particularly those with very early onset high-
grade single OF or multi-organ failure termed as fulminant pancreatitis.
19, 31
The mortality due to OF is high even after the first 2 weeks. Patients with persistent OF who
survive the first 2 weeks are prone to develop infected necrosis, which accounts for the late
mortality. In a French study of 148 patients, 40 of 53 (75%) patients with persistent OF
developed infected pancreatic necrosis (IPN).
41
In another study, 76% of patients with
persistent OF developed IPN after they survived the first 2 weeks.
9
Hypotension in the first
week of AP was an independent risk factor for IPN.
42
There is not much difference between
mortality due to early onset OF and late onset OF (Table 2) Two recent studies have focused
attention on the issue of timing of onset of OF and outcome in AP. In a study of 614 patients,
early onset primary OF resulted in early mortality in 15.8% of patients and a further 42.8%
late mortality due to development of infected necrosis.
9
In a Dutch study of 639 patients,
219 patients with persistent OF had a mortality of 38%. Mortality was not related to timing
of onset of persistent OF. Mortality due to persistent OF developing within the first week,
1-2 weeks, 2-3 weeks and >3 weeks from the onset was 42%, 46%, 36% and 29%
respectively in that study.
10
Patients with OF and IPN have a high mortality termed ‘critical
AP’ according to the Determinant based classification.
43
But the data are inconsistent as to
whether they have a higher mortality than those with early persistent OF without IPN. In the
Dutch study, similar mortality rates were observed in patients with OF with and without IPN
(28% vs. 34%, p=0.33) after excluding patients with mortality within 10 days of admission.
10
In summary, the progression of an early systemic inflammatory response to organ failure
defines severe AP and is associated with a high risk of mortality. Development of infected
necrosis later in the clinical course exacerbates the initial injury and worsens the outcome.