Issue 47.
Routine Home Treatment of
Deep Vein Thrombosis
Aggregate data from a recent meta-analysis of randomised
trials, also summarised in a Cochrane systematic review, show that low molecular
weight heparin is at least as effective and safe as unfractionated heparin for
the initial treatment of deep vein thrombosis. Unlike unfractionated heparin,
which is usually given by continuous intravenous infusion, low molecular weight
heparin can be given subcutaneously in a fixed, weight adjusted dose without the
need for laboratory monitoring. This has simplified the initial management of
deep vein thrombosis and facilitated the potential for home treatment. The
safety and efficacy of low molecular weight heparin for home treatment of
proximal deep vein thrombosis have subsequently been confirmed in several
randomised trials. Home treatment has the additional advantages of greater
efficiency of healthcare delivery and improved quality of life for patients.
Nevertheless, uncertainty remains about the optimal selection
of patients for home treatment. In the randomised trials up to half of
outpatients presenting with proximal deep vein thrombosis were ineligible for
inclusion because of a history of recurrent venous thromboembolism, concomitant
symptomatic pulmonary embolism, coexisting conditions requiring hospitalisation
or associated with an increased risk of bleeding, or concerns about the
feasibility of administering low molecular weight heparin at home. Even among
patients randomised to home treatment, up to half were initially admitted to
hospital, and in one trial 25% of patients randomised to home treatment received
all their low molecular weight heparin in hospital. This has led to questions
about the generalisability of these trials to everyday clinical practice and may
account for the reluctance of some centres to consider home treatment.
In this issue Schwarz et al report their recent experience
with home treatment of acute deep vein thrombosis. In a cohort of 117
consecutive outpatients with confirmed proximal or distal deep vein thrombosis,
three patients (2.6%; 95% confidence interval 0.9% to 7.1%) were excluded from
home treatment based on their medical condition, while an additional 22 patients
(18.8%; 12.2% to 27.1%) were admitted because they could not inject the heparin
or undergo daily testing at home or presented outside working hours. In the 92
patients (78.6%, 70.1% to 85.7%) treated at home, no episodes of clinical
pulmonary embolism or major bleeding were observed during three months of
follow-up.
These data add to a growing body of evidence supporting the
safety and feasibility of routinely treating patients with acute deep vein
thrombosis at home. In one of the first studies to evaluate this question
outside a randomised trial, Lindmarket et al showed that about 80% of 434
consecutive patients could be safely treated at home for at least a part of the
acute treatment phase. These findings were confirmed in prospective cohort
studies from Canada and the United Kingdom involving a combined total of 1693
consecutive patients, of whom about 80% were treated at home without ever being
admitted. The incidences of recurrent venous thromboembolism (3.6-6.7%), major
bleeding (0-2.2%), and death (0.9-8.7%) in these studies were comparable with
those reported in the trials of highly selected patients.
Ref:
(Web)
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Restricting pack
sizes of paracetamol and salicylate
This shortened version of a BMJ paper looked at the effects on suicidal
behaviour of legislation limiting the size of
packs of paracetamol and salicylates sold over the counter.
UK population, with detailed monitoring of data from five
liver units and seven general hospitals, between September 1996 and September
1999.
People who died by suicidal or accidental overdose with
paracetamol or salicylates, or who died of undetermined causes; patients
admitted to liver units with hepatic paracetamol poisoning; patients presenting
to general hospitals with self poisoning after taking paracetamol or
salicylates.
Mortality from paracetamol or salicylate overdose; numbers of
patients referred to liver units or listed for liver transplant; numbers of
transplantations; numbers of overdoses and tablets taken; blood concentrations
of the drugs; prothrombin times; sales to pharmacies and other outlets of
paracetamol and salicylates.
Numbers of tablets per pack of paracetamol and salicylates
decreased markedly in the year after the change in legislation on 16 September
1998. The annual number of deaths from paracetamol poisoning decreased by 21%
(95% confidence interval 5% to 34%) and the number from salicylates decreased by
48% (11% to 70%). Liver transplant rates after paracetamol poisoning decreased
by 66% (55% to 74%). The rate of non-fatal self-poisoning with paracetamol in
any form decreased by 11% (5% to 16%), mainly because of a 15% (8% to 21%)
reduction in overdoses of paracetamol in non-compound form. The average number
of tablets taken in paracetamol overdoses decreased by 7% (0% to 12%), and the
proportion involving > 32 tablets decreased by 17% (4% to 28%). The average
number of tablets taken in salicylate overdoses did not decrease, but 34% fewer
(2% to 56%) salicylate overdoses involved > 32 tablets. After the legislation
mean blood concentrations of salicylates after overdose decreased, as did
prothrombin times; mean blood concentrations of paracetamol did not change.
Legislation restricting pack sizes of paracetamol and
salicylates in the United Kingdom has had substantial beneficial effects on
mortality and morbidity associated with self poisoning using these drugs.
Ref
(web)
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Limiting operations to
high volume teams
Four out of 10 consultant firms would no longer be able to
carry out at least one of 12 common elective procedures if the NHS moved to a
system where only firms that carried out a high volume of specific operations
were allowed to perform that particular operation.
Because it is widely believed that a higher volume of work
results in better quality, organisations representing clinical specialists have
begun to set minimum volume thresholds for their members.
But now researchers from Birmingham University, have shown
that if a volume threshold of at least 59 procedures a year were set for a range
of 12 common elective procedures, then about 40% of firms would no longer be
eligible to provide one of these procedures.
“ Even if a lower ‘one
a month’ threshold were set, about 20% of firms would still not be eligible to
provide that procedure”, the report said. They point out that the relationship
between volume and quality was supported by only a modest amount of evidence.
But the researchers added that the relation was “probably real enough to
justify these policies”.
“ Some consultants would
see the introduction of a high-volume policy as an opportunity to further
specialise and super-specialise. Others would see it as a policy that restricts
them to providing a narrower range of procedures, makes their professional
practice less interesting, and reduces their professional autonomy.
“ Postgraduate training
institutions need to consider the possibility and implications of high-volume
policies, as many junior doctors would probably need to learn to provide a
narrower range of skills
than at
present”.
One of the authors, epidemiologist Dr Richard Wilson, said, “The
implications are quite profound, and that is one of the alarming things about it”.
He added that even a threshold of 50 procedures a year “would require a vast
change in the way services are delivered”.
Ref
(Web)
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