To the Editor:—

We read the article by Hosokawa et al.  1with interest. The authors must be commended on doing this study in small children with a group of resident/fellow trainees. However, we have a few concerns.

Most people would agree with us that a randomized study associated with risks will automatically require informed consent. Although the authors argue that informed consent was not required because of the wide use of ultrasound in their practice, it is likely that if the trainee was unsuccessful after a few needle passes with the skin-marking technique (in real practice outside of the study), they would probably have resorted to using real-time guidance. Also, we are intrigued to note that when one trainee is unsuccessful after three attempts (we assume that an attempt is a single needle pass; this needs to be defined in the Materials and Methods section), he or she is replaced by another trainee (is the other trainee going to follow the same puncture marks on the line or going to pick another mark, and if so, who guides them?). The authors do not report the range (or the mean) of the number of attempts with both techniques, and we would like to know where they produced the trainees from (especially in case of multiple attempts). We also question whether the practice of replacing one trainee with another was their standard of care or whether it was only for this study. Trainee failure and dismissal is followed by the attending in all training programs with which we are familiar. We believe that with their study design, informed consent is mandatory.

The authors bring the “old dog and new trick” concept. By their own admission, the ultrasound manipulations were done by the two experienced attending physicians and not by the trainees. How does this concept work in their case? Besides, the authors need to state clearly (in their Discussion) that the real-time ultrasound-guided technique (in their study) was a two-person approach. The study by Grebenik et al.  2involved just one person. This is an important observation because it is easier to control needle manipulations with both hands without having to manipulate the ultrasound. We would also like to know in what way the attending anesthesiologist intervened if the trainee was advancing the needle toward the internal carotid artery (or in any other wrong direction) with the real-time ultrasound-guidance technique. Were they also giving directions to the trainee?

The fundamental principle of visualizing the needle passing through tissue and penetrating the vessel being better than surrogate, blind landmarks (skin markings, muscles, or pulsations) is undeniable. Making the technology–operator interface work satisfactorily is what is needed.

*The Children’s Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.


Hosokawa K, Shime N, Kato Y, Hashimoto S: A randomized trial of ultrasound image–based skin surface marking versus  real-time ultrasound-guided internal jugular vein catheterization in infants. Anesthesiology 2007; 107:720–4
Grebenik CR, Boyce A, Sinclair ME, Evans RD, Mason DG, Martin B: NICE guidelines for central venous catheterization in children: Is the evidence base sufficient? Br J Anaesth 2004; 92:827–30