Acute Abdomen in the ICU Patient

1
Acute Abdomen in the ICU Patient

• Simon Kimm and Edward Melkun
• December 11, 2006

2
Definition

• Acute abdominal pathology that if left untreated
  will increase patient MM

3
Physiology

• Visceral and parietal peritoneum
• Peritoneal fluid normally lt50ml
• Absorbed via lymphatics in omentum and
  diaphragmatic peritoneum (30)
• Omentum acts as physiologic patch for
  perforation or infection

4
Physiology

• Pain somatic and visceral
• Somatic from direct irritation of parietal
  peritoneum, visceral follows embryologic origin
  or major splanchnic vessels
• Refered pain ex. Shoulder and phrenic nerve

5
Pathophysiology

• Similar incidence of common diseases as general
  population plus more unique processes
• Post-surgical state
• Hypotension and low flow states
• Antibiotic therapy (Overgrowth ex. C. diff)
• Narcotics
• Poor nutrition
• Co-morbidities
• Trauma

6
Presentation

• Always start with ABCs, eyeball test, and
  adjuncts to ABCs
• HP
• If possible review symptoms in awake patient
• OLDCARTS

7
History

• Location gives clues to pathology
• Character crampy usually from hollow viscus
• Progression often more important in post op
  patients

8
Physical

• Again difficult in non-awake patients
• Vitals
• Remember lines and wounds
• Inspect, auscultate, percuss, palpate
• Genital and rectal exam

9
Labs

• CBC wbc trend, left shift, anemia
• UA wbcs, LE, Nitrite
• LFTs tbili can be elevated in biliary dz,
  sepsis, hemolysis, and cholestasis from TPN
• Amylase/Lipase amylase elevated in
  pancreatitis, perfed ulcer, mesenteric ischemia,
  parotid injury or inflam, and ruptured ectopic
• ABG acidosis, hypoxia

10
Imaging

• Bedside films vs. in department
• CXR free air,PNA, effusions
• Abd films colonic volvulus, obstruction,
  stones, pneumobilia
• US biliary system
• CT little use in 1st post-op week for
  abscess
• Angio mesenteric ischemia, GI bleeds
• Nuclear scans tagged rbc

11
Imaging

• Endoscopy UGI bleed, colonic ischemia, ? Role
  in C. diff (1/3 negative toxin assays)

12
Postoperative Considerations

• Bleeding
• Anastamotic leak
• Fascial Dehiscence
• Bowel obstruction
• Abscess
• Abdominal Compartment Syndrome

13
Bowel obstruction

• Diagnosis often confounded by normal post-op
  adynamic illeus
• Patients on narcotic pain meds
• Management per standard protocol
• Complete obstruction or nonresolving/ worsening
  PSBO requires reoperation

14
Leak

• In cases where leak controlled by drainage with
  little or no peritoneal contamination, may not
  need early operative intervention
• Percutaneous drainage
• NPO, TPN, ? octreotide
• If peritoneal spillage or signs of intraabdomial
  sepsis, need emergent reoperation

15
Abscess

• Need approximately 7 post op days to organize an
  abscess
• Small may only require abx
• Larger or those with continued enteric
  contamination (leak) require drainage
• Percutaneous, operative if not accessible

16
Cholecystitis

• Acalculous may see sludge in GB in US or
  nonvisualization on HIDA (hepato-iminodiacetic
  acid) scan
• Can see these findings in nl patients maintained
  on TPN
• Percutaneous cholecystostomy tube for critically
  ill patients

17
Ischemic Bowel

• Low flow
• Embolic
• Abd films pneumatosis, pneumobilia, free air,
  double wall sign
• CTA
• Lactate levels