Wayne Jowett died a month after the mistake.
Wayne Jowett, aged 18, was diagnosed with Acute Lymphoblastic Leukaemia in June 1999. He was enrolled on the UK Medical Research Council's UKALL Trial XII and received his treatment at Queen's Medical Centre (QMC), in Nottingham. In June 2000 his disease was in remission and he entered the maintenance phase of his treatment. This consisted of the following drugs:
- 6-Mercaptopurine, PO, daily
- Methotrexate, PO, weekly
- Prednisolone, PO, three-monthly
- Vincristine, Intravenously, 3-monthly
- Cytosine, Intrathecally, 3-monthly
In December 2000 Wayne was due to be admitted for the administration of Vincristine and Cytosine. But because of the Christmas festivities, it was arranged that Wayne would have his course of chemotherapy on January 4th 2001. This information was not communicated on E17, the ward where Wayne was usually treated.Morning of Thursday January 4th 2001
On the morning of January 4th 2001, the sister on E17 discovered that the chemotherapy drugs for Wayne were not prepared and asked Dr Musuka, Wayne's consultant, to prescribe them. The latter entered the 2 agents on the drug chart:
- Vincristine, dose 2 mg, route IV, date to be administered '5.1.1'
- Cytosine, dose 50 mg, route changed from IV to IT and bracketed (IT) to mark the change, date to be administered '4.1.1'
However, Wayne did not arrive for his appointment on the morning of January 4th 2001. Dr Musuka told the nursing staff that he would leave the ward but wanted to be notified upon Wayne's arrival. This instruction was not directed to anyone in particular and it was not noted in the patient's medical notes.
The Pharmacist responsible for E17 was not aware of Wayne's appointment either, and when he got the drug chart later in the morning at the Sterile Production Unit (where chemotherapeutic agents are prepared), he assumed that this was needed urgently. He noted that cytosine was needed on the same day and arranged its preparation immediately. He also noted that vincristine would be given the following morning and wrote in his production log that it would be required for 'FRI AM'. However, he asked that the vincristine be prepared at the same time as well, to save time. This was common practice at QMC, with the intention of avoiding long waiting times by patients. The pharmacist noted down that the two drugs should be sent separately. The two agents were subsequently prepared, checked and put into two mini grip bags. When a few minutes later the pharmacy staff received a phone call requesting the chemotherapy for Wayne, both bags were sent together.Afternoon of Thursday January 4th 2001
Wayne arrived at E17 at 1530hrs and Staff Nurse Vallance notified Dr Morton, a senior House officer, who was covering the ward. Dr Musuka was not informed. According to guidelines, intrathecal administration of chemotherapeutic agents should be supervised by a registrar. Therefore Dr Mulhemm, the only registrar on the ward on that afternoon, was called to help Dr Morton. Staff nurse Vallance went to the Day case unit refrigerator, where she found the only chemotherapy item in there. It was a transparent plastic bag, containing the 2 mini grip bags. She took the plastic bag to the treatment room and recalls saying: 'here's Wayne's chemo'. Ms Vallance then left the room and the two doctors went on with the procedure. The lumbar puncture site was marked and local anaesthetic was infiltrated in the area. Dr Mulhem had a brief look at the prescription chart, but failed to recognize that vincristine was due to be given the following morning or that it should be given intravenously. Dr Morton performed the lumbar puncture. Dr Mulhem then read out aloud the name of the patient and the name and dose of the drug to be given. He did not mention the route of administration. Taking the syringe, Dr Morton asked whether the drug was 'Cytosine' and Dr Mulhem confirmed that it was. Dr Morton then injected the contents of the syringe into Wayne's spine. Cytosine was successfully injected in Wayne's spine. Dr Mulhem then read out aloud the name and dose of the second drug (vincristine) and gave the syringe to Dr Morton. A few moments later Dr Morton injected Vincristine in Wayne's spine, unaware of the devastating effects that this would soon have. Vincristine, when given intrathecally, causes Central Nervous System toxicity producing progressive assending myeloencephalopathy.
It was only a few minutes later that the two of them realized that a serious mistake had happened. None of them knew the consequences of this mistake. Dr Mulhem immediately called for senior help. Other members of the medical and nursing team were subsequently involved and remedial treatment was commenced.
Wayne Jowett subsequently suffered leg paralysis and respiratory failure. He was transferred to the Intensive Care Unit, where he was intubated and ventilated. His ventilator was switched off 4 weeks later, at 8:10 am on February 2nd 2001.
The case received a lot of publicity and featured in the British newspapers for months. Dr Mulhem spent 11 months in custody while waiting for his trial on charges of manslaughter and medical negligence. He was eventually found guilty and was sentenced to 8 months, which he had already spent, therefore he was let free.
Despite the legal implications of the case, the coroner declared the cause of death of Wayne Jowett as accidental. And indeed, an independent external inquiry of the incident found that Wayne's death was caused by a series of accidental mistakes and systems failures.The Swiss cheese hypothesis
Errors can be viewed (or studied) either by a personal approach or a system approach. The former looks into all the factors that might contribute to an individual making a mistake, for example forgetfulness, irritation, carelessness and poor motivation. The latter looks into how institutions are organised. The systems approach also states that mistakes are inevitable and its purpose is to put some 'countermeasures' in place that can prevent potential disasters.
The swiss cheese model of how defences, barriers and safeguards maybe penetrated by an accident rajectory. Figure 1
In any organisation, there are many safety nets for the prevention of disaster. These range from simple things like alarms and physical barriers to more complicated ones like electronic shut downs and administrative controls. Each one of them acts as a separate safety net. Even if one or two fail, the rest will still be enough to prevent an adverse event.
This can be compared to many slices of Swiss cheese. Each slice has a few holes, which are in different places. In some unfortunate cases though, everything seems to go wrong: the holes in many layers momentarily line up to permit a trajectory of accident opportunity, bringing hazards into damaging contact with victims. The figure 1 explains this concept.
It would therefore be interesting to see what 'holes'in the chemotherapy system at QMC on Thursday January 4th 2001 permitted the vincristine mistake to happen and thus led to Wayne Jowett's death.Non-coherence and potential unfamiliarity with protocol
The UKALL Trial XII protocol states that the 3 agents given on a 3-montlhy basis (Prednisolone, Vincristine and Cytosine) should be administered on the same day. However, QMC protocol stated that Vincristine and Cytosine should not be given on the same day, but on two consecutive days, to prevent any errors in their method of administration. Despite this guideline, and the fact that this was also noted by the pharmacist during the preparation of the drugs, these were sent together. The pharmacists dispatching them and the nurse receiving them did not question this and staff nurse Vallance, who was helping with the lumbar puncture, also failed to notice it. The reason for this is not known. Was it because the individuals involved were not aware of this protocol? Or was it because they all mutually assumed that each other knew what they were doing?Prescription chart
Both drugs were prescribed on the same prescription chart. In a number of hospitals intrathecal chemotherapy is prescribed on a separate prescription chart, using a different colour, to drugs administered intravenously. Firstly, a different coloured prescription chart would have flagged to the physicians concerned that particular care was required. Secondly, the Vincristine would not have been entered on to the prescription chart and thus Dr Mulhem would have had a drug present that had not been prescribed. Thus clearly signalling that something was wrong.Closed loop communication
This is a fairly new concept which puts a stronger emphasis on effective communication. It describes the practice of repeating back information when one member the team makes a request of another. For example, in this particular case study, Dr Musuka asked the nursing staff to inform him about Wayne's arrival. However, this piece of information was not directed to a particular person. No one took overall responsibility of this task. The loop remained open. Had Dr Musuka directed the instruction to someone in particular, that person would then feel responsible of carrying it out. Likewise, if a nurse repeated the instruction back to Dr Musuka, she would have closed the loop, she would have confirmed that the instruction was noted and would be taken care of.The packaging of the 2 drugs
Picture showing a syringe containing Cytosine and a syringe containing Vincristine, similar to the ones used in Wayen's case.
Unfortunately, while there are a number of physical dissimilarities between a syringe that contains Vincristine and one that contains a drug to be administered intrathecally, there are four visual similarities between the two syringes.
- The syringes used can be of the same size.
- The volumes of the 2 drugs used were similar.
- Cytosine and vincristine have no individually recognizable colours. They are both clear fluids.
- A syringe containing vincristine can be connected to a spinal needle and thus be delivered intrathecally.
It is therefore hard for an individual to recognize which drug is in each syringe. Had the two drugs had different colours, or had they been in different sized syringes, the potential mistake might had been picked up. For example Methotrexate, another chemotherapeutic drug, comes as a yellow solution for exactly this reason.The dispatching of the 2 agents
According to the QMC protocol the two drugs (vincristine and cytosine) should not be placed in the same bag. It remains unclear why pharmacy staff dispatching and nursing staff receiving the medication allowed this to happen. It proved impossible for the inquiry panel to determine exactly why both types of chemotherapy came to be in the same bag.Staff on E17
Wayne was supposed to be admitted on E17 in the morning of January 4th, at a time when there were a lot of registrars and consultants around to supervise chemotherapies. Tragically, no chemotherapies were scheduled to happen on Thursday afternoon and therefore no registrars or consultants were present at the time of Wayne's arrival on the ward.The particulars of Dr Morton's employment and experience
Dr Morton had only been on E17 for 5 weeks and was still learning how things worked. That was his first oncology rotation and he had only administered intrathecal chemotherapy once before, under the supervision of his seniors. Dr Morton had not received any training regarding the intrathecal administration of chemotherapy agents. On January 4th 2001, he thought that Dr Mulhem was very experienced on chemotherapy and followed his advice without questioning it.The particulars of Dr Mulhem's employment and experience
It was Dr Mulhem's 2nd day on the ward, when the incident took place. This was also his first job as a registrar. He had no experience with chemotherapy in the past. He had not received any training on chemotherapy.
The "induction process" on Ward E 17 for new registrars (SpR) is informal. During the first two weeks, a new SpR is allocated a more experienced Staff Grade Doctor to act as a Mentor. A new SpR is told to "shadow" the Mentor, however there does not appear to be any explicit definition of what such shadowing might consist of. Nor what the new SpR should do with their time when the Mentor is not present. Dr Mulhem was informed that he would not be doing much on the ward for the first couple of weeks and that he should "shadow" Dr Grimley, a staff grade doctor, to see how the system on the ward worked. When he was called to supervise Dr Morton, he thought that his presence was only typical as he had presumed that Dr Morton had administered intrathecal chemotherapy agents many times in the past. He later told the inquiry, that his exact role and responsibility were not clearly explained to him and that he presumed that Dr Morton had a lot of experience.Varying guidelines between different NHS Trusts
Prior to his appointment as a registrar on E17, Dr Mulhem worked as a Senior House Officer on a haematology ward at Leicester Royal Infirmary. There different protocols exist, where drugs that cannot be given intrathecally are not allowed to be kept in the treatment room. He therefore assumed that in order for the 2 drugs to be found in the chemotherapy box, it meant that they were safe to be given. He states:
"The system for the administration of chemotherapy at Leicester was that drugs for administration intrathecally were never available on the ward at the same time as drugs for administration by another route. When I administered chemotherapy, only intrathecal drugs were in the chemotherapy box."Involuntary Automaticity
During the procedure, protocol says that one should read out loud the name of the drug to be given, so that any misunderstandings can be clarified and mistakes are avoided. This is called a verbal challenge—response protocol, and has been developed and used in the aviation. It is another kind of a closed loop communication. Dr Mulhem therefore said out aloud that the drug to be given was Vincristine. Although he knew that vincristine should not be given intrathecally, at the time of the procedure he thought that the drug being administered was methotrexate. Even though he read out loud the name VINCRISTINE, in his mind he thought that it was methotrexate. On direct questioning later, he cannot recall whether he:
"...actually said the word 'Vincristine' but once again I had clearly fixed in my mind that the drug was Methotrexate and not a drug for administration other than IT. If I had consciously appreciated that the drug was Vincristine I would have stopped the procedure immediately and would never allowed Dr Morton to administer it."
This is a recognized error, called involuntary automaticity. It was first described in the aviation, who check their equipment so often, that the procedure becomes routinized and only a superficial amount of attention is paid. In Wayne's case even though Dr Mulhem read out loud the name Vincristine, he was not fully concentrated on the task, and in his mind he was thinking of methotrexate.
Dr Mulhem cannot explain why he translated the word "Vincristine" for "Methotrexate", except for the fact that his mindset was that drugs for administration by a route other than intrathecal would simply not be available in the treatment room at the same time.Hierarchy
The overall purpose of the double-checking response protocol is that the piece of information is being checked by 2 different professionals. Therefore if one misses or overlooks something, the other one will pick it up. In a way, it acts as a double safety net. If the first net is broken, there will be another one which can still prevent a disaster. In this case Dr Mulhem did not recognise that the drug to be administered was Vincristine. Therefore it was up to Dr Morton to recognise this mistake and stop the procedure. And indeed Dr Morton did recognize the mistake. He recalls repeating the name of the drug emphatically: 'Vincristine?'. To which Dr Mulhem answered affirmatively. Dr Morton was still not convinced and further questioned Dr Mulhem: 'Intrathecal vincristine?' at which point Dr Mulhem again replied positively, thinking that they were talking about methotrexate. At that point Dr Morton thought that he was wrong and that his superior did know better. He recalls:
"First of all, I was not in a position to challenge on the basis of my limited experience of this type of treatment. Second, I was an SHO and did what I was told to do by the Registrar. He was supervising me and I assumed he had the knowledge to know what was being done. Dr Mulhem was employed as a Registrar by QMC which is a centre for excellence and I did not intend to challenge him."
This is quite an important point, especially for junior staff with no major clinical experience. What is the point of a double-response safety protocol, if one of the two participants does not feel that they are in a position to challenge the other? On the other hand, Dr Morton did raise some concerns about intrathecal vincristine. Shouldn't that had been enough to stop the procedure?
Junior Staff are not used to challenge their superiors. This is more of an issue in some countries than in others. For example in Japan, the hierarchy is very strictly followed and someone would never think about challenging a more senior colleague. On the other hand in Denmark, the hierarchy system is more loose, and people feel more comfortable expressing their opinions and concerns. Had Dr Morton felt more confident in his knowledge and challenged Dr Mulhem further, the death of Wayne could have been prevented.Assumptions and the newcomer syndrome
The different professionals involved in Wayne's medical care held a number of assumptions
For example Dr Mulhem assumed that:
- chemotherapy agents with different routes of administration could not be on the ward at the same time (as happens at Leicester Royal Infirmary Practices)
- He was competent to supervise Dr Morton.
- Dr Morton was familiar with Wayne's case.
- Both drugs present were for intrathecal administration.
Dr Morton's assumptions were:
- Dr Mulhem was authorised to supervise him.
- As a registrar, Dr Mulhem knew about the particular drugs and the dangers associated with them.
- He should not challenge a senior colleague.
Van Maanen (1977:20) has observed:
"A newcomer assumes that he knows what the organization is about, assumes others in the setting have the same idea, and practically never bothers to check out these assumptions."
Professor Toft, who led the Independent Inquiry into Wayne Jowett's death notes on the matter:
"Dr Mulhem and Dr Morton both appear to have experienced the newcomer syndrome (…) They failed to recognise that their taken-for-granted assumptions about the working environment, themselves and each other were at variance with reality. The gap between their subjective perceptions of the situation and objective reality led to errors of judgement being made and subsequently to the death of Mr Jowett."
A study performed in 2006 identified 55 cases of inadvertent intrathecal vincristine administration since 1968. These occurred in the US, UK, Australia, Israel, Saudi Arabia and Singapore. The study also found that the 3 most commonly cited errors in vincristine administration were:
- Physician/nurse AND pharmacy error (69%)
- Pharmacy error only (19%)
- Physician/nurse error only (12%)
This shows that in the majority of cases at least two consecutive errors were 'needed' to 'allow' the mistake to happen. This also confirms the Swiss cheese hypothesis.Conclusion:
It is clear that the reasons leading to the tragic event on Thursday January 4th 2001 were very complex. These involved a combination of human and system errors. Although many new protocols and guidelines have been produced to prevent any future adverse events, it is up to each and everyone of us to stop these mistakes from happening.