Ultrasound-Guided Long vs Short Peripheral IV Catheters in Neonates With Congenital Syphilis Receiving Antibiotics

Congenital syphilis remains a significant public health problem and requires prolonged intravenous antibiotic therapy, typically with crystalline penicillin. In this context, reliable peripheral venous access is essential to ensure treatment continuity and safety. However, vascular access in newborns is particularly challenging due to small vessel caliber, tissue fragility, and increased susceptibility to complications, often resulting in high rates of catheter failure and repeated insertion attempts.

Short peripheral intravenous catheters inserted using conventional techniques are the most commonly used devices in neonatal care. Despite their widespread use, these devices are associated with limited dwell time and a higher likelihood of failure. Current guidelines recommend the use of adjunct technologies, such as ultrasound guidance, as well as devices with longer dwell times to improve vascular access outcomes. Ultrasound-guided insertion allows better visualization of vessels, potentially increasing first-attempt success and reducing complications. In addition, long peripheral intravenous catheters may provide greater stability and prolonged functional use compared with short catheters.

This study is a randomized, controlled, parallel, prospective clinical trial designed to compare ultrasound-guided long peripheral intravenous catheters inserted by a specialized vascular access team with conventional short peripheral catheters inserted by neonatal nurses. The study will be conducted in the Neonatal Intermediate Care Unit of the Hospital de Clínicas de Porto Alegre, Brazil, between May 2026 and March 2028.

Eligible participants are newborns diagnosed with congenital syphilis who require intravenous antibiotic therapy with crystalline penicillin for a planned duration of ten days. After enrollment, participants will be randomly assigned to either the intervention group (ultrasound-guided long peripheral intravenous catheter) or the control group (short peripheral catheter inserted using conventional technique).

The primary outcome is functional catheter dwell time, defined as the duration from catheter insertion to removal due to completion of therapy or occurrence of failure. Secondary outcomes include catheter failure, number of insertion attempts, first-attempt success, incidence of complications (such as infiltration, extravasation, obstruction, and phlebitis), and total number of devices required during treatment.

Data will be collected prospectively using standardized forms, and outcome assessment will be performed by trained personnel not directly involved in catheter insertion. Statistical analysis will follow the intention-to-treat principle, and results will be reported in accordance with CONSORT guidelines.

It is hypothesized that ultrasound-guided long peripheral intravenous catheters will result in longer functional dwell time, fewer failures, and reduced need for repeated punctures, contributing to improved vascular preservation, enhanced patient safety, reduced neonatal pain and stress, and more efficient use of healthcare resources.

• Ultrasound-Guided Long Peripheral Intravenous Catheter (Procedure): Participants in the intervention group will undergo ultrasound-guided insertion of a long peripheral intravenous catheter, performed by nurses from the Vascular Access Program. A portable ultrasound system with a high-frequency linear transducer (6-13 MHz), suitable for visualization of superficial vessels in neonates, will be used. Long peripheral intravenous catheters available at the institution will be used, in sizes 24G (32 mm) and 22G (64 mm), composed of radiopaque polyurethane and indicated for ultrasound-guided insertion. Procedures will follow institutional protocols for ultrasound-guided peripheral venous access and device selection. A maximum of four insertion attempts per participant will be allowed, with up to two attempts performed by one professional and, if necessary, two additional attempts by another nurse from the Vascular Access Program.
• Short Peripheral Intravenous Catheter (Conventional Technique) (Procedure): Participants in the control group will undergo insertion of a short peripheral intravenous catheter using the conventional technique (visualization and palpation), performed by bedside nurses from the Neonatology Service. Short peripheral intravenous catheters available at the institution will be used, in sizes 24G (19 mm) and 22G (25 mm), composed of radiopaque polyurethane and intended for single-use peripheral venous access. Procedures will follow institutional protocols for conventional peripheral venous access and device selection. A maximum of four insertion attempts per participant will be allowed, with up to two attempts performed by one professional and, if necessary, two additional attempts by another bedside neonatal nurse.

Primary outcomes

• Functional Catheter Dwell Time [Up to 10 days]: Time (in hours) from successful catheter insertion to device removal for any reason, excluding planned removal at completion of antibiotic therapy.

Sex: All, ages: 1 Day to 28 Days

Inclusion Criteria:

* Newborns admitted to the Neonatal Intermediate Care Unit;
* Diagnosis of congenital syphilis;
* Indication for intravenous penicillin therapy for an estimated duration of 10 days;
* Enrollment on the first day of treatment.

Exclusion Criteria:

* Newborns who have received any type of peripheral venous catheter prior to study enrollment;
* Clinical instability at the time of vascular access indication and/or requirement for admission to a Neonatal Intensive Care Unit;
* Requirement for concomitant administration of another antimicrobial agent in addition to crystalline penicillin;
* Need for catheter insertion outside the operating hours of the Vascular Access Program (7:00 AM to 7:00 PM, Monday to Friday).

• Eneida R. Rabelo da Silva, ScD, Principal investigator, Hospital de Clinicas de Porto Alegre