Green blood plasma from a patient with breast cancer after sentinel lymph node biopsy : European Journal of Anaesthesiology | EJA

Secondary Logo

Journal Logo


Green blood plasma from a patient with breast cancer after sentinel lymph node biopsy

López-Gómez, Victoria; Moreno-Martínez, Antonio; Varela-Durán, Marina

Author Information
European Journal of Anaesthesiology: December 2018 - Volume 35 - Issue 12 - p 983-984
doi: 10.1097/EJA.0000000000000854
  • Free


We would like to report the case of a hypertensive 76-year-old patient who received Patent Blue V dye to guide a lymph node biopsy. An arterial blood gas sample was sent to the laboratory, and the analysis (using Werfen Gem Premier 5000; Instrumentation Laboratory, Bedford, Massachusetts, USA) revealed the presence of hypoxaemia with pH 7.37, Pa O2 6.3 kPa (47 mmHg), HCO3 26 mmol l−1 and Sa O2 81%. However, when the sample was removed from the analyser, it had a striking appearance (Fig. 1). At around the time her blood sample was taken, her blood pressure had dropped to 105/35 mmHg, and she had developed a severe bradycardia (20 bpm). Measuring oxygen saturation in the operating room from a pulse oximeter (GE TruSignal sensor; GE Healthcare, Little Chalfont, UK) indicated a fall from 100 to 89% within 15 min after the initiation of surgery. She was transferred to the resuscitation room where she required an isoprenaline sulphate infusion following unsuccessful treatment with atropine sulphate.

Fig. 1:
Green blood plasma from a patient with breast cancer after sentinel lymph node biopsy.

The patient was undergoing lymph node biopsy, and she received Patent Blue V dye to identify potential sentinel nodes in the presence of breast cancer. After its subdermal injection, most of the Patent Blue V enters the bloodstream,1 causing green plasma. Patent Blue V dye has a maximum absorption at a wavelength of 640 nm. This peak overlaps with the wavelength used for deoxygenated haemoglobin (660 nm) and methaemoglobin (630 nm), and it can mimic a low oxygen saturation value by pulse oximetry and a false indication of methaemoglobinaemia co-oximeter-dependent.2 The fictitious oxygen desaturation caused by Patent Blue V appears rapidly after its administration, but, contrary to our clinical case, it is not accompanied by true hypoxaemia. Co-oximetry is the test recommended to evaluate true oxygen content of the blood in the presence of such an emergency situation, as it measures (rather than estimates). On the contrary, this analysis could not be performed at the time of the occurrence of the adverse event. Nevertheless, as Patent Blue V dye does not affect Pa O2 measurement (amperometry), our patient was managed as if she had a real hypoxaemia according to the clinical symptoms and the alterations in the arterial blood gas analysis. The anaesthesiologist in charge of the patient suspected an allergic reaction to Patent Blue V dye. This can cause adverse effects such as allergic skin reaction, bronchospasm and, less frequently, severe hypotension and anaphylaxis.3 The frequency of allergic reactions to Patent Blue V has been estimated to be from 0.2 to 2.7%.2 Patent Blue V remains the dye of choice for intra-operative sentinel lymph node mapping. It remains imperative to keep reporting these adverse reaction cases to maintain adequate pharmacological vigilance.

Finally, a green blood specimen must alert laboratory technicians about the presence of significant amounts of Patent Blue V and may prompt advice to the anaesthesiologist about interference with pulse oximeter readings and measurement of methaemoglobin. To monitor arterial Pa O2 in these patients, it is advisable to ensure appropriate measurements of oxygen with a co-oximeter. Written permission for publication was obtained from the patient.

Acknowledgements relating to this article

Assistance with the letter: none.

Financial support and sponsorship: none.

Conflicts of interest: none.


1. Tsopelas C, Sutton R. Why certain dyes are useful for localizing the sentinel lymph node. J Nucl Med 2002; 43:1377–1382.
2. Yusim Y, Livingstone D, Sidi A. Blue dyes, blue people: the systemic effects of blue dyes when administered via different routes. J Clin Anesth 2007; 19:315–321.
3. Haque RA, Wagner A, Whisken JA, et al. Anaphylaxis to patent blue V: a case series and proposed diagnostic protocol. Allergy 2010; 65:396–400.
© 2018 European Society of Anaesthesiology