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Ultrasound gel causes inflammation in subcutaneous tissue and muscle in Wistar rats. Dr Paul Lee-Archer Royal Children’s Hospital Brisbane, Australia. Background. Ultrasound guided procedures are increasingly being used in anaesthesia
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Ultrasound gel causes inflammation in subcutaneous tissue and muscle in Wistar rats Dr Paul Lee-Archer Royal Children’s Hospital Brisbane, Australia
Background • Ultrasound guided procedures are increasingly being used in anaesthesia • Hollow needles introduce small amounts of gel into tissues • Ultrasound gel is designed to be topical only, its safety as an injectable has not been assessed • This study aimed to determine what effect ultrasound gel has on subcutaneous tissue and muscle
Background • Current evidence mainly limited to case reports of contact dermatitis • Preservatives and stabilisers implicated in these reactions • Infection/contamination risk • Report of cell lysis in FNA samples contaminated with gel • Exact composition of gels not always known
Methods • 20 Wistar rats anaesthetised and injected with Parker Aquasonic 100 sterile ultrasound gel • Two injection sites: • Subcutaneously in chest • Intramuscularly in thigh • Corresponding sites on opposite side of the body injected with saline to act as a control
Methods • After seven days the rats were euthanised, sites examined and tissue harvested • Slides of the tissue samples were prepared • The examining pathologist was blinded as to which samples were controls
Results • Macroscopically, the ultrasound gel injection sites developed a hard, mobile lump and some skin necrosis • Microscopically all the ultrasound gel samples exhibited a florid inflammatory reaction • The presence of giant cells suggests a foreign-body reaction
Results Fig 1. Site of subcutaneous ultrasound gel injection exhibiting swelling and skin necrosis seven days after injection.
Conclusions • Ultrasound gel causes inflammation in rat tissue • Limitations: • Rat model may not be representative • Relatively large volumes used • Only one brand of ultrasound gel tested • Is there any clinical relevance?
Conclusions • Possible solutions • Avoid injecting through a layer of gel • Use a different medium such as sterile water • Develop a new ultrasound gel that is safe to inject
References • 1. Belavy D. Regional Anesthesia Needles Can Introduce Ultrasound Gel into Tissues. Anesth Analg. 2010 Sept; 111: 811-812. • 2. Ando M, Ansotegui J, Munoz D, Fernandez de Corres L. Allergic contact dermatitis from imidazolidinyl urea in an ultrasonic gel. Contact Dermatitis 2000; 42: 109-110. • 3. Ayadi M, Martin P, Bergoend H. Contact dermatitis to a carotidian • Doppler gel. Contact Dermatitis 1987; 17: 118-119. • 4. Eguino P, Sánchez A, Agesta N, Lasa O, Ratón JA, Díaz-Pérez JL. Allergic • contact dermatitis due to propylene glycol and parabens in an ultrasonic gel. • Contact Dermatitis. 2003 May; 48(5): 290. • 5. Erdmann SM, Sachs B, Merk HF. Allergic contact dermatitis due to methyldibromoglutaronitrile in Euxyl K 400 in an ultrasonic gel. Contact Dermatitis. 2001 Jan; 44(1): 39-40. • 6. Gebhart M, Stuhlert A, Knopf B. Allergic contact dermatitis due to Euxyl K 400 • in an ultrasonic gel. Contact Dermatitis. 1993 Nov; 29(5): 272. • 7. Horiguchi Y, Honda T, Fujii S, Matsushima S, Osaki Y. A case of allergic • contact dermatitis from propylene glycol in an ultrasonic gel, sensitized at a • leakage skin injury due to transcatheter arterial chemoembolization for • hepatocellular carcinoma. Int J Dermatol. 2005 Aug; 44(8): 681-3. • 8. Kessler J, Schafhalter-Zoppoth I, Gray AT. Allergic contact dermatitis caused • by ultrasonic gel. Reg Anesth Pain Med. 2006 Sep-Oct; 31(5): 480-1. • 9. Khan IJ, Azam NA, Goyal R, Nabi NU. Contact urticaria to ultrasonic gel. Eye • (Lond). 2007 Jul; 21(7): 1016. • 10. Leitner B, Hemmer W, Focke M, Gotz M, Jarisch R. Contact dermatitis against ultrasonic gel. Dermatosen in Beruf und Umwelt. 1999; 47(4): 164-165. • 11. Uter W, Schwanitz HJ. Contact dermatitis from propylene glycol in • ECG electrode gel. Contact Dermatitis 1996; 34: 230-231. • 12. Villa A, Venegoni M, Tiso B. Cases of contact dermatitis caused by • ultrasonographic gel. J Ultrasound Med. 1998 Aug; 17(8): 530 • 13. Hutchinson J, Runge W, Mulvey M, Norris G, Yetman M, Valkova N, Villemur R, Lepine F. Burkholderia cepacia Infections Associated with Intrinsically Contaminated Ultrasound Gel: The Role of Microbial Degradation of Parabens. Infect Control Hosp Epidemiol. 2004; 25(4): 291-296. • 14. Molyneux AJ, Coghill SB. Cell Lysis Due to Ultrasound Gel in Fine Needle Aspirates: An Important New Artefact in Cytology. Cytopathology. 1994; 5:41–45. • 15. Sinha R, Punj J, Pandey R. Use of saline infusion instead of gel for ultrasound-guided (USG) central venous cannulation. Acta Anaesthesiologica Scandinavica. 2008 May; 52(5): 721.