Peripherally inserted central catheters versus central venous catheters in critically ill patients under standardized insertion protocols: a propensity score–matched cohort study

Abstract

Background

The safety of peripherally inserted central catheters (PICCs) in critically ill patients remains controversial, particularly regarding the risk of thrombosis and infection compared with centrally inserted central venous catheters (CVCs). With the adoption of contemporary vascular access techniques and standardized insertion protocols, the complication profile of these devices may have changed.

Methods

We conducted a retrospective cohort study including adult ICU patients who underwent PICC or CVC placement between January 2023 and December 2024. All insertions followed standardized protocols (Safe Insertion of PICCs and Safe Insertion of Central Venous Catheters). Propensity score matching (1:2) was performed to balance baseline characteristics. Primary outcomes were symptomatic deep vein thrombosis (DVT) and central line–associated bloodstream infection (CLABSI). Secondary outcomes included catheter dislodgement and occlusion.

Results

A total of 250 patients were included, and 214 remained after propensity score matching (81 PICC vs. 133 CVC). Symptomatic DVT occurred in 2.5% of PICC patients and 3.0% of CVC patients. The corresponding incidence rates were 2.16 and 2.68 events per 1,000 catheter-days, respectively. CLABSI occurred in 2.5% and 2.3% of patients, corresponding to 2.16 and 2.01 events per 1,000 catheter-days, respectively. Because the number of outcome events was small, these estimates were associated with substantial statistical uncertainty.

Conclusions

In this single-center matched cohort, no statistically significant differences in symptomatic DVT or CLABSI were observed between PICCs and CVCs. However, the small number of outcome events limited statistical power. These findings should be interpreted as exploratory and hypothesis-generating rather than as evidence of equivalence between catheter types.

Supplementary Information

The online version contains supplementary material available at https://doi.org/10.1186/s12871-026-04115-0.

Introduction

Reliable vascular access is a cornerstone of patient management in the intensive care unit (ICU), enabling the administration of vasoactive medications, parenteral nutrition, hemodynamic monitoring, and frequent blood sampling. Centrally inserted central venous catheters (CVCs) and peripherally inserted central catheters (PICCs) are the two most commonly used central venous access devices in critically ill patients. However, the use of PICCs in the ICU has long been controversial [1–4].

The 2015 Michigan Appropriateness Guide for Intravenous Catheters (MAGIC) [5] suggested that PICCs may be associated with a higher risk of catheter-related thrombosis (CRT) in critically ill patients and recommended preferential use of non-tunneled CVCs when the expected catheter dwell time is ≤ 14 days. As a result, PICC use in the ICU has often been discouraged in clinical practice.

Nevertheless, the recommendations of the MAGIC guideline were largely derived from earlier studies conducted more than a decade ago, many of which were based on non-standardized insertion practices and outdated vascular access techniques. Emerging evidence suggests that the risk of catheter-related complications, including thrombosis and infection, may depend less on the catheter type itself and more on insertion technique, catheter-to-vein ratio (CVR), and adherence to standardized care protocols [6]. In the contemporary era of vascular access, complication rates have been substantially reduced through the implementation of evidence-based insertion bundles, such as the Safe Insertion of PICCs (SIP) protocol and the Safe Insertion of Central Venous Catheters (SIC) protocol [7–8].

Recent evidence has challenged the long-standing perception that PICCs represent a high-risk vascular access option in critically ill patients. Reported rates of PICC-associated DVT vary substantially across studies, depending on patient population, catheter characteristics, diagnostic strategy, and whether routine surveillance imaging is performed. Earlier studies and meta-analyses reported higher rates of catheter-related thrombosis, particularly in critically ill or oncology populations, whereas more recent studies using ultrasound guidance, appropriate catheter-to-vein ratio, and optimized tip positioning have reported lower symptomatic DVT rates. A meta-analysis by Balsorano et al. reported that [9] the incidence of symptomatic deep vein thrombosis (DVT) associated with PICCs was as low as 2.4% when modern practices—including ultrasound guidance, appropriate CVR, and accurate tip positioning—were applied. Furthermore, a contemporary meta-analysis by Schears et al. demonstrated [10] that PICCs were associated with a significantly lower risk of catheter-related bloodstream infection (CLABSI) compared with CVCs, with an approximately 48% reduction in infection risk when best practices were followed. Consistent with these findings, the 2024 GAVeCeLT expert consensus [11] on vascular access in critically ill patients emphasizes that device selection should be guided by the patient’s clinical needs rather than outdated concerns about PICC-related complications, and strongly recommends the use of standardized insertion protocols in the ICU.

Despite these evolving perspectives, real-world comparative data remain limited regarding the safety of PICCs versus CVCs when both devices are inserted under strict adherence to contemporary best-practice protocols. In particular, few studies have directly evaluated complication rates when standardized insertion bundles such as SIP and SIC are systematically applied.

Therefore, this study aimed to compare the incidence of symptomatic DVT and CLABSI between PICCs and CVCs under contemporary standardized vascular access protocols and to describe the observed complication profile of these devices in a single-center ICU cohort.

Methods

This retrospective cohort study was conducted at The Affiliated Suzhou Hospital of Nanjing Medical University. Adult patients admitted to the intensive care unit (ICU) between January 2023 and December 2024 who required central venous access were screened for eligibility. The study protocol was reviewed and approved by the institutional ethics committee of The Affiliated Suzhou Hospital of Nanjing Medical University. Given the retrospective nature of the study and the use of anonymized clinical data, the requirement for informed consent was waived.

Patients were included if they underwent placement of either a PICC or a CVC during their ICU stay. Patients were excluded if relevant clinical or catheter-related data were missing, if the catheter was not inserted according to the standardized insertion protocols used in our institution, or if the patient had been admitted to the ICU primarily for the treatment of DVT or pulmonary embolism (PE). Patients admitted primarily for DVT or PE were excluded because the thrombotic outcome of interest was incident catheter-associated DVT occurring after catheter placement. Including patients with pre-existing thromboembolic disease could have introduced outcome misclassification and confounded the assessment of catheter-related thrombotic risk.

In our center, all vascular access procedures were performed by trained nurses with experience in vascular access techniques. PICC insertions were conducted according to the Safe Insertion of PICCs (SIP) protocol [8], while CVC insertions followed the Safe Insertion of Central Venous Catheters (SIC) protocol [7]. After insertion, both PICCs and CVCs were managed according to the same institutional vascular access maintenance protocol. This included standardized dressing changes, hub disinfection before line access, routine catheter flushing, aseptic line-access procedures, daily assessment of catheter necessity, and prompt catheter removal when central venous access was no longer clinically required.

Clinical and catheter-related data were retrospectively extracted from the electronic medical records. Collected variables included demographic characteristics (age and sex), disease severity measured by the Acute Physiology Score III (APS III) score, primary ICU admission diagnosis, and catheter-related characteristics such as device type, insertion site, catheter size, number of lumens, vein diameter at the puncture site, and catheter days. Catheter days was calculated as the interval between catheter insertion and removal.

The primary outcomes of this study were the incidence of symptomatic DVT and CLABSI. CLABSI was defined according to CDC/NHSN criteria, and incidence was reported as events per 1,000 catheter-days. Symptomatic DVT was defined as clinically suspected venous thrombosis occurring after catheter placement and confirmed by compression ultrasonography or contrast-enhanced computed tomography. Diagnostic evaluation was performed when patients developed signs or symptoms suggestive of venous thrombosis, including limb swelling, pain, erythema, or unexplained catheter dysfunction. Routine surveillance screening for asymptomatic DVT was not performed. Therefore, asymptomatic DVT was not included, because routine screening ultrasonography was not part of institutional practice and the study focused on clinically relevant thrombotic events. Secondary outcomes included catheter dislodgement and catheter occlusion.

To reduce potential confounding caused by baseline differences between patients receiving PICCs and those receiving CVCs, propensity score matching (PSM) was performed. Propensity scores were calculated using a logistic regression model that included age, sex, APS III score, and ICU admission diagnosis. Nearest-neighbor propensity score matching was performed without replacement, allowing up to two CVC controls to be matched to each PICC patient within a caliper width of 0.2 of the standard deviation of the logit of the propensity score. Because not all PICC patients had two suitable matches within the predefined caliper, the final matched cohort reflected a variable matching ratio. Standardized mean differences (SMD) < 0.1 were considered indicative of adequate balance.

Continuous variables were summarized as mean ± standard deviation or median with interquartile range, depending on data distribution, and were compared using Student’s t-test or the Mann–Whitney U test, as appropriate. Categorical variables were summarized as counts and percentages and were compared using the chi-square test or Fisher’s exact test. Odds ratios with 95% confidence intervals were calculated for binary clinical outcomes. Incidence rates for symptomatic DVT and CLABSI were expressed as events per 1,000 catheter-days and compared between groups using Poisson rate tests. A two-sided P value < 0.05 was considered statistically significant. All statistical analyses were performed using RStudio (version 4.4.3; R Foundation for Statistical Computing, Vienna, Austria).

Results

Study population

A total of 263 patients who underwent placement of either a PICC or a CVC in the ICU were initially screened. Thirteen patients were excluded due to missing data (n = 3), protocol violations (n = 6), or admission for DVT/PE (n = 4). The final cohort included 250 patients, comprising 82 patients in the PICC group and 168 patients in the CVC group. After propensity score matching, 214 patients remained in the matched cohort, including 81 PICC patients and 133 CVC patients (Fig. 1).

Fig. 1.

Flow diagram of patient selection and propensity score matching

Baseline characteristics

Baseline demographic and clinical characteristics before and after propensity score matching are summarized in Table 1. Prior to matching, some imbalance was observed in APS III scores and ICU admission diagnoses, with ARDS more prevalent in the PICC group and respiratory failure more common in the CVC group. After matching, age, sex distribution, and ICU admission diagnosis were well balanced between groups, with SMDs below 0.1. APS III had a post-matching SMD of 0.100, which was at the predefined balance threshold.

Table 1.

Baseline demographic and clinical characteristics before and after propensity score matching

Characteristics	Before PSM			After PSM
	CVC (N = 168)	PICC (N = 82)	SMD	CVC (N = 133)	PICC (N = 81)	SMD
Age (years, Mean (SD))	55.57 (22.51)	56.98 (19.92)	0.066	56.20 (22.23)	56.80 (19.99)	0.028
Gender (n (%))			0.062			0.019
Female	87 (51.8)	45 (54.9)		71 (53.4)	44 (54.3)
Male	81 (48.2)	37 (45.1)		62 (46.6)	37 (45.7)
Diagnosis (n(%))			0.423			0.099
ARDS	25 (14.9)	21 (25.6)		24 (18.0)	20 (24.7)
Cardiogenic shock	26 (15.5)	14 (17.1)		21 (15.8)	14 (17.3)
Postoperative care	37 (22.0)	14 (17.1)		28 (21.1)	14 (17.3)
Respiratory failure	24 (14.3)	4 (4.9)		7 (5.3)	4 ( 4.9)
Sepsis	29 (17.3)	17 (20.7)		28 (21.1)	17 (21.0)
Trauma	27 (16.1)	12 (14.6)		25 (18.8)	12 (14.8)
APS III (points, Mean (SD))	23.99 (7.76)	22.55 (8.05)	0.182	23.50 (7.84)	22.68 (8.01)	0.100

APS III Acute Physiology Score III, ARDS Acute Respiratory Distress Syndrome, SMD Standardized Mean Difference

Catheter characteristics

Catheter-related characteristics in the matched cohort are presented in Table 2. As expected, PICCs were inserted into smaller peripheral veins compared with CVCs (mean vein diameter 5.34 ± 1.22 mm vs. 9.54 ± 1.97 mm). PICCs were associated with smaller catheter size (4.48 ± 0.50 Fr vs. 6.04 ± 1.00 Fr) but slightly higher catheter-to-vein ratios (CVR 0.29 ± 0.04 vs. 0.22 ± 0.06). The duration of catheterization was comparable between the two groups (mean 11.44 ± 5.26 days for PICC vs. 11.21 ± 5.02 days for CVC). These differences reflect the anatomical and device-specific characteristics of PICCs and CVCs and are consistent with expected clinical practice.

Table 2.

Catheter-related characteristics in the propensity score–matched cohort

Characteristics	CVC (N = 133)	PICC (N = 81)	P-value
Vein diam (mm, Mean (SD))	9.54 (1.97)	5.34 (1.22)	< 0.001
Cath size (Fr, Mean (SD))	6.04 (1.00)	4.48 (0.50)	< 0.001
CVR (Mean (SD))	0.22 (0.06)	0.29 (0.04)	< 0.001
Catheter days (day, Mean (SD))	11.21 (5.02)	11.44 (5.26)	0.746

CVR Catheter-to-Vein Ratio

Clinical outcomes

Clinical outcomes in the matched cohort are summarized in Table 3. The incidence of symptomatic DVT was 2.5% in the PICC group and 3.0% in the CVC group (OR 0.82, 95% CI 0.07–5.85; P = 1.000). When expressed per 1,000 catheter-days, the incidence of symptomatic DVT was 2.16 events per 1,000 catheter-days in the PICC group and 2.68 events per 1,000 catheter-days in the CVC group, with no statistically significant difference between groups (incidence rate ratio [IRR] 0.80; P = 1.000). Similarly, the incidence of CLABSI was 2.5% in the PICC group and 2.3% in the CVC group (OR 1.09, 95% CI 0.09–9.79; P = 1.000). The corresponding CLABSI incidence rates were 2.16 and 2.01 events per 1,000 catheter-days, respectively, with no statistically significant difference between groups (IRR 1.07; P = 1.000). Secondary outcomes, including catheter dislodgement (1.2% vs. 0.7%) and catheter occlusion (4.9% vs. 1.5%), were infrequent. Because of the very small number of events, these findings were considered descriptive and exploratory, and no reliable comparative inference could be drawn.

Table 3.

Clinical outcomes in the propensity score–matched cohort

Characteristics	CVC (N = 133)	PICC (N = 81)	OR (95% CI)/IRR	P-value
Symptomatic DVT (n (%))	4 (3.0)	2(2.5)	0.82 (0.07–5.85)	1#
events/1000 catheter-days*	2.68	2.16	0.80	1
CLABSI(n (%))	3 (2.3)	2 (2.5)	1.09 (0.09–9.79)	1#
events/1000 catheter-days*	2.01	2.16	1.07	1
Dislodgement (n (%))	1 (0.7)	1 (1.2)	1.65 (0.02–130)	1#
Occlusion (n (%))	2 (1.5)	4 (4.9)	3.38 (0.47–38.2)	0.203#

*The total catheter-days used as denominators for incidence rate calculations were 1,491 catheter-days in the CVC group and 927 catheter-days in the PICC group

# Fisher’s exact test, IRR incidence rate ratio, Symptomatic DVT Symptomatic deep vein thrombosis, CLABSI Central line–associated bloodstream infection, OR odds ratio

Discussion

In this retrospective cohort study of critically ill patients requiring central venous access, we compared catheter-related complications between PICCs and CVCs under standardized insertion and maintenance protocols. After propensity score matching, no statistically significant differences were observed in symptomatic DVT or CLABSI between groups. However, the absolute number of outcome events was small, resulting in wide confidence intervals and limited statistical power. Therefore, these findings should be interpreted as exploratory observations rather than evidence of equivalent safety between PICCs and CVCs.

Historically, the use of PICCs in intensive care settings has been debated [12–15]. Earlier studies suggested that PICCs might be associated with a higher risk of catheter-related thrombosis compared with centrally inserted catheters [16, 17]. These concerns were reflected in earlier clinical recommendations that discouraged PICC placement in critically ill patients, particularly when short-term access was expected [5]. However, many of these earlier observations were based on heterogeneous cohorts and older vascular access techniques, limiting their generalizability to contemporary practice.

In recent years, advances in ultrasound-guided cannulation, optimized catheter size selection, and the implementation of standardized insertion bundles (such as SIP and SIC protocols) have substantially improved the safety of both PICCs and CVCs [7, 8, 18]. The low observed complication rates may reflect not only standardized insertion practices but also standardized post-insertion catheter maintenance, including dressing care, hub disinfection, flushing practices, daily necessity assessment, and timely catheter removal.

Our findings are consistent with contemporary evidence suggesting that catheter-related complications may be influenced not only by catheter type but also by insertion technique, catheter selection, catheter maintenance, and patient-related factors [6, 10, 11, 18, 19]. In our study, all vascular access procedures were performed by trained personnel using SIP and SIC protocols [7, 8], which likely contributed to the overall low complication rates.

The catheter-related characteristics observed in the matched cohort also reflect the inherent differences between the two devices. PICCs were inserted into smaller peripheral veins, associated with smaller catheter sizes but slightly higher catheter-to-vein ratios (CVR) compared with CVCs. The observed symptomatic thrombosis rates were numerically similar between groups; however, the small number of events precludes reliable inference regarding comparative thrombotic risk. This observation further supports the concept that appropriate catheter selection and adherence to standardized insertion techniques can mitigate thrombosis risk even in smaller peripheral vessels [20, 21].

These results have important clinical implications. In critically ill patients, vascular access decisions are often influenced by clinician preference, anticipated duration of therapy, and perceived complication risk. Our findings suggest that, in selected ICU patients managed under standardized vascular access protocols, PICCs may be considered as one potential central venous access option when clinically appropriate. However, device selection should continue to be individualized according to patient condition, catheter indication, expected dwell time, vascular anatomy, and thrombosis or infection risk.

This study also has several strengths. First, we included a well-defined ICU population and applied strict inclusion and exclusion criteria to minimize confounding factors. Second, the use of propensity score matching allowed us to balance key baseline variables, including age, sex, illness severity, and admission diagnoses, thereby improving comparability between the PICC and CVC groups. Third, all catheter insertions were performed according to standardized institutional protocols, providing a relatively controlled real-world setting for evaluating device-related outcomes.

Nevertheless, several limitations should be acknowledged. First, residual confounding remains an important limitation of this retrospective observational study. Although propensity score matching balanced age, sex, illness severity, and ICU admission diagnosis, several clinically relevant factors associated with both catheter selection and complication risk were not consistently available for matching. These factors include active malignancy or chemotherapy, immunosuppressive therapy or neutropenia, vasopressor exposure, parenteral nutrition, anticipated duration of intravenous therapy, and pre-catheter hospital length of stay. Therefore, confounding by indication cannot be fully excluded. Second, this was a single-center study, which may limit generalizability to institutions with different patient populations or vascular access practices. Third, the number of complication events was relatively small, resulting in wide confidence intervals for some outcomes. Future multicenter prospective studies with larger sample sizes are warranted to confirm these findings and to further evaluate catheter-related outcomes associated with PICCs and CVCs in critically ill patients.

Conclusion

In this single-center matched cohort, no statistically significant difference in symptomatic DVT or CLABSI was observed between PICCs and CVCs. However, the number of outcome events was small, resulting in limited statistical power and substantial uncertainty. These findings should therefore be interpreted as exploratory and hypothesis-generating rather than as evidence of equivalence between catheter types. Larger multicenter prospective studies are needed to confirm these observations.

Authors’ contributions

Xiaofang Wu and Xiujuan Wu contributed equally to this work and share first authorship. Xiaofang Wu and Xiujuan Wu contributed to study conception and design, data collection, and manuscript drafting. Jiajia Xiong and Min Wang participated in data collection and data verification. Qiong Wu and Changguang Lv contributed to data analysis and interpretation of the results. Niankai Cheng and Chongjing Mu supervised the study, contributed to study design, and critically revised the manuscript for important intellectual content. All authors read and approved the final manuscript.

Funding

Not applicable.

Data availability

The datasets generated and/or analyzed during the current study are not publicly available due to institutional data protection policies but are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

This study was conducted in accordance with the Declaration of Helsinki and was approved by the Institutional Ethics Committee of The Affiliated Suzhou Hospital of Nanjing Medical University. Owing to the retrospective nature of the study and the use of anonymized clinical data, the requirement for informed consent to participate was waived by the Institutional Ethics Committee of The Affiliated Suzhou Hospital of Nanjing Medical University.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.