Just about anything that can land
a patient in a hospital can also put them at risk of
a blood clot.
Yet everyone who works in one knows
that prophylaxis of venous thromboembolism (VTE) is
an underused procedure. Just how big a problem is this
in Canada? Pretty darn big, according to a study soon
to be published in Thrombosis Research.
FAILURE
TO TREAT
Guidelines recommending prophylaxis for at-risk medical
inpatients have been around for a long time. If followed
religiously, they would indicate such treatment for
a frank majority of those admitted, even an overwhelming
majority. But in the real world, this never seems to
happen.
To try and understand why, researchers
from hospitals associated with McGill, McMaster, Calgary
and Laval universities looked at 1,894 medical patients
admitted to 29 Canadian hospitals over a three-week
period. Twenty were teaching hospitals and nine were
community hospitals, spanning six provinces: British
Columbia, Alberta, Saskatchewan, Ontario, Quebec and
Nova Scotia.
The results were not encouraging.
While 90% of the patients in the analysis were proper
candidates for prophylaxis, according to the guidelines
of the American College of Chest Physicians, only 23%
received it. And only two-thirds of those who were treated
received the type of prophylaxis appropriate to their
condition. The most common mistake was the use of mechanical
methods, such as elastic stockings, in patients who
were eligible for pharmacological treatment, namely
anticoagulants.
GLOBAL
RISK
McGill University's Dr Susan Kahn, who led the study,
doubts the utility of such methods. "Mechanical prophylaxis
has not been convincingly shown to prevent clots in
medical inpatients," she says. Add the patients who
received it anyway to those considered not to have received
appropriate prophylaxis, and the percentage who actually
got the right treatment drops to 16%. As the authors
described it, this is "unacceptably low".
Take a look at the list of risk
factors that indicate prophylaxis for VTE, and it quickly
becomes clear why, in the end, practically everyone
who crosses a hospital's threshold should be treated.
Risk factors include: heart attack, stroke, congestive
heart failure, severe infection, malignacy, chemotherapy,
hormone replacement, contraception, varicose veins,
surgery, lower limb trauma, immobilisation or paralysis,
pregnancy and thrombophilia.
Dr Kahn argues that it would probably
be better to just give prophylaxis to everyone than
to achieve such minimal coverage as was seen in this
study. "I'm more concerned about the risk of under-prophylaxis
of at-risk patients than over-prophylaxis of low-risk
patients," she says.
The few cases of non-indicated
treatment that turned up in the study didn't concern
her overmuch. "Prophylaxis is not likely to be harmful.
The approach of prophylaxis for all patients has already
been taken, with success, in orthopaedic surgery patients,
where risk of VTE is considered high enough to warrant
it," she argues. The risk in medical patients is lower,
of course, but "still high enough," she adds. Dr Kahn
estimates that, based on previous research she co-authored
in the journal Chest, appropriate prophylaxis
should prevent about one in six cases of symptomatic
VTE.
PRIORITY
PASS
So why are our hospitals underutilizing this simple
treatment to such an alarming extent? There are some
clues in the findings. Tertiary care centres used the
treatment about 50% more than community hospitals, suggesting
that doctors in the latter group are less exposed to
lectures and education on the subject, suggests Dr Kahn.
Specifically Canadian guidelines might help a little,
she says, but the American College of Chest Physicians'
guidelines are well known among Canadian doctors.
Internists were also more likely
than other specialities to use prophylaxis, which may
reflect a broader, more holistic approach to patient
care. And this may be the key. Physicians are simply
missing the wood for the trees. Cancer patients notably
received the least prophylaxis of all. Quite simply,
says Dr Kahn, "treatment of a patient's other acute
problems tends to take precedence over preventing a
condition that hasn't yet arisen."
|
