Transcript Dr Paul Lee
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.