Bacteriology of chronic sinusitis after amoxicillin-clavulanate potassium therapy

Systemic and topical antibiotics for chronic rhinosinusitis

BACKGROUND

This review is one of six looking at the primary medical management options for patients with chronic rhinosinusitis.Chronic rhinosinusitis is common and is characterised by inflammation of the lining of the nose and paranasal sinuses leading to nasal blockage, nasal discharge, facial pressure/pain and loss of sense of smell. The condition can occur with or without nasal polyps. Systemic and topical antibiotics are used with the aim of eliminating infection in the short term (and some to reduce inflammation in the long term), in order to normalise nasal mucus and improve symptoms.

OBJECTIVES

To assess the effects of systemic and topical antibiotics in people with chronic rhinosinusitis.

SEARCH METHODS

The Cochrane ENT Information Specialist searched the Cochrane ENT Trials Register; CENTRAL (2015, Issue 8); MEDLINE; EMBASE; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the search was 29 September 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with a follow-up period of at least three months comparing systemic or topical antibiotic treatment to (a) placebo or (b) no treatment or (c) other pharmacological interventions.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcomes were disease-specific health-related quality of life (HRQL), patient-reported disease severity and the commonest adverse event - gastrointestinal disturbance. Secondary outcomes included general HRQL, endoscopic nasal polyp score, computerised tomography (CT) scan score and the adverse events of suspected allergic reaction (rash or skin irritation) and anaphylaxis or other very serious reactions. We used GRADE to assess the quality of the evidence for each outcome; this is indicated in italics.

MAIN RESULTS

We included five RCTs (293 participants), all of which compared systemic antibiotics with placebo or another pharmacological intervention.The varying study characteristics made comparison difficult. Four studies recruited only adults and one only children. Three used macrolide, one tetracycline and one a cephalosporin-type antibiotic. Three recruited only patients with chronic rhinosinusitis without nasal polyps, one recruited patients with chronic rhinosinusitis with nasal polyps and one had a mixed population. Three followed up patients for 10 to 12 weeks after treatment had finished. Systemic antibiotics versus placebo Three studies compared antibiotics with placebo (176 participants).One study (64 participants, without polyps) reported disease-specific HRQL using the SNOT-20 (0 to 5, 0 = best quality of life). At the end of treatment (three months) the SNOT-20 score was lower in the group receiving macrolide antibiotics than the placebo group (mean difference (MD) -0.54 points, 95% confidence interval (CI) -0.98 to -0.10), corresponding to a moderate effect size favouring antibiotics (moderate quality evidence). Three months after treatment, it is uncertain if there was a difference between groups.One study (33 participants, with polyps) provided information on gastrointestinal disturbances and suspected allergic reaction (rash or skin irritation) after a short course of tetracycline antibiotic compared with placebo. We are very uncertain if antibiotics were associated with an increase in gastrointestinal disturbances (risk ratio (RR) 1.36, 95% CI 0.22 to 8.50) or skin irritation (RR 6.67, 95% CI 0.34 to 128.86) (very low quality evidence). Systemic antibiotics plus saline irrigation and intranasal corticosteroids versus placebo plus saline irrigation and intranasal corticosteroids One study (60 participants, some with and some without polyps) compared a three-month course of macrolide antibiotic with placebo; all participants also used saline irrigation and 70% used intranasal corticosteroids. Disease-specific HRQL was reported using SNOT-22 (0 to 110, 0 = best quality of life). Data were difficult to interpret (highly skewed and baseline imbalances) and it is unclear if there was an important difference at any time point (low quality evidence). To assess patient-reported disease severity participants rated the effect of treatment on a five-point scale (-2 for "desperately worse" to 2 for "cured") at the end of treatment (three months). For improvement in symptoms there was no difference between the antibiotics and placebo groups; the RR was 1.50 (95% CI 0.81 to 2.79; very low quality evidence), although there were also slightly more people who felt worse after treatment in the antibiotics group. There was no demonstrable difference in the rate of gastrointestinal disturbances between the groups (RR 1.07, 95% CI 0.16 to 7.10). General HRQL was measured using the SF-36. The authors stated that there was no difference between groups at the end of treatment (12 weeks) or two weeks later. Systemic antibiotics versus intranasal corticosteroids One study (43 participants, without polyps) compared a three-month course of macrolide antibiotic with intranasal corticosteroids. Patient-reported disease severity was assessed using a composite symptom score (0 to 40; 0 = no symptoms). It is very uncertain if there was a difference as patient-reported disease severity was similar between groups (MD -0.32, 95% CI -2.11 to 1.47; low quality evidence). Systemic antibiotics versus oral corticosteroids One study (28 participants, with polyps) compared a short course of tetracycline antibiotic (unclear duration, ˜20 days) with a 20-day course of oral corticosteroids. We were unable to extract data on any of the primary efficacy outcomes. It is uncertain if there was a difference ingastrointestinal disturbances (RR 1.00, 95% CI 0.16 to 6.14) or skin irritation (RR 2.00, 95% CI 0.20 to 19.62) as the results for these outcomes were similar between groups (very low quality evidence).

AUTHORS' CONCLUSIONS

We found very little evidence that systemic antibiotics are effective in patients with chronic rhinosinusitis. We did find moderate quality evidence of a modest improvement in disease-specific quality of life in adults with chronic rhinosinusitis without polyps receiving three months of a macrolide antibiotic. The size of improvement was moderate (0.5 points on a five-point scale) and only seen at the end of the three-month treatment; by three months later no difference was found.Despite a general understanding that antibiotics can be associated with adverse effects, including gastrointestinal disturbances, the results in this review were very uncertain because the studies were small and few events were reported.No RCTs of topical antibiotics met the inclusion criteria.More research in this area, particularly evaluating longer-term outcomes and adverse effects, is required.

Bacterial influence on consolidation of bone grafts in maxillary sinus elevation

OBJECTIVES

The aim of this study was to identify microorganisms present on the maxillary sinus floor at the moment of sinus elevation surgery and, using tomography, to investigate the repercussions these might have for regenerated bone 9 months after the procedure.

MATERIALS AND METHODS

174 patients (90 women and 84 men) with a mean age of 55.92 years underwent 227 sinus elevations (120 left sinus, 107 right sinus). As the membrane was lifted, a sample of the maxillary sinus floor was collected with a cotton swab, and placed on a blood agar and chocolate agar culture to incubate for 48 h at 37°C; the samples then underwent microbiological analysis. Orthopantomographs and computerized tomographs were made immediately after the sinus grafting and after 9 months to measure the amount of remaining and regenerated bone in vertical and transversal direction.

RESULTS

18.1% of 227 cultures were bacteria-positive. 45% of the germs were of the Streptococcus genus, most of which belonged to the S. viridans group (61.1%). Patients presenting negative cultures had 5% more regenerated bone than patients with bacteria-positive cultures, which represents an additional 2.28 mmof vertical bone (with a confidence interval between 0.83 mm and 3.73 mm).

CONCLUSIONS

Patients with bacteria-positive cultures obtained previously to the sinus grafting procedure have greater risk of bone height loss after 9 months, which indicates that bacterial contamination may influence bone graft regeneration.

Prevalence of pus in radiologically diseased sinuses in patients undergoing surgery for chronic rhinosinusitis

OBJECTIVE

To establish the prevalence of pus in radiologically diseased sinuses in patients undergoing sinus surgery and to correlate this with the bacterial load in the sinuses.

STUDY DESIGN AND SETTING

A prospective study performed on adult patients with the diagnosis of chronic sinusitis undergoing endoscopic sinus surgery at an Adelaide group of academic hospitals. In 45 consecutive and unselected patients, a radiologically diseased sinus was surgically opened, and a specially designed suction aspirator was placed into the sinus under endoscopic control. These aspirates were Gram stained and cultured to quantify the polymorphonuclear neutrophil count, bacterial flora, and bacterial colony count. The CT scans of all patients were graded by using the Lund-Mackay scoring system.

RESULTS

A variety of bacteria, most commonly staphylococci, were cultured from a radiologically diseased sinus in 88% of patients. There was no correlation between the bacterial colony count and presence of pus, and only 11% of patients had microscopic evidence of inflammation in sinus aspirates. There was no correlation between the Lund-Mackay CT score and the presence of pus in the sinus.

CONCLUSIONS

The majority of patients undergoing surgery for chronic sinusitis did not have a purulent exudate, and there was no correlation with the bacterial load. The usefulness of antibiotics in the treatment of chronic rhinosinusitis, in the absence of macroscopic pus, is questionable.

Bacteriology in Patients with Chronic Sinusitis who have been Medically and Surgically Treated

Chronic sinusitis is a disease that afflicts a significant percentage of the population and causes considerable long-term morbidity. The common use of multiple broad-spectrum oral antibiotics and endoscopic sinus surgery to treat this condition may alter the pathogenes that promote persistence of chronic sinusitis. Forty-eight culture-positive patients with chronic sinusitis who had been medically treated for at least 3 months and had undergone sinus surgery were bacteriologically evaluated. Swab specimens of the middle meatus and sphenoethmoid recess were aseptically obtained endoscopically and cultured for aerobes. Coagulase-negative staphylococci were the most common isolates (45.8%), followed by Streptococcus pneumoniae (16.7%), Enterobacteriaceae (16.7%), Staphylococcus aureus (10.4%), and Pseudomonas aeruginosa (10.4%). Coagulase-negative staphylococci were the most frequently isolated organisms in our study, as in many other studies. Despite the significant predominance of these organisms, they have always been assumed to be contaminants, and their presence in culture has been discounted. Coagulase-negative S aureus may be a pathogen in the chronic sinusitis process, and sensitivities of this isolate should be obtained for evaluation and possible treatment of the disease.

The role of infection in chronic rhinosinusitis

Chronic rhinosinusitis is a common condition, yet little is understood about its pathogenesis. Chronic infection traditionally has been considered a significant factor in the etiology and manifestations of chronic rhinosinusitis. Bacteria can be recovered in most cases of chronic rhinosinusitis, most commonly consisting of Staphylococcus species, anaerobes, and in some cases, gram-negative bacteria. Increasing trends toward bacterial resistance have been identified in chronic rhinosinusitis. Recently, a potential role for fungal infection has emerged. A knowledge of the microbiology of chronic rhinosinusitis will help guide treatment, but more research is required to understand further the exact role of infection in the pathophysiology of chronic rhinosinusitis.