Ultrasound for Localization of Central Venous Catheter: A Good Alternative to Chest X-Ray?

Are routine chest radiographs still indicated after central line insertion? A scoping review

Introduction

Central venous catheters are increasingly inserted using point-of-care ultrasound (POCUS) guidance. Following insertion, it is still common to request a confirmatory chest radiograph for subclavian and internal jugular lines, at least outside of the operating theater. This scoping review addresses: (i) the justification for routine post-insertion radiographs, (ii) whether it would better to use post-insertion POCUS instead, and (iii) the perceived barriers to change.

Methods

We searched the electronic databases, Ovid MEDLINE (1946-) and Ovid EMBASE (1974-), using the MESH terms ("Echography" OR "Ultrasonography" OR "Ultrasound") AND "Central Venous Catheter" up until February 2023. We also searched clinical practice guidelines, and targeted literature, including cited and citing articles. We included adults (⩾18 years) and English and French language publications. We included randomized control trials, prospective and retrospective cohort studies, systematic reviews, and surveys.

Results

Four thousand seventy-one articles were screened, 117 full-text articles accessed, and 41 retained. Thirteen examined cardiac/vascular methods; 5 examined isolated contrast-enhanced ultrasonography; 7 examined isolated rapid atrial swirl sign; and 13 examined combined/integrated methods. In addition, three systematic reviews/meta-analyses and one survey addressed barriers to POCUS adoption.

Discussion

We believe that the literature supports retiring the routine post-central line chest radiograph. This is not only because POCUS has made line insertion safer, but because POCUS performs at least as well, and is associated with less radiation, lower cost, time savings, and greater accuracy. There has been less written about perceived barriers to change, but the literature shows that these concerns- which include upfront costs, time-to-train, medicolegal concerns and habit- can be challenged and hence overcome.

Pulsed-wave Doppler for ultrasound-based tip location using bubble test: A pilot study

BACKGROUND

MicroBubbles Time test (MBT), consisting in the rapid infusion of saline with addition of air microbubbles, visualized by B-mode echocardiography, represents a potential alternative to Intracavitary ECG (IC-ECG) and chest X-ray for central venous catheters (CVCs) tip location. Even if promising, this technique lacks of standardization: a clear time cut-off between bubble infusion and their detection in heart's right chambers hasn't been yet established. At these regard, microbubbles could be also detected as microembolic signals (MES) with an alternative ultrasound technique: the pulse wave Doppler (PW).

OBJECTIVE AND METHODS

The first aim of this pilot study is to establish agreement of MBT with PW test (MBT-PW) compared with reference standard IC-ECG and normal MBT for tip location on CVCs. Corrected tip's position was established through reference standard IC-ECG, afterward MBT-PW was performed, with the sample volume placed at tricuspid valve to detect MES simultaneously with micro-bubbles injection in CVCs. The second aim was to evaluate inter-observer variability for MES detection and grading.

RESULTS

Eight patients were enrolled; we obtained three records for each patients (24 with MBT and 24 with MBT-PW, the two techniques were acquired simultaneously). Inter-methods agreement through reference standard IC-ECG versus MBT-PW and MBT versus MBT-PW methodic was satisfying (Cohen's kappa value = 1). MBT-PW and MBT signals were recorded within the first heart beat after microbubble infusion in all patients. Mean time delay thorough MBT-PW and MBT was 0.76 ±0.07 and 0.78 ± 0.07 s respectively; Intraclass correlation coefficient was 0.992 (95% CI: 0.981-0.996) suggesting excellent correlation. Inter-observer variability for positive MBT-PW evaluation was optimal (Cohen's kappa value was 1), while indicated substantial agreement for MES grade evaluation (Fleiss' Kappa value was 0.704; 95% CI: 0.328-1.000).

CONCLUSIONS

Our study supports agreement between MBT-PW and reference standard IC-ECG for tip location. Satisfactory agreement was observed also for MBT-PW and MBT.

ECHOTIP: A structured protocol for ultrasound-based tip navigation and tip location during placement of central venous access devices in adult patients

Central venous access devices are routinely used in clinical practice for administration of fluids and medications, for drawing blood samples and for hemodynamic monitoring. The adoption of ultrasound guided venipuncture has significantly reduced procedure-related complications, as documented by the recommendations of most recent guidelines. Ultrasound has also an important role also in other aspects of central venous catheterization, such as in the pre-procedural evaluation of the venous patrimony and in the detection of early and late non-infective complications. Recently, bedside ultrasound has been regarded as a promising tool also for ensuring an accurate and intraprocedural method of tip navigation and tip location. The aim of this paper is to review all the evidence about the accuracy of ultrasound methods for tip navigation and tip location in adult patients, and to suggest a structured standardized protocol for clinical practice.

Contrast enhanced ultrasound as a new tool to estimate the performance of midline catheters in the single patient

BACKGROUND

Contrast enhanced ultrasound (CEUS) through MicroBubbles Time (MBT) (time from infusion of saline with addition of micro-bubbles of air to visualization of first bubbles in right atrium (RA), visualized by subxiphoid or apical echocardiography) is an alternative to Intracavitary ECG and chest X-ray in evaluation of tip location in central venous catheters.

OBJECTIVE

To evaluate feasibility and variability of CEUS in peripheral catheters (Midline-MC) in a cohort of patients and in a subgroup where tip location was also performed through chest X-ray. Secondary outcomes were verifying the correlation between MBT and distance between tip of MC and RA (anthropometric and radiological measures), body mass index (BMI), vein diameter at point of insertion.

METHODS

Patients with insertion of MC were enrolled in this prospective cohort. After catheter insertion, CEUS was performed recording MBT.

RESULTS

One hundred thirty-two MCs were inserted, 45 performed Chest X-ray. MBT wasn't feasible in 7 (5%) because of low quality echocardiographic images. Subcostal view was available in 114 patients (91.2%), while 11 patients (8.8%) were examined through apical four-chamber view. Mean MBT in the whole population was 2.3 ± 0.8 s. Significant correlation between anthropometric and radiological measures, BMI and MBT was found. 32.8% of MC had a MBT ⩽2 s.

CONCLUSIONS

CEUS could be useful to estimate tip position. Our study showed how 2 s is not a suitable cutoff to confirm central catheter's tip.

Supradiaphragmatic central venous catheter malposition detection using the parasternal long-axis echocardiographic view and dextrose 50% contrast solution: A pilot study

Background

Contrast-enhanced ultrasonography (CEUS) using saline was studied to detect supradiaphragmatic central venous catheter malposition. Commonly used echocardiographic views are apical 4-chamber (A4c) and subcostal views. However, this standard method is not feasible in certain situations. We explored the feasibility of the right ventricle inflow parasternal long axis (RVI-PLAX) echocardiographic view and dextrose 50% (D50%) contrast solution for detecting supradiaphragmatic central venous catheter malposition.

Method

This pilot study screened 60 patients who underwent ultrasound-guided supradiaphragmatic central venous catheter insertion. We compared the investigators' guidewire's J-tip detection, D50% rapid atrial swirl sign (RASS) findings on the RVI-PLAX view and the central venous catheter tip on chest radiograph. We also compared the mean capillary blood sugar level before and after the 5 ml D50% flush.

Results

No guidewire J-tips were detected from the RVI-PLAX view. The first and second investigators' diagnosis of central venous catheter malposition detected on RVI-PLAX CEUS achieved an almost perfect agreement (κ = 1.0 (95% confidence interval (CI): 0.90 to 1.0), p < .0001). The RVI-PLAX CEUS was not able to detect two central venous catheter malpositions (one atrial malposition and one left brachiocephalic vein venous catheter malposition). The capillary blood sugar was significantly elevated (8.96 mmol/L vs. 9.75 mmol/L) after D50% flush (p < 0.005) with no complications reported within 30 minutes after the D50% flush.

Conclusion

RVI-PLAX view should not be used for guidewire detection. CEUS using D50% and RVI-PLAX view are potentially useful tools in detecting central venous catheter malposition. Further studies comparing them with conventional methods are needed.

ACR Appropriateness Criteria® Intensive Care Unit Patients

Chest radiography is the most frequent and primary imaging modality in the intensive care unit (ICU), given its portability, rapid image acquisition, and availability of immediate information on the bedside preview. Due to the severity of underlying disease and frequent need of placement of monitoring devices, ICU patients are very likely to develop complications related to underlying disease process and interventions. Portable chest radiography in the ICU is an essential tool to monitor the disease process and the complications from interventions; however, it is subject to overuse especially in stable patients. Restricting the use of chest radiographs in the ICU to only when indicated has not been shown to cause harm. The emerging role of bedside point-of-care lung ultrasound performed by the clinicians is noted in the recent literature. The bedside lung ultrasound appears promising but needs cautious evaluation in the future to determine its role in ICU patients. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Dynamic changes in the regulatory T-cell heterogeneity and function by murine IL-2 mutein

Single-cell RNA-seq analysis reveals that IL-2 mutein treatment expands multiple sub-states of regulatory T cells with superior suppressive function in mice.

The therapeutic expansion of Foxp3⁺ regulatory T cells (Tregs) shows promise for treating autoimmune and inflammatory disorders. Yet, how this treatment affects the heterogeneity and function of Tregs is not clear. Using single-cell RNA-seq analysis, we characterized 31,908 Tregs from the mice treated with a half-life extended mutant form of murine IL-2 (IL-2 mutein, IL-2M) that preferentially expanded Tregs, or mouse IgG Fc as a control. Cell clustering analysis revealed that IL-2M specifically expands multiple sub-states of Tregs with distinct expression profiles. TCR profiling with single-cell analysis uncovered Treg migration across tissues and transcriptional changes between clonally related Tregs after IL-2M treatment. Finally, we identified IL-2M–expanded Tnfrsf9⁺Il1rl1⁺ Tregs with superior suppressive function, highlighting the potential of IL-2M to expand highly suppressive Foxp3⁺ Tregs.

Bedside ultrasound to detect central venous catheter misplacement and associated iatrogenic complications: a systematic review and meta-analysis

Background

Insertion of a central venous catheter (CVC) is common practice in critical care medicine. Complications arising from CVC placement are mostly due to a pneumothorax or malposition. Correct position is currently confirmed by chest x-ray, while ultrasonography might be a more suitable option. We performed a meta-analysis of the available studies with the primary aim of synthesizing information regarding detection of CVC-related complications and misplacement using ultrasound (US).

Methods

This is a systematic review and meta-analysis registered at PROSPERO (CRD42016050698). PubMed, EMBASE, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched. Articles which reported the diagnostic accuracy of US in detecting the position of CVCs and the mechanical complications associated with insertion were included. Primary outcomes were specificity and sensitivity of US. Secondary outcomes included prevalence of malposition and pneumothorax, feasibility of US examination, and time to perform and interpret both US and chest x-ray. A qualitative assessment was performed using the QUADAS-2 tool.

Results

We included 25 studies with a total of 2548 patients and 2602 CVC placements. Analysis yielded a pooled specificity of 98.9 (95% confidence interval (CI): 97.8–99.5) and sensitivity of 68.2 (95% CI: 54.4–79.4). US examination was feasible in 96.8% of the cases. The prevalence of CVC malposition and pneumothorax was 6.8% and 1.1%, respectively. The mean time for US performance was 2.83 min (95% CI: 2.77–2.89 min) min, while chest x-ray performance took 34.7 min (95% CI: 32.6–36.7 min). US was feasible in 97%. Further analyses were performed by defining subgroups based on the different utilized US protocols and on intra-atrial and extra-atrial misplacement. Vascular US combined with transthoracic echocardiography was most accurate.

Conclusions

US is an accurate and feasible diagnostic modality to detect CVC malposition and iatrogenic pneumothorax. Advantages of US over chest x-ray are that it can be performed faster and does not subject patients to radiation. Vascular US combined with transthoracic echocardiography is advised. However, the results need to be interpreted with caution since included studies were often underpowered and had methodological limitations. A large multicenter study investigating optimal US protocol, among other things, is needed.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-1989-x) contains supplementary material, which is available to authorized users.

Central Venous Line Insertion Revealing Partial Anomalous Pulmonary Venous Return: Diagnosis and Management

Central venous line malposition is a well-known complication of line insertion. Rarely, it can be mal-positioned in an anomalous pulmonary vein. We present an unusual case of a 56-year-old woman that was found to have partial anomalous pulmonary venous return on central venous line insertion. In this report, we describe a systematic approach to diagnosis and management of this unusual situation.