Medication Safety in Theatre – The Problems of Preparation and Labelling

Dr James Richard Skelly

Medication safety in theatre is paramount as we all have the power to harm our patients with the medications we administer - we are the patient’s last line of defence against the medications in the drug press. If we examine the process of medication preparation in theatre there are pitfalls at every step. For the first step, we select the vials and ampoules that we intend to use. These come in varieties of packaging with some labelling, both of which are independent factors that can influence safe medication use. Drug packaging, names, or labels are rarely (if ever) designed or selected with reference to known principles of the science of human factors. As such there are frequent issues relating to the blandness of the outside packaging, a highlighting of trade rather than pharmacological names, and a minimisation of drug concentration information, while the ampoule itself frequently contains information (name, concentration, expiry date) in diminutive font that often lacks effective contrast with the label colour. Certainly, there is no attempt made at aligning with the standard colour coding system used for labelling syringes, representing a considerable failure on the part of the manufacturers to aid recognition, or indeed to regard safety as an important or even relevant part of their process. More could, and should, be done by suppliers to offset these risks. Unfortunately, the present situation simply creates conditions of risk - for a drawer potentially to be full of lookalike medications. In addition, as a consequence of ever-changing providers/suppliers, it is possible for the same medication to be found in boxes or ampoules of different shapes, sizes or colours within a single department. While some manufacturers do provide stickers to label syringes, these generally prioritise the brand name, sometimes completely leave out the generic drug name, and fail to be colour coded. Standardised colour coding or bar code labelling could improve safety. While there is a Specific ISO standard (ISO 26825) related to the colour coding of labels attached to syringes, this does not apply to the labelling of the same medication at any other point, including the manufacturers labelling. It would be helpful if the current ISO standard was to be extended to manufacturers labelling, or a new standard created which would encompass labelling at all stages. Prefilled syringes are often argued for as one solution to medication errors, but these may also look alike each other, and appropriate labelling standards should also apply here.

First hurdle navigated. Next, we draw up the medications. We all have our distinct quirks and methods of maintaining safety at this point, and for the most part they work – for us. These idiosyncratic methods are personally sacrosanct (to most of us) because they make us feel safer. You might always draw up paralytics in a 5ml and antibiotics in a 20ml as a method of pattern recognition. But what about the NCHD you let out for coffee - who probably drew up, or constituted, the medications. What are their foibles? How do their personal safety methods measure up when you are the one administering the medication? Personally, I always double-label (360o) for safety, and feel deeply uncomfortable at the sight of single labelled syringes of suxamethonium and atropine lying neatly side by side in the emergency tray, with the label applied up the spine of the syringe. [As a side note, bear in mind that medications are often drawn up under conditions of distraction, and the person who administers any drug needs to be confident that the syringe label correctly identifies the contents. One possible current distraction might be that the NCHD was listening to a ZOOM teaching session while drawing up drugs for the list. While this is a discussion for another day, some consideration might need to be given to the principle of drawing up medications in a quiet or distraction-free area.] A variety of safety mechanisms have been introduced that can improve safety:

  1. Some, like the familiar colour coded labelling system, have been proven to have medication safety in anaesthesia. One study identified that drug class–specific colour coding “reduced potentially very dangerous syringe swap errors” between drug classes by 66% [1].
  2. Prefilled syringes are of benefit as they obviously skip the first hurdle [2]. They are not available everywhere and certainly not for all medications. In addition, they may not be consistently available because of manufacturing shortages. Although some hospital pharmacies can prepare prefilled syringes, clean rooms are usually overburdened resources at the best of times [3]. The economics of prefilled syringes can also cause difficulty [4], and the aforementioned issue of similarly looking prefilled syringes is a concern. It seems probable that most anaesthesiologists will continue to prepare at least some of their medications from vials for the foreseeable future [3].
  3. Rainbow trays are a relatively new innovation aimed at designing in patient safety [5]. However, in my opinion, these raise concerns as they actively divert the anaesthesiologist’s pattern of medication recognition away from the labels on the syringe, instead increasing dependence on syringe placement to aid identification.
  4. Barcode medication administration (BCMA) technology has also been credited with preventing medication errors. BCMA technology automates the process of medication verification by scanning the barcodes on vials before drug preparation, creating syringe labels that include barcodes, and scanning the syringe label barcodes before drug administration [6]. However, this process imposes several new steps in the preparation-administration sequence that would require user acceptance in order to avoid inevitable workarounds that can lead to new forms of error.

Standardisation of anaesthesia medication preparation should be implemented, especially where more than one person is accessing one set of drugs. Colour coded prefilled syringes with bar-codes would seem like a prudent step forward in anaesthetic medication safety. However, we seem as far away from this, and have to make do with our present equipment and medications. In the meantime, we should strive to strengthen the safety mechanisms that we currently have in order to maximise medication safety in our theatres [7].


  1. Webster et al. Clinical assessment of a new anaesthetic drug administration system: a prospective, controlled, longitudinal incident monitoring study. Anaesthesia 2010; 65:490–9.
  2. Yang et al. A Human Factors Engineering Study of the Medication Delivery Process during an Anesthetic: Self-filled Syringes versus Prefilled Syringes. Anethesiology 2016 124(4):795-803.
  3. Bowdle et al. Why we scan the barcodes of anaesthetic medications. Br J Anaesth 2019; 122: E24-E26
  4. Jelacic et al. Relative costs of anesthesiologist prepared, hospital pharmacy prepared and outsourced anesthesia drugs. J Clin Anesth 2017; 36: 178-183
  5. Almghairbi et al. An observational feasibility study of a new anaesthesia drug storage tray. Anaesthesia 2018; 73(3): 356-64.
  6. Jelacic et al. A System for Anesthesia Drug Administration Using Barcode Technology: The Codonics Safe Label System and Smart Anesthesia Manager. Anesth Analg 2015; 121(2):410-21.
  7. Whittaker D. Standardisation, syringe labelling and prefilled syringes.