emDOCs Revamp – Diverticulitis

Author: Eric Fellin, DO (EM Resident Physician, Killeen, TX); Alec Pawlukiewicz, MD (Attending Physician, Killeen, TX); Rachel Bridwell, MD (EM Attending Physician: Charlotte, NC) // Reviewed by: Alex Koyfman, MD (@EMHighAK); Brit Long, MD (@long_brit)

Welcome to emDOCs revamp! This series provides evidence-based updates to previous posts so you can stay current with what you need to know.

A 60-year-old obese male presents with achy, non-radiating left lower quadrant pain for 2 days. He endorses subjective fevers and nausea without vomiting. He denies urinary symptoms or changes in his bowel movements.

Triage vital signs: BP 145/85, HR 85, T 99.6, oral, RR 14, SpO2 99% on RA,

Focused abdominal exam: Normal appearing abdomen without pulsatile masses. Soft, with mild tenderness to palpation in the left lower quadrant without rebound or guarding.

What is the likely diagnosis, and what are the next steps in your evaluation and treatment?

Answer: Diverticulitis^1-37

Epidemiology:

• Diverticulosis: Small sac-like herniations within the wall of the intestinal tract¹
  • Affects 50% of Americans over age 60¹
• Diverticulitis: inflammation of diverticulum ^2–4
• 5% of those with diverticulosis will develop diverticulitis, accounting for 371,000 annual emergency department visits in the US^2–4
• Incidence increased by 85% in ages 30-39 and 132% in ages 40-49 from 1980s to 2000s⁵
• Risk factors: Increasing age, male sex, obesity, smoking, regular (≥2 times per week) nonsteroidal anti-inflammatory (NSAID) use, and corticosteroid use

Pathophysiology:

• Pathogenesis of diverticulosis:
  • Combination of age, genetics, lifestyle factors, and altered gut motility –>Herniation of mucosa/submucosa⁶
  • Most commonly occurs at vasa recta insertion⁶
•  Traditional theory
  • Fecalith obstructs diverticula increased local pressure, ischemia, and micro-perforations –> infection⁶
• Contemporary research
  • Altered gut microbiome, diet, genetics, and lifestyle factors –> reduced immune function and inflammation²

Clinical Presentation:

• Acute to subacute left lower quadrant pain, fever, nausea without vomiting, and a change in bowel habits^7,8

Evaluation

• Physical Exam
  • Assess for quadrant tenderness, palpable mass, or rebound tenderness¹⁴
  • Taken together, history and physical exam have a sensitivity of 40-65% ⁹

Laboratory evaluation

• Complete blood count (CBC) with differential
  • Evaluate the degree of leukocytosis, increased neutrophil-to-lymphocyte ratio (NLR), and systemic inflammation
  • NLR ≥ 4.2 80% sensitive (SN), 64% specific (SP), negative predictive value (NPV) 96%, and positive predictive value (PPV) of 18% for complicated diverticulitis¹⁵
  • White blood cell (WBC) count >9-10,000 cells/uL has SN of 54–80% and SP of 41–70%^9–12
• C-reactive protein
  • >10 mg/L has SN 89–96% and SP 28-61%^9–12
  • >140 mg/L (OR 2.86) and WBC count of >15,000 cells/uL (OR 3.66) are associated with an increased risk of progression from uncomplicated to complicated¹⁶
• Complete metabolic panel (CMP) and urinalysis
  • Assess for evidence of end-organ dysfunction or possible etiologies on differential diagnosis

Imaging

• Computed Tomography (CT):
  • CT with intravenous (IV) contrast is the gold standard study
    • SN 98% and SP 99%¹⁷
    • Best study for identifying complicated diverticulitis, staging disease, and guiding management¹⁸
  • CT without IV contrast:
    • Second line study, appropriate for those with contraindications to contrast
    • SN 95-99% and SP 86-100% for uncomplicated, BUT only SN 58–73% sensitive and SP 78–100% for complications¹⁹
•  Imaging in Pregnancy
  • Rare in pregnancy with only 13 case reports published^20,21
  • 1^st Line: Ultrasonography (US)
    • SN 92%, SP 97% for uncomplicated²²
    • May misdiagnose up to 79% of complicated cases²³
  • 2^nd line: If US is inconclusive, non-contrast Magnetic Resonance Imaging (MRI) may be pursued²⁴
    • SN of 98%, SP 70-78%²⁵
  • 3rd line: CT with IV contrast only if suspicion is high and the benefit to the mother is thought to outweigh the risks to the fetus²⁴
• No imaging
  • May consider foregoing imaging in individuals with the following^26,27:
    • No significant comorbidities
    • ASA I or II
    • No immunosuppression
    • Prior, imaging-confirmed uncomplicated diverticulitis
    • Signs and symptoms consistent with prior presentation
    • No evidence of sepsis
    • Pain well controlled
    • PO tolerant
  • Ensure close follow-up and strict return precautions for these patients

Definitions and Classification

• Uncomplicated diverticulitis– colonic thickening and peri-colonic inflammation with maintained wall integrity⁷
• Complicated diverticulitis — Inflammation with abscess, stricture, obstruction, fistula, or perforation²⁸
• Modified Hinchey classification system aids surgeons in selecting appropriate medical or surgical management²⁹

• Hospital admission for IV antibiotics is usual therapy for Ib and II²⁸
  • Percutaneous drainage vs surgery for failure of conservative management²⁸
• Stages III and IV require emergent surgical intervention²⁸

Treatment:

• Diet/Hydration⁷
  • Clear liquid diet initially with advancement gradually with symptomatic improvement
    • Should be able to advance within 3-5 days
    • Urgent follow-up needed if not improving
  • IV hydration if PO intolerant
• Analgesia:
  • First line: Acetaminophen 1g every 8 hours
  • Use caution with NSAIDs and opioids
    • Associated with an increased incidence of diverticular perforation³⁰
•  Antibiotics
  • Recent data suggest antibiotics may not be necessary for all patients with uncomplicated diverticulitis
    • Endorsed by the American Gastroenterological Association, the World Society of Emergency Surgery, the American College of Physicians, and the American Society of Colon and Rectal Surgeons after two large RCTs showing no benefit in this population^{7,18,27,32–34}
    • Variable adoption into clinical practice
• When indicated, the typical duration of antibiotics is 4-7 days³⁶
• Consider management without antibiotics for the following patients:
  • Acute, uncomplicated left-sided diverticulitis
  • Immunocompetent
  • No evidence of sepsis
  • No risk factors for progression to complicated disease

• Consider oral antibiotics in the following patients:
  • Acute, uncomplicated diverticulitis
  • Presence of risk factors for progression to complicated disease
  • PO tolerant
  • No evidence of sepsis
  • Well-appearing and otherwise suitable for outpatient management

• Consider admission for IV antibiotics in patients with the following:
  • Complicated diverticulitis
  • Sepsis
  • Significant comorbidities
  • Immunosuppression
  • Risk factors for treatment failure/adverse outcomes

• Patients requiring IV antibiotics should be stratified into low- and high-risk groups^35,36
• Low-risk patients:
  • No evidence of sepsis
  • APACHE II score <10
  • No risk factors for treatment failure/adverse outcome

• High-risk patients:
  • ≥1 or more risk factors for treatment failure/adverse outcome
  • Immunosuppression
  • Sepsis
  • APACHE II ≥10

• Consider the following IV antibiotics for low-risk patients:^35,36

• Consider the following IV antibiotics for high-risk patients:^35,36

• Consider adding specific therapies for MRSA, Enterococcus, resistant gram-negative bacilli and Candida in patients with the following:

Disposition:

• Consider outpatient management if:
  • Uncomplicated without signs of sepsis
  • PO tolerant
  • Pain well controlled
  • No major comorbidities or immunosuppression
• Consider inpatient management if:
  • Complicated diverticulitis
  • Sepsis
  • Significant comorbidities or immunosuppression
  • Severe, uncontrolled pain
  • PO intolerance
  • Non-adherence with care, poor follow-up
  • Failure of outpatient management
• • Referral to Gastroenterology for colonoscopy 6-8 weeks after resolution for:
    • All complicated diverticulitis and first episode of uncomplicated diverticulitis⁷
• To reduce the rate of recurrence, counsel patients to:⁷
  • Consume a high-quality diet
    • High in fruits, vegetables, whole grains, and legumes and low in red meat and processed sugar
    • Consumption of nuts, seeds, and/or corn is NOT associated with an increased risk of diverticulitis³⁷
  • Maintain a normal body mass index (BMI)
  • Engage in regular physical activity
  • Smoking cessation
  • Avoid routine (≥2 times per week) NSAID use
    • Exception: aspirin for secondary prevention of cardiovascular disease

Pearls:

• History and physical alone are often insufficient to confirm or exclude the diagnosis of diverticulitis
• CT with IV contrast is the gold standard for diagnosis of complicated and uncomplicated diverticulitis
• Consider selective rather than routine antibiotic use for acute, uncomplicated, left-sided diverticulitis in immunocompetent individuals if supported by clinical location and consulting surgeons
• Outpatient management includes a clear liquid diet and acetaminophen as the first-line analgesia
• Use caution when prescribing NSAIDs or opioids due to the risk of diverticular perforation
• Hinchey class III or IV diverticulitis should receive urgent general surgery consultation
• Patients with complicated diverticulitis or a first-time episode of uncomplicated diverticulitis should be referred to Gastroenterology for a colonoscopy in 6-8 weeks

Further reading:

• https://www.emdocs.net/emdocs-podcast-episode-88-ed-evaluation-of-diverticulitis/
• https://www.emdocs.net/emdocs-podcast-episode-89-antibiotics-for-uncomplicated-diverticulitis/
• https://emottawablog.com/2023/09/taking-a-dive-into-diverticulitis/
• https://foamcast.org/2023/02/03/management-of-acute-uncomplicated-diverticulitis/
• https://first10em.com/antibiotics-are-not-needed-in-uncomplicated-diverticulitis/
• https://rebelem.com/the-dinamo-study-efficacy-and-safety-of-non-antibiotic-outpatient-treatment-in-mild-acute-diverticulitis/

Disclaimer: The view(s) expressed herein are those of the author(s) and do not reflect the official policy or position of Carl R. Darnall Army Medical Center, Brooke Army Medical Center, the U.S. Army Medical Department, the U.S. Army Office of the Surgeon General, the Department of the Army, the Department of the Air Force and Department of Defense or the U.S. Government.

References:

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