Adverse events are
common in patients with cancer. Sometimes these are events potentially
anticipated as a result of their treatment. But many
adverse events in cancer patients are also potentially preventable.
Researchers at Memorial Sloan Kettering Cancer Center recently looked at
a sample of cancer patients to see how often they suffered adverse events and
how often such were preventable (Lipitz-Snyderman
2017). The sample included 400 randomly selected
patients from a population of patients with lung, colorectal or breast cancer. Overall,
they found 304 adverse events (AE’s), for an overall rate of 2.3 events per
1000 patient days (91.2 per 1000 inpatient days and 0.9 per 1000 outpatient
days). Thirty-four percent of the patients had 1 or more AE’s and 16% of the
patients had 1 or more preventable or mitigable AE’s.
The AE rate for patients with breast cancer was lower than the rate for
patients with colorectal or lung cancer. Sixty-three percent of AE’s occurred
in the inpatient setting, for a rate of 79.0 AE’s per 100 hospital admissions.
Nearly a third of
all AE’s (32%) were deemed definitely or
probably preventable. The rate of preventable or mitigable
AE’s for inpatients was 29.9 AE’s per 100 hospital admissions. For preventable AE’s,
the rates were 31.52 per 1000 inpatient days and 0.24 per 1000 outpatient days.
For mitigable AE’s, the rates were 3.82 and 0.08,
respectively. The overall rate of
preventable AE’s was 0.73 per 1000 patient days, and the rate of mitigable AE’s was 0.13 per 1000 patient days.
The AE and
preventable or mitigable AE rates by setting differed
by cancer type. The largest proportion of preventable or mitigable AE’s of the total AE’s belonged to lung cancer
(47%), followed by colorectal cancer (36%) and breast cancer (20%). Regarding
stage of disease, overall AE’s and preventable/mitigable
AE’s occurred more frequently in patients with advanced disease for colorectal
cancer, but not for lung or breast cancer.
The study does not go into great detail
about the actual adverse events but does provide general categories for them.
Infectious events (such as C. diff infection) were the most common AE’s. Other frequent
types included things like mucositis, hematologic events like thrombocytopenia,
and metabolic events like hypokalemia or hypomagnesemia.
Approximately half of all AE’s occurred within 3 months of
the first treatment.
Regarding harm, 6%
of overall AE’s and 4% of preventable AE’s were deemed to have resulted in
permanent harm, to have required life-sustaining intervention, or to have resulted
in death.
One of the types of adverse event that cancer patients are
particularly vulnerable to is medication error. Complex regimens and multiple
venues where they receive medications may be contributing factors. In our May 5, 2015 Patient Safety Tip of the Week “Errors
with Oral Oncology Drugs” we described many of the other factors involved
in such errors. In addition, chemotherapy agents are high-alert medications,
meaning that errors related to these drugs have a high potential for causing
patient harm.
The Pennsylvania Patient Safety Authority (PPSA) recently
reported on over 1000 medication errors from outpatient hematology and oncology
clinics reported to the Pennsylvania Patient Safety Reporting System (PA-PSRS)
over a two year period (Banasser
2017). High-alert medications were reported in 55.5% of the events,
with antineoplastic agents making up 94.3% of those medication errors reported
with high-alert medications. (Other high-alert medications in this patient
population included opioids and anticoagulants). But chemotherapy
pre-medications, colony-stimulating agents, and corticosteroids were other
agents involved in reports.
Though errors most frequently involved the prescribing node
followed by the administering mode, errors occurred in every step of the
medication use process (i.e., prescribing, transcribing, dispensing,
administering, and monitoring).
Dose omissions (15.3%) and wrong dose/over dosage (13.1%)
were among the most common errors encountered. The medication classes most frequently
associated with dose omissions were antineoplastic agents, colony stimulating
factors, and systemic corticosteroids.
Drugs involved most often in wrong dose/overdose events were
antineoplastic agents and corticosteroids. Fortunately, two-thirds of these
events were intercepted before reaching the patient and none resulted in
patient harm. But the one-third that did reach the patient required monitoring
or interventions to prevent harm.
Because so many of these drugs have dosages calculated based
upon variables such as incorrect patient weight, height, body surface area
(BSA), or serum creatinine level, it is not surprising that incorrect
information about those factors contributed to some of the wrong dose errors.
The authors point out that one patient safety intervention designed to prevent
errors, i.e. having CPOE systems calculate dosages based upon such variables,
will result in error if the underlying patient information is incorrect. We’ve
done several columns on the importance of accurate and up-to-date weights (see
list of columns below). Particularly in a cancer patient population, where
weight loss may be frequent, it is important to have an up-to-date weight to
use in dosage calculations. Some of the errors might also result from not
having the most up-to-date laboratory information when dosage calculations or
decisions about whether to proceed with a medication are made.
7.8% of errors were “wrong time” events. These were most
often due to schedule errors or to delays in treatment.
Wrong drug errors also accounted for 7.8% of the errors.
Name confusion was a common theme (for example, confusing PACLitaxel
and DOCEtaxel or CARBOplatin
and CISplatin). And our old favorite of confusion
between morphine and HYDROmorphone was also reported.
Infusion-rate errors, omission of drugs or hydration, and
improper preparation of drugs were also reported, albeit less frequently.
The PPSA paper has numerous recommendations to help avoid
medication errors in this patient population and setting:
One very interesting study was reported at the recent
Congress of the Oncology Nursing Society (Sato-DiLorenzo 2018). Laboratory values are typically
checked prior to administration of chemotherapy to ensure the chemotherapy can
be safely given. The researchers identified many near-misses related to this
process and identified contributing causes, including lack of clear treatment
criteria, a delay in lab processing, and patients expressing distress due to
long wait times. They then developed two interventions to help prevent
near-misses or actual adverse events:
Prior to the intervention there were 4-11 near-misses/week.
In the 3 months after the intervention there was only a single near-miss.
However, continued surveillance for the next 7 months found 0-3
near-misses/week. They identified barriers to full success, such as returning
to past habits and the primary nurse simply telling the second verifying nurse
that pre-treatment labs have been verified. They suggest there may be a limit
to how human actions alone can produce sustainable changes.
We’ve done multiple columns on the limitations of double checks (see, for example, our
Patient Safety Tips of the Week for October
16, 2012 “What
is the Evidence on Double Checks?” and April 19, 2016 “Independent
Double Checks and Oral Chemotherapy”). Nevertheless, double checks do have an important role when
dealing with high-alert medications, like chemotherapy agents. But those must
be truly “independent” double checks. That means the second healthcare worker
needs to independently verify a dose calculation or lab data prior to
discussing results with the other healthcare worker.
Our April 19, 2016 Patient
Safety Tip of the Week “Independent
Double Checks and Oral Chemotherapy” noted that the number opportunities for double checking is typically
far less for oral chemotherapy compared to intravenous chemotherapy. Also, with
oral chemotherapy in some settings you may be dealing with community
pharmacists who are less experienced (compared with cancer center pharmacists)
with the many complexities of chemotherapy regimens.
The Just Bag It!
campaign calls for health care professionals to always dilute vincristine in a
50ml mini-IV drip bag and never in a syringe to minimize the risk of such
incidents.
The other has to do with both the
route and method of administration. The complex nature of some chemotherapy,
involving multiple drugs and cycles, also contributes to medication errors in
cancer patients. One type of chemotherapy adverse event we have been
particularly concerned with is that in which a chemotherapy drug intended to be infused over several days gets infused
much more rapidly (see our Patient Safety Tips of the Week for September 11, 2007 “Root
Cause Analysis of Chemotherapy Overdose”, April 6, 2010 “Cancer
Chemotherapy Accidents”
and September 15, 2015 “Another
Possible Good Use of a Checklist”).
In those columns on home infusion chemotherapy we noted no one seemed to be
asking “what is the highest dose that a patient could tolerate in one day (or
less) if there was inadvertent administration of the infusion?”. A safety
culture would design the protocol with sublethal dosages that would protect the
patient in the event of “what can go wrong will go wrong”. It also would not
put the healthcare workers at the “sharp end” in a situation none of us would
want to be in. The same question should apply to oral chemotherapy regimens and
be “What would be the highest aggregate dose a patient could tolerate over a
specified period?” and avoid prescribing more than that inadvertently. Yes, the
patient might be inconvenienced by having to do another physician or clinic
visit to get a prescription for the next cycle or the second part of a complex
regimen. But isn’t that preferable to receiving a chemotherapy overdose due to
an avoidable error?
And there is always
yet the problem of patient
misidentification. A recent report identified several factors that
contributed to such an incident (Schulmeister 2018):
“In a busy outpatient registration area, a recently hired clerk followed the
facility’s procedure and entered the name printed on the patient’s driver’s
license. She clicked the first name in the list that appeared on her computer
screen and created a wristband, unaware that other patients with the same name
existed in the system. The clerk asked the patient if the information on the
band was correct, and he said yes. In court testimony later, he stated that he
was not wearing his glasses at the time and was relying on the hospital staff
to apply the correct wristband. The patient was sent to the busy infusion area
at noon for his second chemotherapy treatment. A registered nurse asked him if
his name was John Jones (name changed here for privacy) and if his birthday was
the date that she read from his wristband. He nodded yes. But an error was
made. The patient received the chemotherapy intended for another patient who
had the same name but a different birthdate.” The problem of patient
misidentification, of course, is not unique to cancer patients. But, given that
chemotherapy agents are high-risk drugs, the consequences of such misidentifications
in an oncology setting are likely to be particularly devastating.
Lastly a recent review of interventions to improve oral
chemotherapy safety and quality shows we still have lots of room for
improvement (Zerillo
2018). A literature search strategy identified almost 8000 abstracts
in the peer-reviewed literature but only 16 full-text articles met inclusion
criteria and the overall quality of the literature had shortcomings. Even those
studies that had positive findings may not be generalizable because they were
single institution studies or focused primarily on specific drugs or diseases. Many
of the interventions and studies focused on adherence to chemotherapy. But
among those that focused on safety/toxicity there was a trend toward lower
toxicity profile in those interventions that focused on increased monitoring.
Telephone calls, usually by an oncology nurse or pharmacist, shortly after
initiation of a chemotherapy regimen were the most successful intervention. But
the optimal frequency of calls and how long such calls should be continued are
unknown. Drug diaries and pharmacist education on adverse effects were also
noted to be useful interventions.
Our prior columns related to chemotherapy safety:
Some of our other
columns on errors related to patient weights:
References:
Lipitz-Snyderman A, Pfister D,
Classen D, et al. Preventable and mitigable adverse
events in cancer care: Measuring risk and harm across the continuum. Cancer
2017; 123(23): 4728-4736
http://onlinelibrary.wiley.com/doi/10.1002/cncr.30916/abstract
Banasser G, Karpow
C, Gaunt MJ, , Grissinger M.
Medication Errors in Outpatient Hematology and Oncology Clinics. Pa Patient Saf Advis 2017; 14(4): 1-15
http://patientsafety.pa.gov/ADVISORIES/Pages/201712_oncology.aspx
Sato-DiLorenzo A, Wright D,
Carvalho M, Coletti E, Zerillo
J, Shea M. Combating chemotherapy verification fatigue: nurse-led quality
improvement interventions in pre-treatment lab evaluation. Oral presentation
at: ONS 43rd Annual Meeting; May 17-20, 2018; Washington, DC; presented May 18,
2018
https://ons.confex.com/ons/2018/meetingapp.cgi/Paper/2802
Schulmeister L. Cancer Treatment
to the Wrong Patient: Why Does This Still Happen? Oncology Nursing News 2018;
March 08, 2018
Zerillo JA, Goldenberg BA, Kotecha RR, et al. Interventions to Improve Oral Chemotherapy Safety and Quality. A Systematic Review.
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