Cardiac Arrest Due to Leaky Equipment

By ThinkReliability Staff

A patient death associated with equipment that does not perform properly is one of the “Never Events” (i.e. events that should never happen).  A case where a leaking piece of equipment caused the cardiac arrest of a child is described by the ECRI Institute.  We can record this information in a Cause Map, or visual root cause analysis in order to show the relationships between the causes and suggested solutions.  The root cause analysis investigation can be seen by clicking on “Download PDF”.

Because a patient suffered cardiac arrest, there was an impact to the patient safety goal.  We begin this impacted goal and ask “Why” questions to add more causes to the Cause Map.  The cardiac arrest was caused by suffocation.  The suffocation was a result of undetected excessive carbon dioxide (CO2) levels.  The levels were undetected because the child was under anesthesia (thus making it difficult to judge the breathing air quality) and because there was no device to detect high CO2 levels.  The CO2 levels were high due to rebreathing.  (The high CO2 levels were an impact to the patient services  and environmental goals as well.)

The rebreathing occurred because of a lower than normal fresh gas (breathing oxygen) flow.  With a breathing system of this type, the rebreathing (or taking in exhaled CO2) is inversely proportional to the fresh gas flow.  As the gas flow decreases, the rebreathing increases.  The reduced fresh gas flow was caused by a leaky humidifier.  (The leaky humidifier can be considered an impact to the property goal.)  The leaky humidifier was caused by an unrepaired pressure drop through the gas flow passages.  The pressure drop was caused by an inadequate seal on those passages due to two (of four) loose screws that were apparently not noticed.

The leak had been detected during the pre-use test of the equipment.  The leak was believed to be repaired, but instead of performing another pre-use test of the equipment, the system was put together, and a test was done on the whole system.  The system has a higher allowed leak rate than each individual piece of equipment, so the fact that the leak was not in fact repaired was not noticed.

Some of the suggestions given by ECRI Institute to prevent this kind of incident from recurring are to install a CO2 detector on the breathing circuit, ensure the anesthesia equipment is on a regular inspection and maintenance program, and to redo individual equipment tests after repairs.