The Indian Anaesthetists’ Forum

: 2022  |  Volume : 23  |  Issue : 1  |  Page : 74--75

Filter syringes: Knowing the unknown

Abhijeet Shekhawat, Manbir Kaur, Priyanka Sethi, Pradeep Bhatia 
 Department of Anesthesia and Critical Care, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India

Correspondence Address:
Dr. Manbir Kaur
Department of Anesthesia and Critical Care, All India Institute of Medical Sciences, Jodhpur - 342 005, Rajasthan

How to cite this article:
Shekhawat A, Kaur M, Sethi P, Bhatia P. Filter syringes: Knowing the unknown.Indian Anaesth Forum 2022;23:74-75

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Shekhawat A, Kaur M, Sethi P, Bhatia P. Filter syringes: Knowing the unknown. Indian Anaesth Forum [serial online] 2022 [cited 2022 Dec 5 ];23:74-75
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There has been a rising trend in the practice of medicine to err on the side of safety. In that context, via this article, we would like to discuss whether the practice of using specialized filter needles to aspirate drugs from breakable glass ampules should be more prevalent or not.

Many drugs are manufactured as a glass ampule due to the benefits of easy portability and high sterility standards. These glass particle contaminations (GPC) may be introduced either during manufacturing, opening, or injection. The American Society of Health-System Pharmacists (ASHP) guidelines recommend using a 5μm filter needle to minimize particulate contamination risk.[1]

These particles can cause pain at the injection site, infusion phlebitis, tissue injury, necrosis, pulmonary thrombi and micro-emboli, end-organ inflammation (kidney, liver, spleen, and lungs), granuloma formation, and modulating inflammatory effects, especially in at-risk patient groups like neonates and those receiving long term intravenous drugs.[2],[3]

Multiple studies have shown that filter less aspiration of drugs from glass ampules leads to, at the very least, tens and at most, hundreds of glass particulates being injected in patients. The size of the particles ranging from 2μm to 500μm.[4],[5]

Filter needles [Figure 1] are not used in India's routine practice because the risk of glass contamination is often not known or often overlooked by medical practitioners. They are expensive and cumbersome to use, which leads to reluctance on the practitioner's part. Awareness on this topic is also low, leading to a callous attitude towards the contaminants' risks. The probability of misdiagnosing and misattributing the detrimental effects of particulate matter would be very high since particulate contamination is rarely if ever, considered in the differential diagnosis.{Figure 1}

Hence it is always recommended to be safer than necessary and err on the side of caution and bring into practice filtered needles for aspirating from glass ampules.

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Conflicts of interest

There are no conflicts of interest.


1American Society of Health System Pharmacists. ASHP guidelines on compounding sterile preparations. Am J Health Syst Pharm.2014;71(2):145-66
2Caudron E, Tfayli A, Monnier C, Manfait M, Prognon P, Pradeau D. Identification of hematite particles in sealed glass containers for pharmaceutical uses by Raman microspectroscopy. J Pharm Biomed Anal. 2011;54:866-8.
3Chiannilkulchai N, Kejkornkaew S. Safety concerns with glass particle contamination: improving the standard guidelines for preparing medication injections. Int J Qual Health Care. 2021;33:mzab091.
4Joo GE, Sohng KY, Park MY. The effect of different methods of intravenous injection on glass particle contamination from ampules. Springerplus. 2016;5:15
5Sabon RL Jr, Cheng EY, Stommel KA, Hennen CR. Glass particle contamination: influence of aspiration methods and ampule types. Anesthesiology. 1989;70:859-62