Sinusitis From Microbiology to Management - part 7 ppsx

sinus wall which leads to bony erosion. After eroding through the sinus wall, the mucocele can extend into surrounding structures. Mucoceles most frequently involve the frontal sinus, followed by the ethmoid and maxillary sinuses (5). Symptomatic frontal or ethmoid sinus mucoceles can cause head- aches, diplopia, and proptosis. The proptotic globe is typically displaced downward and outward. Maxillary sinus mucoceles are usually an incidental finding on radiographs of the sinus. Mucoceles in this location rarely cause symptoms becau se the maxillary sinuses are large and the mucoceles rarely become large enough to cause bony abnormalities. Maxillary sinus mucoceles can become symptomatic, if they obstruct the ostium of the maxillary sinus. Mucoceles can also become symptomatic in any sinus when they become infected, forming mucopyocele. Diagnosis is usually made by CT of the sinuses. Symptomatic mucoceles are treated with surgical removal and possi- ble sinus obliteration. ORBITAL INFECTIONS Orbital infections can be caused by penetration of the orbit during either surgery or trauma; most frequent ly the result of a bacterial spread is from an infected sinus. As the orbit is bordered by several sinuses—the frontal, ethmoid, and maxillary—infection from any of these sinuses can potentially spread to the orbit. The ethmoid sinus is almost exclusively implicated in the spread of infection to the orbit. This is related to the thickness of the sinus wall lining the orbit. The thinner the wall, the easier is for infection to spread through it. The ethmoid sinus has the thinnest wall, the lamina papyracea, which lines the lateral wall of the sinus and the medial wall of the orbit. Most orbital infections are, therefore, on the medial side of the orbit. Although much less common, the thicker wall sinuses can also be the source of an orbital infection. Once infection has spread past the sinus wall, the periosteal lining of the sinus wall serves as an additional barrier to protect the orbit from the spread of the infection. If an abscess forms between the wall and periosteum, it is call ed a subperiosteal abscess. If the periosteum is violated, then an orbital abscess may form. Etiology Many organisms can be isolated in patients with orbital infections (Table 2). These may be single or multiple organisms, anaerobic or aerobic organisms, or mixture of both. Frequently, the isolates are the same as those found in the infected sinus. To best determine the type of organism, patients should be divided into two groups. The first group consists children of under 9 years old. These patie nts typically have single aerobic organisms, which include alpha and beta hemolytic Streptococcus spp., Staphylococcus spp., non- Haemophillus influenzae, and Moroxalla catarrhalis (6). The second group 272 Schwartz and White of patients is over nine years old, and typically have complex infections with mixed aerobic and anaerobic organisms. This is especially true for patients in their teens or older. Although aerobic organisms are frequently the same as those found in younger children, the anaerobic organisms are usually oral flora such as anaerobic gram-negative bacilli, Peptostreptococus spp., Fusobacterium spp., and Veillonella parvule. These rules are not absolute, as there are reports of anaerobic ba cteria isolated in young children (7,8). There are several theories that explain the causes of this trans ition; they include the increased incidence of chronic infections in older children and adults and the relative size of the osteo meatal opening. The relative size of the osteo meatal opening to the sinus cavity is larger in younger indivi- duals compared to that of older ones and therefore less likely to become occluded. Occlusion of the opening blocks the sinus cavity, which becomes anaerobic and promotes the growth of anaerobic organisms. Diagnosis In an article, Chandler described a classification system for orbital infection that still in use today (9) (Table 3, Fig. 1). The spectrum of orbital infec- tions is classified into five groups; each represents a progressively more serious infection. Group 1 is preseptal cellulitis, a simple cellulitis of the eyelids which manifests as swelling of the eyelids. Infection is limited to the skin in front of the orbital septum. Group 2 is orbital cellulitis, seen as diffuse edema of the lining of the orbits. It manifests as eyelid swelling and pain with extraocular muscle movement. Group 3, subperiosteal abscess, is character- ized by edema of the orbital lining with a collection of fluid below the Table 2 Common Organisms Isolated from Patients with Orbital Infections Aerobic bacteria Streptococcus spp.: Streptocococcus pneumoniae, Streptococcus viridans, and Streptococcus viridans Staphylococcus spp.: Staphylococcus aureus, and Staphylococcus epidermidis Haemophilus influenzae Moraxella catarrhalis Anaerobic bacteria Gram-negative bacilli (Prevotella, Porphyromonas, and Bacteroides spp.) Veillonella parvula Peptostreptococcus spp. Fusobacterium spp. Proprionibacterium spp. Immunocompromised hosts Pseudomonas aeruginosa Fungal species: aspergillosis, and mucormycosis Complications of Sinusitis and Their Management 273 periosteum usually involving the medical wall of the orbit. Clinically patients with this condition are similar to Group 2 but proptosis may also be noted. Group 4, orbital abscess, is characterized as a true abscess in the orbital space. This may manifest with proptosis, impaired eye movement, and in the worse case, blindness. Group 5 is cavernous sinus thrombosis with rapidly progres- sive bilateral chemosis, ophthalmoplegia, retinal engorgement, and loss of visual acuity, along with possible meningeal signs and high fever. The most important decision in dealing with a patient with a swollen eye is determining whether a preseptal or orbital process exists. Obtaining a thorough history, phy sical examination, and potentially imaging studies can very often assist in this. Preseptal cellulitis is most often caused by local trauma. The history may reveal an insect bite or other trauma to the skin around the eye, which becomes secondarily infected. This infection is usually insidious in onset. H. influenzae type B infection causes rapid eyelid swelling and eyelid closure within hours. With the advent of the H. influenzae type B Figure 1 (1) Preseptal cellulitis, (2) Orbital cellulitis, (3) Subperiosteal abscess, (4) Orbital abscess, and (5) Cavernous sinus thrombosis. Source: From Ref. 49. Table 3 Chandler Classification Group 1: Periorbital cellulitis Group 2: Orbital cellulitis Group 3: Subperiosteal abscess Group 4: Orbital abscess Group 5: Cavernous sinus thrombosis. Source: From Ref. 9. 274 Schwartz and White vaccine, a hematogenous source of infection very rarely is identified as the cause of preseptal cellulitis (10). Patients with H. influenzae infection typi- cally develop rapid eyelid swe lling with eyelid closure within hours. As preseptal cellulitis is an inflammatory process, evidence of local eye inflammation is present. Findings include warmth, redness, induration, and pain with palpation. In patients with red swollen eyelids which are boggy, painless to palpation, and not indurated, an allergic reaction or venous con- gestion because of an underlying sinusitis should be considered. Regardless of the cause of preseptal cellulitis, there should be no visual problem, no proptosis, or no significant pain with eye movement. Orbital infections (group 2–4) are h arder to i dentify and ar e typically more insidious in o nset. P atients f requently sh ow a history of n asal drain age, h ead- ache or pressure, and fever. If infection is in the orbit, visual loss may be present. Orbital infections may present in a similar way to preseptal infections. These patients present with evidence of orbital inflammation. The presence of eyelid swelling is not indicative of inflammation. As space is limited in the orbit, any inflammatory mass could impact the surrounding structures. A simple orbital infection exerts pressure on the ocular muscles and causes pain with eye movement. If a subperiosteal abscess or abscess forms, there may be pressure placed on the orbit causing proptosis. If the inflammatory pro- cess pushes on the optic nerve, blindnes s may result. Early on, the findings of orbital infection may be minimal, but become more apparent if the infec- tion is allowed to progress. Imaging As there can be an overlap in the symptoms of orbital infection, preseptal cellulitis, and other causes of eyelid swelling, some clinicians recommend imaging in all patients with a swollen eye. However, a more common approach would be to reserve imaging studies for those with nonclassic pre- sentations of preseptal cellulitis and those with presumed preseptal cellulitis, who do not improve following one to two days of treatment. All patients with evidence of orbital cellulitis need an imag ing study. The most frequently used imaging study is a CT scan, with or without contrast, using thin slices through the orbit with coronal and axial images. A CT scan is highly sensitive in documenting these infections. Patients with preseptal cellulitis show evidence of eyelid swelling without orbital involve- ment. The CT scan images of patients with Chandler group 2 (orbital cellu- lites) frequently show an opacified ethmoid sinus with an ill-defined mass on the orbital side of the lamina papyracea (Fig. 2). In addition, there may also be inflammation of the rectus muscle. This is the mildest and most common type of orbital infection (Fig. 3). Group 3 (subperiosteal abscess) shows evidence of inflammation with periosteum elevation and rim enhancement, rectus muscle displacement, Complications of Sinusitis and Their Management 275 and if large enough, some degree of proptosis of the eye (Fig. 3). Findings for group 4 (orbital abscess) show inflammatory material in the orbital space with proptosis. An MRI is possibly a better type of imaging study, but can be proble- matic since most orbital infections are in young children who will need sedating for the procedure. An MRI is best reserved for the complicated infection with intracranial extension, such as cavernous sinus thrombosis (group 5) or epidural abscess. There is no value in obtaining plain radio- graphs of the sinuses to diagnose an orbital infection. Figure 2 Ethmoid sinusitis with inflammation of the medial wall of the right orbit. Figure 3 Ethmoid sinusitis with subperiosteal abscess in an adolescent who presented to an emergency department with eyelid swelling and pain with eye movement. 276 Schwartz and White Treatment Until the past few years, there has been much disagreement on how to treat orbital infections. Until recently, surgical drainage was thought to be neces- sary in the majority of patients. Now medical management is the treatment of choice in the majority of patients with this type of infection. To success- fully treat patients with orbital infections, the patients are to be stratified into low and high risk groups based on likelihood of complications. Low risk patients have over 90% cure rate with antibiotic therapy alone (11). Low risk patients are thoseunder 9 years old, who most likely have single aero- bic organisms causing the infection. In addition to young age, low risk patients must also have no visual compromise, at most a modest-sized subperiosteal abscess on the medial side of the orbit, and no evidence of intracranial infection (Table 4). They also must be able to cooperate with frequent ophthalmolo- gic examinations. How frequent ly an exam mu st be repeated is not known. Published studies recommend ophthalmic examinations from once a day to multiple times a day (11,12). The antibiotics selected should be able to cover aerobic gram-positive cocci. Adequate choices include a third-generation cephalosporin (ceftriax- one or cefotaxime) unless there is a high likelihood of recovery of resistant S. pneumoniae. In these cases, vancomycin should be given. As anaerobic organisms are rarely seen in young patients, ad ministering antibiotics that cover these organisms is probably unnecessary. Generally, treatment includes less than a week of parenteral antibiotics and is followed by a prolonged period of two to three week s of o ral a ntibiotic such as high dose of ampicillin/clavu- lanic acid (90 mg/kg/day in children and 4 g/day in adults) (13,14). In addition to antibiotics, all patients should be started on a nasal decongestant, such as oxymetazoline. Most patients who fit into this low risk category re spond appro- priately with only antibiotic treatment. However, if the patient’s condition deteriorates, it may be necessary to have the abscess and sinus drained. Indica- tions for surgery in this low risk group include visual loss, afferent papillary defect, fever after 36 hours of antibiotic treatment, or absence of clinical improvement a fter 72 hours. There is no indication for repeating the CT scan when deciding whether to perform surgery or not. Findings on the CT scan Table 4 Low Risk Group for Complications Age under 9 years old No visual compromise At most, modest-size abscess on medial side of orbit No evidence of intracranial complication Ability to cooperate with serial ophthalmologic exams Not immunocompromised Complications of Sinusitis and Their Management 277 may worsen before they imp rove, even in patients who are responding appropri- ately to antibiotics. Young children who are not likely to be cured by antibiotics alone include those with subperiosteal abscess not on the medial side of the orbit and those with over 2 mm of proptosis (14). A more aggressive approach is needed to treat older children and adults, as they have more complex infections that are not as reliably treated with antibiotics alone. Recommended antibiotics for complex infections are a second-generation cephalosporin that covers anaerobic and anaerobic organ- isms (i.e., cefoxitin or cefotetan), clindamycin, or ampicillin/sulbactam. Other combinations of antibiotics, such as penicillin and metronidazole, can also be used as long as they cover both aerobic and anaerobes. If there is a high like- lihood of recovering resistant S. pneumoniae vancomycin can be added. Even with the administration of appropriate antibiotics, cultures from an infected sinus or orbital abscess frequently can still grow organisms after several days of therapy. Until the abscess or infected sinus is sterile, there is a risk of the infection spreading. For these patients, a trial of antibiotic therapy alone can be given, but it will likely not cure the infection and place the patient at a continued risk for complications. Some clinicians will wait for 24 hours to see how these patients with complex infections respond, whereas others will proceed to urgent surgery to drain the abscess along with administering parenteral antibiotics. Surgery can be done either endoscopically or through an open approach, depending on the location of the subperiosteal abscesses and the physician’s preference. INTRACRANIAL COMPLICATIONS OF SINUSITIS Introduction Intracranial complications of sinusitis are rare , o ccurring one to three times per year in major referral centers (15–23). Undoubtedly, the advent of antibiotic therapy h as decreased t he incidence o f intracranial infectious complications of sinusitis. Over the three decades spanning 1950–1980, Bradley et al. (24) noted a four-fold decrease in intracranial abscess arising from sinus infection, despite improvements in diagnostic modalities which would otherwise have increased the number of diagnosed cases. Yet, because th ese intracr anial infections repre- sent the most lethal consequences of diagnostic or treatment failure of sinusitis, it is imperative for clinicians to understand the clinical presentation, diagnostic options, and therapeutic approach to treat each of these entities. Intracranial complications of sinusitis include: (1) meningitis, (2) epidural abscess, (3) subdural abscess, (4) brain abscess, and (5) dural sinus thrombosis. In contrast to intraorbital infections, sinusitis underlies only 3% to 9% of suppurative intracranial infections (15–17,20) an d is responsible for less than 1% of cases of meningitis (17). 278 Schwartz and White However, extra-axial abscesses (subdural and epidural) as discrete entities are most commonly of sinogenic origin, and epidural abscess is the most common intracranial complication from sinusitis in some series (15,16,21), although meningitis is more common in other series (23). Menin- gitis may be under-represented as lumbar puncture is to be avoided in the setting of intracranial space -occupying lesions and would likely only be performed when a CT or MRI scan fails to demonstrate an intracranial abscess or when an intracranial abscess is not considered. Conversely, concomitant sinusitis may fail to be diagnosed in patients diagnosed with meningitis if a neuro-imaging study is not performed, a likelihood in the management of many patients diagnosed with meningitis. Dural venous sinus thrombosis/thrombophlebitis (sagittal, transverse, and cavernous) is the least common complication, absent in some case series (16,19), and accounting for 3% to 9% of intracranial complications in others (15,18,23). In most cases, venous sinus thrombosis is not an isolated compli- cation, but occ urs in concert with subdural suppurat ion. Patients commonly have more than one intracranial complication, such as epidural/subdural abscess in association with cerebral abscess and/or meningitis. Table 5 summarizes the relative frequency of each intra- cranial complication from data pooled from several recent studies that used similar inclusion criteria and selection methods. Most studies have d emonstrated a large male predominance (grea ter than 3:1, male/female) for intracranial suppuration from sinusitis (16–20,22). This male predominance remains unexplained, but prevails at all age groups and may suggest sex-related anatomical differences in sinus structure/sinus venous drainage. Pathogenesis The pathogenesis for intracranial suppuration mirrors that of intraorbital infection. Intracranial infection can develop follo wing direct extension through sinus wall invasion to contiguous bone, and then to intracranial Table 5 Relative Frequency of Intracranial Complications a Intracranial complication Relative frequency (%, range) Meningitis 34% (14–54) Brain abscess 27% (0–50) Epidural abscess 23% (0–44) Subdural abscess 24% (9–86) Dural sinus thrombosis 8% (0–27) Percent of patients with >1 intracranial complication 28% Note: Study reference 30 excluded meningitis cases as a complications. a Pooled data from 131 patients in eight studies (15–17,19,20,23,30,48). Complications of Sinusitis and Their Management 279 structures through either osteitis orcongenital or traumatic defects. In contrast to orbital infections, the more common method of intracranial suppurative spread is by the propagation of septic emboli via calvarial diploic veins and the valveless venous system responsible for drainage of the midface and paranasal sinuses (15,16,20,23). Although many of these complications arise in the setting of pansinu- sitis, some intracranial infections are more strongly associated with specific sinus involvement. Meningitis often arises from ethmoid or sphenoid sinus involvement (23). Cavernous sinus thrombosis is also associated with sphe- noiditis and ethmoiditis (25,26), although it was more commonly associated with frontal sinusitis prior to use of current antibiotic regimens (25). The frontal sinuses are most frequently implicated in the development of extra-axial and intracerebr al abscesses as well as infection of the remaining dural sinuses (15,16,21,23). Clinical Presentation Because of the shared pathogenic origin, it common for a patient to have more than one intracranial complication. Therefore, it is difficult to attribute a presenting symptom to an isolated intracranial cause. Similarly, the signs and symptoms of rhinosinusitis also overlap to some degree with the presenta- tion of intracranial infection. Common presenting features will be discussed in this section, and specific presentations more common or unique to a parti- cular intracranial pathological entity will subsequently be discussed. Table 6 summarizes presenting symptoms and signs, collated from recent studies with similar inclusion criteria. Headache, commonly frontal or retro-orbital, is the overwhelmingly prominent symptom, occurring in approximately 70% of patients with intra- cranial infection arising from sinusitis. Most patients have fever (>38.5  C) as wel l. As would be expected, many p atients have sy mptoms of sinonasal disease with purulent rhinorrhea and sinus pressure/pain. Compared to adults, Table 6 Presenting Symptoms/Signs of Intracranial Infection Arising from Sinusitis a Headache (%) 69 Fever (%) 60 Altered mental status (ranging from confusion to obtundation; %) 41 Nausea/vomiting (%) 30 Cranial nerve palsy (%) 18 Seizure (%) 14 Other focal neurologic signs (hemiparesis/hemiplegia, aphasia, ataxia, motor/sensory deficits; %) 14 Nuchal rigidity (%) 10 a Pooled data from 91 patients in seven studies (15–17,19,20,30,48). 280 Schwartz and White children rarely have prominent rh inorrhea or upper respiratory symptoms, and complications often arise during a more acute course of sinusitis. Patients also commonly have symptoms of increased intracranial pres- sure, including alterations in mental function, vomiting, and photophobia. Arachnoid irritation may be indicated by nuchal rigidity (15–17,19,20). Later neurological symptoms and signs for intracranial infections include seizures, focal paresis, and cranial nerve palsies. Diagnosis Prior to the advent of computerized cross-sectional neuro-imaging (CT and MRI), diagnosis of space-occupying intracranial infections was primarily based on clinical evaluation and judgment (22). CT and MRI scans are complementary techniques, each of which can yield diagnostic informat ion helpful in the definitive management of intra- cranial complications. CT scan is readily available, can demonstrate most cases of intracranial suppuration, and is a technique of choice to evaluate bony involvement. CT scanning is the imaging modality of choice for initial evaluation of complications from sinusitis and for planning sinus surgery because of its superior ability to delineate air–bone and air–soft tissue interfaces. MRI, on the other hand, has better resolution for intracranial pathology and has higher diagnostic accuracy for intracranial infections. In one study comparin g CT and MRI for the diagnosis of suppurative com- plications from sinusitis, CT scan was diagno stic for 36 of 39 cases (92%) compared to 100% with MRI. MRI was also able to detect meningitis in 14 cases compared to three for CT scan. CT scanning missed one subdural abscess and one intracerebral abscess. Both modalities exceeded diagnoses made on clinical grounds, which had an accuracy of 82% overall (22). Contrasted CT scan may be contraindicated in patients with renal insufficiency or those with life-threatening contrast allergies. MRI should be employed as the first method of evaluation in such cases. If such patients are unsuitable for MRI because of implanted ferromagnetic devices, pace- makers, implanted defibrillators, or other contraindications, patients with renal insufficiency may gain some nephro-protective effect from the adminis- tration of n-acetyl cysteine (27) or from hydration with sodium bicarbonate (28) prior to contrast administration. Meningitis Clinical Presentation Meningitis most frequently presents as headache. The majority of pa tients also have fever (>38.5  C) and more than half have neck stiffness/nuchal rigidity. Other symptoms include vomiting, mental status changes, and less Complications of Sinusitis and Their Management 281 [...]... complications of sinusitis Laryngoscope 19 97; 1 07( 7):863–8 67 17 Giannoni C, Sulek M, Friedman EM Intracranial complications of sinusitis: a pediatric series Am J Rhinol 1998; 12(3): 173 – 178 18 Hytonen M, Atula T, Pitkaranta A Complications of acute sinusitis in children Acta Otolaryngol Suppl 2000; 543:154–1 57 19 Ong YK, Tan HK Suppurative intracranial complications of sinusitis in children Int J Pediatr Otorhinolaryngol... chronic eosinophilic sinusitis and in the bronchoalveolar lavage fluid of patients with asthma (12–14,22) Cytokine Mediators Both chronic sinusitis and asthma may demonstrate a variety of common cytokine mediators, including IL-4, IL-5, IL-9, IL-13, CCL11 (eotaxin), Sinusitis and Asthma 293 Table 1 Chemical, Cytokine, and Cellular Mediators of Airway Disease Type Chemical Mediator Histamine Prostaglandin... the antigen-presenting cells (APCs) and presented, after the migration of APCs to the lamina propria, to CD4 T-Helper and B cells Activated B cells begin to produce IgEs that in turn will bind to high-affinity IgE receptors of mast cells and basophils and to low-affinity IgE receptors of macrophages, monocytes, platelets, and eosinophils (13) It is still an enigma Rhinosinusitis and Allergy 3 07 why, in... kininogen from blood, leading to the generation of kininis, which in turn causes vasodilatation, edema, and plasma exudation (15) Moreover, mast cells appear to release some cytokines, namely TNF-a, IL-4, IL-5, and IL-13 in this phase TNF-a and IL-4 induce the expression of adhesion molecules on the surface of nasal endothelium; moreover, they seem to have a direct chemical-attractant effect for inflammatory... Produce/release IL-4, IL-5, IL-9, IL-13 a TH2 lymphocytes are a major mediator in allergic rhinosinusitis and allergic asthma; these cells are a less significant component in non-allergic airway inflammation and TNF-a In patients with underlying allergic disease, all of these mediators are present throughout the airway; in non-allergic eosinophilic airway disease, IL-5, eotaxin, and TNF-a are predominating... authors speculated that sinusitis might somehow reduce overall airway b-adrenergic responsiveness, possibly down-regulating receptors This could be a spurious effect and simply due to an increased use of b-adrenergic medication in active asthma (a known down-regulator of b-receptors) This postulated mechanism remains a conjecture until further appropriate b-adrenergic receptor studies can be performed... radiographic evidence of rhinosinusitis (4–11) Chronic sinusitis and asthma share several pathophysiological features: chemical mediators, e.g., histamine, cysteinyl leukotrienes, and prostaglandin D2; cytokines, e.g., interleukin-4 (IL-4), IL-5, IL-9, IL-13, and CCL11 (eotaxin); and cellular mediators, principally eosinophils and TH2 lymphocytes (12–14) These observations have led to the concept of ‘‘one... sinus thrombosis secondary to sinusitis J Otolaryngol 2002; 31(3):165–169 26 Bhatia K, Jones NS Septic cavernous sinus thrombosis secondary to sinusitis: are anticoagulants indicated? A review of the literature J Laryngol Otol 2002; 116(9):6 67 676 27 Birck R, Krzossok S, Markowetz F, Schnulle P, van der Woude FJ, Braun C Acetylcysteine for prevention of contrast nephropathy: meta-analysis Lancet 2003;... complications of sinusitis, other than meningitis, in children: 12-year review Clin Infect Dis 1994; 18(5): 75 0 75 4 SECTION V SINUSITIS AND SPECIFIC DISEASES 14 Sinusitis and Asthma Frank S Virant University of Washington, Seattle, Washington, U.S.A INTRODUCTION Sinusitis and asthma are commonly seen simultaneously in clinical practice (1–3) In fact, nearly 50% of asthmatics demonstrate upper airway symptoms... magnetic resonance imaging in patients with sinusitis with complications Laryngoscope 2002; 112(2):224–229 23 Younis RT, Lazar RH, Anand VK Intracranial complications of sinusitis: a 15-year review of 39 cases Ear Nose Throat J 2002; 81(9):636–638, 40–42, 44 24 Bradley PJ, Manning KP, Shaw MD Brain abscess secondary to paranasal sinusitis J Laryngol Otol 1984; 98 (7) :71 9 72 5 25 Amran M, Sidek DS, Hamzah M, . of sinusitis. Laryngoscope 19 97; 1 07( 7):863–8 67. 17. Giannoni C, Sulek M, Friedman EM. Intracranial complications of sinusitis: a pediatric series. Am J Rhinol 1998; 12(3): 173 – 178 . 18. Hytonen. pace- makers, implanted defibrillators, or other contraindications, patients with renal insufficiency may gain some nephro-protective effect from the adminis- tration of n-acetyl cysteine ( 27) or from. as a compli- cation of sinusitis: are diagnostic and treatment trends changing?. Ear Nose Throat J 2002; 81 :77 1 77 5. 6. Harris GJ. Subperiosteal abscess of the orbit. Age as a factor in the bacteriology and