Acute Abdomen
Erin Burrell ACNP-BC
Vanderbilt University Medical Center
Surgical Intensive Care Unit
Objectives
• Define an acute abdomen
• Obtain adequate history and physical
• Order the appropriate labs and imaging
• Recognize appropriate differential diagnoses
• Recognize surgical emergencies
Definition of the Acute Abdomen
“Signs and symptoms of abdominal pain or
tenderness, a clinical presentation which
often requires surgical intervention”
Acute abdomen = Peritonitis
Definition of Pain
• Visceral pain – autonomic nerve fibers responding to
sensations of distention and muscular contraction
– Typically vague, dull, and nauseating
– Poorly localized and tends to be referred to areas corresponding to the
embryonic origin of the affected structure
– Upper abdominal pain - stomach, duodenum, liver, and pancreas
– Periumbilical pain - small bowel, proximal colon, and appendix
– Lower abdominal pain - distal colon and GU tract
• Somatic pain – comes from parietal
peritoneum
– Sharp and well localized
• Referred pain - perceived pain distant from
its source and results from convergence of
nerve fibers at the spinal cord
• Peritonitis - inflammation of the peritoneal cavity
History
• Onset and location of pain
• Associated symptoms:
– Nausea & Vomiting (include character of vomit)
– GERD
– Constipation/Diarrhea
– Obstipation (failure to pass stools or gas)
– Hematochezia/Melena
– Hematuria
– Weight Loss
Past Medical History
• Previous illnesses or diagnoses?
• Medication Usage?
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Narcotics
NSAIDS
Steroids
Immunosuppressants
Anticoagulants
EtOH abuse
Recreational drugs
Physical Exam
• General appearance of the patient
• Abdominal examination
– Inspection
• Note any surgical scars
– Auscultation
– Palpation
• Begin gently, away from the area of greatest pain
• Note areas of particular tenderness as well as guarding, rigidity, rebound
tenderness, and masses
• Surgical scars examined for hernia
– Percussion
– Make sure to include the groin in your exam
• Rectal and pelvic examination should be performed
– Lower abdominal pain only
– search for evidence of colonic impaction, tumor, GIB, retrocecal appendicitis, fallopian
tube infection, ovarian mass
Labs
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CBC
BMP
ABG, Lactate, Ionized calcium
Blood cultures x2, UA/Urine culture, Sputum
cultures
• LFT’s
• Amylase/Lipase
• Pregnancy test
Imaging
CXR/KUB
• Rarely diagnostic
• May be helpful in identifying air or stool in rectum
• CXR can identify subdiaphragmatic air
Abdominal Ultrasound
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Wide availability in the ED
Lower cost
Absence of radiation exposure
Useful in viewing the liver and gallbladder
Excellent for detecting pelvic processes in women (ectopic pregnancy)
CT Scan
• Study of choice – IV and PO contrast preferred
• Enteral contrast is required to distinguish bowel from other gas or fluid-filled
structures like abscesses
• IV contrast only if unable to tolerate PO contrast
Causes of the Acute Abdomen
Obstruction
Ischemic
Perforated
Infectious
Hemorrhagic
What is wrong with this picture?
Obstruction
• Occurs when normal flow of intraluminal contents is
interrupted (functional vs mechanical)
• Risk factors: Prior abdominal or pelvic surgery, abdominal
wall or groin hernia, neoplasm, prior irradiation, foreign body
ingestion
– Adhesions, incarcerated hernias and malignancy cause 75% of cases
• Four types of obstruction:
1. Small bowel obstruction
2. Large bowel obstruction
3. Volvulus
4. Intussusception
Small Bowel Obstruction
• S&S:
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Colicky, crampy, intermittent abdominal pain
N&V
Obstipation with complete obstruction
Decreased bowel function but still present with partial
obstruction
– Severe, steady pain suggests strangulation
• Physical exam:
– Hyperactive, high-pitched bowel sounds early
– Hypoactive bowel sounds late
– Dilated loops of bowel may be palpable
Small Bowel Obstruction
• Imaging:
– Flat/upright KUB – multiple air fluid levels with distal evacuation
of colon and rectum
– UGI with small bowel follow
through
– CT scan – can identifity transition
point
• Treatment:
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NGT to LIWS
Hydration with IVF
Electrolyte repletion
Surgical intervention
Colonic Obstruction
• S&S:
– Similar symptoms as an SBO – more urgent intervention
needed
– Increasing constipation which leads to obstipation and
ABD distention
– Vomiting not common (only 50%)
• Physical Exam:
– Typically shows a distended abdomen with loud
borborygmi
– No tenderness
– Empty rectum
Colonic Obstruction
• Imaging:
– “Comma sign” or “kidney bean” appearance
– Mechanical obstruction has “cutoff” sign at level of obstruction with
air in the proximal colon and small bowel and a gasless distal colon.
– An acute increase of cecal diameter >10cm, perforation of the colon
may be imminent
• Treatment:
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NGT to LIWS
Hydration with IVF
Replete electrolytes
Surgical intervention
Volvulus
• Refers to a twisting of a segment of the intestinal
tract around a fixed point
– Leads to ischemia and necrosis of the bowel
• Most common sites of volvulus are the cecum and
sigmoid colon
– Small bowel volvulus is less common in adults
– Sigmoid volvulus are common in bedridden, institutionalized patients
• S&S:
– Abrupt onset in continuous pain with superimposed colicky pain
during peristalsis
– N&V (1-3 days after onset of pain)
– Abdominal distention
– Constipation
Volvulus
• ABD Exam:
– Tympany upon auscultation
– Distended, tender abdomen
• Imaging:
– CT scan – “whirl pattern” or “bird beak” appearance, absence of rectal
gas, split wall sign and two crossing sigmoid transition points
projecting from a single location ; may see bowel necrosis
– KUB – U-shaped distended sigmoid colon extending from pelvis to
RUQ as high as diapraghm
• Points LLQ for sigmoid and RLQ for cecal
Sigmoid volvulus
Volvulus
Treatment:
– Sigmoid volvulus
• Can attempt endoscopy first – successful in 75-95% of
patients
• Surgery if endoscopy is unsuccessful
• 40-50% will not have recurrence
– Cecal volvulus
• Resection and anastomosis of involved segment
Intussusception
• Intenstines slide or “telescope” into an adjacent part
of the intestine
– Cause of only 1-5% of bowel obstructions
• S&S:
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Intermittent abdominal pain
N&V
Melena
Constipation
Intussusception
• ABD Exam:
– Distended, tender abdomen
• Imaging:
– KUB – may show distal small bowel obstruction
– CT scan is diagnostic – distended loop of bowel is
thickened because it represents two layers
– “Target sign”
• Treatment:
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Surgical resection
NGT to LIWS
IV hydration
ABX if perforated
“Pseudo-obstruction”
Ogilvie syndrome
• S&S of bowel obstruction
present without mechanical
cause
• Associated with:
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Bedridden patients
Electrolyte abnormalities
Opiate administration
Critical illness
Spinal cord injury
Recent surgery
Trauma
Infection
Ogilvie’s syndrome
• Imaging:
– KUB – dilated colon often from cecum to splenic flexure
and occasionally to the rectum
– CT scan – confirms diagnosis and excludes mechanical
obstruction
• Treatment:
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Normalize electrolytes
Minimize narcotics
NGT to LIWS
Anti-cholinergic agents (Neostigmine or Methylnaltrexone)
Colonic decompression - scope
Ischemic Acute Abdomen
• Ischemia due to a reduction in blood flow due to acute
arterial occlusion, venous thrombosis, or hypoperfusion
– Risk factors: abdominal surgery, cardiac bypass surgery, MI, atrial
fibrillation, hemodialysis
• Two main types:
1.
Colonic ischemia
• Most common form of intestinal ischemia
• Most often affects patients 60yo and older
• Approximately 15 percent of patients with colonic ischemia develop
gangrene
2.
Mesenteric ischemia
• Mortality is 70%
Ischemic Acute Abdomen
• ABD exam:
Acute mesenteric ischemia – rapid onset periumbilical pain
out of proportion to exam, N&V
Ischemic colitis – rapid onset of mild abdominal pain over
affected bowel, typically the left side, hematochezia within 24H of
pain
**Septic shock may be the presenting symptom if perforation or
infarction has occurred **
• Imaging:
– CT scan of Abdomen/pelvis with IV contrast – thickening of
the bowel wall, air in portal vein, or focal bowel dilitation
however CT is not always accurate
• Treatment
Mesenteric Ischemia
– IVF resuscitation
– Correction of electrolyte
abnormalities
– Cultures
– Empiric abdominal sepsis
antibiotic coverage
– Anticoagulate if embolic
cause for ischemia
– Immediate surgical
intervention for peritoneal
signs and diagnostic findings
of intestinal perforation or
infarction
**Strangulating obstruction can progress to
infarction and gangrene in as little as SIX
hours.**
Perforated Acute Abdomen
• Associated with h/o colonic obstruction, PUD, UC,
Crohn’s dx, diverticulitis, and trauma
• S&S
– N&V
– Quiet to absent bowel sounds
– Anorexia
• ABD exam: depends on location of perforation
– Esophageal, gastric, duodenal perf – abrupt onset of severe
generalized pain and peritonitis
– Other GI site perf – usually gradually developing, localized pain that
has worsened
Perforated Acute Abdomen
• Imaging:
– KUB – subdiaphragmatic air
– Abdominal CT is highly sensitive showing free
intraperitoneal air not contained within any visible
bowel wall
Perforated Acute Abdomen
• Treatment:
– Fluid resuscitation
– Broad spectrum ABX to cover intraabdominal flora
– Immediate surgical intervention
• S&S:
Infectious Acute Abdomen
– N&V, anorexia
– Location and onset of pain help determine cause
of infectious process
• Causes: appendicitis, pancreatitis,
intraabdominal abscesses, diverticulitis,
cholecystitis, SBP, c. difficile colitis
Infectious Acute Abdomen
• ABD Exam - depends on cause of infectious process
– Appendicitis – periumbilical or epigastric pain that shifts to RLQ –
increased pain with passive extension of the right hip
– Pancreatitis – upper ABD pain with radiation to the back
– Intraabdominal abscesses – related to recent abdominal surgery or
inflammatory disease processes
– Diverticulitis – LLQ pain with rebound and guarding
– Cholecystitis – right subcostal pain worsened by inspiration upon
palpation
– SBP – associated with hepatic dysfunction
Infectious Acute Abdomen
• Imaging:
– CT with IV contrast is preferred
• Treatment:
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Broad spectrum ABX coverage for intraabdominal flora
Pan cultures
IVF resuscitation
Supportive care
May need surgical intervention to obtain source control
Hemorrhagic Acute Abdomen
• S&S:
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Hematemesis
Hematochezia vs melena
Easy bleeding or bruising
Weakness
Fatigue
Dizziness
Syncope
• Physical Exam:
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Tachycardia
Hypotension
Pallor
Diaphoresis
Abdominal discomfort
Hemorrhagic Acute Abdomen
• Causes:
– GI bleed
• Associated with liver disease, NSAID abuse, PUD, aortoenteric
fistula, diverticulosis, CA
– Abdominal aortic aneurysm
• Associated with tender, pulsatile mass and back pain
– Ruptured ectopic pregnancy
• Associated with amenorrhea and/or vaginal bleeding
• Ruled out with negative pregnancy test
– Recent abdominal surgery
– Trauma
**If patient has orthostatic hypotension, this indicates
a >/= 15% blood loss**
Hemorrhagic Acute Abdomen
• Imaging:
– CT with IV contrast to evaluate active extrav
– Do not halt surgical intervention to obtain imaging
• Treatment:
– Supportive care
– NGT
– Resuscitate and correct coagulopathy
– Serial labs
– Scope vs IR vs Operating Room
Things to Remember
The most rapidly lethal condition compatible with the
presentation should be considered first, particularly in
patients with overt abdominal signs and shock
Shock associated with acute abdomen is usually
attributable to vascular disruption with intra-abdominal
hemorrhage or severe sepsis
References
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Bordeianou, L, et al. (2014). Epidemiology, clinical features, and diagnosis of
mechanical small bowel obstruction in adults. Retrieved from www.uptodate.com.
Elder, K. et al. (2009) Clinical appproach to colonic ischemia. Cleveland Clinic
Journal of Medicine, 767, 401-409.
Grubel, P. et al. (2014). Colonic Ischemia. Retrieved from www.uptodate.com
Hodin, R., and Bordeianou, L., (2012). Small bowel obstructions: Causes and
management. Retrieved from www.uptodate.com.
Kendall, J. et al. (2014). Evaluation of the adult in the emergency department with
acute abdominal pain. Retrieved from www.uptodate.com
Maloney, N. (2005) Acute Intestinal Pseudo-Obstruction (Ogilvie's Syndrome).
Clinics in Colon and Rectal Surgery, 18 (2), 96-101.
Penner, R. et al. (2014). Diagnostic approach to abdominal pain in adults. Retrieved
from www.uptodate.com.
Tendler, D et al. (2014). Acute Mesenteric Ischemia. Retrieved from
www.uptodate.com
The Acute Abdomen. Retrieved from
http://www.ece.ncsu.edu/imaging/MedImg/SIMS/Module2/GE2_4.html.
Tulandi, T. (2014). Clinical manifestations and diagnosis of ectopic pregnancny.
Retrieved from www.uptodate.com.