Introduction

Long peripheral catheters (LPCs) are an alternative to short peripheral catheters (SPCs) in situations requiring intravenous therapy lasting > 5 days, usually up to 28 days (e.g. antibiotic therapy, fluid therapy, administration of non-irritant drugs in concentrations that can be used in peripheral veins) [1]. They are particularly recommended for patients with difficult intravenous access (DIVA), in whom short peripheral catheters require frequent replacement, and there are no absolute indications for the insertion of a central venous access device (CVAD) [2].

In clinical practice, various types of catheters and insertion techniques are used, which may affect the duration of use, the risk of complications, and patient comfort. The two types of LPCs most used in our centre are the Smartmidline Vygon, inserted using the direct Seldinger technique (DST), and the BullPuP, inserted using the ‘over-the-needle’ method. Previous reports suggest that the choice of technique and type of catheter may be important for the effectiveness of therapy and patient safety, but data in this area are limited, especially in retrospective analyses [3, 4]. The use of BullPuP or Smartmidline Vygon catheters reduces the number of punctures, limits the risk of catheter-associated bloodstream infection (CABSI), and improves patient comfort and staff efficiency [5]. They are increasingly becoming part of the standard of care in hospital wards, as well as in outpatient and home care [6].

Long peripheral catheters may also be useful in the early stages of treatment in the Emergency Department for patients requiring increased fluid or drug flow, especially when intravenous access is difficult to obtain [7].

The aim of the study was to retrospectively evaluate the effectiveness and compare two types of long peripheral catheters inserted using the DST method and the ‘over-the-needle’ method. An additional aim was to identify differences between the two techniques that could form the basis for optimising clinical practice in terms of the choice of catheter type and method of insertion.

Material and methods

Study population

The study was approved by the Bioethics Committee of the Medical University of Warsaw (No. AKBE/103/2023). The study covered the documentation of patients hospitalised at the University Clinical Centre of the Medical University of Warsaw who underwent long peripheral catheter insertion using the Seldinger technique (group 1) or the ‘over-the-needle’ method (group 2). A retrospective review of the medical records of patients hospitalised between January 2021 and December 2024 was conducted. A total of 478 cannulation and vascular access observation records were analysed, covering 282 women and 196 men aged 19 to 99, hospitalised in various hospital wards, including surgical, internal medicine, intensive care and monitored wards. All patients who underwent long peripheral catheter insertion using the Seldinger technique or the over-the-needle method during the study period met the inclusion criteria. Exclusion criteria included patients who did not have this type of catheter inserted during the study period.

Variables

The medical records contained data on the age and gender of patients, indications for catheter insertion, insertion site (limb and anatomical location), catheter type, length, diameter and reason for removal. Additionally, the time to insertion, number of insertion attempts, vein diameter before tourniquet, withdrawal, and dwell time were collected. All patient data were anonymised, and the analysis was performed in accordance with applicable personal data protection regulations. The main variables of the study were catheter dwell time, withdrawal time, and reason for catheter removal.

Catheter dwell time was defined as the total number of days from insertion to removal. The withdrawal time was defined as the number of days during which blood aspiration from the catheter was possible. The reason for removal was classified as: end of therapy, catheter dysfunction (e.g. occlusion or inability to aspirate), phlebitis, thrombosis, suspected or confirmed infection, or accidental displacement. The characteristics and definitions of vascular access devices were adopted in accordance with the NAVIGATE nomenclature [5].

Comparisons were made to determine whether catheter length or diameter affected dwell time, withdrawal time, or reason for removal, and whether there were differences between catheter types in these parameters.

Statistical analysis

All data were first analysed descriptively. The Mann-Whitney U test and Kruskal-Wallis test were applied for variables with non-normal distributions, ordinal scales, or small sample sizes. The chi-square test was used for nominal variables to assess associations between categorical data. Normality of continuous variables was assessed using the Shapiro-Wilk test. Results with a significance level of p < 0.05 were considered statistically significant. Calculations were performed using IBM SPSS Statistics 29 software.

Limitations

The study was retrospective in nature, which means that there was limited control over the completeness and quality of the data collected. The information used in the analysis came from vascular access observation charts, which were completed by nursing staff as part of routine clinical documentation. For this reason, not all data were available or fully completed, which may have affected the accuracy and completeness of the analysed results. These limitations should be taken into account when interpreting the results obtained. A notable limitation of this study is the marked imbalance in the sizes of the groups, which reduces the statistical power of between-group comparisons and limits the direct comparability of the two catheter types. To address this issue, an additional analysis was performed on the 4 Fr catheter subgroups, in which group sizes were more balanced.

Results

The analysis covered 478 patients who had a long peripheral catheter inserted. Women predominated in the study population (n = 282, 59%). The median age was 68 years, and the age distribution of patients was characterised by a wide range of values. The group representing the largest percentage comprised patients hospitalised in internal medicine wards (n = 239, 49.89%), while the group representing the smallest percentage consisted of patients in intensive care units (n = 26, 5.43%) (Table 1).

The most common indication for catheter placement was the simultaneous occurrence of difficult intravenous access and the need for therapy lasting more than 5 days (n = 264, 55.35%). Catheters were placed more often in the right limb (n = 194, 61.20%). Among the vessels, the most frequently selected were basilic veins (n = 221, 68.42%), less frequently cephalic veins (n = 27, 8.36%), and brachial veins (n = 74, 22.91%). The dominant type of catheter was group 1 (n = 401, 83.72%). Catheters with a length of 12 cm constituted the majority (n = 352, 73.49%), and a diameter of 3 Fr was the most commonly used (n = 289, 60.59%). Among the reasons for catheter removal, the end of therapy was the most common (n = 225, 47.37%). Less frequently indicated reasons included self-removal by the patient (n = 39, 8.21%), suspected infection (n = 13, 2.74%), thrombosis (n = 13, 2.74%) and catheter damage (n = 5, 1.05%). No cases of phlebitis were reported (Table 2).

The mean time to catheter placement was 8.94 days (SD = 16.33), with a median of 3 days. The longest recorded time was 153 days. In most cases, catheters were placed on the first attempt. The mean diameter of the vein before tourniquet was 4.04 mm (SD = 0.88), with a median of 4.00 mm. The mean catheter dwell time was 9.44 days (SD = 10.24), with a median of 7 days. The longest dwell time was 147 days. The catheter withdrawal time was 6.74 days on average (SD = 6.82), with a median of 5 days. The Shapiro-Wilk test showed a lack of normality in the distribution of all analysed variables (p < 0.05) (Table 3).

Comparison of the use and maintenance according to catheter size

The average dwell time was longest for 8 cm catheters (10.83 days). For 10 cm catheters, it was 9.08 days, while for 12 cm catheters, it was 9.56 days. The Kruskal-Wallis test showed that there were no significant differences between the catheter length groups (p > 0.05). The mean withdrawal time was also longest for 8 cm long catheters (10.83 days), for 10 cm long catheters it was 6.99 days, and for 12 cm long catheters it was 6.59 days. The Kruskal-Wallis test showed no significant differences between catheter length groups (p > 0.05).

The average dwell time was 7.65 days for 2 Fr diameter catheters, 9.19 days for 3 Fr diameter catheters, and 10.71 days for 4 Fr diameter catheters. The Kruskal-Wallis test showed no significant differences between catheter diameter groups (p > 0.05). The mean withdrawal time was 6.04 days for 2 Fr catheters, 6.28 days for 3 Fr catheters, and 7.95 days for 4 Fr catheters. The Kruskal-Wallis test showed no significant differences between catheter diameter groups (p > 0.05).

An analysis of the reasons for catheter removal indicates that catheter length had a significant impact on reasons such as ‘self-removal’ (p < 0.05) and ‘suspected infection’ (p < 0.05). Completion of therapy was the most common reason in all groups, but the highest percentage was recorded among 10 cm catheters (n = 68, 57.63%). Self-removal was most common with 12 cm LPCs (n = 26, 7.45%). Furthermore, the reason ‘suspected infection’ was most common in the group of 8 cm catheters, where the percentage was 16.67% (n = 1), compared to the 10 cm and 12 cm groups, where the percentages were lower.

Analysis of the reasons for catheter removal indicates that diameter had a significant effect on occlusion as a reason for removal (p < 0.05). The highest percentage was observed in the group of catheters with a diameter of 2 Fr (n = 20, 38.46%) and the lowest in the 4 Fr group (n = 17, 12.69%).

Comparison of the use and maintenance of Smartmidline Vygon and BullPuP catheters

Most catheters inserted were group 1 (n = 399, 83.72%), while group 2 catheters were used much less frequently (n = 78, 16.28%). The average dwell time was 9.30 days for group 1 and 10.18 days for group 2. The median for both groups was 7 days, which indicates a relatively even distribution of retention time in both cases, despite greater variability in group 2. Similarly, for withdrawal time, the mean time was 6.60 days for group 1 catheters and 7.44 days for group 2 catheters. The time to catheter placement was significantly shorter for group 2 (2.42 days, SD = 2.81). The median for group 1 catheters was 3 days, and for group 2 it was 1 day, indicating a faster time to catheter placement for group 2 compared to group 1. In both cases, the median number of attempts required to insert the catheter was 1. The Mann-Whitney U test indicated that the differences between the groups were not significant (p > 0.05) (Table 4).

Analysis of the reasons for catheter removal showed that catheter type had a significant impact on reasons such as ‘end of therapy’ (p < 0.05) and ‘occlusion’ (p < 0.05). In group 1, a lower percentage of termination of therapy was observed (n = 178, 44.50%) compared to group 2 (n = 47, 62.67%). In the case of occlusion, 21.75% (n = 87) of cases concerned group 1 catheters, while in group 2, occlusion was almost non-existent (n = 2, 2.67%). To summarise the results obtained, it should be noted that no significant differences in dwell time or withdrawal were found between the catheter groups. However, the type of catheter had a significant impact on ‘treatment completion’ and ‘occlusion’ as reasons for its removal (Fig. 1).

The withdrawal time equal to the dwell time was more frequent in group 2 (n = 58, 74.36%) than in group 1 (n = 208, 51.87%). Overall, in 55.53% of cases, the withdrawal time was equal to the catheter dwell time, indicating greater temporal consistency in group 2.

Comparison of the use and maintenance of Smartmidline Vygon and BullPuP catheters of 4 Fr size

Since the number of 4 Fr catheters in both groups was similar, these differences were examined taking into account only LPCs of the specified size. The average dwell time was 10.75 days for group 1 and 10.67 days for group 2. The Mann-Whitney U test showed a significant difference between these groups (p < 0.05). In the analysis of withdrawal time, the mean time for group 1 was 8.09 days and for group 2 was 7.81 days, but the Mann-Whitney U test did not show a significant difference (p > 0.05) (Table 6). Analysis of the reasons for catheter removal showed that the type of catheter had a significant association with reasons for removal, including ‘end of therapy’ (p < 0.05), ‘occlusion’ (p < 0.05) and ‘suspected infection’ (p < 0.05). In group 1, a lower percentage of end of therapy (n = 30, 43.48%) was observed compared to group 2 (n = 42, 64.62%). In the case of occlusion, 24.64% of cases concerned group 1 (n = 17), while in group 2 there was no occlusion. ‘Suspected infection’ occurred in 8.70% (n = 1) of cases in group 1 and did not occur in group 2 (Fig. 2).

Discussion

The results of the study provide important information on the use and maintenance of long peripheral catheters such as Smartmidline Vygon and BullPuP inserted using various techniques.

The highest percentage of patients from internal medicine wards indicates that this group of patients most often requires long-term intravenous access for infusion therapy or antibiotic treatment. Internal medicine patients often have multiple chronic diseases, which increases the need for stable and safe routes of drug administration [8].

The most common indication for their insertion was simultaneous difficult intravenous access and planned hospitalisation exceeding 5 days, which indicates an optimal solution in situations where it is necessary to maintain stable intravenous access for more than a few days but there are no indications for inserting a CVAD or midline catheter. This procedure is recommended by the Infusion Nurses Society [9]. In view of the above, long peripheral catheters can also be used in hospital emergency departments or admission rooms [7].

In our study, the observed maximum dwell time of long peripheral catheters was 147 days, exceeding the durations recommended in current guidelines. This finding can be explained by several factors, including the experience of the staff inserting and monitoring vascular access, careful maintenance, the individual clinical status of patients, and a cautious approach to deciding on catheter removal. These results suggest that, with appropriate supervision and risk assessment, it may be possible to safely extend the catheter dwell time in selected patients. Nevertheless, this issue warrants further investigation, as current guidelines recommend maintaining vascular access only as long as clinically necessary in the absence of complications. The prolonged use observed in our centre reflects adherence to our established protocol, and the results of this study support the safety of this practice.

The observed tendency to insert long peripheral catheters into the right limb (61.20%) and the predominance of basilic vein cannulation (68.42%) may result from the better accessibility of these vessels and greater comfort during the procedure, while Sam et al. indicated the brachial vein as the most frequently chosen [10].

The most commonly selected catheters, with a length of 12 cm and a diameter of 3 Fr, appear to be the optimal choice in clinical practice, combining access stability, vascular safety and ease of insertion in most patients, although they may not be suitable for administering large volumes of medications and fluids.

No significant impact of catheter size on dwell time or withdrawal was observed. However, the analysis indicated that catheter length influenced the reasons for removal, with self-removal and suspected infection occurring significantly more frequently in specific groups. The highest number of therapy completions was observed for 10 cm catheters, self-removals for 12 cm catheters, and suspected infections for 8 cm catheters.

The average number of attempts required to insert the catheter was 1.37, suggesting that in most cases it was successfully inserted on the first attempt. In a study conducted by Weber et al., most long peripheral catheters were also inserted on the first attempt, while the success rate was higher in the authors’ analysis, which may indicate greater experience of the staff and the use of appropriate insertion techniques [11].

The average maintenance time for both groups was similar when comparing all catheter sizes, but when considering only 4 Fr catheters (due to the equal number of patients in this group), group 1 showed a significantly longer maintenance time.

The time to catheter placement was significantly shorter in group 2, which may indicate greater availability of this method and a more efficient patient selection process.

In our study, the most common reason for catheter removal, regardless of size, was the end of therapy, while Weber et al. indicated catheter displacement as the primary reason. These differences may result from different clinical protocols, catheter fixation methods, and patient characteristics, suggesting that adequate securing of the puncture site allows access to be maintained until the end of therapy [11].

Conclusions

Long peripheral catheters represent a safe and effective option for patients requiring prolonged intravenous therapy, particularly in those with difficult intravenous access. Catheter-related factors, including length, diameter, insertion site, and device design, may influence complication rates – especially catheter occlusion – even when dwell time and withdrawal effectiveness are comparable. These findings highlight the importance of individualized catheter selection, structured surveillance, and standardized maintenance protocols, and support the need for further prospective studies to optimize clinical use of long peripheral catheters.

Disclosures

This research received no external funding.

The study was approved by the Bioethics Committee of the Medical University of Warsaw (Approval No. AKBE/103/2023).

The authors declare no conflict of interest.

References