"Knowledge and error flow from the same mental resources, only success can tell the one from the other." - Ernst Mach (1905)Can a small nick, cut or scrape kill anyone? The answer in the affirmative seems to have been the unfortunate outcome for a strapping 12-year old lad, Rory Staunton, who cut himself while diving for the basketball in gym class. The simple cut led to an irreversible series of events -- when the wound was infected by bacteria (Group A streptococcus) leading to septic shock -- that resulted in the untimely death in a New York City Hospital. (You can read the full story here as reported by New York Times)
Patient safety -- and the prevention of iatrogenic error (medical error) -- is of very big concern to medical practitioners, insurers and hospital systems -- and, last but not least, the patients and their family. Despite a wealth of research over the last several years on this topic, by scholars ranging from doctors to human factors scientists, there is still an occurrence of mishaps like the one reported above. Fortunately, the more egregious kind, wrong limb amputation or wrong-site surgery, by and large have been mitigated in recent years due to change in procedures.
Returning to Rory, he displayed signs such as fever, an upset stomach and blotches on the skin. The first doctor, his pediatrician, to treat him seems to have concluded that they were unrelated to the wound; perhaps caused by a stomach flu? (Although on hindsight it is now possible to infer that those signs may have been the first signs of septic shock.) When his signs didn't subside, the pediatrician sent him to the emergency department at the NYU Langone Medical Center (LMC).
This transfer of care, from one physician and clinic to another, is the beginning of complexity as knowledge about the case and information, from Rory (the patient himself), family, pediatrician had to be passed on to the hospital. These entities together form a socio-technical system as it consists of many players, technologies, and moving parts.
One of the first things that is done, to an incoming patient at LMC's Emergency Department (ED) is to screen him/her for sepsis. This is done using a checklist -- which was also done to Rory upon admission. At that time, he didn't have the required 3 or more indications for sepsis, which is used to raise the red flag. The initial hypothesis of a stomach flu, first formulated by the pediatrician, was pursued by LMC's emergency physician as well. The emergency department physician thus decided to alleviate Rory's condition, under the assumption they were caused by the stomach flu. She administered IV fluids, which seem to have improved Rory's condition. This improvement seems to have provided a sufficient, but NOT necessary, condition for the ED physician to discharge Rory from the hospital. Because later readings collected and tests (Fig. 1) done by LMC -- a few hours after admission -- did reveal that Rory was entering into septic shock. Neither the ED physician nor the hospital seem to have mentally registered this newly acquired information, which could have either prevented the premature discharge; or could have been used as a trigger to contact Rory's family even after the patient was discharged to begin treatment for sepsis.
Fig. 1 Severe Sepsis Triage Screening Tool (via NYT -- See this bigger image for details)
Rory's physicians seem to have deployed an "anchoring heuristic," as they held firm with their first hypothesis of stomach flu and never saw his signs and symptoms under a different light. The anchoring heuristic is not unusual to human cognition, where one mistakenly anchors to the first hypothesis and doesn't consider alternatives resulting in a decision bias, or first hypothesis error.
Once Rory was incorrectly discharged, it turned out to be a point of no return. He went into septic shock at home (fever, nausea, pain, etc.). He was rushed back to the LMC's emergency department and despite the best efforts of the doctors he could not be revived.
Ex post facto, of course, with our "hindsight bias," it is easy to blame the emergency physician for prematurely discharging the patient and attribute it to negligence or at-risk, reckless behavior. But one has no idea as to the circumstances (technical to financial pressures) that may have led to that incorrect decision. And it is highly likely that this was an unintentional error on the part of the physician at that time as she had no idea on what may occur thereafter.
In this posting, I will simplify this somewhat complex systems issue and highlight just two major theories that may partly explain the failure of the system in Rory's case:
1) Swiss cheese model
2) Blunt-end/Sharp end
Despite the safety barriers we humans devise in complex and safety-critical systems (aviation, nuclear power, medicine, etc.) somehow an adverse event worms its way through the "holes" in these barriers. This was iconically explained by the safety expert James Reason with his Swiss Cheese Model (Fig. 2).
Fig. 2: Swiss Cheese Model for Accident (via S2S)
The latent failures are "invisible" (hidden in the system), until the stresses and strains in the system cause the proverbial holes in the Swiss Cheese slices expose them.
Often times, after a tragic accident has occurred, the spot light is put on the human agent -- whether it be a physician, pilot or operator -- who is on the front-lines making the final call, decision or intervention. This is referred to as the sharp end of the system. Little attention is paid to the "back office" or blunt-end of the system where policies, procedures, training, financial/throughput pressures exist and may influence how the sharp-end performs. This was best captured by Woods & Cook in their blunt-end/sharp-end model (Fig. 3).
Fig. 3 Blunt-end/Sharp-end (via Woods & Cook)
When one analyzes the blunt-end, it is possible that any one of these (or more) could have contributed to the physicians unintentional errors:
- Are the physicians trained to avoid diagnostic biases (e.g., anchoring heuristic)?
- Insufficient time due to "throughput" pressures
- Patient turnover due to financial pressures
- Capacity of ER (does the ER have the resources (room, medical staff, etc.) to permit a wait, watch and observe protocol for a patient whose recovery status is unclear?; or is there pressure to make room for the next incoming patient due to patient volume?)
- So that even if the professionals missed something flagged by EMR, the patient or his caregivers would be notified electronically (smart phone, computer, etc.), and they can in turn resume the dialogue with the professional healers to clarify it or seek further assistance.
There are also things that can be done outside the system. For instance, how about educating the public that a freshly incurred wound should be washed under running water before putting on a band-aid? Because washing the wound is the first line of defense against infection and possible sepsis down road.
Blaming a physician at the "sharp-end" of the system may be emotionally satisfying. The physician's poor judgment or flawed decision making at the sharp-end are more than likely to have been a product of a fragile socio-technical system. What is needed is a more reasoned and seasoned approach at the socio-technical systems level, with its many layers, to prevent the next tragic error.
Ernst Mach observed "Knowledge and error flow from the same mental resources, only success can tell the one from the other." And a well designed healthcare socio-technical system has the potential to favor knowledge over error, promote recovery rather than adverse outcomes.
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