Comparison between ultrasound-guided dynamic needle tip positioning and palpation technique for radial artery cannulation: Systematic review and meta-analysis

Abstract

Background and Aims:

The dynamic needle tip positioning (DNTP) technique has recently been introduced, but the effectiveness of the DNTP and traditional palpation methods for radial artery cannulation remains unknown. Therefore, we conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) to compare the effectiveness and safety of ultrasound-guided DNTP and palpation techniques during radial artery cannulation in patients undergoing elective surgery.

Methods:

We conducted a thorough search of electronic databases from inception through 31 January 2025 to identify relevant studies. We searched PubMed, Embase, Cochrane Library, and Web of Science and identify relevant studies. RCTs comparing US-guided DNTP versus the palpation method in all age groups requiring radial artery cannulation were included. The primary outcome was the first attempt success rate. Secondary outcomes included overall success rate, cannulation time, and incidence of complications. Statistical analysis was performed using RevMan software.

Results:

A total of six studies with 388 participants were included. Our meta-analysis showed a higher first-pass success rate in the DNTP group compared to the palpation group (Risk Ratio = 1.44; 95% Confidence Interval: 1.19, 1.73). We also observed a higher overall success rate in the DNTP group. Cannulation times were similar between the two groups. Meta-analysis indicated a lower complication rate in the DNTP group compared to the palpation group.

Conclusion:

This meta-analysis showed a higher first-pass success rate and overall success rate and fewer complications in the DNTP group compared to the traditional palpation group during radial artery cannulation. Additionally, there was no significant difference in cannulation time between the two groups.

INTRODUCTION

Arterial catheterisation is a common invasive procedure that enables continuous blood pressure monitoring, regular blood sampling, and evaluation of fluid responsiveness.[1] Arterial cannula can be placed at several sites; however, the radial artery is frequently selected due to its easy accessibility, superficial course, and low complication rate.[2,3] Arterial cannulation may lead to several complications such as infection, haematoma formation, vasospasm, and potential nerve injury.[4,5] Additionally, the risk of complications increases with repeated failure of the radial artery cannulation.[6,7] Many previous studies have shown that ultrasonography (US)- guided radial arterial cannulation is superior to the traditional palpation technique, with an improved first-pass success rate.[8,9,10,11,12,13] Two imaging techniques are commonly applied for arterial cannulation: the short-axis (SA) out-of-plane method and the long-axis (LA) in-plane (IP) method.[3] Although the SA approach offers better visualisation of the surrounding structure, posterior vessel wall puncture (PVWP) might not be avoided during US-guided arterial catheterisation.[14,15]

Clemmesen et al.[16] first reported that the dynamic needle tip positioning technique demonstrated a higher success rate (97% vs. 81%) than the LA-IP technique for US-guided vascular access in a phantom study. The DNTP technique combines the advantages of both the SA and LA, increasing the success rate and decreasing the complications associated with ultrasound-guided radial artery cannulation.[16,17,18,19,20,21,22] A meta-analysis by Wu et al.[23] of 11 randomised controlled trials (RCTs) showed that the dynamic needle tip positioning (DNTP) method significantly improved first-attempt success and reduced cannulation time compared to palpation during arterial catheterisation in small children and infants. Although several studies have previously compared the use of US with the conventional palpation technique, scientific evidence regarding the efficiency of the US-guided DNTP method of radial artery cannulation is lacking.[17,18,19,20,21,22,23,24,25]

The primary objective of this meta-analysis was to evaluate whether the US-guided DNTP technique improves first-pass success rate compared to the traditional palpation technique. Secondary objectives included comparing overall success rate, cannulation time, and the incidence of complications. Therefore, we conducted this meta-analysis to compare the efficacy and safety of the US-guided DNTP and the traditional palpation method for radial artery cannulation in patients undergoing elective surgery.

METHODS

This systematic review and meta-analysis adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.[26] The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) (ID: CRD42022341458).

Eligibility criteria

Inclusion criteria: Studies comparing DNTP with the palpation technique in patients across all age groups (adults, elderly, neonates, and children) who required radial artery cannulation were included. The studies contained data on first-pass success rates, and only RCTs published in English were considered.

Exclusion criteria: Non-randomised controlled trials (non-RCTs), such as retrospective studies, case reports, systematic reviews, meta-analyses, and protocols; RCTs conducted on phantoms and animals; and studies involving haemodynamically unstable patients were excluded.

Information sources: A comprehensive search was conducted across the PubMed, Embase, Cochrane Library, and Web of Science electronic databases from inception through 31 January 2025.

Search strategy: Our electronic search used search terms related to dynamic needle tip positioning OR DNTP AND palpation [MeSH Terms] OR palpation OR traditional OR conventional AND ultrasound. Additionally, we reviewed the reference list of all included RCTs for potential publications. The detailed search strategy for each database is presented in Supplementary Table 1.

Supplementary Table 1.

Search Strategy

Search number	Query	Results	Time
12	((((dynamic needle tip positioning[MeSH Terms]) OR (dynamic needle tip positioning)) OR (DNTP)) AND ((palpation[MeSH Terms]) OR (((palpation) OR (traditional)) OR (conventional)))) AND ((ultrasound[MeSH Terms]) OR (ultrasound))	25	01:39:12
11	(ultrasound[MeSH Terms]) OR (ultrasound)	21,10,120	01:38:59
10	ultrasound	21,10,120	01:38:38
9	ultrasound[MeSH Terms]	5,27,434	01:38:28
8	(palpation[MeSH Terms]) OR (((palpation) OR (traditional)) OR (conventional))	13,02,367	01:38:10
7	((palpation) OR (traditional)) OR (conventional)	13,02,367	01:38:02
6	palpation[MeSH Terms]	9,023	01:37:37
5	((dynamic needle tip positioning[MeSH Terms]) OR (dynamic needle tip positioning)) OR (DNTP)	2,669	01:36:38
4	DNTP	2,606	01:36:30
3	(dynamic needle tip positioning[MeSH Terms]) OR (dynamic needle tip positioning)	85	01:35:06
2	dynamic needle tip positioning	85	01:34:54
1	dynamic needle tip positioning[MeSH Terms]	1	01:34:22

Study Selection: Two authors (AP and SP) independently conducted the database search and selected studies. Only studies that met the inclusion criteria after full-text review were included. Any disagreements between the two authors during the study selection process were resolved with input from the third author (NK).

Data extraction: Two authors (AP and SP) separately extracted data from the included studies using a pre-defined standardised data collection form. If they disagreed on any point, a third author (NK) helped resolve the issues.

Data items: Information collected through the standardised form includes the first author’s name, year of publication, country of origin, number of patients, patient type, patient age, gender, body mass index (BMI), catheter size, ultrasound machine, and probe used. The primary outcome was the first-attempt success rate. The secondary outcomes included the overall success rate, cannulation time, and the incidence of complications [haematoma, posterior vessel wall puncture (PWVP), and vasospasm].

The first attempt success rate was defined as successful radial artery cannulation, indicated by an arterial waveform, after one needle puncture of the skin. The overall success rate referred to successful radial artery cannulations confirmed by an arterial blood flash or an observed arterial waveform within the time or attempt limits specified by each study (e.g., within 5 minutes or within 10 minutes, or ≤5 attempts). Cannulation time was the period from the start of the procedure (skin perforation, skin puncture or skin contact with the ultrasound probe, or palpation of the radial artery) to the confirmation of successful cannulation, shown by free arterial flow, or the presence of an arterial waveform on the monitor. A haematoma was a localised, visible, or palpable swelling around the cannulation site following the procedure. Posterior wall vessel puncture (PVWP) of the radial artery was defined if the needle punctured through the posterior wall during cannulation, as observed by the operator. Vasospasm was defined as a condition where the lumen of the radial artery narrowed by more than 50% in diameter.

Risk of Bias Assessment: The risk of bias in the included RCTs was assessed using the Cochrane Risk of Bias tool 2.0, and assessments were conducted using RevMan 5.4 software (Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2020).[27]

Two independent authors (AP, SP) evaluated the methodological quality of all RCTs separately. Any disparities in quality assessment were resolved through discussion with the third author (NK). We evaluated the studies based on potential bias within five domains: bias arising from the randomisation process, bias due to deviations from intended interventions, bias due to missing outcome data, bias in measurement of the outcome, and bias in selection of the reported result. RCTs were categorised as having low risk, some concerns, or high risk for each bias domain.

Statistical analysis: For continuous variables, we extracted the mean and standard deviation (SD) for each group to calculate the mean difference (MD) along with a 95% confidence interval (CI) as a combined result. Dichotomous outcomes were presented as a pooled risk ratio (RR) with 95% CIs. The statistical analysis was performed using RevMan software (version 5.4, Copenhagen, Denmark: Nordic Cochrane Centre and the Cochrane Collaboration). For the pooled analysis of the primary endpoint, we used a random-effects model. Heterogeneity within the trials, evaluated using a Chi-square test and I² statistics. An I² score of 50% or higher was considered significant heterogeneity.[28] A P value less than 0.05 was deemed statistically significant. The assessment of publication bias was performed using a funnel plot along with the Egger test.[29] The Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) system was employed with the help of GRADEpro GDT software (McMaster University, Hamilton, Canada) to evaluate the overall quality of evidence for each outcome. This system classified evidence into four levels: very low, low, moderate, and high quality of evidence, based on five criteria: risk of bias, inconsistency, indirectness, imprecision, and publication bias.[30] The numerical measure of quality of the included trials was again assessed using the modified Jadad score scale, which ranges from 0 to 8. A score of 3 or less was deemed low quality, while a score of 4 or greater was referred to as high-quality studies.[31] Subgroup analysis was performed to examine the impact of patient age group and the size of the arterial catheter. To explore the heterogeneity of the primary outcome (first pass success rate), we have performed a sensitivity analysis by removing outliers. The sensitivity analysis was also performed in secondary outcomes (overall success rate and cannulation time). We conducted a Trial Sequential analysis (TSA) using TSA software (TSA 0.9.5.10 Beta; Copenhagen Trial Unit’s TSA Software, Copenhagen, Denmark) to evaluate the reliability of our study’s results and determine if the findings were not due to chance. The Required Information Size (RIS) was calculated using a 5% Type I error and 80% power.

RESULTS

Study selection

A PRISMA flow diagram summarises the database search and study inclusion process [Figure 1]. Overall, 162 research articles were identified, and subsequently, the eligibility of ten full-text articles was assessed. Finally, six studies met the inclusion criteria and were included in the systematic review and meta-analysis.[17,18,19,20,21,22]

Figure 1.

PRISMA flow chart. PRISMA = Preferred Reporting Items for Systematic Reviews and Meta-analyses

Study characteristics

The study characteristics of the included studies are summarised in Table 1. These studies were chosen based on the predefined ‘PICO’ criteria [Table 2]. Six RCTs[17,18,19,20,21,22] with 776 participants were included; 388 participants were allocated to the DNTP group, and 388 participants were assigned to the palpation group.

Table 1.

Characteristics of included studies

Author	Country	Number of patients		Patient Type	BMI (kg/m2)		Age Years		Sex (F/M)		Catheter size	Machine
		Palpation	DNTP		Palpation	DNTP	Palpation	DNTP	Palpation	DNTP
Hansen et al., 2014[22]	Denmark	18	22	Adult			65.8±16.1				20G	BK-Medical
Gopalasingam et al., 2017[17]	Denmark	20	20	Adult/elderly	30±8	31±7	71	71	12/28	12/28	20G	BK-Medical
Kiberenge et al., 2018[21]	USA	132	128	Adult			58±15	61±16	58/74	62/66	20G	Sonosite
Liu et al., 2019 [20]	China	30	30	Neonates			15.1±10.3	15.0±8.1	8/22	10/20	24G	GE
Kim et al., 2021[18]	South Korea	128	128	Elderly	24±4	24±4	72	74	85/43	82/46	22G	Sonosite
Siddaramaiah et al., 2023[19]	India	60	60	Adult			48.1±14.8	52.1±15.5	37/23	36/24	20G	GE
	Probe (Linear Transducer)	All attempted cases		First pass success rate		Overall success rate		Cannulation Time (s)		Complications		Jadad Score
		Palpation	DNTP	Palpation	DNTP	Palpation	DNTP	Palpation	DNTP	Palpation	DNTP
Hansen et al., 2014[22]	18-MHz	40	40	38	23	NM	NM	NM	NM	NM	NM	5
Gopalasingam et al., 2017[17]	18-MHz	40	40	36	28	NM	NM	NM	NM	0	7	5
Kiberenge et al., 2018[21]	13-6 MHz	132	128	109	62	118	83	82.4±11.7	79.3±24.5	0	0	6
Liu et al., 2019[20]	5-13 MHz	30	30	12	3	29	18	91.4±55.4	287.7±153.6	1	8	3
Kim et al., 2021[18]	13-6 MHz	128	128	110	75	127	119	42.1±4.4	53.3±8.1	9	32	5
Siddaramaiah et al., 2023[19]	5.0-13.0 MHz	60	60	40	40	58.98	57	77.1±25.9	60.06±19.9	1	3	5

DNTP: =dynamic needle tip positioning; GE=General Electronics; MHz=Megahertz; F=Female; M=Male; NM=Not Mentioned; G=Birmingham Gauge; s=second; kg=kilogram; m=meter; BMI=Body mass Index

Table 2.

PICO Table

Criteria	Determinants
Population	Patients with all age groups that require radial artery cannulation
Intervention	Dynamic Needle Tip Positioning (DNTP) technique
Control	Palpation technique
Outcome	Primary - First attempt success rate Secondary - Overall success rate, cannulation time, incidence of complications

Risk of Bias Assessment: The majority of the studies analysed exhibited a low risk of bias, as determined by the risk-of-bias assessment [Figure 2]. We evaluated six studies for our risk-of-bias analysis.[17,18,19,20,21,22] Four out of six studies indicated low risk of bias,[18,19,20,21] while two studies show some concerns.[17,22]

Figure 2.

Risk of Bias (ROB) summary

Primary outcome: All six studies[17,18,19,20,21,22] reported the first-pass success rate. We used a random effects model, and significant heterogeneity was observed (I² = 69%). According to the meta-analysis, DNTP group had a higher first-pass success rate than the palpation group (RR = 1.44; 95% CI: 1.19, 1.73; P = 0.0001; Figure 3a). A sensitivity analysis was conducted to examine the heterogeneity in the primary outcome. Upon removing one study[19], heterogeneity was reduced to 44% from 69%, which reveals that the study conducted by Siddaramaiah et al. may have contributed to heterogeneity [Supplementary Figure 1 ^{(4.2MB, tif)} ].

Figure 3.

Forest plots: (a) First pass success rate, (b) Overall success rate, (c) Cannulation Time, and (d) Complications. CI = confidence interval, DNTP = Dynamic needle tip positioning

Secondary outcomes: With four studies[18,19,20,21] out of six, the overall success rate was reported. We used a random effects model and found significant heterogeneity (I² =93%). The meta-analysis indicated a higher overall success rate in the DNTP group compared to the palpation group (RR = 1.21; 95% CI: 1.01, 1.44; P = 0.04; Figure 3b). The sensitivity analysis performed to explore the heterogeneity in overall success rate reveals that no single study contributes to heterogeneity [Supplementary Figure 1 ^{(4.2MB, tif)} ].

Four[18,19,20,21] out of six studies reported cannulation time. We used a random effects model and found significant heterogeneity (I² = 98%). According to the meta-analysis, there was no significant difference between the DNTP group and the palpation group (MD = -0.67; 95% CI: -1.82, 0.48; P = 0.25; Figure 3c). The sensitivity analysis conducted to examine the heterogeneity in cannulation time reveals that no single study contributed to heterogeneity [Supplementary Figure 1 ^{(4.2MB, tif)} ].

Four[17,20] out of six studies reported the incidence of complications. A fixed-effects model was used, and no significant heterogeneity was observed (I² =0%). The meta-analysis revealed that the incidence of complications in the DNTP group is lower than in the palpation group (RR = 0.23; 95% CI: 0.12, 0.42; P = 00001; Figure 3d).

Subgroup analysis: Our subgroup analysis revealed no differences between the two techniques based on patients’ age groups (adults, toddlers/neonates, and the elderly; P = 0.87) or catheter sizes (20 G, 22 G, and 24 G; P = 0.21). This suggests that the patient’s age group and catheter size do not affect the efficiency of palpation compared to DNTP. The overall heterogeneity was found to be 0% for the patient’s age groups and 35.3% for catheter sizes [Supplementary Figure 2 ^{(4.4MB, tif)} ].

Publication bias: Using Egger’s Test, a regression analysis for publication bias revealed no evidence of bias among the included trials (Egger’s Test; z = -0.213; P = 0.831). The funnel plot shows mild asymmetry, which may suggest potential publication bias [Figure 4]. After excluding outlier studies[19,21] (Siddaramaiah et al. and Kiberenge et al.), we re-analysed the results, and Egger’s Test revealed no potential publication bias among the included trials (Egger’s Test; P = 0.341), which means that outliers were likely responsible for asymmetry in funnel plot [Supplementary Figure 3 ^{(1.5MB, tif)} ].

Figure 4.

Funnel plot for assessment of publication bias in the first pass success rate

Summary of findings (GRADE): The certainty of evidence (CoE) for first pass success rate was moderate. The CoE for the overall success rate was considered low. The CoE for cannulation time was very low, while the CoE for the incidence of complications was high [Supplementary Table 2].

Supplementary Table 2.

GRADE Pro Evidence Profile

Certainty assessment							No. of patients		Effect		Certainty
No. of studies	Study design	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations	DNTP	Palpation	Relative (95% Cl)	Absolute (95% Cl)
6	randomised trials	not serious	seriousa	not serious	not serious	none	345/430 (80.2%)	231/426 (54.2%)	RR 1.44 (1.19 to 1.73)	239 more per 1,000 (from 103 more to 396 more)	⨁⨁⨁◯ Moderate
4	randomised trials	not serious	very seriousa	not serious	not serious	none	333/350 (95.1%)	277/346 (80.1%)	RR 1.21 (1.01 to 1.44)	168 more per 1,000 (from 8 more to 352 more)	⨁⨁◯◯ Low
4	randomised trials	not serious	very seriousa	not serious	seriousb	none	350	346	-	SMD 0.67 lower (1.82 lower to 0.48 higher)	⨁◯◯◯ Very low
4	randomised trials	not serious	not serious	not serious	not serious	none	11/238 (4.6%)	50/238 (21.0%)	RR 0.23 (0.12 to 0.42)	162 fewer per 1,000 (from 185 fewer to 122 fewer)	⨁⨁⨁⨁ High

CI=confidence interval; RR=risk ratio; SMD=standardised mean difference

Modified Jadad score: Using a modified Jadad scale, we assessed the quality of the six included studies.[17,18,19,20,21,22] Five of the six studies were found to be of high quality (Jadad score >4),[17,18,19,21,22] while only one study received a modified Jadad score indicating low quality[20] (Jadad score = 3) [Supplementary Table 3].

Supplementary Table 3.

Modified Jadad scores of the included studies

Corresponding author	Was the research described as randomised?	Was the approach of randomization appropriate?	Was the research described as blinding?	Was the approach of blinding appropriate?	Was there a presentation of withdrawals and dropouts?	Was there a presentation of the inclusion/ exclusion criteria?	Was the approach used to assess adverse effects described?	Was the approach of statistical analysis described?	Total
Hansen, 2014[22]	+ 1	+ 1	0	0	+ 1	+ 1	0	+ 1	5
Gopalasingam, 2017[17]	+1	+1	0	0	+1	+1	0	+1	5
Kiberenge, 2018[21]	+1	+1	0	+1	+1	+1	0	+1	6
Liu, 2019[20]	+1	0	0	0	+1	0	0	+1	3
Kim, 2021[18]	+1	+1	0	0	+1	+1	0	+1	5
Siddaramaiah, 2023[19]	+1	+1	0	0	+1	+1	0	+1	5

Trial sequential analysis (TSA): The TSA was performed on the primary outcome first pass success rate [Figure 5]. The TSA graph indicated that a sufficient number of patients were included, and the result exceeded the threshold that indicated a clear benefit. This means the findings are strong and trustworthy, and further studies may not be necessary to confirm that the DNTP method is more effective than the palpation method. The TSA confirms that the difference we found is real and not due to random variation.

Figure 5.

Trial Sequential Analysis of primary outcome (first pass success rate)

DISCUSSION

This meta-analysis showed that, for ultrasound-guided radial artery cannulation, the DNTP technique had a higher first-attempt success rate and overall success rate and shorter cannulation time compared to the traditional palpation technique. Additionally, the rate of complications, such as haematoma, was lower in the DNTP group than in the palpation group. Radial artery cannulation is often performed in ICU patients and those undergoing major surgery, and it can be technically challenging in certain situations. Successful radial artery cannulation requires two steps: puncturing the arterial wall and allowing the needle tip to enter the blood vessels, followed by advancing the catheter into the blood vessels.[21] Therefore, it is essential to visualise the needle tip within the plane of the image and keep it centred in the lumen of a blood vessel during any US-guided procedure.[32] Over the past few years, numerous clinical studies and meta-analyses have demonstrated that US-guided radial artery cannulation is superior to the traditional palpation approach.[33] In the updated meta-analysis conducted by Gu et al.,[34] which comprised 12 RCTs, the authors demonstrated that, compared to the palpation method, dynamic two-dimensional ultrasound guidance was associated with a lower first-attempt failure rate, fewer attempts required to succeed, and fewer haematoma complications for radial artery cannulation. Tang et al.[8] performed a meta-analysis that included 7 RCTs. They found that the success rate of the first attempt was higher (RR: 1.51) with ultrasound guidance compared to the palpation method during radial artery catheterisation. Similarly, White et al.[35] performed a meta-analysis that included 11 RCTs and reported that US use significantly increased first-attempt success and reduced the number of attempts needed for radial artery catheterisation in both adult and child populations. Traditionally, two types of methods, short-axis and long-axis, are used for ultrasound-guided arterial cannulations. The SA method provides better visualisation of the target artery and surrounding tissue. However, with the SA approach, identifying the needle tip can be challenging because a fixed image plane is created, leading to confusion between the needle shaft and the needle tip.[36,37] The LA method, by contrast, facilitates the visualisation of both the needle shaft and tip during the entire procedure.[38,39] The debate continues about which option is more effective: the SA or LA approach for US-guided radial artery cannulation.[37,38,40,41] Technically, operators’ experience and hand–eye coordination play an essential role in achieving successful outcomes during US-guided arterial cannulation. The primary focus that contributes to enhanced safety and efficacy is the comprehensive visualisation of the needle, along with the superior image quality achieved through the LA technique. In a randomised study conducted by Sethi et al.,[42] it was found that US-guided SA radial artery cannulation exhibits comparable efficacy to the LA technique in terms of first-attempt success rate (80% vs. 62.6%) and cannulation time in adult patients.

DNTP represents an adaptation of the standard SA approach, as proposed by Clemmesen et al.,[16] for the purpose of peripheral venous cannulation. In this technique, the needle and probe are alternately moved to keep the needle tip continuously in view. Multiple recent investigations have shown that DNTP is more effective than the conventional palpation method for radial artery cannulation. Kim et al.[18] demonstrated that the DNTP technique increased the first-attempt success rate (85.9% vs 72.3%) and decreased the incidence of hematoma formation (7% vs 24.2%) for US-guided radial artery cannulation in elderly patients. Kibrenge et al. compared DNTP with traditional palpation methods for radial artery cannulation in adult surgical patients. They found that the DNTP technique significantly improved the first-attempt success rate (83% vs 43%).[21] In a randomised study, Nam et al.[43] demonstrated that the DNTP technique reached a higher success rate of radial artery cannulation (94% vs 68%) compared to the traditional LA method in adult patients undergoing cardiac surgery. Research by Takeshita et al.[25] found that the DNTP technique greatly increased the success rate on the first attempt (from 50% to 85%) and decreased PVWP in children under 3 years of age with a radial artery depth of at least 4 mm, compared to the standard approach. A recent meta-analysis by Wu et al., which included 11 RCTs, demonstrated that the DNTP method significantly enhanced first-attempt success and reduced cannulation time compared to the palpation method during arterial catheterisation, particularly in small children and infants. Results of this meta-analysis are consistent with those of an earlier meta-analysis conducted by Wu et al.,[23] which indicate an aggregate relative risk (RR = 1.792). Shi et al.[24] conducted a meta-analysis comprising six RCTs and one retrospective study, demonstrating that the DNTP method improved the success rate across all subgroups, except for infants, compared to the palpation method for arteriovenous puncture. However, this study included five studies on arterial catheterisation and two studies on venous catheterisation, and it did not further analyse arterial catheterisation. A notable difference between our meta-analysis and the previous one is that we compared two approaches for arterial cannulation across all patient age groups (adults, elderly, neonates, and children) and included the recently published RCTs in our analysis.

This systematic review and meta-analysis has several strengths. Our meta-analysis followed the PRISMA guideline, and the GRADE assessment was used to evaluate the quality of evidence in our meta-analysis. We also performed a subgroup analysis and a sensitivity analysis to explore the heterogeneity among the included studies. Additionally, a trial sequential analysis was conducted to check if the current evidence is reliable and conclusive. Still, this meta-analysis also has some limitations. Inclusion of RCTs was limited, and the studies included generally had small sample sizes. Secondly, a substantial amount of heterogeneity was observed between the included studies, which limits the generalisability of the results. Finally, we did not search for studies other than those in English, unpublished studies, or manually review conference proceedings, experts’ correspondence, or clinical trial registries, which may introduce publication bias.

CONCLUSION

This meta-analysis demonstrated a higher first-pass success rate and overall success rate, along with a lower incidence of complications, in ultrasonography guided dynamic needle positioning compared to the traditional palpation method during radial artery cannulation. However, there was no significant difference in calculation time between the two groups.

Presentation at conferences/CMEs and abstract publication

NA

Study data availability

De-identified data may be requested with reasonable justification from the authors (email to the corresponding author) and shall be shared after approval as per the authors’ institution’s policy.

Disclosure of use of artificial intelligence (AI)-assistive or generative tools

The authors confirm that no AI tools or language models (LLMs) were used in the writing or editing of the manuscript, and no images were manipulated using AI

Declaration of use of permitted tools

The scales, scores, figures, and tables are freely available and not copyrighted.

Authors contributions

AP was involved in drafting, literature search, data extraction, data analysis and editing; NK was involved in drafting, literature search and writing the manuscript; SP was involved in data extraction and literature search; AB was involved in review and proofreading; KG was involved in review and conceptualisation.

Supplementary material

This article has supplementary material and can be accessed at this link. Supplementary Material at http://links.lww.com/IJOA/A54.

Conflicts of interest

The authors declare that they have no conflicts of interest.

Supplementary Figure 1

Sensitivity analyses (a) First-pass success rate after excluding Siddaramaiah et al., (b) Overall success rate after excluding Liu et al., (c) Overall success rate after excluding Kim et al., (d) Cannulation time after excluding Kiberenge et al., (e) Cannulation time after excluding Liu et al. CI = confidence interval, DNTP = dynamic needle tip positioning

Supplementary Figure 2

Subgroup analysis [a] Age group, [b] Catheter size

Supplementary Figure 3

Funnel plot after removing outliers

PubMed search history

Embase search history

Embase

Session Results

No. Query Results Results Date

#6. #3 AND #4 AND #5 20 11 Jan 2025

#5. ‘ultrasound’/exp OR ultrasound 722,900 11 Jan 2025

#4. ‘palpation’/exp OR ‘palpation’ OR traditional OR 1,649,663 11 Jan 2025

conventional

#3. #1 OR #2 7,762 11 Jan 2025

#2. ‘dntp’/exp OR dntp 7,728 11 Jan 2025

#1. ‘dynamic needle tip positioning’/exp OR ‘dynamic 57 11 Jan 2025

needle tip positioning’ OR ((‘dynamic’/exp OR dynamic) AND (‘needle’/exp OR needle) AND tip AND (‘positioning’/exp OR positioning))

Cochrane Search history

Search Name:

Date Run: 11/01/2025 10:39:27

#1 (Dynamic needle tip positioning OR DNTP):ti, ab, kw (Word variations have been searched) 103

#2 MeSH descriptor: [Palpation] explode all trees 508

#3 (palpation):ti, ab, kw OR (conventional):ti, ab, kw OR (traditional):ti, ab, kw (Word variations have been searched) 142278

#4 MeSH descriptor: [Radial Artery] explode all trees 858

#5 (radial artery cannulation):ti, ab, kw (Word variations have been searched) 454

#6 (Ultrasound guided):ti, ab, kw (Word variations have been searched) 15970

#7 #2 AND #4 30

#8 #1 AND #3 AND #6 26

#9 #7 OR #8 52

Web of Science

1: ALL = (dynamic needle tip positioning) Date Run: Sat Jan 11 2025 13:05:58 GMT + 0530 (India Standard Time) Results: 110

2: ALL = (DNTP) Date Run: Sat Jan 11 2025 13:06:35 GMT + 0530 (India Standard Time)

Results: 2757

3: #2 OR #1 Date Run: Sat Jan 11 2025 13:07:18 GMT + 0530 (India Standard Time)

Results: 2848

4: ((ALL = (palpation)) OR ALL = (traditional)) OR ALL = (conventional) Date Run: Sat Jan 11 2025 13:08:10 GMT + 0530 (India Standard Time) Results: 2154302

5: ALL=(radial artery cannulation) Date Run: Sat Jan 11 2025 13:08:35 GMT + 0530 (India Standard Time)

Results: 786

6: ALL = (ultrasound) Date Run: Sat Jan 11 2025 13:08:58 GMT + 0530 (India Standard Time)

Results: 471945

7: #3 AND #4 AND #5 AND #6 Date Run: Sat Jan 11 2025 13:09:06 GMT + 0530 (India Standard Time)

Results: 19

Google scholar

dynamic needle tip positioning, OR DNTP, and palpation, OR traditional, OR conventional, AND “radial artery cannulation “ Results: 46

Question: DNTP compared to palpation for [ultrasound-guided radial artery cannulation]

Setting: Hospital

Explanations

1. I2 >50% visual inconsistency and statistical analysis also showing heterogeneity.

2. wide confidence interval likely due to heterogeneity

Funding Statement

Nil