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Pediatric Imaging |
1 From the Departments of Radiology (B.L.F., J.M.R., T.D., L.F.D., N.D.J.) and Pediatrics (J.M.R., L.F.D., R.M.T., N.D.J.), Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039; and the University of Cincinnati College of Medicine, Cincinnati, Ohio (J.M.R., L.F.D., N.D.J.). From the 2002 RSNA Scientific Assembly. Received November 13, 2003; revision requested February 6, 2004; revision received April 7; accepted May 24. Address correspondence to J.M.R. (e-mail: john.racadio@cchmc.org).
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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MATERIALS AND METHODS: This study was approved by the hospital’s institutional review board, which waived the requirement for informed consent. In a children’s hospital, 843 PICCs were placed in 698 patients (age range, 0 days to 26 years; mean, 6.9 years) during a 14-month study period. All PICCs were placed by a specialized team of PICC nurses and interventional radiology technologists in an angiography suite with the supervision of pediatric interventional radiologists. All catheters were threaded blindly to a previously estimated length by either a PICC nurse or a pediatric interventional radiologist, according to National Association of Vascular Access Networks guidelines, and the initial PICC tip location was then determined by means of spot fluoroscopy. PICC tips were regarded as central if they resided anywhere within the superior vena cava (SVC). All catheters were then manipulated with intermittent fluoroscopic guidance to achieve a final central position in the distal third of the SVC. A 
2 test was used to compare initial and final PICC tip locations according to patient age, catheter size, accessed vein, and need for radiologist assistance. A t test was used to compare procedure time with and without radiologist assistance.
RESULTS: Analysis included 843 consecutively placed pediatric PICCs, of which 723 (85.8%) had a noncentral initial PICC tip position and required additional manipulation. After catheter repositioning performed with intermittent fluoroscopic guidance, a final central PICC tip location was achieved in 760 PICCs (90.2%).
CONCLUSION: Pediatric PICC placement without fluoroscopic guidance required catheter manipulation of initial PICC tip position in 723 cases (85.8%). PICC placement with fluoroscopic guidance is highly successful, and the authors believe it is best performed in an angiography suite.
© RSNA, 2005
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Currently, practices also vary as to where within the hospital PICCs are placed. Some advocate placement of the PICC at the patient’s bedside, followed by chest radiographic confirmation of correct catheter tip position (10,11). In that situation, if the catheter isplaced incorrectly, it is usually blindly repositioned and another chest radiograph is then obtained. Others place PICCs with fluoroscopic guidance in an interventional radiology suite, where the tip position can be confirmed immediately and corrected if necessary (2). The cost of the latter approach, however, is a concern (12).
The rate of successful initial placement (catheter tip in a correct position) is key to determining the advantages of either approach. If the rate of successful initial placement were high, then bedside placement would be more advantageous. However, if the rate for bedside placement were low, therefore requiring further catheter manipulations to achieve correct tip position, placement in an interventional suite with fluoroscopic capabilities would probably be more advantageous. The purposes of our study were to simulate as accurately as possible bedside placement of PICCs (without imaging guidance) in an interventional radiology suite and to determine how often such placement results in an initially correct central venous catheter tip location.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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PICC Placement
All PICCs were placed by a specialized team of PICC nurses and interventional radiology technologists with the supervision of pediatric interventional radiologists in an interventional radiology suite. All fluoroscopy was performed by either an interventional radiology technologist (RT degree) or a pediatric interventional radiologist (MD degree). All members of this team, including the PICC nurses, completed a fluoroscopy training program and passed an examination before working in the interventional radiology suite. When ultrasonographic (US) guidance was needed to gain access because the PICC nurses could not find an adequate vein with palpation or visualization, when guidewire manipulation of the catheter after initial PICC placement had failed, or when sedation was necessary, a pediatric interventional radiologist was called into the interventional radiology suite for hands-on assistance. The pediatric interventional radiologist would then complete the procedure, per clinical protocol.
The catheter and needle systems used in this study included a 2-F catheter with a 22-gauge needle, a 3-F catheter with a 19-gauge needle, and a 4-F catheter with a 17-gauge single-lumen silicone PICC with a peel-away sheathed needle (V-Cath; HDC, San Jose, Calif). Patients who required sedation were immobilized with a swaddled papoose (Olympic Medical, Seattle, Wash). Before PICC insertion, catheter length was estimated according to recommendations from the National Association of Vascular Access Networks in the Journal of Vascular Access Devices guidelines (13). Most of the catheters were inserted in the upper extremities at or slightly above the antecubital fossa with direct visualization or palpation of the vein. A scalp vein was used as an alternative if access was difficult in the upper extremities. After access was obtained, all catheters were threaded blindly to the previously estimated length by either a PICC nurse or a pediatric interventional radiologist, and the initial PICC tip location was then determined by means of spot fluoroscopy.
PICC tips were defined as central if they resided anywhere within the SVC. The superior border of the SVC was defined by the right tracheobronchial angle (14,15), and the inferior border of the SVC was defined at or slightly below the chest radiographic silhouette of the right lateral border of the heart (15). PICC tips residing in the superior two-thirds of the SVC were regarded as central but were further manipulated to the correct position of the inferior third of the SVC, either by a PICC nurse or by a pediatric interventional radiologist when hands-on assistance was requested, per National Association of Vascular Access Networks guidelines (13). All other catheter tip positions were regarded as noncentral, and those tips were then manipulated with fluoroscopic guidance by a PICC nurse (or a pediatric interventional radiologist) to a final central position in the inferior third of the SVC.
All PICCs inserted before, during, and after our study were placed in an interventional radiology suite per clinical protocol, and this practice continues. There was no change in this clinical protocol for the purposes of the study. On the rare occasions when a PICC is placed at bedside, due to severity of illness, exactly the same protocol is used, but a chest radiograph instead of a spot fluoroscopic image is obtained to confirm the initial tip position. No data from bedside placements were included in this study.
Data concerning failed PICC attempts were reviewed before any repeated attempt, and the extremity site and any obstructive venous anatomy were noted. The initial attempt at PICC insertion failed in 27 patients, who had to return to the interventional radiology suite for another attempt at insertion. All repeated attempts at PICC insertion were performed in different virgin sites.
Data Acquired
Data that were reviewed included the accessed vein, catheter size, initial catheter tip location, final catheter tip location, procedure time, and the need for hands-on assistance by a pediatric interventional radiologist with US-guided access, guidewire manipulation, or sedation. Procedure time was defined as the time from when the patient was wheeled into the angiography suite to when the patient left the suite. A PICC nurse (T.D.) and a radiology resident (B.L.F.) used data sheets to collect data about each patient from a digital database at a picture archiving and communication system workstation, and the latter deidentified the data and stored them in a secure database. All images were read by a pediatric interventional radiologist (J.M.R., L.F.D., or N.D.J.) to determine the initial and final PICC tip locations in consensus.
Statistical Analysis
A 2 test was used to compare initial and final PICC tip locations according to PICC size (2 vs 3 F), accessed vein (basilic vein vs cephalic vein), and need for assistance from a pediatric radiologist. Initial and final PICC tip locations were compared according to patient age, in 5-year increments (eg, 0–5 years, 5–10 years), by means of a five-by-two 2 test. A further two-by-two 2 test was conducted to compare final PICC tip locations according to patient age, to identify any significant differences between age groups. For example, the frequency of final central PICC tip location in the 0–5-year-old age group was compared with that in all other age groups combined. This comparison was performed for each age group. Procedure times with and without hands-on assistance from a pediatric interventional radiologist were compared by means of a t test. All statistical analyses were performed with statistical software (SAS, version 8.2; SAS Institute, Cary, NC). Differences with P values less than .05 were considered statistically significant.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Concerning the final PICC tip location, 365 (86.7%) of 421 tips in the 0–5-year-old age group were central, compared with 130 (90.9%) of 143 in the 5–10-year-old group, 154 (93.9%) of 164 in the 10–15-year-old group, 85 (95.5%) of 89 in the 15–20-year-old group, and 24 (92.3%) of 26 in those older than 20 years. There were significant differences in final PICC tip location between age groups (P < .026). Additional analysis of the 0–5-year-old group showed that this group was significantly different from the others (P = .05). Analyses of other age groups showed no further differences (P > .05).
A 2-F catheter was used in 290 cases, a 3-F catheter in 514, and a 4-F catheter in 25. In 14 cases, the size of the catheter was unrecorded. There was no significant difference, however, between 2-F and 3-F catheters with regard to initial (P < .087) or final (P < .192) PICC tip location. The basilic vein was used for access in 473 cases, the cephalic vein in 307 cases, and a scalp vein in 22 cases; in 41 cases, the accessed vein was not recorded. There were no statistically significant differences in initial (P < .418) or final (P = .538) PICC tip location between PICCs placed through the basilic vein and those placed through the cephalic vein.
Hands-on intervention by a radiologist was required in 322 (38.2%) cases. The intervention involved US assistance in obtaining access in 207 cases (24.6%), guidewire manipulation in 138 (16.4%), and sedation in 49 (5.8%), with some cases requiring more than one type of intervention. Of these 322 cases, initial fluoroscopy showed a central catheter tip position in 22 (6.8%), compared with 98 (18.8%) of 521 PICCs in which hands-on interventional assistance was not necessary; this difference was statistically significant (P < .001). The final location of the catheter tip was noncentral in 61 (18.9%) of the 322 PICCs requiring a radiologist’s intervention, compared with 24 (4.6%) of the 521 placed without such assistance (P < .001). Thus, the pediatric interventional radiologists were able to manipulate 239 (79.7%) of 300 PICC tips that were initially noncentral into a final central position.
The average total procedure time was 41 minutes 54 seconds without hands-on intervention by a radiologist and 64 minutes 42 seconds with intervention, another significant difference (P < .001).
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Whereas the importance of central tip placement for central venous catheters in children has been reported in the literature (2–8), the correct position for the catheter tip has been subject to debate (9). In 1989, the Food and Drug Administration stated that "catheter tips should not be placed in or allowed to migrate into the heart" (9,21). Several nursing societies have advocated that central venous catheter tips should reside in the SVC at or close to the right atrial junction (9,13,22). The National Kidney Foundation has published guidelines stating that tunneled hemodialysis catheter tips should be placed at the junction of the SVC and the right atrium or in the right atrium but that temporary hemodialysis catheter tips should be placed at that junction or within the SVC (9,23). Thus, the literature does agree that for most temporary central venous catheters, such as PICCs, the optimal tip position is the distal SVC (9).
There has also been debate, however, concerning the radiographic definition of the SVC (9). The carina (24–26) and skeletal structures (27,28) have been mentioned as possible radiographic landmarks. The upper border of the SVC can be defined by the right tracheobronchial angle (14), and Vesely (9) has stated that this angle best defines the boundaries of the SVC. The right superior border of the heart is not reliable for predicting the inferior border of the SVC, as the left atrium is the inferior border in 38% of patients (15). In the pediatric literature, the right third intercostal space (29) and the sixth thoracic vertebral body (30) have been reported as radiographic landmarks for accurate central catheter tip placement.
Unfortunately, parallax and unusual spinal anatomy make guidelines that are based on skeletal structures unreliable. Furthermore, definitions of the inferior boundary of the SVC in the literature are dependent on a measured distance from the right tracheobronchial angle in adults (9,15). We could not assume that a measured distance in adults would correlate with the inferior border of the SVC in children. We incorporated data showing that the inferior border of the SVC was either at or caudad to the right superior border of the heart on a chest radiograph (15). Thus, we defined the superior boundary of the SVC with the right tracheobronchial angle and the inferior border of the SVC as at or below the right superior cardiac border on a chest radiograph. We aimed to place the PICC tip at or slightly superior to that right superior border, to allow for catheter migration.
The previously mentioned definition was implemented in each patient to determine whether the PICC tip resided in a central position. After we determined whether the PICC tip was positioned anywhere in the SVC, a central position, we used the National Association of Vascular Access Networks recommendation that "the most appropriate location for the tip of PICCs is the lower one third of the SVC, close to the junction of the SVC and the right atrium" to refine further the location of the PICC tip (13). Thus, although we used the entire SVC as our definition of a central position for PICC tips, we further manipulated those catheters tips in the superior SVC to the inferior third of the SVC for optimal performance.
In the literature about this procedure in adults, rates for successful initial central PICC tip placement without imaging guidance ranged from 44% to 99% (6,7,12,31–34). The definition of "central," however, varied among these studies, which likely contributed markedly to this wide variation in initial success rates (2,6,7,12,31–34). To our knowledge, there have been no previous reports in the pediatric population. Our pediatric study revealed an initial central position of the PICC tip in only 14.2% of cases. This considerably lower rate of success may be caused by the smaller-caliber veins in children, as well as our necessarily more restricted definition of "central" in this population. Patient age did not significantly affect the frequency of initial central PICC tip position, but there was a significant difference in final tip position between the 0–5-year-old age group and all other age groups, perhaps because of the smaller veins found in the youngest group. Catheter size and accessed vein did not significantly affect the initial or final success rates for central tip positioning.
Placement of PICCs in an interventional radiology suite offers several advantages. Many noncentral PICC tips were coiled, looped, or in an area where simple manipulation would not suffice to achieve a correct central tip location. If those PICCs had been placed at bedside, they would most likely have required several manipulations and multiple chest radiographs, delaying treatment. In an interventional radiology suite, PICC tips can be manipulated to the correct central location at the time of the initial procedure, in real time and with fluoroscopic guidance, allowing treatment to begin or resume without delay.
Another benefit of placing PICCs in the radiology department is the availability of an interventional radiologist to assist with US-guided access, guidewire catheter manipulation, or sedation. At least one of these interventions was necessary in 37.4% of cases in our study. It is logical to conclude that the same percentage of procedures would fail if performed at the patient’s bedside, where assistance from an interventional radiologist is not readily available.
There were significant differences in both initial and final PICC tip locations depending on the need for hands-on assistance from a pediatric interventional radiologist. The pediatric interventional radiologist had a lower frequency of both initial and final central PICC tip positions. The hands-on assistance was required for US-guided access, catheter guidewire manipulation, and sedation. Since the pediatric interventional radiologists assisted in the more difficult cases, the differences in success rate were expected. Still, in those cases requiring hands-on assistance, 79.7% of the initially noncentral PICC tips could be manipulated to a final central catheter tip position. Thus, the hands-on assistance is a highly beneficial resource for difficult cases. Furthermore, the average procedure time for cases in which a pediatric interventional radiologist assisted was significantly longer than it was for cases not requiring assistance. Again, this difference is expected, since assistance was requested in the more difficult cases, sometimes after an unsuccessful attempt at placement by the PICC nurses.
Although we believe there are multiple benefits to placing PICCs in the radiology department with fluoroscopic assistance, elevated costs are a concern. Results of a cost-effectiveness analysis of the literature about this procedure in adults indicated that if a specific tip location is required, such as the inferior third of the SVC, then placement in an interventional radiology department is more cost-effective than placement at bedside (12). Because of the low rate of initial correct PICC tip position documented in this study and the need for repeated positioning, which prolongs the procedure time, the cost of a one-time procedure in the radiology department might actually be the same as or less than that of repeated attempts at the patient’s bedside.
Furthermore, few children’s hospitals can afford to use an expensive angiography suite for placement of PICCs by nurses. We are fortunate to have two dedicated pediatric interventional suites. A less expensive "C-arm procedure room" would be ideal, providing all the benefits of an interventional radiology suite and radiologist assistance without tying up a dedicated angiography suite. As our practice continues to expand, we are planning such a room.
Ideally, we would like to compare placement of PICCs at the patient’s bedside directly with placement in an interventional radiology suite. Although we used exactly the same protocol in our angiography suite that is used at the bedside in our children’s hospital, our use of the angiography suite is a limitation of this study. Unfortunately, a direct-comparison study would be difficult to undertake, would have to be multi-institutional, and would add more variables that may complicate data interpretation.
PICC placement without imaging guidance resulted in an initial correct catheter tip location in only 14.2% of cases in this study. After further repositioning with intermittent fluoroscopic evaluation, a final central catheter tip location was achieved in 90.2% of cases.
The low rate of initial success creates a need for repeated manipulation and repeated chest radiographic confirmation. This, in turn, markedly increases procedure time when the procedures are performed at the patient’s bedside. We also observed a frequent need for radiologist intervention, which we believe is best accomplished within the radiology department. Therefore, overall we believe that pediatric PICC placement should be performed in an interventional radiology suite, although a cost-effectiveness analysis is currently in progress at our pediatric institution.
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FOOTNOTES |
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Abbreviations: PICC = peripherally inserted central catheter, SVC = superior vena cava
Authors stated no financial relationship to disclose.
Author contributions: Guarantors of integrity of entire study, B.L.F., J.M.R.; study concepts and design, all authors; literature research, B.L.F., J.M.R.; clinical studies, B.L.F., J.M.R., T.D., L.F.D., N.D.J.; data acquisition and analysis/interpretation, all authors; statistical analysis, B.L.F., J.M.R., R.M.T.; manuscript preparation and editing, B.L.F., J.M.R., L.F.D.; manuscript definition of intellectual content, B.L.F., J.M.R.; manuscript revision/review and final version approval, all authors
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REFERENCES |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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This article has been cited by other articles:
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  T. Venkatesan, N. Sen, P. J. Korula, N. R. S. Surendrababu, J. P. Raj, P. John, and S. Christopher Blind placements of peripherally inserted antecubital central catheters: initial catheter tip position in relation to carina Br. J. Anaesth., January 1, 2007; 98(1): 83 - 88. [Abstract] [Full Text] [PDF]
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