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Table 1 Guideline Statements and Strengths for Acute Bacterial Rhinosinusitis and Chronic Rhinosinusitis

From: Canadian clinical practice guidelines for acute and chronic rhinosinusitis

Statement Strength of Evidence* Strength of Recommendation
Acute Bacterial Rhinosinusitis
1: ABRS may be diagnosed on clinical grounds using symptoms and signs of more than 7 days duration. Moderate Strong
2. Determination of symptom severity is useful for the management of acute sinusitis, and can be based upon the intensity and duration and impact on patient's quality of life. Option Strong
3: Radiological imaging is not required for the diagnosis of uncomplicated ABRS. When performed, radiological imaging must always be interpreted in light of clinical findings as radiographic images cannot differentiate other infections from bacterial infection and changes in radiographic images can occur in viral URTIs. Moderate Strong
Criteria for diagnosis of ABRS are presence of an air/fluid level or complete opacification. Mucosal thickening alone is not considered diagnostic. Three-view plain sinus X-rays remain the standard. Computed tomography (CT) scanning is mainly used to assess potential complications or where regular sinus X-rays are no longer available.   
Radiology should be considered to confirm a diagnosis of ARBS in patients with multiple recurrent episodes, or to eliminate other causes.   
4: Urgent consultation should be obtained for acute sinusitis with unusually severe symptoms or systemic toxicity or where orbital or intracranial involvement is suspected. Option Strong
5: Routine nasal culture is not recommended for the diagnosis of ABRS. When culture is required for unusual evolution, or when complication requires it, sampling must be performed either by maxillary tap or endoscopically-guided culture. Moderate Strong
6: The 2 main causative infectious bacteria implicated in ABRS are Streptococcus pneumoniae and Haemophilus influenzae. Strong Strong
7: Antibiotics may be prescribed for ABRS to improve rates of resolution at 14 days and should be considered where either quality of life or productivity present as issues, or in individuals with severe sinusitis or comorbidities. In individuals with mild or moderate symptoms of ABRS, if quality of life is not an issue and neither severity criterion nor comorbidities exist, antibiotic therapy can be withheld. Moderate Moderate
8: When antibiotic therapy is selected, amoxicillin is the first-line recommendation in treatment of ABRS. In beta-lactam allergic patients, trimethoprim-sulfamethoxazole (TMP/SMX) combinations or a macrolide antibiotic may be substituted. Option Strong
9: Second-line therapy using amoxicillin/clavulanic acid combinations or quinolones with enhanced gram positive activity should be used in patients where risk of bacterial resistance is high, or where consequences of failure of therapy are greatest, as well as in those not responding to first-line therapy. A careful history to assess likelihood of resistance should be obtained, and should include exposure to antibiotics in the prior 3 months, exposure to daycare, and chronic symptoms. Option Strong
10: Bacterial resistance should be considered when selecting therapy. Strong Strong
11: When antibiotics are prescribed, duration of treatment should be 5 to 10 days as recommended by product monographs. Ultra-short treatment durations are not currently recommended by this group. Strong Moderate
12: Topical intranasal corticosteroids (INCS) can be useful as sole therapy of mild-to-moderate ARS. Moderate Strong
13: Treatment failure should be considered when patients fail to respond to initial therapy within 72 hours of administration. If failure occurs following use of INCS as monotherapy, antibacterial therapy should be administered. If failure occurs following antibiotic administration, it may be due to lack of sensitivity to, or bacterial resistance to, the antibiotic, and the antibiotic class should be changed. Option Strong
14: Adjunct therapy should be prescribed in individuals with ABRS. Option Strong
15. Topical INCS may help improve resolution rates and improve symptoms when prescribed with an antibiotic. Moderate Strong
16. Analgesics (acetaminophen or non-steriodal anti-inflammatory agents) may provide symptom relief. Moderate Strong
17. Oral decongestants may provide symptom relief. Option Moderate
18. Topical decongestants may provide symptom relief. Option Moderate
19. Saline irrigation may provide symptom relief. Option Strong
20. For those not responding to a second course of therapy, chronicity should be considered and the patient referred to a specialist. If waiting time for specialty referral or CT exceeds 6 weeks, CT should be ordered and empiric therapy for CRS administered. Repeated bouts of acute uncomplicated sinusitis clearing between episodes require only investigation and referral, with a possible trial of INCS. Persistent symptoms of greater than mild-to-moderate symptom severity should prompt urgent referral. Option Moderate
21: By reducing transmission of respiratory viruses, hand washing can reduce the incidence of viral and bacterial sinusitis. Vaccines and prophylactic antibiotic therapy are of no benefit. Moderate Strong
22: Allergy testing or in-depth assessment of immune function is not required for isolated episodes but may be of benefit in identifying contributing factors in individuals with recurrent episodes or chronic symptoms of rhinosinusitis. Moderate Strong
Chronic Rhinosinusitis   
23: CRS is diagnosed on clinical grounds but must be confirmed with at least 1 objective finding on endoscopy or computed tomography (CT) scan. Weak Strong
24: Visual rhinoscopy assessments are useful in discerning clinical signs and symptoms of CRS. Moderate Moderate
25: In the few situations when deemed necessary, bacterial cultures in CRS should be performed either via endoscopic culture of the middle meatus or maxillary tap but not by simple nasal swab. Option Strong
26: The preferred means of radiological imaging of the sinuses in CRS is the CT scan, preferably in the coronal view. Imaging should always be interpreted in the context of clinical symptomatology because there is a high false-positive rate. Moderate Strong
27: CRS is an inflammatory disease of unclear origin where bacterial colonization may contribute to pathogenesis. The relative roles of initiating events, environmental factors, and host susceptibility factors are all currently unknown. Weak Moderate
28: Bacteriology of CRS is different from that of ABRS. Moderate Strong
29: Environmental and physiologic factors can predispose to development or recurrence of chronic sinus disease. Gastroesophageal reflux disease (GERD) has not been shown to play a role in adults. Moderate Strong
30: When diagnosis of CRS is suggested by history and objective findings, oral or topical steroids with or without antibiotics should be used for management. Moderate Moderate
31: Many adjunct therapies commonly used in CRS have limited evidence to support their use. Saline irrigation is an approach that has consistent evidence of benefiting symptoms of CRS. Moderate Moderate
32. Use of mucolytics is an approach that may benefit symptoms of CRS. Option Moderate
33. Use of antihistamines is an approach that may benefit symptoms of CRS. Option Weak
34. Use of decongestants is an approach that may benefit symptoms of CRS. Option Weak
35. Use of leukotriene modifiers is an approach that may benefit symptoms of CRS. Weak Weak
36: Failure of response should lead to consideration of other possible contributing diagnoses such as migraine or temporomandibular joint dysfunction (TMD). Option Moderate
37: Surgery is beneficial and indicated for individuals failing medical treatment. Weak Moderate
38: Continued use of medical therapy post-surgery is key to success and is required for all patients. Evidence remains limited. Moderate Moderate
39 Part A: Patients should be referred by their primary care physician when failing 1 or more courses of maximal medical therapy or for more than 3 sinus infections per year. Weak Moderate
39 Part B: Urgent consultation with the otolaryngologist should be obtained for individuals with severe symptoms of pain or swelling of the sinus areas or in immunosuppressed patients. Weak Strong
40: Allergy testing is recommended for individuals with CRS as potential allergens may be in their environment. Option Moderate
41: Assessment of immune function is not required in uncomplicated cases. Weak Strong
42: Prevention measures should be discussed with patients. Weak Strong
  1. *Strength of evidence integrates the grade of evidence with the potential for benefit and harm.
  2. Strength of recommendation indicates the level of endorsement of the statement by the panel of experts.