Preventing Medication Mix-Ups: LASA and Safety Strategies

An ampoule of epinephrine instead of atropine, sufentanil instead of fentanyl, potassium chloride instead of sodium chloride – medication mix-ups are among the most common preventable critical incidents in emergency medicine and anesthesiology. The consequences range from hemodynamic instability to cardiac arrest. The causes are rarely a lack of knowledge – they are almost always systemic weaknesses: similar-sounding or similar-looking preparations, time pressure, lack of standardization, and inadequate read-back routines. This article examines the LASA problem (Look-Alike, Sound-Alike) in detail and presents concrete safety strategies that have been proven to reduce mix-ups – from standardized syringe labels to Tall-Man-Lettering to consistent read-back technique.

The LASA Problem: Why Mix-Ups Are So Common

LASA stands for Look-Alike, Sound-Alike and describes medications that sound similar in name (Sound-Alike) or whose packaging, ampoule shape, or labeling is visually confusable (Look-Alike). In emergency medicine, this risk is amplified by several factors:

• Time pressure: During a resuscitation or anaphylactic shock, there is no time for thorough reading.
• Stress-induced cognitive impairment: Under stress, the brain processes visual and auditory information more superficially – a phenomenon known as confirmation bias. You read what you expect to read.
• Standardized ampoule sizes: Many manufacturers use identical glass ampoules with only minimal differences in labeling.
• Similar storage: In emergency bags or anesthesia carts, medications are often stored in immediate proximity to one another.

Classic LASA Pairs in Emergency Medicine

The following list shows frequently confused medication pairs that repeatedly appear in Critical Incident Reporting Systems (CIRS):

Sound-Alike Pairs	Look-Alike Pairs
Epinephrine ↔ Atropine	KCl ampoules ↔ NaCl ampoules
Sufentanil ↔ Fentanyl	Midazolam ↔ Metoclopramide (similar ampoule color)
Dobutamine ↔ Dopamine	Norepinephrine ↔ Epinephrine (clear ampoules, similar labels)
Heparin ↔ Insulin	Propofol ↔ Intralipid (white emulsions)
Ondansetron ↔ Granisetron	Succinylcholine ↔ other clear solutions
Vecuronium ↔ Verapamil	Thiopental ↔ other yellow solutions

A mix-up of succinylcholine with another clear medication can be immediately life-threatening in a patient who cannot be intubated. The confusion of potassium chloride with sodium chloride – often packaged in nearly identical ampoules – has led to documented deaths worldwide and is a textbook example of systemic Look-Alike failure.

Standardized Syringe Labels According to ISO 26825

The international standard ISO 26825 defines a color-coded system for syringe labels in anesthesiology and emergency medicine. The goal is to make medication groups visually and unambiguously identifiable through uniform colors. This system is not merely a recommendation – it is required as a standard by the DGAI, the ÖSG, and international professional societies.

Color Coding by Medication Group

Color	Medication Group	Examples
Blue	Opioids	Fentanyl, Sufentanil, Morphine, Remifentanil
Orange	Neuromuscular blocking agents	Rocuronium, Succinylcholine, Cisatracurium
Yellow	Induction hypnotics	Propofol, Thiopental, Etomidate, Ketamine
Red	Neuromuscular blocking agent antagonists / Emergency medications	Sugammadex, Neostigmine, Epinephrine
Violet	Vasopressors	Norepinephrine, Phenylephrine, Vasopressin
Green	Anticholinergics	Atropine, Glycopyrrolate
Light blue (Cyan)	Benzodiazepines	Midazolam, Diazepam
Salmon	Antagonists	Naloxone, Flumazenil

Correct Application in Clinical Practice

The mere availability of colored labels is not sufficient. What matters is consistent implementation:

• Every syringe is labeled immediately after drawing up – never set down unlabeled syringes.
• Never accept prepared syringes from other people without verifying the contents yourself.
• Use uniform labels throughout the entire facility – mixed systems (handwritten, different manufacturers) increase the risk of error.
• Discard unlabeled syringes – a syringe without a label is by definition not safely identifiable.

A common mistake in practice: The color coding is used as the sole identification. However, the color identifies the group, not the individual medication. Rocuronium and succinylcholine both carry an orange label – a mix-up within the group therefore remains possible and can only be prevented by reading the drug name.

Tall-Man-Lettering: Visual Differentiation at the Character Level

Tall-Man-Lettering (TML) is a typographic strategy in which the differing letters of similar-sounding medication names are highlighted in uppercase letters. The goal: The eye is deliberately directed to the differentiating syllables, and the automated (and error-prone) reading process is interrupted.

Examples of Tall-Man-Lettering

• DOBUTamine vs. DOPamine
• SUFentanil vs. FENTanyl vs. ALFentanil vs. REMIfentanil
• hydrALAZINe vs. hydrOXYzine
• ePINEPHrine (Epinephrine) vs. ePHEDrine
• CLONidine vs. CloZAPine
• predniSOLONe vs. predniSONe

The evidence on Tall-Man-Lettering shows a significant reduction in mix-ups in controlled studies, particularly for Sound-Alike pairs. The FDA, ISMP (Institute for Safe Medication Practices), and numerous European drug regulatory agencies recommend the implementation of TML in clinical information systems, medication labels, and prescribing systems.

Implementation in Practice

• Integration into computerized physician order entry systems (CPOE)
• Use on storage labels in the emergency cart and anesthesia workstation
• Training the entire team so that the logic behind the capitalization is understood
• Combination with color coding for maximum effect

Read-Back Technique: Closed-Loop Communication for Medications

The read-back technique (closed-loop communication) is a communication standard originating from aviation that has been established in medicine as a key safety instrument. In the context of medication administration, it follows a three-step process:

The Three-Step Process

1. Order (Call-Out): The prescribing person gives a clear, complete order. "Please give epinephrine 1 mg intravenously."

2. Read-Back: The administering person repeats the order aloud and completely. "Epinephrine 1 mg intravenously – drawn up."

3. Confirmation: The prescribing person confirms the correctness. "Correct, please administer."

Common Sources of Error and How to Avoid Them

• Incomplete orders: "Give some epinephrine" – without dose, without route of administration. Always state drug name, dose, and route of administration.
• Nonverbal confirmation: A nod is not an adequate read-back. Verbal repetition is essential.
• Omission under time pressure: Especially during resuscitation, the read-back technique is frequently abbreviated or skipped. Yet this is precisely when the risk of error is highest.
• Similar-sounding dosages: "Fifteen" and "fifty" are frequently confused under noise and stress. Better: "One-five milligrams" instead of "fifteen milligrams."

The read-back technique is not a bureaucratic formality – it is an active error intervention strategy. Studies from anesthesiology show that closed-loop communication can reduce the error rate in medication administration by up to 50%.

Additional Systemic Safety Strategies

Five Rights Rule

The classic Five Rights Rule forms the foundation of every safe medication administration:

1. Right patient
2. Right medication
3. Right dose
4. Right route
5. Right time

Some institutions expand this concept with additional "rights": right documentation, right indication, right rate (for infusions). What matters is not the number of "rights" but the consistent application as a mental checklist before every single administration.

Storage and Organization

• Physical separation of LASA pairs: Medications that can be confused should never be stored next to each other.
• Removal of concentrated potassium chloride from ward areas – it belongs exclusively in the pharmacy or in specially secured cabinets.
• Standardized stocking of the emergency cart: Always identical compartments, identical arrangement. Any deviation creates uncertainty.
• Avoidance of stocking similar-looking medications in the same compartment.

Barcode Scanning and Electronic Safety Systems

Modern safety systems complement human strategies with technological barriers:

• Barcode-based medication verification: Before administration, the ampoule is scanned and electronically matched against the prescription.
• Smart Pumps: Infusion pumps with integrated medication libraries that alert to dose exceedances.
• Automated Dispensing Systems: Cabinet systems that release only the prescribed medication.

These systems are highly effective, but they do not replace human vigilance. Technical systems can be bypassed (override functions), and in prehospital emergency medicine, they are often unavailable.

The Role of Team Culture: Speaking Up and Just Culture

All technical and organizational measures fail if the team culture does not allow concerns to be voiced. Speaking Up – actively addressing a perceived error or uncertainty – is one of the most effective safety barriers of all.

In hierarchical structures, which are still prevalent in the medical field, nurses or junior colleagues frequently remain silent, even when they notice a mix-up. A Just Culture, on the other hand, promotes:

• Fear-free reporting of errors and near-misses (CIRS systems)
• Appreciation of questions: Whoever asks questions demonstrates a sense of responsibility, not incompetence
• Standardized escalation phrases: e.g., "I am concerned that…" or "Stop – I would like to double-check the medication together."
• Debriefing after critical events: Systematic review to learn from errors

The Swiss Cheese Model by Reason

James Reason's model illustrates why a single error rarely leads to harm – it must penetrate multiple safety barriers simultaneously. Each of the strategies described here forms such a barrier:

• Color-coded labels
• Tall-Man-Lettering
• Read-back technique
• Five Rights Rule
• Physical separation
• Speaking Up

Only when all holes in the cheese align simultaneously does patient harm occur. The goal is therefore never the perfect individual measure, but redundancy: as many independent barriers as possible that back each other up.

Summary: Your Personal Checklist

Medication mix-ups are not a matter of individual failure but of systemic vulnerability. The following measures should be part of your daily routine:

• Read the ampoule – read it aloud – before drawing up and after drawing up
• Label every syringe immediately – in compliance with ISO 26825
• Apply the read-back technique consistently – even under time pressure, especially under time pressure
• Know LASA pairs and physically separate them
• Understand Tall-Man-Lettering and implement it where possible
• Discard unlabeled syringes – without exception
• Practice Speaking Up – voicing doubt is patient safety
• Never accept a syringe from someone else's hand without verifying it yourself

Practical Training

Medication safety can be understood in theory, but it can only be internalized through practice. In realistic simulation scenarios – under time pressure, in a team, with genuine stress – it becomes apparent how susceptible even experienced colleagues are to mix-ups. This awareness is the first step toward sustainable error prevention. In the emergency training courses by Simulation Tirol, you train structured medication administration, closed-loop communication, and CRM principles in a safe environment – with the goal that safe routines hold up even when it really matters.