Alert: Flow control tubing for mechanical infusion pump

Safer Care Victoria was recently notified of 5 adverse events where incorrect tubing had been connected to a mechanical infusion pump, resulting in an anaesthetic agent being administered at a higher rate than intended. 

Poor design of tube labelling and lack of other system-based safety guards likely contributed to these adverse events. 

Background and issue

In each of these clinical incidents, lignocaine was being administered via a mechanical infusion pump connected to tubing that controlled the flow of medication. The wrong tubing was used, and the lignocaine was delivered at a faster rate than intended. 

Three of these adverse events resulted in patient harm relating to temporary neurological toxicity.

Poor label design of tubing connectors

The different flow control tubing sets were identical except for the labels indicating the flow rate. The labels on the tubing had different colours, but the flow rate was written on the labels in a similar format, in the same font and text colour (Figure 1). There were 12 different flow rates of tubing available for use. 

Figure 1: Examples of tubing labels

Medication errors due to similarities in packaging or labelling are a common and significant challenge in delivering safe healthcare. Healthcare environments are complex, high stakes, under resourced and often time pressured. Under these conditions, poorly designed healthcare equipment can impact the decision-making of frontline staff, as humans have a natural tendency to rely on visual cues.

Unfortunately, healthcare is behind other high-risk industries when it comes to applying good Human Factors design principles  that help support human performance effectively. For medication errors these might be:

• distinct labelling and colour coding
• physical separation/barriers
• forcing functions such as different connectors to prevent accidental inadvertent connections. 

Medication errors can be mitigated by implementing systems and processes that reduce a reliance on visual cues. 

Resources and advice for health services

The following actions may help mitigate the occurrence of similar medication errors. The strongest risk controls focus on physical changes such as forcing functions or physical separation or re-design to aid visual recognition, rather than education or policies.

Changes to the physical environment

Consider using smart pumps to deliver intravenous medications. If well designed, smart pumps can provide additional safeguards against medication errors but come with their own risks and challenges including cost.

Safer Care Victoria and the Institute for Safe Medication Practices Canada recently delivered a webinar on intravenous and ambulatory pump medication safety, highlighting:

• how we need to be aware of human capabilities and limitations when implementing smart pumps 
• opportunities for implementation of system safeguards, safety enhancements, and continuous improvement.

Remove unnecessary options. In the flow tubing adverse events, multiple tubes were being used on the ward. Consider if the number of options can be reduced to minimise the room for confusion. If all the flow rates are required, move the faster flow rate tubes to a different location. 

Guidelines, protocols and warnings

Develop evidence-based decision support tools

For example, a lignocaine infusion guideline that includes specific guidance on administration and monitoring considerations. The National Safety and Quality Health Service Medication Safety Standard provides strategies for improvement on information and decision support tools for medicines.

Additional alerts and warnings

Consider additional warning through labelling or alerts at points of potential error. For example, when the tubing is selected, when the nurse collects the medication from the imprest shelf, or when pharmacy dispenses the medication.

Reiterate the six rights of safe medication administration

Right patient, right medication, right dose, right time, right route, and right documentation. 

Strength of the recommendations

Effective recommendations focus on actionable design improvements across the system. They avoid solely addressing an individual component or focusing on addressing human behaviour through more training and education.

A hierarchy of risk control is a well-known framework to guide the development of strong recommendations from a human factors engineering perspective*. The above actions have been rated as strong, moderate, or weaker. The stronger actions are focused on system-based changes, whereas the weak recommendations are focus on improving the system by attempting to change human behaviour through more training or new policies and procedures.

Table 1 contrasts the proposed systems improvements for tubing connector adverse events against the three different levels of strengths. 

Table 1: Rating the strength of recommendations – hierarchy of risk controls

* [1] U.S. Department of Veterans Affairs – VA National Center for Patient Safety (2015). Root Cause Analysis Tools, https://www.patientsafety.va.gov/media/rca.asp, p. 22