Intensive Care Medicine

, Volume 45, Issue 2, pp 261–262 | Cite as

The ‘blinking frog’ ultrasound sign establishes the presence of pretracheal vasculature

  • Pieter R. TuinmanEmail author
  • David van Westerloo
  • Stefanie Slot
  • Hugo R. W. Touw
Open Access
Imaging in Intensive Care Medicine

Percutaneous dilatational tracheostomy is a common bedside procedure in intensive care units (ICUs) worldwide. A feared complication of the procedure is bleeding. Ultrasound guidance during percutaneous dilatational tracheostomy can reduce the risk of bleeding by identifying the presence of vasculature in the pretracheal or paratracheal regions and is recommended in recent guidelines.

In a 71-year-old patient with community-acquired pneumonia and ICU-acquired weakness, an indication for tracheostomy was made after a failed extubation. During ultrasound scanning of the trachea in the transverse plane, the presence of pretracheal vasculature was identified (Fig. 1a, b; Movie 1). The image of the trachea with two inferior thyroid veins on both sides above the trachea resembles the head of a frog with its eyes open (Fig. 1a). Applying slight pressure with the probe makes the vessels disappear, which looks like closing of the eyes (Fig. 1b). We call this the ‘blinking frog sign’. The risk of per-procedural bleeding was considered to be increased.
Fig. 1

Presence of pretracheal vasculature on ultrasound image in 2D mode. The white arrows show the presence of two pretracheal vessels (a) which are compressible (b). The white star marks the trachea

In conclusion, the ‘blinking frog’ ultrasound sign establishes the presence of pretracheal vasculature and is a relative contraindication to tracheostomy at this particular part of the trachea. A higher or lower puncture location should be considered.


Author contributions

PRT, DW, SS and HT contributed substantially to the study design and the writing of the manuscript.

Compliance with ethical standards

Conflicts of interest

The authors declare they have no conflict of interest relevant to this manuscript

Ethical approval

The Commission for Medical Ethics (METc) of VUmc has approved this research: METC: 2016.053.

Informed consent

Written informed consent was given by the family of the patient.

Supplementary material

Supplementary material 1 (MPEG 3403 kb)

Copyright information

© The Author(s) 2018

Open AccessThis article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (, which permits any noncommercial use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Department of Intensive Care MedicineAmsterdam UMC, Vrije Universiteit Medical CenterAmsterdamThe Netherlands
  2. 2.Research VUmc Intensive Care (REVIVE)Amsterdam UMC, Vrije Universiteit AmsterdamAmsterdamThe Netherlands
  3. 3.Amsterdam Cardiovascular Sciences (ACS)Amsterdam UMC, Vrije Universiteit AmsterdamAmsterdamThe Netherlands
  4. 4.Amsterdam Infection and Immunity Institute (AI&II)Amsterdam UMC, Vrije Universiteit AmsterdamAmsterdamThe Netherlands
  5. 5.Department of Intensive CareLeiden University Medical CenterLeidenThe Netherlands
  6. 6.Radboud University Medical CenterNijmegenThe Netherlands

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