The emergency department performs greater numbers of various treatments and procedures than any other department in your institution. Unfortunately, the emergency department also is the most frequent location for death and disability because of inefficient care and a frequent site of adverse events in medicine, according to the Joint Commission.
The ability to maintain quality control and patient safety is increasingly an unachievable goal. We need to design our work environment to prevent errors, to alert the team when an error has occurred, and to reduce the effects of user errors. This is a monumental task.
Mistake-proofing is the use of process or design features to prevent errors and their negative effects. In Japanese slang, this concept is known as poka-yoke (pronounced poka-yokay), and nowhere has it been systematized better than at Toyota under mistake-proofing guru Shigeo Shingo. Formalized by Japanese manufacturers in the 1960s, mistake-proofing was translated into English in the 1980s.
The process is older than that, however. The Otis elevator brake, which stopped an elevator between floors when a cable broke, was introduced in the 1850s. The elevator cable could still sever or disconnect, but the Otis brake allowed the elevator operator to mitigate the damage by stopping the elevator mid-floor. Another example of mistake-proofing involves the filing cabinet; early ones would tip over if more than one was open at a time. The mistake-proof design, though, locks the other drawers when one drawer is open. Human ingenuity has been used to prevent or mitigate mistakes humans make. It is high time such efforts took off in our work environment.
One scheme for understanding how we turn thought into action (and how we make mistakes) notes that a task involves two steps: determining the intent of the action and executing the action based on that intent. Mistakes occur when the wrong intent is formulated and when the intent is correct but the action does not occur as intended.
We can think of mistakes as errors of intent and errors in execution. To mistake-proof, you need to anticipate the errors in execution to design around them. A great example of mistake-proofing in the ED is the end-tidal CO2 monitor. The intent here is to put a tube into a trachea, but as we know, that action can fail in many ways during execution. Devices use colorimetric information or digital readouts to cue users that the ET tube is in the esophagus, detecting errors in execution before damages occur.
Knowledge in the World
Donald A. Norman wrote in The Design of Everyday Things (Doubleday, 1989) that knowledge in the head is information in the human memory, and efforts at mistake-proofing historically involved putting more knowledge in the head. Knowledge in the world is information provided as part of the environment in which a task is performed.
Too often in the ED we try to remedy errors with training: putting more information in the user's head when knowledge in the world is more effective. Lookalike medications, such as eye preparations containing papillary-dilating drugs, are an example. After a nurse inadvertently puts papillary-dilating medication into the eyes of a patient with acute angle closure glaucoma, the traditional paradigm would involve retraining and reprimands, but making the labels on these preparations visibly red has increasingly prevented this error.
A better example involves instruction manuals that outline tasks with many steps unfamiliar to the user. By copying the information on only one side of the paper, however, the user can't inadvertently go to the wrong page when a manual is open. Another change is to do away with manuals and use real-time cues. When computer technology is employed, pop-up screens with immediate feedback to the user informing him that the action has been performed incorrectly encourages correct performance of complex tasks.
As manufacturing and service industries have realized, knowledge in the head and safety that depends on people is far less effective than using knowledge in the world and safety that depends on systems or design.
Another error that is typically only whispered about after a sentinel event is placement of enteric nutrition fluids into IV sites. The remedy here is to make the IV hub and the feeding tube incompatible. Mislabeled lab specimens also plague EDs everyday, often because lab specimens are obtained before the patient's registration is complete and labels are printed after the specimen is collected. Asking staff to label a rainbow collection of blood tubes by hand is time-consuming, and compliance is difficult to maintain. One solution stores multiple tubes of blood with one handwritten label, and an even better system involves a wristband with preprinted labels and a unique ID number. As the blood is drawn, the labels are peeled from the patient's wristband and applied to the tubes. These tubes may be sent to the lab for stat results or held until a permanent ID number is assigned. Reconciliation of the data can occur at any time.
In general, mistake-proofing is inexpensive, and most experts say interventions will save money because reduced errors save money and time. (Mistake-Proofing the Design of Healthcare Processes. AHRQ Publications, May 2007.) ED staff have a long history of improvisation and jury-rigging the world to facilitate their patients' needs, such as using a Foley catheter balloon as posterior nasal packing, using the Seldinger technique and a central line guidewire for retrograde intubation, and using bed sheets as levers to relocate a shoulder. It is time to use that ingenuity to make our work foolproof and our departments safer for our patients.