound guidance. After passing a guidewire, an exchange was made for a 4.5-French peel-away introducer. An appropriate-length 4-French single-lumen PowerPICC (Bard Access Systems, Salt Lake City, UT, USA) was measured by the
From December 2010 to December 2011, 424 patients had a PICC placed using the Sherlock II tip location system. Forty patients were excluded from the study (2 PICCs were exchanges; 36 patients with short PICCs in the brachial, axillary, or subclavian veins; and 2 patients with catheters placed in the arterial system). Three hundred seventyfive of 384 (97.7%) patients had the tip of the catheter positioned at or near the SVC/RA junction (Table 1). Only nine (2.3%) patients were found to have malpositioned catheter tips. Malpositioned sites were
V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921
919
Fig. 2. Sherlock II tip location system with (A) electromagnetic sensor placed on patient chest (B, C) indicating progression of PICC tip shown (arrows) (D) to the final location of choice (arrows).
as follows: three in the contralateral brachiocephalic vein, two in the ipsilateral internal jugular vein, two coiled/tip pointing upwards in the SVC, one coiled in the ipsilateral subclavian vein, and one in the azygos vein (Table 2, Fig. 1B–D). These patients were brought to the angiography suite where the catheter tip was repositioned. No significant differences with respect to age, sex, or side of access were found between accurate and malpositioned PICCs (Table 3).
bedside PICC placement has certain advantages. These include lack of ionizing radiation; elimination of need to transport critically ill patients for a relatively simple procedure, as well as cost savings that can be as high as $2800 per procedure [8–11]. According to the Infusion Nursing Standards of Practice, the optimal position of the tip should be in the lower one third of the SVC near its junction with the RA [12–15]. At this location, the catheter tip lies parallel to the vein wall and has less contact with the wall because of the vessel’s large diameter. Furthermore, the SVC has a high blood
4. Discussion Bedside PICC placement is a fairly common practice. Although fluoroscopy provides direct visualization for optimal placement,
Table 1 Subgroup analysis of appropriately positioned PICC Location
Number of patients
SVC/RA junction RA Brachiocephalic/ inominate vein Total
324 25 26 384
% of desired location 86.4 6.7 6.9 100
% total 84.4 6.5 6.8 97.7
Table 2 Subgroup analysis of malpositioned PICC Location
Number of patients
% of malpositioned
% total
Contralateral brachiocephalic vein Ipsilateral internal jugular vein Coiled/pointing superiorly in SVC Kinked/coiled in ipislateral subclavian Azygos vein Total
3
33.3
0.78
2
22.2
0.52
2
22.2
0.52
1
11.1
0.26
1 9
11.1 100
0.26 2.3
920
V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921
Table 3 Demographic data analysis
Sex
Male Female Side of access Left Right Average age (range)
Desired location
Malpositioned
P value
194/375 181/375 108/375 267/375 53.1
3/9 6/9 3/9 6/9 52.8
PN.05
(51%) (49%) (29%) (71%) (18–92)
(33.3%) (66.6%) (33.3%) (66.6%) (25–83)
PN.05 PN.05
Demographic data comparing sex, age, and side of access amongst the two groups. Note: no significant differences exist between groups.
flow rate, and at this location, the tip is oriented in the direction of blood flow, which assists in dilution of the infusion [16]. If the tip is placed proximal to the SVC, there is an increased risk of contact between the catheter tip and the wall of the vessel, which can lead to damage to the vessel wall. This vessel wall damage may have significant consequences such as formation of a thrombus or perforation [16,17]. Aberrant positioning of the catheter tip into a small tributary vessel or crossing the midline into a contralateral vessel would position the tip in the opposite direction of blood flow, also increasing the chance of vessel wall injury. On the other hand, catheter tips that are placed distal to the SVC enter the RA. This may lead to cardiac complications such as arrhythmias [18,19]. Bedside maneuvers including turning the chin towards the side of placement, lifting the chin up, and having the patient perform a Valsalva maneuver while advancing the catheter can help place the catheter tip in the SVC. A postprocedural chest radiograph is performed to confirm the position of the catheter tip. Malpositioned catheter tips are generally repositioned, and imaging studies are repeated to reensure optimal tip position [12,13]. This process may delay the use of the catheters. Catheter tip location systems have been developed to aid in placing bedside PICCs and assist the operator in placing the tip at the desired location. These include ultrasound [5], electrocardiography [6,7], and electromagnetic devices [20,21]. The Sherlock II Tip Location System by Bard Access Systems uses magnet tipped catheters that are detected by a portable sensor that is placed on the patient’s upper chest, which senses the tip of the catheter as it passes through the patient’s vasculature towards the SVC/RA junction. The sensor has a visual display that provides the operator real-time information pertaining to the catheter tip’s location, direction, and depth in relation to the sensor. The system locates and displays the PICC tip position accurately within 1 cm and can only be used with Bard catheters that have the magnetic stylet approved for use with this system [22]. Few peer-reviewed studies have been published evaluating the use of magnetic sensors for PICC placement. Gonzalez et al. demonstrated the use of electromagnetic assistance in placing catheters in swine [23]. This study evaluated 44 catheter placements utilizing an experimental sensor. When comparing the position of the tip using the system versus fluoroscopic guidance, there was an average error difference measurement of only 0.4 cm. Buehrle et al. evaluated the Navigator BioNavigation System (CORPAK Med Systems, Buffalo Grove, IL, USA), an electromagnetic tip location system. This study evaluated 300 catheter placements using the device and successfully placed 99% in the SVC and 1% in the RA [20]. The authors concluded that using that electromagnetic guidance could negate the need for a postprocedural chest X-ray. This conclusion was also drawn with other guidance systems [5]. Naylor [21] evaluated malposition rates using the Sherlock II tip location system. The study consisted of 317 catheter placements using the tip location system with a malposition rate of 2.5% with two lines in the internal jugular, one crossing midline to the contralateral side, two coiled in the sublclavian vein or the SVC, and 3 stopping in the brachiocephalic vein. The author reported a 13.4% malposition rate for bedside PICCs placed without the use of a navigation system divided
amongst the malposition sites mentioned. Our study produced a similar rate of 2.3%. There are a few limitations of our study. In the group with accurately positioned catheters, we included 26 PICCs with their tip in the brachiocephalic vein close to the SVC (Table 1). These catheters were considered to be in satisfactory position on the postprocedure radiograph at the time and not replaced. Thus, we included them in our accurately positioned group. These catheters may have been sized inappropriately by the operator and thus cut slightly short of the SVC/RA junction. While they may not be ideally positioned, these PICCs did not evaluate the accuracy of the Sherlock II system as catheter sizing is still subjective and operator dependent. Thus, these catheters can be excluded from our analysis as short PICCs. Excluding these 26 catheters from our analysis, we have a total of 358 PICCS in our study, of which 349 were appropriately placed. This analysis yields a success rate of 97.4% and is not notably different than our reported results. Several reasons may account for this small failure rate of the Sherlock II tip location device. Firstly, PICC placement is still operator dependent. We believe that, with increased operator experience, the rate of malpositioning may be less. According to the manufacturer instructions, the electromagnetic sensor component of the device must be placed completely flat on the patient’s chest with the sensor as close to the neck as possible. We observed that optimal placement of the sensor device in the recommended anatomical position on the chest is often difficult in uncooperative and critically ill patients. This could in turn reduce the accuracy of catheter tip detection by the electromagnetic system. In addition, patient's body habitus may play a role in the accuracy of the electromagnetic detection system. Unfortunately, our procedure notes did not document if the operator had difficulty placing the device on the patient’s chest or experienced lack of cooperation from the patient. It is unclear if this was definitely a contributing factor for failure of the device. However, future studies looking at correlation between patient body habitus and malposition rates may be helpful. A larger study may allow subset analysis of patients in which the device was placed easily over the chest versus patients where the device placement was difficult due to patient condition. The Sherlock II tip location system is an electromagnetic tip detection device that shows the location, direction, and depth of the PICC tip. Our study concludes that this system allows for accurate bedside PICC placement with a 97.7 % success rate. With increased operator experience, success rates may be even higher. Future larger studies may help elucidate the reasons for the small failure rate of the device, some of which may be resolved by operator experience. We believe that the use of electromagnetic tip location devices such as the Sherlock II may eventually eliminate the need for postprocedure chest radiographs, thus saving costs and time associated with bedside PICC placement. References [1] Amerasekera SS, Jones CM, Patel R, Cleasby MJ. Imaging of the complications of peripherally inserted central venous catheters. Clin Radiol 2009;64(8):832–40. [2] Cardella JF, Fox PS, Lawler JB. Interventional radiologic placement of peripherally inserted central catheters. J Vasc Interv Radiol 1993;4(5):653–60. [3] Trerotola SO, Thompson S, Chittams J, Vierregger KS. Analysis of tip malposition and correction in peripherally inserted central catheters placed at bedside by a dedicated nursing team. J Vasc Interv Radiol 2007;18(4):513–8. [4] Sansivero GE. Features and selection of vascular access devices. Semin Oncol Nurs 2010;26(2):88–101. [5] Matsushima K, Frankel HL. Bedside ultrasound can safely eliminate the need for chest radiographs after central venous catheter placement: CVC sono in the surgical ICU (SICU). J Surg Res 2010;163(1):155–61. [6] Pittiruti M, La Greca A, Scoppettuolo G. The electrocardiographic method for positioning the tip of central venous catheters. J Vasc Access 2011;12(4):280–91. [7] Gaard SSP, Erikson M. Improving the Health Literacy of Hospitals; 2010 [Madison, WI] http://www.healthliteracywisconsin.org/. Accessed on July 18, 2012. [8] Royer T. Nurse-driven interventional technology. A cost and benefit perspective. J Infus Nurs 2001;24(5):326–31.
V. Lelkes et al. / Clinical Imaging 37 (2013) 917–921 [9] Hunter MR. Development of a vascular access team in an acute care setting. J Infus Nurs 2003;26(2):86–91. [10] Hornsby S, Matter K, Beets B, Casey S, Kokotis K. Cost losses associated with the "PICC, stick, and run team" concept. J Infus Nurs 2005;28(1): 45–53. [11] Miller DL, Balter S, Dixon RG, et al. Quality improvement guidelines for recording patient radiation dose in the medical record for fluoroscopically guided procedures. J Vasc Interv Radiol 2012;23(1):11–8. [12] Statement. NAoVANP. Tip location of peripherally inserted central catheters. J Vasc Access Device 1998;3:8–10. [13] Infusion nursing standards of practice. J Infus Nurs 2006;29(1Suppl):S1–S92. [14] Kidney DD, Nguyen DT, Deutsch LS. Radiologic evaluation and management of malfunctioning long-term central vein catheters. AJR Am J Roentgenol 1998;171(5): 1251–7. [15] Tan PL, Gibson M. Central venous catheters: the role of radiology. Clin Radiol 2006;61(1):13–22. [16] Racadio JM, Doellman DA, Johnson ND, Bean JA, Jacobs BR. Pediatric peripherally inserted central catheters: complication rates related to catheter tip location. Pediatrics 2001;107(2):E28.
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[17] Kundra P, Chandran BV, Subbarao KS. Unanticipated complication of a malpositioned central venous catheter. J Anesth 2009;23(2):275–7. [18] Elsharkawy H, Lewis BS, Steiger E, Farag E. Post placement positional atrial fibrillation and peripherally inserted central catheters. Minerva Anestesiol 2009;75(7–8):471–4. [19] Orme RM, McSwiney MM, Chamberlain-Webber RF. Fatal cardiac tamponade as a result of a peripherally inserted central venous catheter: a case report and review of the literature. Br J Anaesth 2007;99(3):384–8. [20] Buehrle D. PICC placement in humans using electromagnetic detection. http://www.corpakmedsystems.com/supplement_material/Supplement_PDFs/ Navigator/Buehrle_Article.pdf. Accessed on July 18, 2012. [21] Naylor CL. Reduction of malposition in peripherally inserted central catheters with tip location system. J Assoc Vasc Access 2007;12(1):29–31. [22] BardAccess. Sherlock II tip location system: instructions for use. http://www. bardaccess.com/assets/pdfs/ifus/0715972_Sherlock_II_TLS_IFU_web.pdf. Accessed on July 18, 2012. [23] Gonzales AJ, Pestka C, Silverstein F, Golden RN. Peripherally inserted central catheter placement in swine using magnet detection. J Intraven Nurs 1999;22(3): 144–50.