Central venous catheterization is one of the commonly performed interventional procedures and is done by a wide range of medical practitioners such as pediatricians, critical care specialists, anesthesiologists, nephrologists, radiologists, cardiologists, and oncologists, for varied indications such as hemodynamic monitoring, drug administration, dialysis, and parenteral nutrition.

Mechanical complications rates are almost equal between jugular and subclavian catheterization, however, existing guidelines suggest that subclavian vein catheterization benefit from lower infection rates as compared to jugular vein insertion [1, 2].

A systematic review suggested that dynamic ultrasound use reduces failed subclavian vein catheterizations and adverse events associated with traditional “blind” landmark techniques, thereby improves patient safety [3]. There have been a limited number of randomized controlled trials of variable methodological quality that have addressed ultrasound use for subclavian catheterization.

Exiting data has few limitations in reporting the technical challenges, exact rate of infection, arrhythmias, cardiac tamponade, nerve injuries and air embolism.

Complication rate and success rate also varies with clinician’s experience (inexperienced resident vs. experienced senior physician) in ultrasound techniques, anatomical variations (superficial vs. deep) and patient population (newborn child vs. older children).

The paper by Pang et al. published in this issue of the Journal clearly highlights the advantages of ultrasound in initial cannulation and use of fluoroscopy for final positioning of catheter tip [4]. Also they have clearly mentioned the subclavian catheterization in step wise manner, which is easy to understand for the readers.

There are a few limitations of this study; the authors have not defined the complications as serious vs. non-serious; there is no mention of how many attempts were made by individual physician for a particular patient before referring to a more senior physician and the authors have not addressed the technical challenges. Since, all catheterizations were done only on right side, authors have not mentioned any particular reason for this selection bias. Was there a technical difficulty in accessing left-side subclavian vein? Overall rate of malposition of catheter tip is more on the right side as compared to the left side since right subclavian vein enters innominate vein at sharper angle than on left side [5].

Also it is important to address, the issue of accessing the subclavian vein using infraclavicular approach or supraclavicular approach, since infraclavicular approach has greater technical complications than supraclavicular approach [6].

Some solutions to overcome technical challenges in accessing subclavian vein are, use of virtual convex/trapezoid setting using high frequency linear probe to access deep seated subclavian veins, use of micropuncture set for cannulating smaller veins and not to inject contrast without ensuring needle tip is in the lumen by aspirating blood.

Because of heterogeneous data, there is a need for more well-designed randomized controlled trials with more clearly defined criteria’s to provide a solid evidence base for future updates of clinical practice guidelines [7,8,9].