Transcript Evidence-based apporach in managing acute pancreatitis

Evidence-based approach
in managing acute
pancreatitis
James Fung
Department of Surgery
Tseung Kwan O Hospital
Topic for discussion
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Serum amylase – how to use it in diagnosis?
Severity assessment
Antibiotic prophylaxis in SAP – is it useful?
Serum amylase – how to use it?
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Peaks within 12 – 24 hr from onset, normalize
within 3 – 5 days
Pitfalls:
Falsely high level: intra-abdominal inflammation;
salivary gland pathology
 Falsely normal level: delayed presentation;
pancreatic insufficiency; hypertriglyceridaemia1
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1.
Spechler SJ et al. Prevalence of normal serum amylase levels in patients with acute alcoholic pancreatitis.
Dig Dis Sci 1983; 28:865-9
Serum amylase – how to use it?
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Sn and Sp varies with diagnostic cut-off value
Steinberg et al1
Thomson et al2
Cut-off
(IU/L)
326
Sensitivity Specificity
94.9%
86%
600
92.3%
100%
316
95.6%
97.6%
1000
60.9%
100%
1.
Steinberg WM et al. Diagnostic assays in acute pancreatitis. A study of sensitivity and specificity. Ann Intern
Med 1985;102:576-80
2.
Thomson HJ et al. Diagnosis of acute pancreatitis: a proposed sequence of biochemical investigations.
Scand J Gastroenterol 1987;22:719-24
Use of serum amylase –
summary
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Useful only when used in a correct clinical
context
Diagnostic accuracy depends on threshold
Use supplementary tools when in doubt
Severity assessment
Acute pancreatitis
Mild acute
pancreatitis (80%)
Severe acute
pancreatitis (SAP) (20%)
Severity scoring systems
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Glasgow score1
Within 48 hrs
 PaO2 <60mmHg
 Albumin <32 g/L
 Ca++ <2mmol/L
 WBC >15 x 109/L
 AST/ALT >200U/L
 LDH > 600U/L
 Glucose >10mmol/L
 Urea >16mmol/L

Ranson score2
On admission:
 Age, WBC, glucose, LDH,
AST
Within 48 hr:
 Haematocrit, BUN,
estimated fluid shift,
PaO2, base deficit, Ca++
1.
Blamey et al. Prognostic factors in acute pancreatitis. GUT 1984; 25:1340-6
2.
Ranson et al. Etiological and prognostic factors in human acute pancreatitis: a review. Am J Gastroenterol
1982;77:633-8
Severity scoring systems
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Sn for predicting poor outcome:
Glasgow score – 61%1
 Ranson score – 70%2
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48hr for complete scoring
1.
Corfield et al. Prediction of severity in acute pancreatitis: Prospective comparison of three prognostic indices.
Lancet 1985;2:403-7
2.
Ranson et al. Etiological and prognostic factors in human acute pancreatitis: a review. Am J Gastroenterol
1982;77:633-8
Severity scoring systems
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APACHE II
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12 physiological / biochemical findings + age +
chronic health survey
Sn up to 95%1
 Daily / repeated scoring as reassessment
 Immediate scoring after admission
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 Too
1.
complicated for use outside ICU
Wilson C et al. Prediction of outcome in acute pancreatitis: a comparative study of APACHE II, clinical
assessment and multiple factor scoring systems. BJS 1990;77:1260-4
Severity assessment – CRP
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CRP
Serum level increase the degree of SIRS
 Cut-off value of 150mg/L (Sentorini Consensus)1
 Sn and Sp (prediction of septic complication) ~
80%2
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Peaks by 36hr after onset
1.
Dervenis C et al. Diagnosis, objective assessment of severity, and management of acute pancreatitis. Santorini Consensus Conference. Int J Pancreatol
1999;25:195-210
2.
Vesentini S et al. Prospective comparison of CRP level, Ranson score and contrast-enhanced computed tomography in the prediction of septic
complications of acute pancreatitis. BJS 1993;80:755-7
Severity assessment – summary
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Should not rely on scoring system for severity
assessment
Frequent clinical +/- biochemical assessment is
most important
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Aim at early detection of organ dysfunction
Treatment – antibiotics prophylaxis?
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Rationale:
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To prevent the life threatening bacterial infection of
pancreatic necrosis
Concerns:
Antimicrobial resistance1
 Opportunistic fungal infection2
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1.
Bassi C et al. Controlled clinical trial of Pefloxacin versus Imipenem in severe acute pancreatitis.
Gastroenterology 1998; 115:1513-17
2.
Eatock FC et al. Fungal infection of pancreatic necrosis is associated with increased mortality. BJS 1999;86
supp 1:78
Treatment – antibiotics prophylaxis?
RCTs
Patient Prophylaxis
no.
regimen
Infected
necrosis
(Rx vs con)
Mortality
(Rx vs con)
Pederzoli
(1993)
74
Imipenem
12% vs 30%
7% vs 12%
Sainio (1995) 60
Cefuroxime
30% vs 40%
3% vs 23%
Schwarz
(1997)
26
Olofloxacin +
metronidazole
62% vs 54%
0% vs 15%
Nordback
(2001)
58
Imipenem
4% vs 18%
8% vs 15%
Treatment – antibiotics prophylaxis?
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Cochrane review 2007
Included 5 RCTs comparing antibiotics prophylaxis
vs no prophylaxis
 Significant reduction of mortality in antibiotics
prophylaxis group (6% vs 15%)
 Both significant reduction of infected necrosis (16%
vs 29%)and mortality (6% vs 17%) in beta-lactam
prophylaxis subgroup
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Antibiotics prophylaxis – summary
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Current evidence is still not concrete enough to
make clear conclusion
Antibiotics prophylaxis probably gives a
marginal benefit to SAP patients
Duration of treatment should last for at least 14
days
Thank you