Blood Incompatibility
Cause Mapping Example:
On February 22nd, 2003, a patient at Duke University Medical Center died after receiving her second heart-lung transplant. The first transplant she received was rejected by her body due to a blood type incompatibility (she was Type O, the organs were Type A). The loss of her life was tragic enough, but it was compounded by the fact that the two rare heart-lung block donations she received could have saved the lives of others as well.
This is an example of how the Cause Mapping process can be applied to a specific incident. In this case the transplant blood type mismatch is captured as an example of the Cause Mapping method. The three steps are 1) Define the problem, 2) Conduct the analysis and 3) Identify the best solutions. Each step will be discussed below.
Step 1. Define the Problem
The first step of the Cause Mapping approach is to define the problem by asking the four questions: What is the problem? When did it happen? Where did it happen? And how did it impact the goals? Here, we'll define the problem as "incorrect blood type in organ transplant." The magnitude of this incident is defined by the impact to the goals.
The second question is the "When?" which is the date and time of the incident. When captures the timing of the issue and also has a line for what was different or unusual in this occurrence. The question of what was different is fundamental in any investigation. On the transplant issue we capture the date as February 7, 2003 and the time of 4:50 p.m. when the transplant surgery began. The important difference here is that the patient was blood type O, and the organs were blood type A.
In an investigation there can be several pieces of information that need to be captured when specifying the location. At a minimum the physical/geographic location and the process should be captured. The physical location is where geographically the incident happened. Here, it occured in the Pediatric Intensive Care Unit of Duke University Medical Center of Durham, North Carolina. The process was a heart/lung transplant.
The next section is the impact to the overall goals. A hospital's overall goal is to have zero patient injuries. In this case, the patient who received the transplant died. Another one of the other goals is to provide needed patient services. This case resulted in organs that were no longer available for other patients. Additionally, the liability goal was affected but the magnitude of the loss of life makes any other goals less significant. The two main goals that are impacted in the transplant example are the patient safety goal and the patient services goal.
Step 2. Identify the Causes (The Analysis)
The analysis step is where the incident is broken down into causes which are captured on the Cause Map. The Cause Map starts by writing down the goals that were affected as defined in the problem outline. For the transplant issue, the patient safety goal was impacted because of the patient that was killed and the patient services goal was impacted because of the loss of organ availability. These are the first two cause-and-effect relationships in the analysis.
The analysis can continue by asking Why questions and moving to the right of either of the cause-and-effect relationships above. In this example we’ll start with the loss of life which was caused by the recipient's health condition deteriorating. The next question is “Why did her health deteriorate?” It deteriorated due to the immune system response and the second transplant surgery, both of which occurred because the recipient's body rejected the first set of organs.
The recipient's body rejected the first set of organs because organs were transplanted with the wrong blood type. This occurred because organs with the incorrect blood type were delivered to the operating room (OR), the blood type mismatch wasn't discovered in the ER, and the laboratory did not notify the OR of a blood mismatch until too late in the surgery. We'll look at each of these causes in more detail.
Organs of the incorrect blood type were delivered to the OR because the match was missed at pickup because the procuring surgeon did not know the recipient's blood type, and because organs with the incorrect blood type was matched to the recipient. This happened because donor services offered organs with the incorrect blood type because they didn't ask the patient's blood type, the surgeon did not verify the blood type of the organs because he assumed they would not have been offered if they were incompatible, and because of confusion. (A type A recipient, type O organ WOULD have been compatible.)
The mismatch was not recognized in the OR because the blood types were not checked. This is because there is no protocol for checking the blood type of organs and because the staff was in a hurry. They were in a hurry because the recipient's organs had already been removed because surgery begins while the organs are en-route due to the limited viability of the organs.
The laboratory did not notify the OR of the blood mismatch until too late in surgery (after 5 hours) because the surgery had already begun (see above) and because the testing was not performed until after the organs arrived (at which point the surgery was already well underway.)
Even more detail can be added to this Cause Map as the analysis continues. As with any investigation the level of detail in the analysis is based on the impact of the incident on the organization’s overall goals.
Step 3. Select the Best Solutions (Reduce the Risk)
Once the Cause Map is built to a sufficient level of detail with supporting evidence the solutions step can be started. The Cause Map is used to identify all the possible solutions for given issue so that the best solutions can be selected. It is easier to identify many possible solutions from the detailed Cause Map than the oversimplified high level analysis of "don't perform surgery with the wrong blood type organs."
There are causes to every issue. The transplant tragedy at a high level has only one cause. At a more detailed level it has 4 causes, 18 causes and 49 causes. All of the levels of the Cause Map are accurate - some simply have more detail that others. An issue should be worked to a sufficient level of detail to prevent the incident, meaning to reduce the risk of the incident occurring to an acceptable level. This is why solutions and work processes at a coffee shop are not as thorough or detailed as an airline or nuclear power facility. The risk or impact to the goals dictates how effective the solutions should be. Lower risk incidents will have relatively lower detail investigations while significantly high risk to an organization’s goals requires a much more through analysis.
Solutions are evaluated based on the acceptable risk level determined by an organization's overall goals. Once solutions are selected for implementation, they are assigned a person responsible and a due date and added to the action items list. The action items listed based on this analysis is shown below.
Cause Mapping Improves Problem Solving Skills
The Cause Mapping method focuses on the basics of the cause-and-effect principle so that it can be applied consistently to day-to-day issues as well as catastrophic, high risk issues. The steps of Cause Mapping are the same, but the level of detail is different. Focusing on the basics of the cause-and-effect principle make the Cause Mapping approach to root cause analysis a simple and effective method for investigating safety, environmental, compliance, customer, production, equipment or service issues.
Click on "Download PDF" above to download a PDF showing the Cause Map and Process Map.
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