Rhinosinusitis in the intensive care unit patients: a review of the possible underlying mechanisms and proposals for the investigation of their potential role in functional treatment interventions.

PURPOSE: Nosocomial rhinosinusitis (NS) is diagnosed in 2% to 26% of intubated patients and is associated with ventilator-associated pneumonia, septicemia, and fever of unknown etiology. The purpose of this study was to review the underlying pathogenetic mechanisms and the treatment options that derive from them. RESULT: The pathogenesis of NS seems to be mainly a combination of the failure of the local defenses and self-clearance mechanisms and the development of topical factors, which favor the colonization of the nasal and antral cavities with pathogens. The systemic administration of antibiotics, which are the current treatment of NS, have a limited, if any, effect on any of the above pathophysiologic mechanisms. However, the review of the literature demonstrates that the research on functionally orientated treatment options has been limited to the effect of orotracheal vs nasotracheal intubation. There are no clinical trials investigating the effect, which combinations of pathophysiology-based measures may have on the prevalence and treatment of NS and ventilator-associated pneumonia. CONCLUSION: An update of the pathogenetic mechanisms demonstrates that the prevention and treatment of nosocomial rhinosinusitis may expand well beyond the systemic administration of antibiotics.

Short-term pathophysiologic changes and histopathologic findings of the auditory pathway after closed head injury, using a rabbit model.

Hearing impairment is a well-known consequence of closed head injury (CHI). The aim of this study was to elucidate the pathogenesis of CHI-induced hearing loss, using a rabbit model. Twelve New Zealand white rabbits were divided into two groups of 6. In the first group, CHI was induced mechanically, whereas the rabbits of the second group served as controls. Baseline distortion product otoacoustic emissions (DPOAEs), contralateral suppression (CS) of the DPOAEs and auditory brainstem response (ABR) were obtained. The same measurements were performed in the first group after CHI. Three hours later, the animals were sacrificed and their brain was excised and subjected to histopathologic examination. Mean I-III ABR latencies were increased and DPOAE amplitudes and CS values were reduced in the trauma group after CHI, at a statistically significant level. Histopathologic examination of the temporal lobe and brainstem showed multiple hemorrhagic and necrotic areas, with edema in the surrounding region. The vestibulocochlear nerve was severely damaged at its emerging site at the brainstem. In conclusion, both peripheral and central involvement of the auditory pathway was found after CHI. Otoacoustic emissions in conjunction with ABR may provide significant information on both peripheral and central auditory function.