Bowel!
Puja Chopra
PGY-1
Emergency Medicine
Case
History:
• 50 yo male complains of periumbilical and left
lower quadrant abdominal pain that began
earlier that day.
• Intermittent and crampy pain, accompanied
by anorexia and vomiting
• Normal BM yesterday
• No History of this pain has had prior
abdominal surgery
…continued
Physical Exam:
• Afebrile
• Moderate distress due to his abdominal pain
• Bowel sounds present
• Abdomen: mildly distended with periumbilical
tenderness but no rebound
DDx
Small Bowel Obstruction
Definitions:
• Mechanical obstruction:
– Physical barrier to the flow of intestinal contents
• Simple Obstruction:
– Partial or complete occlusion, proximal intestinal
distention, no compromise to blood flow
• Closed Loop Obstruction:
– Obstruction at two sequential sites, twisting around
an adhesion or hernia, higher risk of ischemia
• Strangulation:
– Vascular compromise to the obstructed area
• Adynamic Illeus
– Disturbance in gut motility leading to a failure in flow
of intestinal contents.
Etiologies: abdominal trauma, infection (retroperitoneal,
pelvic, intrathoracic), laparotomy, narcotics and other
meds, metabolic disease (hypoK), renal colic, MSK
inury
Etiology
• Extraluminal Causes (Most common)
– Adhesions
• Post pelvic surgery, appendectomy, colorectal surgery
– Hernia
– Cancer
• Intrinsic Causes:
–
–
–
–
Congenital (stenosis, atresia)
Neoplasm
Infection from chrones/colitis
Intuscception
• Intraluminal Causes:
–
–
–
–
Gallstones
Foreign body
Barium
Cancer
• Most common cause:
– Adhesions
• Most likely to lead to strangulation:
– Hernia
Pathophysiology
Obstruction to intestinal contents occurs: proximal bowel distention, accumulation of fluid and intestinal
contents
Distention triggers peristalsis above and below the obstruction: early you may have diarrhea
Distention triggers fluid release from epithelial secreatory cells perpetuating dilation
Loss of ability to reabsorb fluid and electrolytes: dehydration
Increased intraluminal pressure, obstruction of lymphatics and capillary flow: edema with eventual loss of
mucosal blood supply
Increased bacterial proliferation in the small intestine (e coli, streptococcus faecalis, klebsiella)
Clinically
• History:
– Colicky abdominal pain q4-5minutes
– Abdominal pain is worse with a proximal
obstruction
– Nausea and vomiting
– Later: obstipation and constipation
– Be aware of the pain that changes from
intermittent and colicky to constant and severe:
intestinal ischemia and perforation
• Physical Exam:
– Inspection: surgical scars, distended hernia,
distended abdomen, peristalsis
– Auscultation: early: you may hear high pitched
bowel sounds, later you may hear no bowel
sounds
– Percussion: Tympany
– Palpation: Masses
– Look for any peritoneal signs
Complications of SBO
•
•
•
•
•
•
•
•
Hypovolemia
Intestinal ischemia and infarction
Peritonitis
Sepsis
Respiratory distress (due to diaphragm elevation)
Reoccurrence
Aspiration pneumonia
Perforation
Imaging
Plain Films
•
1. Normal small bowel gas pattern:
– Absence of small bowel gas or small amounts of gas with up to four variably
shaped non-distended loops of small bowel (less than 2.5 cm in diameter)
•
2. Abnormal but non-specific gas:
– One loop of borderline or mildly distended small bowel (2.5 to 3 cm), with
three or more air-fluid levels.
– Normal colonic gas pattern
•
3. Probable SBO:
– Multiple gas or fluid filled loops of dilated small bowel with a moderate
amount of colonic gas
•
4. Definite SBO:
– Dilated gas or fluid filled loops of small bowel in the setting of a gasless colon
Supine
Limitations to Abdominal Radiography
• Negative and non-specific illeus patterns do
not exclude the diagnosis
– Can be too early thus the colon size and small
bowel size are similar
– Can be too proximal and thus only a small
segment is dilated
– Can be too fluid filled to see dilation
CT
• Recommended when abdo xrays are non
diagnostic
• Detecting signs of ischemia and closed loop
obstruction
• When patients have failed conservative
treatment
• Can detect etiology – thus useful in patients
that have not had previous surgery
CT for Ischemia
Ultrasound
?Strangulation
• Fevang et al. Early operation or conservative
management of patients with small bowel
obstruction
– Strangulation diagnosed by physical signs and
symptoms including fever, leukocytosis,
peritonitis, tachycardia or metabolic acidosis is
correct only 45% of the time
Strangulation vs Simple
• On univariate analysis other factors that made
one think of strangulation were:
• Hypotension
• Acidosis
• Elevated BUN
• But when put in multivariate analysis this was
not proven
Management
Reoccurrence
• There is about a 50% reoccurrence rate after
the first small bowel obstruction
– Gowen GF, 2003
• There is an 81% reoccurrence rate after 4
obstructive episodes
– Fevang et al., 2004
Case 2
Facts
• 7% lifetime risk of developing appendicitis
• In the ED, 25% of patients younger than 60 yo
with acute abdominal pain have appendicitis
• In the ED, 4% patients older than 60 yo with
acute abdominal pain have appendicitis
• Incidence of perforation: 20%
• 15 to 35% negative laparotomy rate, rises to 45%
in females.
Etiology:
Acute obstruction (usually secondary to an appendicolith but also can be due to calculus, tumor, parasite or enlarged
lmyph node)
Acute obstruction will lead to a rise in intraluminal pressure, and mucosal secreations become such that they cannot be drained. This resulting
distention will stimulate the visceral affernt pathways and results in a dull poorly localized pain
Abdominal cramping may also occur as a result of hyperperistalisi
As the intraluminal pressure exceeds the venous pressure leading to necrosis and ischemia of the appendiz
Bacteria and polymorphic cells will then invade the appendiceal wall
With time the appenix will swell and pain becomes localized
to RLQ
Typical Presentation
Occurs in ????% of cases
• Three Findings With a high positive likelihood
ratio
– RLQ pain:
• Sensitivity: 81%
• Specificity: 53%
• LR+: 7.31, LR-: 0.20
– Rigidity:
• Sensitivity: 27%
• Specificity: 83%
• LR+: 3.76, LR-: 0.82
- Migration:
Sensitivity: 64%
Specificity: 82%
LR+: 3.18, LR-: 0.50
…Ruling out appendicitis?
• Signs with Powerful Negative Likelihood
Ratios:
– Absence of RLQ pain
• LR-: 0.20
– Presence of similar previous pain
• LR-: 0.50
– Lack of migration of pain
• LR-: 0.50
Other Symptoms
Symptom
Sensitivity
Specificity
LR+
Pain before
vomiting
100%
64%
2.76
Fever
67%
79%
1.94
Anorexia
68%
36%
1.27
Vomiting
51%
45%
0.92
Nausea
58%
37%
0.69-1.20
Other Signs…
Sign
Sensitivity
Specificity
LR+
Rebound
tenderness
63%
69%
1.10 to 6.30
Guarding
74%
57%
1.65 to 1.78
Rectal tenderness
41%
77%
0.83 to 5.34
Psoas sign
16%
95%
2.38
McBurney’s Point
Rovsing Sign
Psoas Sign
Obturator Sign
Suspected Appendicitis
Alvarado Score
Sensitivity: 92.77%
Specificity: 58.18%
1-4
Discharge
PPV = 61.82%, NPV
= 79.21%;
5-6
Observation/
Investigation
7-10
Surgical
consult
PPV = 89.16%, NPV
= 41.33%
The use of the Alvarado score in the management of right lower quadrant abdominal
pain in the adult Y. Pouget-Baudry et al. 2010
…but the WBC is normal…they can’t
have appendicitis?
Imaging
• In 50 to 60% of patients the diagnosis of
appendicitis can be made clinically
• Alvarado score 4-6 ….you can wait and watch,
or image
Plain X-ray
Sensitivity of 28%
Specificity of 76%
Ultrasound
• Used to help confirm the diagnosis of
suspected appendicitis
• Sensitivity: 86%
• Specificity: 81%
CT
• Used to help confirm the diagnosis of
suspected appendicitis
• Sensitivity: 95%
• Specificity: 94%
Benefit of imaging
Perforation
Treatment
• Analgesia
– Opioid:
• The use of opioid analgesics in the therapeutic
diagnosis of patients with AAP does not increase the
risk of diagnosis error or the risk of error in making
decisions regarding treatment.
» Manterola et al. Systematic Review: Analgesia in patients with acute abdominal pain. 2010 The
Cochrane Collaboration. Published by John Wiley & Sons, Ltd
– NSAIDs:
• Retrospective chart review case controlled suggesting
that NSAIDs delays treatment
» Frei et al. Is early analgesia associated with delayed treatment of appendicitis? American
Journal of Emergency Medicine (2008)
• IV Fluid
• Perioperative Antibiotics:
High Index of suspicion
required
Clinical
• Need a high index of suspicion
• Ischemia of the viscera: leading to pain out of
proportion with findings
–
–
–
–
Abdominal pain: 83%
Vomiting: 44%
Diarrhea: 19.3%
GI bleeding: 20.1%
• Infarction
Huang et al. Clinical Factors and
Outcomes in Patients with Acute
Mesenteric Ischemia in the
Emergency Department. July
2003: Acad Emerg Med.
Laboratory:
• Non-specific
• Aid in diagnosis when suspicious
• Normal labs do not exclude ischemia
Other Tests…
• LDH
– Sensitivity 70%, Specificity 42%, LR+ 1.2, LR- 0.7
• Lactate
– Sensitivity 90%, Specificity 44%, NPV 96%, PPV 70
• Alpha-GST
– Sensitivity 72%, Specificity 77%, NPV 86%, PPV 58%
• ALP (marker of intestinal mucosal ischemia)
– Sensitivity: 80%, Specificity: 64%, LR+ 2.2, LR – 0.3
Predictors of mortality
•
•
•
•
Bandemia 68.9% sensitive, 74.2% specific
Elevated AST 62.1% sensitive, 78.9.% specific
Elevated BUN 88.5% sensitive, 39.3% specific
Metabolic acidosis: 53.6% sensitive, 85.5.%
specific
Huang et al. Clinical Factors and Outcomes in
Patients with Acute Mesenteric Ischemia in
the Emergency Department. July 2003: Acad
Emerg Med.
Management
• 1. Stabilize the patient
• 2. Antibiotics
– Evidence that survival improved
• 3. Heparin
• 4. Vasodilators
– ? Glucagon
• 5. Papaverine
• 6. Surgery
Glucagon
• Vasodilator
• Intestinal vasodilator and hypotonicity to
reduce oxygen demand
• Used if no evidence of peritonitis
• Studies in rat’s and dogs have shown
improved survival
• No studies in humans
Papaverine
• Phosphodiesterase inhibitor
• Improves mesenteric blood flow
• Arterial embolic disease or non-occlusive
disease
• Intra-arterial (60 mg bolus and then 60mg/h
infusion)
• Survival improvement by 20 to 50%
Asymptomatic Diverticulosis
• CT scan finds incidental diverculosis
• Should we do anything?
– Inverse association between dietary fiber intake
and the risk of subsequently developing clinically
evident diverticular disease
Symptomatic Uncomplicated
Diverticulitis
• History:
– LLQ abdominal pain
– Better with defecation
– Worse with eating
– No rebound
– No guarding
Symptomatic Diverticuli
• History:
– Low grade fever
– Left lower quadrant pain
– Colonic dysfunction (bloating, constipation, diarrhea,
mucous per rectum)
– Signs of obstruction
– Signs of colovescial fistula
• Physical Exam:
– Localized tenderness in the LLQ
– Guarding and reboud
– Palpable mss
Diagnosis
• History and Physical Exam
• Laboratory:
– WBC: can be elevated
– Prospective analysis of 226 cases demonstrated
that 46% of patients with confirmed diverticulitis
had no elevated WBC
– Urinanalysis
• Rule out UTI or fistula
CT
• Sensitivity: 93-98%
• Specificity: 77%
• Water soluble contrast
orally and IV
• Pro’s:
– Therapeutic: percutaneous drainage of abscess (if
>4cm)
– Determine alternate pathology
– Identify complicated diverticulitis
Ultrasonography
• Sensitivity: 84% to 98%
• Specificity: 90 to 93%
• Pros:
– Avoids radiation
– Gyne structures are seen
• Cons:
– Patients often acutely tender here compression by probe is
uncomfortable
– Cannot identify perforation/air
– Obese patient or overlying gas
Endoscopy and MRI:
• Not in the ER
Complicated Diverticulitis
•
•
•
•
Abscess (15%)
Obstruction (10%)
Free Perforation (1%)
Fistula (2%)
• Diverticular hemorrhage
Management
• Symptomatic uncomplicated diverticulitis
Versus…no antibiotics
• Controversy
• Most studies showing symptomatic and
complication rates benefit from antibiotics
versus just bran
Acute Diverticulitis
• Outpatient
– Mild symptoms
– No peritonitis
– Able to tolerate a clear liquid diet
– Close follow-up
– Return to ED: increasing pain, fever, inability to
tolerate oral fluids
Acute Diverticulitis
• Inpatients:
– Elderly
– Immunocompromised
– Severe comorbidities
– High fever
– Significant leukocytosis
Antibiotics
Rosen’s BOX 93-5 INTRAVENOUS ANTIBIOTIC COVERAGE FOR BOWEL FLORA
Mild to Moderate Infection
– Ticarcillin-clavulanate, 3.1 g IV q6h
– Ampicillin-sulbactam, 3 g IV q6h or
– Ciprofloxacin, 400 mg IV q12h, and metronidazole, 1 g IV q12h
Severe Infection
• Ampicillin, 2 g IV q6h, and metronidazole, 500 mg IV q6h, and
(gentamicin, 7 mg/kg q24h, or ciprofloxacin) 400 mg IV q12h or
• Imipenem, 500 mg IV q6h
Surgery
• Emergency: perforation with peritonitis
• Non-emergency: fistula, stricture,
• Elective:
– Recurrent episodes (greater than 2)
– Younger than 40 yo (more likely to have severe
disease)
– Initial attack and immunocompromised
Reoccurrence Risk
• Reoccurrence rate varies from 7 to 45% and
reoccur within a year
Sigmoid Volvulus
• 859 patients with sigmoid volvulus
–
–
–
–
83% were males
17% were females (of which 6.3% were pregnant)
Mean symptom duration of 39.4 hours
Clinical Triad highly suggestive of SV: Abdominal pain
(98.7%), asymmetric abdominal distention (96%),
obstipation (92.3%)