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

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.

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

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Correspondence to Pieter R. Tuinman.

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

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

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Tuinman, P.R., van Westerloo, D., Slot, S. et al. The ‘blinking frog’ ultrasound sign establishes the presence of pretracheal vasculature. Intensive Care Med 45, 261–262 (2019).

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  • Vasculature
  • Percutaneous Dilatational Tracheostomy
  • Inferior Thyroid Veins
  • Extubation Failure
  • Paratracheal Region