INTRODUCTION

Medication errors are a cause of severe lesions and serious perioperative complications. These events are the result of poor standardization of the process of preparation, administration and labeling, particularly with regards to injectable medications.

During anesthesia, several drugs are simultaneously administered, which result in a wide range of effects, in an stressing environment with multiple distractions and a significant work load. On many occasions, there is poor visibility and in some drugs there is often a change in their presentation (depending on changes of pharmaceutical vendors). The process of preparation and administration of injectable drugs is not homogeneous and is sensitive to various causes of error. It is well recognized that medication errors during the perioperative period are a significant source of morbidity and rarely of fatalities. The incidence of error in anesthesia is estimated between 1:133 and 1:274 anesthesia procedures ¹ and mortality as a result of anesthesia errors associated to medications is estimated to be 1:298 (0,3 %). ² Considering that in average each anesthesiologist is responsible for four anesthesia procedures per day (1,252/ year), it is possible to have between four to nine errors of this nature per year. Over 30 years of practice, and if 1% have severe consequences, one to two patients may experience a severe of fatal lesion. ³

Some of the most frequently reported errors associated with the use of medications, include: 1) confusion with the route of administration (intravenous, arterial, epidural); 2) confusion with vials and syringes (Look-Alike Sound-Alike "LASA"), and 3) errors in the medical devices for administration of medications. ⁴

Historically, various strategies have been introduced to mitigate medication errors, including the use of color labels based on the pharmacological group and the introduction of capital letters to facilitate a rapid identification, concentration and route of administration. An analysis of critical incidents in anesthesia found that the introduction of labeling of syringes reduced the number of errors in the administration of mediations from 1:484 to 1:817 anesthesia procedures (59 %). ⁵

These are some of the recommendations used to reduce anesthesia medication errors: 1) careful reading of drug label before it is prepared and injected by the practitioner; 2) double check (nurse and anesthesiologist); 3) legible labeling of syringes and vials (color and letter type which facilitates an adequate identification of the manufacturer and the label placed on the syringe that will be used); 4) have the medications neatly organized in the work area used by the practitioner, and 5) proper storage. ^6,7

The Safety and Quality Guidelines in Anesthesia of the European Union and the Declaration of Helsinki on patient safety, recommend implementing protocols ad guidelines for labeling of medications used in anesthesia, with a standardized international color code. ^8,9

COLOR CODE EXCLUSIVELY FOR ANESTHESIA

A color-based classification code has been established to identify the various groups of pharmacological products which has been adopted and standardized by the Anesthesia Societies of various countries, including the United States, Canada, Spain, England and the United Kingdom, Australia and New Zealand, France, and Italy. ^10-17

Following is a list of the groups of medicines frequently used in anesthesia (Table 1).

Table 1 Medications frequently used in anesthesia and their color code. 

Group	ASTMφ-RGBᵮ - ISO*	Color Sistema Pantone®ϫ
Anesthesia induction agents	255.255.0φᵮ	Yellow
Opioids/narcotics	133.199.227φ	Blue 297
Opioid antagonists/narcotics	133.199.227φᵮ	Blue 297 with white diagonal stripes
Muscle relaxants	255.114.118φᵮ 253-121-86*ᵮ 245.64.41*ᵮ	Fluorescent Red 805 Red 811 Warm Red
Relaxant antagonists	255.114.118φᵮ 253.121.86*ᵮ	Fluorescent red 805 with white diagonal stripes
Local anesthetic agents	194.184.171φᵮ	Grey 401
Anticholinergics	163.217.99φᵮ	Green 367
Benzodiazepines and tranquilizers	255.102.0φᵮ	Orange 151
Benzodiazepine antagonists	255.102.0φᵮ	Orange 151 with white diagonal stripes
Antiemetics/tranquilizers	237.194.130φᵮ	Salmon 156
Vasopressors	222.191.217φᵮ	Violet 256
Hypotensive agents	222.191.217φᵮ	Violet 256 with white diagonal stripes
Betablockers	176.135.112φᵮ	Copper 876U
Anticoagulants & antiplatelet drugs	34.211.197φᵮ	Bluish green
Miscellaneous	255.255.255φᵮ	White

Source: Adapted from:

-Royal College of Anaesthetists, Association of Anaesthetists of Great Britain and Ireland, Faculty of Accident and Emergency Medicine, Intensive Care Society. Syringe labelling in critical care areas review ¹⁴.

- American Society of Anesthesiologist. Statement on labeling of pharmaceuticals used in the practice of Anesthesiology ¹⁰.

- Canadian standards association. Standard for use-applied drug labels in anesthesia and critical care ¹³).

- Sicurezza in Anestesia e Area Critica per la somministrazione dei farmaci ¹⁷.

- Recommendations for labeling of injectable drugs administered in anesthesia. Spanish reporting

system on Anesthesia and Resuscitation Safety - SENSAR ¹⁸.

φ ASTM: American Society for Testing and Materials

ᵮ RGB S3 color combination system: red, green and blue

* ISO: International Organization for Standardization

Ϫ Pantone System - a registered universal color coded scale (https://www.pantone.com/eu/es/)

RECOMMENDATIONS FOR THE PREPARATION OF MEDICATIONS IN ANESTHESIA

The following recommendations are derived from the recommendations of the Spanish Reporting System on Anesthesia and Resuscitation for labeling of injectable drugs administered in anesthesia. ¹⁸

LABEL

The following are the recommendations for labeling of injectable medications administered in anesthesia.

SYRINGE LABELING

Each label should measure between 3.5 and 4.5 cm long and 1.5 to 2.5 cm de wide; made of adhesive material adequate to write with ballpen or any other indelible ink. The label is placed horizontally without covering the numbered markings on the syringe (Figure 1).

Source: Author.

Figure 1 Syringes with color-labeled medications. 

Other recommendations associated with labeling:

Table 2 Labeling of medications used in anesthesia and their color code. 

Therapeutic group	Medications	Label example
Induction of anesthesia agents	Propofol, thiopental ketamine, etomidate
Muscle relaxants	Rocuronium, vecuronium cisatracurium Exception: Succinylcholine (Red with the name over a black strip in the upper part of the label)
Muscle relaxant antagonists	Neostigmine, physostigmine sugammadex
Opioids	Fentanyl, remifentanil morphine, meperidine tramadol, hydromorphone
Opioid antagonist	Naloxone
Benzodiazepines and tranquilizers	Midazolam, diazepam phenytoin
Benzodiazepine antagonists	Flumazenil
Anticholinergics	Atropine
Local anesthetic agents	Lidocaine, bupivacaine levobupivacaine, ropivacaine}
Vasopressors	Phenylephrine, etilefrine adrenaline, noradrenaline dopamine, dobutamine milrinone Exception: Adrenaline (violet with name over a black strip in the upper part)
Antiemetics and major tranquilizers	Ondansetron, metoclopramide dexamethasone, haloperidol
Anticoagulants	Tirofiban, abciximab urokinase Exception heparin (bluish green, with black frame 1-2 m)
Heparin antagonists	Protamine
Miscellaneous	Dexmedetomidine, oxytocin tranexamic acid, amiodarone magnesium, furosemide omeprazole, antibiotics

Source: Adapted from:

- Royal College of Anaesthetists, Association of Anaesthetists of Great Britain and Ireland, Faculty of Accident and Emergency Medicine, Intensive Care Society. Syringe labelling in critical care areas review ^₍₁₄₎ .

- American Society of Anesthesiologist. Statement on labeling of pharmaceuticals used in the practice of Anesthesiology ^₍₁₀₎ .

- Canadian standards association. Standard for use-applied drug labels in anesthesia and critical care ^₍₁₃₎ .

- Sicurezza in Anestesia e Area Critica per la somministrazione dei farmaci ^₍₁₇₎ .

- Recommendations for labeling of injectable drugs administered in anesthesia. Spanish reporting system on

Anesthesia and Resuscitation Safety - SENSAR ^₍₁₈₎ .

LIST OF MEDICATIONS IN CAPITAL LETTERS

Since 2001 the FDA required the manufacturers of generic drugs with similar names to use a combination of Tall Man bold letters to minimize LASA errors and facilitate their identification, since the use of color based on the pharmacological group was not found to be effective enough ^19-21.

These capital letters are not necessarily at the beginning of the name but may be used anywhere and it could 1 or more letters, to differentiate the molecules with a similar name (Table 3).

It should be highlighted that, notwithstanding the implementation of these measures (such as color coding in anesthesia) implemented over two decades ago, its use is not yet widespread in the institutions in our country. Furthermore, compliance has been poor in the institutions where the label methodology is available.

There is a need to create awareness about the importance of using this type of measures in our country and in other countries in the region. Undoubtfully, training, implementation and management by the scientific societies and government agencies may translate into safer surgical care. It is essential to adopt guidelines for labeling of medications used in anesthesia at the national level. Finally, the implementation of a color code, and the inclusion of Tall Man Lettering are most helpful for the correct identification of anesthesia agents. Finally, the implementation of a color code, as well as the inclusion of Tall Man Lettering are extremely helpful for the correct identification of the drugs to be administered and represent an additional protective barrier for a safe anesthesia. Actively improving the implementation of these measures, with the involvement of the pharmaceutical industry and the national policies, with help in reducing these complications.