Nosocomial sinusitis with isolation of anaerobic bacteria in ICU patients

Objective: To determine the frequency and the eventual clinical characteristics of nosocomial sinusitis with anaerobic bacteria isolation in patients in the intensive care unit (ICU).¶Design: Retrospective study.¶Setting: A 12-bed medical ICU in a teaching hospital.¶Patients: 30 adult patients with documented nosocomial maxillary sinusitis.¶Interventions: None.¶Measurements and results: Using appropriate microbiological techniques, 33 anaerobic bacterial strains were isolated in 18/30 patients (60 %) with nosocomial sinusitis. Anaerobic bacteria were associated with aerobic strains in 13 patients (72 %), whereas in 5 patients (28 %) only anaerobic strains were isolated in sinus puncture cultures. The most frequently isolated species were Prevotella sp. (n = 20, 60 %) and Fusobacterium nucleatum (n = 5, 15 %). The production of β -lactamase was demonstrated in 13/27 gram-negative anaerobic bacteria. All patients in whom anaerobic bacteria were isolated from transnasal punctures had had a nasogastric tube. Patients in whom anaerobic bacteria were isolated more frequently had neurological disorders upon admission (p < 0.02). Ten patients (30 %) had nosocomial pneumonia, 8 of whom had at least one identical strain in both lung and sinus cultures, including 2 patients with anaerobic bacteria isolation.¶Conclusions: Using appropriate microbiological techniques, anaerobic bacteria were frequently isolated in nosocomial sinusitis. If necessary, the empirical choice of antimicrobial therapy in patients with nosocomial sinusitis should take into account these results.     

Nosocomial maxillary sinusitis during mechanical ventilation: A prospective comparison of orotracheal versus the nasotracheal route for intubation

Nosocomial maxillary sinusitis during mechanical ventilation may cause life-threatening complications in ICU patients. The aim of this prospective study was to compare the incidence of maxillary sinusitis according to the route of intubation. 111 consecutive adult patients (mean age: 53, mean SAPS: 12) were randomly assigned to receive either orotracheal (n=53) or nasotracheal (n=58) intubation. All had a nasogastric feeding tube. Patients with head trauma or mechanical ventilation for less than 48h were excluded. Sinusitis diagnosis was made by radiography (waters' view) at the bedside. The two groups were similar in age, SAPS, duration of ventilation. Maxillary sinusitis occurred in 1/53 (1.8%) of the orotracheal group (on the nasogastric tube side), and in 25/58 (43.1%) of the nasotracheal group (7 on the nasogastric tube side, 11 on the endotracheal tube side, 7 bilateral;p<0.001). Nine of the 26 cases of sinusitis were initially treated by sinus drainage because of signs of infection (3 failures) and the 17 others were treated by tube removal. This procedure proved successful in 12 out of 17 cases but secondary drainage was performed in 5 cases (1 failure). Incidents related to the route for long-term intubation were significantly (p<0.001) more frequent in the orotracheal group (8/53 vs 2/58), however no patient died because of them. In this study, long-term orotracheal intubation reduced significantly the incidence of maxillary sinusitis in comparison with nasotracheal intubation.     

Nosocomial infections

Hospital-acquired infections cause significant morbidity, mortality and expense. Surveillance and control programs are necessary to reduce the rate of these infections. Measures to control infection include handwashing, sterilization, use of sterile disposable items, closed urinary drainage, intravenous catheter care, non-touch dressing technique, proper care of respiratory equipment and perioperative chemoprophylaxis.     

Nosocomial pneumonia

A variety of physiologic mechanisms repel the threat of infection. Numerous phenomena associated with trauma and surgery serve to increase risk for nosocomial infection. Postoperative pneumonia is a major concern to anesthetists ranking second in overall incidence but first in fatal outcome of hospital-acquired infections. Essential features of nosocomial pneumonia are reviewed including etiology, transmission, pathogenesis and treatment.     

Nosocomial infections

Recent developments in the understanding of nosocomial infection in general and nosocomial respiratory infections in particular are elucidated. Although the discussion focuses on aerobic bacteria, data are presented to indicate the growing realization that unusual and newly discovered microorganisms play a significant role in hospital-acquired infections. Strategies for the control or prevention of nosocomial infections are highlighted.     

Nosocomial pneumonia

Nosocomial pneumonia remains a challenging problem in critically ill patients in terms of both diagnosis and therapy. The clinical picture is often confusing; confounding factors such as congestive heart failure, ARDS, and interstitial lung disease may obscure the presence of pneumonia. Previous antimicrobial therapy or the presence of large numbers of colonizing organisms contribute to the difficulty of diagnosis. The use of sheathed fiberoptic bronchoscopy with quantitative culture and biopsy is probably the best initial invasive test when routine diagnostic methods fail; open lung biopsy remains the ultimate standard for diagnosis. Empiric therapy is often necessary and should be designed to treat organisms suspected of being the etiologic pathogens either on the basis of preliminary laboratory results (gram and acid-fast stains) or the clinical setting.     

Nosocomial pneumonia

Nosocomial pneumonia, or terminal pneumonia as it was formerly called, results from the repetitive microaspiration of contaminated oropharyngeal secretions into the lungs in the presence of impaired host defenses. This pathophysiologic sequence was suggested by the observations of Osler but clarified by the seminal work of Rouby and colleagues. The enormous impact of antimicrobial agents on the organisms responsible for nosocomial pneumonias was first identified by Kneeland and Price who found that organisms of the normal pharyngeal flora virtually disappeared in terminal pneumonias following administration of these drugs, being replaced by gram-negative bacilli. The remarkable susceptibility of seriously ill patients to becoming colonized by exogenous organisms, even in the absence of antimicrobial therapy, was shown by Johanson et al. These factors, antibiotics and the change in bacterial binding receptors in the airways associated with illness, lead to infections caused by exogenous organisms that are frequently resistant to antimicrobial agents. Clinical findings that usually identify patients with respiratory infections are unreliable for the diagnosis of nosocomial pneumonias as shown by Andrews et al. Invasive techniques, especially the protected specimen brush (PSB) technique, avoid contamination of the specimen by proximal secretions and accurately reflect the bacterial burden of the lung, as first shown by Chastre et al. Quantitation of such specimens serves as an excellent proxy for direct cultures of the lung and are the current gold standard for diagnosis.     

Nosocomial dysnatremia

Patients who exhibited both hyponatremia and hypernatremia during a single admission were identified by a review of their biochemistry data. The mortality of patients who developed either hypernatremia or hyponatremia, followed by the opposite abnormality within less than or equal to 10 days, was 42%. This was greater than the 8.2% mortality for an age-, sex-, and admission-matched normonatremic control group (P less than 0.01, chi 2). Eight of the 10 patients who died had had a change in the sodium concentration in serum greater than 20 mmol/L. The interval (days) between the maximum and minimum sodium concentrations in the survivors and those who died was not statistically different. We found no specific clinical features that could be used to predict the development of this biochemical abnormality.     

Childhood sinusitis.

Childhood sinusitis is difficult to diagnose. It is classified on the basis of duration of inflammation--acute or chronic--and cause of inflammation--infectious or noninfectious. Infectious sinusitis is often a result of obstruction of the osteomeatal complex. Inflammation in noninfectious sinusitis is similar to the inflammatory changes detected in respiratory mucosa of patients with asthma. Acute sinusitis is primarily an infectious process similar to a prolonged infection of the upper respiratory tract. Plain radiography has limited value for the diagnosis of acute sinusitis in children. The most effective treatment of acute sinusitis is administration of a beta-lactamase-resistant antibiotic. Chronic sinusitis may be infectious, noninfectious, or both. Coronal computed tomography of the sinuses and nasal endoscopy are the preferred methods for determining the presence of chronic sinusitis. When physicians prescribe therapy for chronic sinusitis, they need to consider whether the underlying cause is infectious, noninfectious, or both. Treatment of chronic infectious sinusitis is most effective when a beta-lactamase-resistant antibiotic is administered. Chronic noninfectious sinusitis may respond to topically intranasally applied corticosteroids. If medical treatment fails to resolve the disease within 3 months, surgical intervention may be necessary. Finally, although an association between asthma and sinusitis exists, a cause-and-effect relationship has not been established.