Acute Abdomen

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Acute Abdomen

• Stuart Danovitch, MD
• Washington VA Medical Center

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Acute Abdomen - Conundrum

• If I operate and the problem is not surgical,
  patient exposed to unnecessary risk, anesthetic,
  etc.
• Risks greater with concomitant illness, older age
• If I do not operate and problem is surgical,
  patient at risk because of wrong therapy.
• Again the older patient is under greater burden.

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A Caricature - Surgery

• Acute pain
• Septic toxic
• Board-like abdomen
• Absent bowel sounds
• WBC 25,000
• Free air under diaphragm

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A Caricature - No Surgery

• Trivial pain
• Robust appearance
• Soft abdomen with no guarding
• Normal bowel sounds
• Normal WBC
• Normal pain and upright films of abdomen

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Acute Abdominal PainNon-surgical Emergencies

• Mesenteric Adenitis
• Acute Enteric Infections
• Acute Enteric Poisonings
• Inflammatory Bowel Disease
• Pancreatitis (usually)

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Acute Abdominal PainMetabolic Causes

• Diabetic Ketoacidosis
• Heavy Metal Poisoning
• Acute Porphyria
• Tabes
• Sickle Cell Crisis

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Acute Abdominal PainClinical Phenomena

• 2/3 of attacks typical, 1/3 atypical
• Acute cholecystitis and perforated DU are rare, lt
  20 years
• Acute diverticulitis rate, lt30 years
• 80 of patients with bowel obstruction had
  previous surgery
• 75 of patients with cholecystitis had previous
  attacks

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Acute Abdominal PainConfounding Clinical Features

• Perforated duodenal ulcer
• 50 of patients had no previous pain
• 50 of patients had bowel sounds
• Diverticulitis
• 40 of patients vomited
• 30 of patients have upper pain
• Obstruction
• 40 of patients have no distension

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Acute Abdominal PainAncillary Diagnostic Studies

• CBC
• Urine
• Amylase
• Plain abdominal films
• Paracentesis and lavage
• Radionuclide Scans

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Acute Abdominal PainThe WBC in 570 patients

• Diagnosis Sensitivity Specificity
• Appendicitis (?) 91 21
• Cholecystitis (?) 78 11
• Obstruction (?) 56 8
• Gastroenteritis (N) 49 11
• Other Non-surgical (N) 62 82
• Predictive value of ? WBC for surgical
  condition 29
• Predictive value of ? WBC for non-surgical
  cond 93

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Acute Abdominal PainSensitivity of Roentgen
Findings - 249 Patients

• Abnormal
• Appendicitis 48
• Cholecystitis 64
• Pancreatitis 60
• Intestinal Obstruction 98
• Perforated Ulcer 60

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Acute Abdominal PainSpecificity of Roentgen
Findings - 249 Patients

• Diagnostic 24
• Helpful 18
• Not Helpful 57
• Misleading 1

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Diagnosis of PancreatitisAmylase - Whats Right

• Cheap
• Quick
• Non-invasive
• A decent first approximation

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Diagnosis of PancreatitisAmylase - Lack of
Specificity

• Organ non-specific
• Disease non-specific

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Diagnosis of PancreatitisHeterogeneity of Serum
Amylase

• 40 pancreatic
• 60 salivary
• If total activity doubles due to pancreatitis,
  p-isoenzyme must ? 3.5 x.

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Diagnosis of PancreatitisTiming of Enzyme
Measurement

• Activity
• Days Trypsin Lipase P-amylase T-amylase
• 0 100 100 100 100
• 1-2 100 100 100 75
• 3-4 100 85 70 35
• 5-7 55 55 35 15

Eckenfeld, Arch Path Lab Med, 1986
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Acute Abdominal PainThe Serum Amylase in 37
Patients

• Amylase ? Amylase NL
• Pancreatitis (23) 17 6
• No pancreatitis (14) 7 7
• Sensitivity Specificity PV -PV
• 74 50 71 54

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Acute Abdominal PainFrequency of Diagnoses in
1000 Patients

• Unknown 41 Cholecystis 4
• Urinary Tract 9 Intestinal Obst 2.5
• Gastroenteritis 7 Constipation 2
• PID 7 Misc 7

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Acute Abdominal PainDiagnostic Errors - 1000
Patients

• False Assessment Pre-op --20 Patients
• Pre-op Post-op
• Appendicitis - 7 Mesenteric Adenitis -
  1Ectopic Pregnancy - 5 PID - 5Acute Abdomen
  - 5 Nothing - 13Diverticulitis -
  2 Pyelonephritis - 1Tubp-ovarian Abscess - 3

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Acute Abdominal PainDiagnostic Errors - 1000
Patients

• False- Assessment Pre-op --11 Patients
• Initial Dx Post-op
• Endometriosis - 1 Appendicitis -
  8 Gastroenteritis - 4 Obstruction - 3 UTI -
  1 Uncertain - 5

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Acute Abdominal PainSaga of 1190 Admissions

• Etiology
• Nonspecific 35 Appendicitis 17 Intest
  inal Obstruction 15 GU 6 GB
  5 Diverticulitis 4 PUD
  3 Pancreatitis 2 Miscellaneous 13

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Acute Abdominal PainSaga of 1190 Admissions

• Effect of Age gt60 (40) lt60 (60)
• Nonspecific 23 43 Appendicitis
  4 25 Intestinal Obstruction 28 6 GU
  3 8 IB 9 3 Diverticulitis 9
  lt1 PUD 4 1 Pancreatitis 4
  2 Miscellaneous 16 11

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Computer-Aided Diagnosisof Acute Appendicitis

• Favoring Dx Against Dx
• ? WBC Normal WBC RLQ location Other
  sites Pain lt 12 hrs gt 48 hrs Vomiting No
  Nausea Rebound, Guarding Female

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Computer-Aided Diagnosisof Acute Appendicitis

• Reliability of Decision Rules
• Negative Lap Rate 15 Sensitivity 90 Spe
  cificity 91 Predictive Value 80 -
  Predictive Value 95

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Decision Analysis in Management of Acute
Abdominal Pain

• Error - lap lap Computer
• Surgery 13 0 0No surgery
  5 2 11Uncertain 11 0
  31Lap contraind 4 5 20

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DiagnosisSmall Bowel Obstruction

• Attribute Relative Risk
• Hx Previous surgery 12.1
• Colicky Pain 2.5
• Distension on PE 13.1
• Abnormal Bowel Sounds 9.0

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Acute Pancreatitis - Pathogenesis

• Bernards Dictum
• No enzymes, No Pancreatitis

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Acute Pancreatitis - PathogenesisMechanisms
Limiting Intrapancreatic Enzyme Activation

• Storage and secretion as proenzymes
• Pancreatic trypsin inhibitors
• ? pH (8-9.5) ? Ca (lt 1mM) abet degradation
• Mesotryptic digestion of enzymes
• Plasma anti-trypsins

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Acute Pancreatitis - PathogenesisHypothesis for
Intrapancreatic Enzyme Activation

• Activation
• Activation by thrombin, plasmin
• Lysosomal cathepsin
• Enterokinase

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Acute Pancreatitis - PathogenesisIn Vivo Enzyme
Activation

• Ascites and surgical findings
• ? phospholipase
• ? elastase
• ? lysosomal enzymes
• ? as,a amto-tryptic activity
• Blood
• ? enzymes - active and inactive

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Etiology of Acute Pancreatitis

• Cause
• Gallstones 40
• EtOH 40
• Hyperlipemia, Drugs, 10 Trauma, Tumor,
  Infection Idiopathic 10

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Drugs Associated with Acute Pancreatitis

• Azathioprine L-Asparaginase
• Diuretics ?-methyldopa
• Pentamidine Captopril
• Sulfonamides Procaninamide 6-MP Nitrofuranto
  in

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Diagnosis of Pancreatitis

• Problems
• Symptoms non-specific
• Laboratory non-specific
• No gold standard

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Diagnosis of Pancreatitis

• Appropriate clinical circumstance
• 3-fold ? amylase activity
• Return to normal in one week
• No gut perforation or infarction
• ? trypsiongen, lipase, pancreatic isoamylase

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DDx of Pancreatitis

• Perforated viscus
• Intestinal obstruction
• Mesenteric vascular events
• Acute cholecystitis
• PID

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DDx of Pancreatitis

• Clue that ? amylase is not due to pancreatitis in
  sick patients
• renal failure
• early bacteremia
• normal calcium
• deterioration in pt with calcified gland
• rising amylase after 48 hrs

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Diagnosis of PancreatitisPancreatic Imaging

• Sensitivity
• Ultrasound 35 CT 65 CT (Severe)
  95-100

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Diagnosis of Pancreatitis Concordance of
Amylase and Imaging

• Amylase lt200u gt200U
• Normal CT 12 20 Abn CT 20
  48

Spechler, Dig Dis Sci, 1983
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Ranson Prognostic CriteriaIn Acute Pancreatitis

• On admission
• Over 55 years
• WBC gt 16,000 / mm3
• BS gt 200 mg / dl
• LDH gt 350 IU / L
• AST . 250 IU / L

• Within 48 hours
• Hct decreased 10
• BUN increased 5 mg/dl
• Ca lt 8 mg/dl
• PaO2 lt 60 mmHg
• Base dificit gt 4 mEq/L
• Fluid sequestration gt 6L

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Local Complications ofAcute Pancreatitis

• Pseudocyst
• Abscess
• Ascites

• Splenic v. occlusion
• Phlegmon
• Gut necrosis / Obstruction

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Systemic Complications ofAcute Pancreatitis

• Diabetes
• Renal failure
• Respiratory failure

• Encephalopathy
• Skin / skeletal
• Sepsis / Shock

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Operative Appearance of the Pancrease Related to
Mortality in 52 Patients Who Underwent Celiotomy
on Days 0-5

• Operative Findings patients mortality
• Edema 25 4 Hemorrhage 14
  86 Phlegmon 14 54