POST 00537E : ASPIRATION BEFORE INJECTION

POST 00537E : ASPIRATION BEFORE INJECTION 4 January 2003 _____________________________________________________________________ Bernard Kaic (mailto:[log in to unmask]) from Croatia has submitted a query that could be of interest to many of you. It is thus reproduced here below with the reply provided by John Clements (mailto:[log in to unmask]) from WHO. _____________________________________________________________________ I am a medical epidemiologist at the Croatian National Institute of Public Health, and also the National EPI manager. There is one thing I noticed reading WHO documents, which puzzles me. Namely, neither of the documents dealing with vaccination, including "Immunization in practice, Modules 1-11, (WHO/EPI/TRAM/98.01-11 REV.1)" recommends aspiration prior to injection a vaccine during intramuscular administration of vaccine. During my medical education I was taught to pull the plunger, once the needle is in the muscle, in order to check if the needle is inside a blood vessel. No vaccine is allowed to be administered into the blood stream. Since I always pull the plunger before injection, I found to be inside a blood vessel with the needle on a few occasions. In such cases, the vaccine has to be discarded and new vaccine administered at a different site. Of course, intramuscular administration of vaccine at recommended sites greatly reduces the risk of intravasal administration, but does not eliminate it. Could you please investigate the reason for omitting the recommendation to pull the plunger before injecting the vaccine via the intramuscular route? Thanks in advance for your response. Best regards, Bernard Kaic, MD, MSc National EPI manager Department of Infectious Disease Epidemiology Croatian national institute of public health Zagreb, Croatia ________________________________________________________ Here is EPIs point of view: It has been traditional in many health care settings to use a medicated swab to prepare the skin before vaccination, and to aspirate the syringe after insertion (1) in attempting to avoid injecting directly into a blood vessel. Neither practice is endorsed by WHO. If the intended vaccination site is visibly dirty, obvious dirt can be removed using clean water, water for injection or saline and a clean tissue, cloth, cotton wool, gauze or other such non-impregnated material. Wipes that are impregnated with medicated chemical must not be used. Such chemicals may interfere with the vaccines, especially live ones. A needle should not be inserted through skin that is obviously infected - this would introduce the infection into lower layers and possibly produce an abscess or worse. Another tradition has been to aspirate the syringe once it has been inserted into the patient. By pulling back on the plunger, the negative pressure produced will draw blood back into the barrel if the needle tip is lying in a blood vessel. Thus, repositioning the tip would theoretically avoid injecting the vaccine directly into the vessel. The theoretical concern that the vaccine might be injected into a vessel is flawed. As well as being virtually impossible to accomplish, large blood vessels are not located around the recommended injection sites, minimizing the possibility of placing the needle tip in a vessel. The practice of aspirating is not "evidence-based" - there is no case report of this occurring with a negative impact. In addition, the difficult action of aspiration prolongs the time the needle is inserted into the patient, and allows for the possibility of loss of control of the syringe if both hands of the vaccinator are used instead of one hand holding the patient. Trauma at the site of injection is likely to be increased during attempts to aspirate. Most auto-disable syringes do not permit aspiration to be performed prior to injection (2). None the less, there is also a lack of evidence supporting not aspirating. As a result, WHO is neither able to support nor offer alternative actions in relation to aspiration undertaken during the administration of vaccines. Until such time as clear evidence becomes available to indicate which method is preferable, vaccinators should make locally appropriate choices. References : (1) General recommendations on immunization. Recommendations of the Advisory Committee on Immunization Practices. Morbidity and Mortality Weekly Report. 1994; 43: RR-1 page 6. (2) Giving safe injections: introducing auto-disable syringes. PATH. Seattle, WA U.S.A. 2000. Dr C John Clements Vaccines and Biologicals World Health Organization ______________________________________________________________________________ Visit the TECHNET21 Website at http://www.technet21.org You will find instructions to subscribe, a direct access to archives, links to reference documents and other features. ______________________________________________________________________________ To UNSUBSCRIBE, send a message to : mailto:[log in to unmask] Leave the subject area BLANK In the message body, write unsubscribe TECHNET21E ______________________________________________________________________________ The World Health Organization and UNICEF support TechNet21. The TechNet21 e-Forum is a communication/information tool for generation of ideas on how to improve immunization services. 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