25 Acute Rhinosinusitis & Infectious Complications Flashcards
How is acute rhinosinusitis defined?
How is acute rhinosinusitis defined?
Acute rhinosinusitis is symptomatic inflammation of the nasal and paranasal sinus mucosa for up to 4 weeks. The most common causes of this condition are viral and bacterial infections. Recurrent acute rhinosinusitis (RARS) is defined as four or more episodes of ABRS per year without persistent symptoms between episodes.
What is the pathophysiology of acute rhinosinusitis?
What is the pathophysiology of acute rhinosinusitis?
Inflammation of the nasal and paranasal sinus mucosa with subsequent edema is the initiating factor in this disease. Most often, this inflammation is caused by viral URI and/or allergic rhinitis. This edema can cause obstruction of normal sinus drainage, impaired mucociliary clearance and altered local immune system function. These changes create an ideal environment for pathogen colonization and growth.
How common is acute rhinosinusitis?
How common is acute rhinosinusitis?
Rhinosinusitis is a major burden on the healthcare system with 13.4% of adults diagnosed with RS annually. The incidence tends to be higher for women (almost two-fold), and adults aged 45 to 74 years are most commonly affected. ARS is the fifth leading indication for antibiotic prescriptions; 21% of antibiotics prescribed for adults are for ARS.
How common are infectious complications of acute rhinosinusitis?
How common are infectious complications of acute rhinosinusitis?
Infectious complications of ARS are extremely rare in immunocompetent individuals with a rate of less than 0.01% per episode of ARS in children, and even less in adults. In immunocompromised patients (diabetes mellitus, HIV positive, immunosuppressed due to chemotherapy) the complication rate is likely higher.
How can the clinician differentiate viral rhinosinusitis (VRS) from acute bacterial rhinosinusitis (ABRS)?
How can the clinician differentiate viral rhinosinusitis (VRS) from acute bacterial rhinosinusitis (ABRS)?
Specific signs and symptoms and their timing are the most important history items in diagnosing ABRS. Symptoms required to diagnose ABRS are purulent rhinorrhea, nasal obstruction, and facial pressure or pain. Occasionally fever and hyposmia are considered as “major” symptoms required for the diagnosis. The following are considered “minor” symptoms: cough (more common in children), malaise, maxillary tooth pain, and ear fullness or pressure. The generally accepted time course for ABRS is persistent symptoms for at least 10 days (but less than 12 weeks) or worsening symptoms after 5 days that were initially improving (“double-sickening” or “worsening course”). Also warranting consideration of ABRS are patients with severe symptoms lasting 3 to 4 days that include high fever (>39° C) and purulent nasal discharge or facial pain.
What bacteria are the most common pathogens in ABRS?
What bacteria are the most common pathogens in ABRS?
Understanding the bacteriology of ARS is paramount to choosing the most effective antibiotic regimen to treat the disease. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis (more common in children) are generlly accepted as the most common pathogens in this disease. Streptococcus pyogenes, Staphlococcus aureis, gram-negative bacilli, and anaearobes are less common.
What is the relevance of antibiotic resistant organisms and vaccination in ABRS?
What is the relevance of antibiotic resistant organisms and vaccination in ABRS?
H. influenzae (30%) and M. catarrhalis (90%) have an increasing prevalence of beta-lactamase producing organisms.S. pneumoniae prevalence seems to be decreasing due to pneumococcal vaccination. However, its resistance to penicillin and macrolides is approximately 30%. Knowledge of regional antibiotic resistance is important to help guide therapy.
What are the goals of treatment of ABRS?
What are the goals of treatment of ABRS?
In treating ABRS, the clinician’s primary goals are attempting to decrease the duration and severity of symptoms, prevent infectious complications, prevent progression to chronic rhinosinusitis (CRS), and restore the patient’s quality of life. Secondary goals include minimizing side effects of medications and unnecessary antibiotics that could promote resistant organisms.
When should antibiotics be prescribed for ABRS?
When should antibiotics be prescribed for ABRS?
Studies in both adult and pediatric patients confirm that patients with ABRS treated with antibiotics experience more rapid resolution of symptoms when compared with placebo. If stringent criteria are used for establishing the diagnosis, empiric antimicrobial therapy should be started as soon as the diagnosis of ABRS is made. Another option of “watchful waiting” or “observation” has been described, when antibiotics are withheld unless the patient does not improve with symptomatic management. Some studies cite a 60% to 70% chance of spontaneous improvement in patients with ABRS by 7 to 12 days, which supports the “watchful waiting” approach.
Which antibiotic should be prescribed for ABRS?
Which antibiotic should be prescribed for ABRS?
In both children and adults, amoxicillin or amoxicillin-clavulanate is recommended as initial empiric antimicrobial therapy. The preference for amoxicillin-clavulanate is due to increasing prevalence of beta-lactamase producing H. influenzae and M. catarrhalis since the use of pneumococcal vaccine. High-dose amoxicillin-clavulanate (90 mg/kg/day PO BID or 2 grams PO BID) is recommended in communities with high prevalence of penicillin-nonsusceptible S. pneumoniae or in high-risk patient populations for antibiotic resistance. Second-line antibiotics include macrolides (clarithromycin or azithromycin), trimethoprim-sulfamethoxazole (TMP-SMX), doxycycline, second or third generation cephalosporins (cefpodoxime, cefixime, cefdinir), clindamycin, and respiratory fluroquinolones (levofloxacin or moxifloxacin). Macrolides have an approximately 30% rate of resistance to S. pneumoniae. TMP-SMX has a 30% to 40% resistance to both S. pneumoniae and H. influenzae. Doxycycline can be used only in adults due to risk of staining teeth in children younger than 8 years old. In children, ceftriaxone single dose (50 mg/kg IV or IM) followed by an oral second or third generation cephalosporin is an option. Due to variable rates of resistance among S. pneumoniae, oral cephalosporins are recommended in combination with clindamycin.
How long should antibiotics be prescribed and when should empiric antibiotics be changed if ineffective?
How long should antibiotics be prescribed and when should empiric antibiotics be changed if ineffective?
The optimal duration of antibiotic treatment is controversial. New guidelines recommend empiric antibiotics for 5 to 10 days in adults (termed “short-term” antibiotics) and 10 to 14 days in children for uncomplicated ABRS. Other studies done in ABRS require patients to complete a 2 week course of antibiotic. If symptoms worsen after 48 to 72 hours or fail to improve after 3 to 7 days, patients should be evaluated for resistant pathogens or a noninfectious etiology.
What other treatments, in addition to antibiotics, should be considered in ARS?
What other treatments, in addition to antibiotics, should be considered in ARS?
Nasal saline irrigations and intranasal corticosteroids are usually the most commonly recommended adjuvant treatments for ARS. Topical or oral decongestants, antihistamines, and mucolytics are also commonly recommended. Some type of analgesia, usually initially in the form of acetaminophen and ibuprofen, should also be considered.
What tests can be performed to help diagnose ABRS?
What tests can be performed to help diagnose ABRS?
The diagnosis of ABRS is made on history, especially in the outpatient clinic setting. Computed tomography (CT) of the paranasal sinuses is nonspecific and generally is not indicated in uncomplicated ABRS. Studies indicate that during uncomplicated viral URI, the majority of patients will have significant abnormalities seen on imaging. Culture from the sinus cavity recovering greater than 10^4 colony forming units (CFU) per mL is the gold standard for the diagnosis of ABRS. Due to issues of patient discomfort, time, and cost, endoscopic guided cultures of the middle meatus have been used as a surrogate for direct sinus cultures.
When is testing appropriate in patients with ABRS?
When is testing appropriate in patients with ABRS?
CT or MRI should be reserved for patients with RARS (more than four episodes per year), severe cases, or when suppurative complications are suspected. CT is generally the preferred initial modality and is superior for defining the bony anatomy of the paranasal sinuses. Contrast should be used if intraorbital or intracranial abscess is suspected. MRI with gadolinium is recommended if the clinician suspects central nervous system complications of ABRS. Endoscopic culture of the middle meatus can be very helpful, especially in patients at high risk for antibiotic resistance (age younger than 2 or older than 65, daycare, prior antibiotics within past month, recent hospitalization, comorbidities, immunosuppression). Sometimes an allergy/immunology evaluation can also be helpful in patients with RARS to identify concurrent predisposing factors causing mucosal inflammation.
What are the suppurative complications of ABRS?
What are the suppurative complications of ABRS?
Sequelae of ABRS can be divided into intraorbital and intracranial complications. The most common complication is orbital involvement and is due to ethmoid sinusitis. The second most common infectious complication is meningitis, usually due to sphenoid sinusitis. The third most common complications are epidural (Figure 25-1) or subdural abscesses due to frontal sinusitis. Brain abscesses, venous thrombosis, mucocele or mucopyocele, and “Pott’s puffy tumor” (osteomyelitis of the frontal bone) are also possible complications.
How are orbital complications of ABRS classified?
How are orbital complications of ABRS classified?
The Chandler classification, published in 1970, is still used to classify orbital complications of ABRS. Stage 1 is preseptal cellulitis and is thought to be due to impaired venous outflow from sinusitis and edema. The next stage is orbital cellulitis which causes impaired extraocular movements, proptosis, and chemosis. The third stage is a subperiosteal abscess in which pus accumulates between the lamina papyracea and the medial periorbita (Figure 25-2). Visual acuity can be impaired and the globe can become inferolaterally displaced. Stage 4 is orbital abscess, usually accompanied by severe visual impairment and complete ophthalmoplegia. The last stage is cavernous sinus thrombosis characterized by bilateral ocular symptoms among other central nervous system signs and symptoms.
What is the role of fungi in acute rhinosinusitis?
What is the role of fungi in acute rhinosinusitis?
Fungal infections can cause rhinosinusitis in one of three ways. Allergic fungal rhinosinusitis occurs when atopic patients inhale fungi causing type I Ig-E mediated hypersensitivity and mucosal inflammation. Diagnosis is made in patients with nasal polyposis and allergies with presence of allergic mucin containing eosinophils, Charcot-Leyden crystals, and possibly fungal hyphae. Fungus ball or mycetoma is a noninvasive fungal infection usually occurring in nonatopic immunocompetent patients. Invasive fungal sinusitis occurs in immunocompromised patients and involves invasion of blood vessels and bony/soft tissue erosion. While all fungal ARS episodes are generally treated surgically to remove the fungal organism, invasive fungal sinusitis requires aggressive surgical debridement and systemic antifungal therapy due to its high morbidity and mortality (Figure 25-3).
