Since our species became Homo
sapiens, about 100 billion humans have walked the
earth, and it's a good bet that peritonitis felled more
of them than any other single medical condition. Today
in developed countries, peritonitis is still surprisingly
common, and can be fatal to those who get it.
Laparotomy followed by a planned
relaparotomy are the favoured methods for tackling these
infections. But now a new Dutch study in the August
22/29 Journal of the American Medical Association
concluded that a more conservative approach of only
re-operating on severe peritonitis patients who meet
certain criteria doesn't increase mortality and morbidity
- and saves time and money in the process.
DOUBLE
TROUBLE
Secondary peritonitis accounts for just under one percent
of hospital admissions in the US, and on top of these
cases, about 14% of patients undergoing elective abdominal
surgery also develop secondary peritonitis. Mortality
rates have been cited ranging from 20% of cases to a
shocking 60%, and the burden of morbidity and hospital
resource use is high.
Because severe peritonitis often
involves abscesses beyond the reach of antibiotics,
the standard treatment is laparotomy with removal of
the loci of infection. But this only clears the infection
in about two-thirds of cases.
To prevent the unnecessary deterioration
of large numbers of patients, many doctors in the 1980s
began to practise automatic relaparotomy, in which a
second operation was scheduled for a fixed period after
the first. This would enable the surgeon to identify
any regrowth of infection and remove it. Several retrospective
studies suggested this approach improved overall outcomes.
But there were no prospective studies
to confirm it, until now. The Dutch researchers writing
in JAMA compared planned relaparotomy to "on-demand"
relaparatomy in which the physician only re-operates
if the patient meets certain pre-defined criteria that
suggest the infection is not cleared.
The new study does not confirm
that preplanned relaparotomy leads to better outcomes.
In terms of the primary outcomes - mortality and morbidity
over 12 months - it showed no significant difference
between scheduled and on-demand relaparotomy, though
the trend was towards better outcomes in the on-demand
group.
This was a superiority hypothesis
study, meaning that its purpose was to prove the new
treatment - on-demand relaparotomy - better than the
old. In the event, the 232-patient, randomized, non-blinded
trial narrowly failed to prove non-inferiority, since
the confidence intervals allowed a small possibility
that the new treatment performed worse than the old.
But that may be enough, given the cost and time savings
it brings.
SHORTER
STAYS
As for the secondary end points - total number of re-operations,
proportion of patients requiring three or more re-operations,
number of percutaneous drainages required, days receiving
ventilatory support, duration of stay and cost - on-demand
outperformed scheduled laparotomy by a significant margin
in each.
That's hardly surprising, given
that the scheduled group had a reoperation rate of 92%,
while in the on-demand group only 42% underwent a second
procedure. Direct medical costs were 23% lower in the
on-demand group. Their median stays were seven days
in intensive care and 27 in the hospital, compared to
11 and 35 days in the scheduled group.
Needless to say, the second surgery
was far more likely to reveal infection in the patients
who were selected after showing symptoms. While 34%
of those in the planned relaparotomy group had positive
findings, 68% of those in the on-demand group did.
But this still translates to a
fairly large number of unnecessary procedures, argues
Dr E Patchen Dellinger of Washington University, in
an accompanying editorial. "The rate of 32% negative
relaparotomy in the on-demand group suggests that even
in this group surgeons may be a little too quick to
operate, and better tools are needed to make this decision,"
he notes.
Overall, he concludes, the Dutch
team's well-designed study has done more than any previous
research to demonstrate that scheduled relaparotomy
is not helpful. But there are obvious exceptions, such
as when surgical packing has been left in the patient,
or when the surgeon closes up suspecting that not all
loci of infection have been removed.
"What surgeons should focus on
now is the search for more accurate and sensitive methods
to recognise in as timely a manner as possible when
a patient will need another intervention. This may include
improved understanding of clinical patterns, novel imaging
techniques and possibly new biomarkers," writes Dr Dellinger.
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