Implementation of modified Seldinger technology for percutaneous catheterization in critically ill newborns

ABSTRACT Objective: To describe the implementation of Modified Seldinger Technology for percutaneous catheterization in critically ill newborns. Method: A quasi-experimental before- and-after study, carried out with neonatologist nurses in a Neonatal Intensive Care Unit. Results: Seven nurses participated in the research. Catheter pre-insertion, insertion and maintenance were assessed using the conventional and modified Seldinger technique. Reliability was satisfactory in pre-test, 5.40 (Md = 6.00), and post-test, 5.94 (Md = 7.00), and perfect in the items about device insertion and maintenance. There was low assertiveness in the items on indication, microintroduction procedure via ultrasound, limb repositioning and disinfection of connections/connectors. Conclusion: Despite the Modified Seldinger Technique expanding some stages of execution over the traditional method of percutaneous catheterization, nurses were more assertive after theoretical-practical training. The technology was implemented and is in the process of being implemented in the health service.


INTRODUCTION
Hospitalized newborns (NB) often require prolonged venous access for drug administration and parenteral nutrition. According to international recommendation (1) , peripheral catheters are indicated for this clientele if intravenous therapy is prescribed for up to seven days and if the drug allows administration via a peripheral route. Therefore, it is concluded that peripheral devices are unfeasible for NB, due to the need for solutions that require longterm central administration (2) . Thus, a central line in critically ill NB becomes mandatory.
The use of a peripherally inserted central catheter (PICC) as an innovative technology in infusion therapy began to be used in Brazil more than three decades ago, when nurses became the professionals most involved in its execution (3) . PICC use prevailed over other traditional catheters for many reasons: lower risk of infection, costeffective and convenient insertion at the bedside (4,5) , reduced patient discomfort due to multiple puncture attempts, resistance to the system peripheral venous hyperos molarity and preservation (6) . Another aspect of fundamental importance in the prevention of complications and iatrogenic events is the fact that this central venous catheter (CVC) has a peripheral insertion, which potentially prevents the occurrence of pneumothorax (7) .
However, it is widely recognized that PICC placement in NB presents a unique set of technical challenges, which are even more potent in preterm infants. Therefore, tools that can increase the success rate and reduce complications associated with the procedure are invaluable (8) . Faced with this difficulty, some technologies have been developed to improve percuta neous catheterization in NB and provide improvements in the health care of this population. One of them is the Modified Seldinger Technique (MST).
Originally, the Seldinger technique has been around since the 1950s, known as classical Seldinger. From technological refinements, this evolved notably, which resulted in greater secu rity in the insertion of central lines. After these increments, the classic technique was modified to assist patients who demand more delicate care, such as NB, which culminated in the nomen clature of the technology (9) .
MST, in turn, adds some steps in relation to the traditional PICC insertion method, as access to the venous network is esta blished through a smallgauge needle, followed by the insertion of a malleable guide wire. After introducing approximately 5 cm of the guide, the needle used for the initial puncture is replaced by a peelaway dilator, which has only the plastic part. Then, the guidewire is withdrawn, and the catheter is introduced through the dilator until the desired measurement is reached. At the end of the progression of the device, the peelaway, which is also bipartite, is broken and the PICC is in situ (10) .
Although previous technologies predominate in clinical practice for PICC insertion, it is already recognized that MST has achieved prominence for making central venous cathete rization minimally invasive in neonates (11) . Moreover, MST complies with the recommendations of guidelines on insertion techniques for central venous catheters and actions aimed at reducing adverse events (12,13) .
What makes MST less traumatic is the use of thinner and more malleable introducers and guides. This characteristic also called this technique microintroduction (13) , contributing to reduce the risk of thrombosis, infection and bleeding during the procedure (14) , in addition to providing a successful and less traumatic experience for NB (15) .
For its use to be satisfactory, access to the venous network requires a trained professional and the use of technologies for venous device insertion (16) . With regard to the implementation of technologies in patient care, it is necessary to train and qua lify the team on which it is intended, with periodic updates in order to improve the ability, in particular, of procedures not performed routinely (17) .
Given the above, the aim of this study was to describe the implementation of MST for percutaneous catheterization in critically ill NB.

Study deSign
This is a quasiexperimental beforeandafter study. It is noteworthy that the MST was implemented in this study and is in the implementation phase in the health service. This research shows the initial phase of a randomized clinical trial entitled "Efetividade da Punção com a Técnica de Seldinger Modificada no cateter central de inserção periférica", with the Brazilian Registry of Clinical Trials (ReBEC) RBR69vks36.

PoPulation
Nurses from the Neonatal Intensive Care Unit (NICU) where the study was developed who provided direct NB care participated. These are professionals qualified in conventional percutaneous catheterization and responsible for the insertion and maintenance of this vascular device.

Site
Data collection took place in the NICU of a reference pedia tric public hospital, specialized in the care of children and ado lescents in the southern region of Brazil. This unit is a reference service in the state for highly complex assistance to NB who use the Brazilian Health System (Sistema Único de Saúde). It offers 20 beds, human and material resources necessary to provide uninterrupted support to the vital functions of hospitalized NB. The service is made up of 113 professionals, such as nurses, nur sing technicians, physicians on duty and physiotherapists who work full time, in addition to psychologists, speech therapists, social workers and occupational therapists.
The use of PICC inserted by the conventional technique in the aforementioned NICU has been taking place since its inau guration in 2009, as it is an indispensable device in assisting this clientele. All PICC insertion procedures are performed at the bedside and any intravenous administration in the unit is per formed with the aid of infusion pumps by nursing professionals.

Selection criteria
All nurses working at the study NICU who consented to participate in the research were included in the survey. Nurses removed from their duties during the training period were excluded from the study.

data collection
The data collection period took place between June and November 2021. The survey was carried out in three stages, which will be described in detail below. In the first, theoretical and practical training of the research team on the MST technique in neonates was carried out (between January and February 2021). In the second stage, data collection instruments were prepared (pre/posttest) (from March to May 2021). Finally, in the third stage, study participants received theore tical and practical training on MST technology (from June to November 2021), taught by the duly trained research team.
In the first stage, two nurses specializing in child health were trained by the technology producing industry based on infusion therapy guidelines. Previously scheduled meetings, training on a virtual platform and in person were held in the study setting, with the use of an appropriate mannequin, totaling 30 hours of training in MST. In the second stage, instruments based on national and international recommendations (1,12,(18)(19)(20)(21) on PICC insertion techniques were prepared by the researchers and subsequently compiled in pre/posttest. This instrument had questions that assessed PICC preinsertion and maintenance, either by conventional technique or MST, and questions referring to PICC insertion by MST. The questionnaire ended with 37 questions, and had "true" or "false" as answer options.
In the third stage, there was the training of nurses, previously scheduled, in after shift work. It was held in the study site's auditorium, with a total duration of six hours. Initially, partici pants completed pretest. Next, theme theorization was carried out through the expositorydialogue method, followed by prac tical activity, taught by specialist researchers and an experienced nurse in MST.
Nurses performed the puncture procedure with the propo sed technology on the mannequin in the hospital's auditorium, accompanied and guided by researchers and expert nurses until the technique was fully and adequately developed, following the stepbystep instructions shown in theory. If professionals did not perform a step or needed to be reminded, they per formed the technique again on the dummy until the correct execution. This monitoring took place through observation with a field diary completed by the research team. At the end of the theoreticalpractical training, the posttest instrument was applied with the same questions asked in pretest, with the aim of verifying whether there was agreement in the answers in the two moments.

data analySiS and treatment
The information was tabulated in an Excel® spreadsheet with independent typing, and analyzed in the Statistical Package for the Social Sciences (SPSS), version 20.0. In descriptive statistics, data were described in absolute and relative frequencies and measure of central tendency (M e = Mean; M d = Median). Pre and posttest reliability assessment was performed using the Kappa coefficient, which consists of the proportion of agreement in the responses before and after professional training. Values were interpreted according to the Landis & Koch classifica tion. McNemar's χ2 test was used to verify equality between the proportions of responses (pre and posttest), and values of p ≤ 0.05 were considered significant.
Paired t test was used in related parametric samples (pre and posttest) by professional category, in order to assess whether the means of the two measures are statistically different. Values of p ≤ 0.05 between the means were considered significant.

ethical aSPectS
The research complies with the guidelines of Resolution 466/12 of the Brazilian National Health Council, and was approved by the Research Ethics Committee on January 12, 2021, in accordance with favorable opinion 4,495,894, (CAAE (Certificado de Apresentação para Apreciação Ética -Certificate of Presentation for Ethical Consideration) 39827120.2.0000.0102).

RESULTS
The study scenario has 8 (n = 8) clinical nurses. After applying the eligibility criteria, seven nurses (n = 7) became research participants. One (n = 1) was excluded because he was away from work activities during the research training period.
Regarding the profile of these professionals, all performed care activities in the NICU and were between 34 and 43 years old (Me = 38 years old). Training time ranged from 12-15 years (Me = 13 years), and time working in the unit ranged from one to 12 years (Me = 9 years).
Regarding the training of participants, Table 1 shows the hits in pre and posttest of nurses on care in PICC preinsertion in MST. Table 2 describes the number of hits in nurses' pre and posttest regarding the necessary care for insertion from the MST. Table 3 shows the number of hits in nurses' pre and posttest on maintaining the PICC in MST training. Table 4 presents the comparison between nurses' assertiveness.

DISCUSSION
The MST implementation process through the training of nurses in the NICU showed satisfactory pretest and posttest reliability. Professionals had prior knowledge in items on device insertion and maintenance, with low assertiveness regarding the indication of technology and procedure for microintroduc tion via ultrasound on limb repositioning and disinfection of connections/connectors. The text will be described in the sequence presented in the results and divided into PICC preinsertion, insertion and maintenance.

PeriPherally inSerted central catheter Pre-inSertion
For a new technology to be incorporated into the health system, training and qualification of professionals involved in its implementation is essential. Safe care requires qualified and committed professionals, a favorable environment and their understanding that effective technical work is transformative and requires work organization. In this context, it is important to understand how advanced nursing practices contribute to patient safety, considering the possibility of minimizing risks through differentiated skills and knowledge (22) . With regard to the need for qualification in MST through a specific course, hits predominated in posttest, COFEN Resolution 258/2001 supports PICC insertion by nurses, pro vided that they undergo qualification through a qualification course (18) . As the MST adds different stages to traditional PICC insertion, in addition to being an Advanced Practice in Nursing, new training is required.
The MST technology does not depend on ultrasound use, which is a support in the technique to increase the procedure assertiveness (13) , and placement of central venous catheters can be performed without the aid of this imaging device. An integrative review that aimed to identify the scientific evi dence about this technology in neonatology showed that the combination of MST with ultrasound is still a recent practice in neonatal units and, therefore, its execution is not always linked to the use of a realtime imaging device (23) . Furthermore, www.scielo.br/reeusp Rev Esc Enferm USP · 2023;57:e20220347 Table 2 -Hits in pre-and post-test of nurses participating in the research (n = 7) on peripherally inserted central catheter insertion in the training of the Modified Seldinger Technique -Campo Largo, PR, Brazil, 2021.

Insertion questions Hit pre-test Hit post-test p
17. Microintroduction or MST is defined by the insertion of a larger gauge catheter than the introducer used for its insertion, which makes venous catheterization less traumatic and painful, increasing assertiveness in the first puncture attempt.

(71%) 7 (100%)
18. NB should be preferably positioned in dorsal decubitus and restrained to facilitate catheter progression, without the need for adequate positioning for each insertion site. 5 (71%) 5 (71%) 1* 0.400 † 19. It is necessary to perform antisepsis of the puncture site with 0.5% alcoholic chlorhexidine for term NB and 0.1% for premature NB, for 30 seconds, and allow the antiseptic to completely dry. The direction of the cleaning movement can be in the "back and forth" direction or with circular movements.

(57%)
4 (57%) 1* 0.417 † 20. After insertion site antisepsis and protection with the sterile field, microintroduction is performed in this sequence: A-Establish access to the venous network through a fine-gauge needle as per the manufacturer; B-After blood reflux, insert the guide wire approximately 5 cm into the needle; C-If necessary, perform the anesthetic button with lidocaine without vasoconstrictor 2 minutes before placing the dilator (peel-away); D-The access needle is subsequently removed over the guide wire, followed by peel-away total placement; E-Insert the PICC catheter until the desired measurement through this dilator. If the catheter progresses successfully, break the peel-away and stabilize the PICC, awaiting confirmation of the distal tip by imaging exam. ultrasound is not always available in health practice; there fore, radiography is the most used method to confirm the procedure's success (24,25) .

PeriPherally inSerted central catheter inSertion
Regarding the appropriation of MST's sequential stages, it was evident that nurses assimilated the technique with greater clarity after the theoreticalpractical training. MST adds some steps in relation to the traditional PICC insertion method. Initially, vessel catheterization is established using a smallgauge needle. After puncture, the flexible tip of the guide wire is inser ted from three to five centimeters through the introducer to guarantee access to the venous network. While professionals hold the guide wire in this position, gently withdraw and remove the needle. The next step is to pass the dilator/introducer over the guidewire, inserting it completely through the skin, as it will follow the same path as the guide, i.e., to the center of the blood vessel. Carefully, the guidewire should be withdrawn, leaving only the dilator/introducer in place. At this point, the catheter should be advanced in the vessel to the desired length (13) . Table 3 -Hits in pre-and post-test of nurses participating in the research (n = 7) on peripherally inserted central catheter maintenance in the training of the Modified Seldinger Technique -Campo Largo, PR, Brazil, 2021.

Maintenance
Hit pre-test Hit pre-test p 31. It is necessary to assess PICC's functionality using a 10 ml syringe or a syringe designed specifically to generate low injection pressure, performing an initial flush, slowly aspirating the catheter until blood returns, which is an important component in catheter function assessment, before the administration of drugs and solutions. 7 (100%) 7 (100%) 1 † 32. The appropriate volume of saline solution for washing the catheter does not need to be followed in care practice, which consists of at least twice the catheter's total internal volume.

(71%)
6 (86%) 1* 0.235 † 33. The positive pressure technique for PICC flushing allows the reduction of blood backflow into the catheter. Measurement of the circumference of the limb where the PICC is inserted should be done frequently to assess signs of deep vein thrombosis, such as edema.  Another item that had the greatest hit after the educatio nal intervention was percutaneous catheter stabilization at the moment of PICC insertion. Stabilizing and securing vascular access devices is part of the main infusion therapy guidelines in order to avoid complications and unscheduled removal. Contrary to what was described in question 23, the use of purpose designed stabilization devices (DSD) contributes to reducing the risk of infection and device displacement. Furthermore, stabilization should not be performed using sutures and/or nonsterile materials. DSD are considered safer than these materials. Nonsterile tape rolls can harbor pathogenic bacteria. Sutures are associated with greater biofilm growth (20) .
The Brazilian National Health Regulatory Agency (ANVISA -Agência Nacional de Vigilância Sanitária) considers the use of sutureless stabilization devices to reduce the risk of bloodstream infection. It also emphasizes that the fixation of any venous catheter must be performed using aseptic technique; therefore, nonsterile tapes and microporous tapes are contrain dicated over the puncture bed (19) .
Regarding question 25, which asks about the location of the distal tip of PICC, greater assertiveness was evidenced in posttest. Misplaced catheters have been reported in various anatomical regions, including the arterial system, mediastinum, pleura, pericardium, trachea, esophagus, arachnoid subspace, and at other aberrant sites. However, the ideal tip location of central venous catheters with the highest safety profile is at the cavoatrial junction (CAJ) for any age group (26) . Avoid placing the tip in vessels distal to the superior/inferior vena cava, such as the innominate, brachiocephalic, subclavian or iliac veins, as positioning in these veins increases the risk of adverse events (20) . For central catheters inserted in the upper extremities, place the distal tip in the lower third of the superior vena cava. For devices inserted in the lower segments, the level of the diaphragm should be considered as an anatomical landmark (20) .
Regarding the measures used to facilitate PICC progression within the blood vessel, no statistical significance was observed between the hits in pre and posttest; however, it is necessary to discuss them, since they are relevant strategies in clinical practice that help professionals on the success of catheter progression. Furthermore, in the case of Brazilian public institutions, the health team does not always have access to recent technologies for the placement of PICCs, leaving only noninvasive maneu vers to direct the tip of the device to the CAJ, in case of difficulty.
In neonates, it is widely recognized that percutaneous cathe terization presents a unique set of technical challenges, which are even more potentiated in premature infants, since the smaller the patient, the greater the technical difficulty of the procedure and the anatomical variations (27) . Thus, during the practice of PICC insertion, nurses observe, in some cases, device non progression, which may be associated with stenosis, tortuous veins, venospasm, bifurcations, closed venous valves, thrombosis and hematomas. To overcome the difficulty of progression in both PICC insertion techniques, bolus saline infusion, gentle vein massage in the direction of blood flow, and warm compress to promote vasodilation are suggested (20,28) .
Another widely disseminated strategy in the literature is limb repositioning and/or rotation, considered maneu vers that may favor PICC progression during the procedure. A quasiexperimental Brazilian study that described the creation of a maneuver to move the shoulder in NB statis tically concluded the inestimable value of this technique, in addition to being easy to apply, without tissue injuries or additional expenses (28) .
In addition to the shoulder maneuver, arm and head move ments are methods that facilitate PICC advancement and are associated with temporary changes in the positioning of the shoulder and upper limbs, modifying the natural course of the great vessels and facilitating the rectification of probable venous curvatures, promoting catheter advancement to the CAJ (29) . The National Association of Neonatal Nurses of the United States also recommends the incorporation of the aforementioned practices to PICC slow insertion inside the vessel to avoid venous irritation and the development of phlebitis. This con duct also allows the catheter to slide more easily in the central circulation with blood flow, requiring a total introduction speed between 30 and 60 seconds. Another complication resulting from rapid catheter introduction into the vein is that this prac tice can lead to poor positioning (13) .
Another noninvasive maneuver that can be used to repo sition the PICC tip is the highflow flush (26) , also referred to as the hydrostatic method, which can also be considered flushing, but technically more vigorous, using pressure. In this maneuver, a saline jet force is applied to the catheter in order to straighten the curve in the centerline (30) .
This technique used in saline solution allows repositioning of the tip both during PICC placement and postinsertion, however there are some limitations of use. If performed during venous catheterization, it is dependent on ultrasound and real time tip visualization technology. The potential for device mal positioning is almost guaranteed at some point during its use, as relatively simple changes in intrathoracic pressure, such as sneezing, coughing, vomiting, can contribute to tip movement to an undesirable location (19,20,26) .

PeriPherally inSerted central catheter maintenance
Bad positioning of central venous accesses has been des cribed in abundance throughout the literature, and the non invasive correction of this complication, even in neonates, has been described in the first 24 hours after the diagnosis of mal position (26) . Another restriction imposed on using the hydrostatic method is that it should never be performed in catheters that are not power PICC, as such excess pressure in devices that are not manufactured with resistant polyurethane can cause line rupture. Although the power PICC is inserted by MST, this type of catheter is dependent on ultrasound to be inserted. In the present study, we used microintroduction, but through direct puncture in conventional PICC catheters. Nurses had a higher hit level in posttest referring to the question that discussed the disinfection routine of PICC connections and connectors. The Infusion Nurses Society (2021) (20) recommends that antisepsis should be performed before any drug/solution enters the catheter lumen. This guideline also points out that the main factors that influence the effectiveness of disinfection are the agent used, the time spent and the method of application. In other words, health professionals need to perform the technique by a vigorous mechanical method, with an alcoholbased solution, for 5 to 15 seconds.
The use of 70% isopropyl alcohol is recommended instead of chlorhexidine, since the drying time is 5 and 20 seconds, respectively, making the latter option less favorable in clinical practice (20) . Likewise, ANVISA recognizes the disinfection of connections and connectors with alcoholic antiseptic solution, with movements applied in such a way as to generate mechanical friction, from 5 to 15 seconds, as a measure to prevent infection related to health care (19) .
The limitations of this study were related to the small number of nurses participating in the research and because it was a study scenario. In general, statistics showed that there was no significant difference between pre and posttest of these professionals, possibly due to type II error associated with the small number of nurses. Moreover, the lack of national studies on the research object and on the neonatal population made it difficult to compare the results with the Brazilian reality.
As a contribution of this study, the importance of training the nursing team in PICC care is highlighted, since the use of this technology is part of their routine, especially in the NICU. Specialized teams can reduce adverse events by performing safe maintenance on the device. PICC is an innovative technology, increasingly necessary in NICUs, which requires professionals to have technical and scientific knowledge to avoid complica tions. For this, compliance with good practices related to its use is essential in neonatal care. Another contribution of this research to practice refers to the potential for expansion to other contexts, by using the same process for the incorporation of new health technologies.

CONCLUSION
The MST implementation process in the NICU showed satisfactory pre and posttest reliability and perfect device insertion and maintenance for nurses. There were more hits in posttest when compared to pretest. Despite the MST exten ding some stages of execution over the traditional method of percutaneous catheterization, there was, by nurses, adherence with greater clarity after theoreticalpractical training. Training showed that health professionals need continuous and perma nent education, especially in the implementation of a new technology.