Otoacoustic emissions as a screening test for hearing impairment in children

Transient evoked otoacoustic emissions (TEOAEs) are low amplitude sound waves produced by the healthy cochlea. They can be recorded with a microphone in the external ear. TEOAEs are abolished by hearing losses of 30 dB or more. The feasibility of using TEOAEs as a screening test for hearing loss in children was studied. TEOAE recordings were attempted in 56 children attending an audiology clinic. Recordings were possible from both ears in 52 children; of these 104 ears, 32 had hearing deficits of 30 dB or more. Hearing status was compared with the results of six TEOAE screening criteria. All criteria had a sensitivity of 1.00. Four standard TEOAE criteria yielded specificities of 0.46-0.58. Two new criteria derived from analysis of limited frequencies from the TEOAE waveform gave specificities of 0.76 and 0.82. It can be concluded that, when appropriate pass/fail criteria are employed, TEOAEs are a feasible screening test in children.     

Angiotensin-converting enzyme activity: a novel way of assessing pulmonary changes during total knee arthroplasty

Emboli after tourniquet release (TR) during total knee arthroplasty (TKA) occur in all patients. This may lead to fat embolism syndrome with lung injury. Angiotensin-converting enzyme (ACE) lines the pulmonary endothelium, and a decrease in ACE metabolism or hydrolysis of (3)HBPAP ((3)H-benzoyl-Phe-Ala-Pro; a substrate specific for ACE) has been associated with lung injury. We evaluated the association of this assay with pulmonary changes during TKA. Eleven consecutive patients undergoing bilateral TKA had the ACE assay performed perioperatively. We determined substrate hydrolysis and pulmonary capillary surface area (capillary perfusion index; CPI) and correlated it with pulmonary vascular resistance (PVR) and clinical outcome. Ten of the 11 patients demonstrated an increase in substrate hydrolysis and CPI along with a decrease in PVR after first or second TR when compared with baseline values (P < 0.05). In the other patient, PVR continued to increase even after TR, whereas CPI and substrate hydrolysis decreased after surgery. Whereas all others did well clinically, this patient developed confusion and hypoxemia. In previous studies, a decrease in PVR with an increase in CPI, as exhibited by the 10 patients, has been associated with pulmonary capillary recruitment. We believe this to be an important mechanism by which the lungs are able to accommodate the burden of emboli at the time of TR.     

Vogt-Koyanagi-Harada syndrome and keratoconjunctivitis sicca

PURPOSE: To discover a relationship between Vogt-Koyanagi-Harada (VKH) syndrome and Sj?gren syndrome. DESIGN: Observational case-control study. METHODS: Sixteen Italian patients with VKH syndrome and 16 controls with diffuse uveitis underwent tear analysis and rheumatologic evaluation. Biopsy specimens of the minor salivary glands were obtained or salivary gland scintigraphy was performed in patients with xerostomia. RESULTS: The Schirmer test (P <.0001), break-up time (P <.0001), the Ferning test (P <.001), and fluorescein and rose bengal staining (P <.0001) resulted in changes in VKH. Biopsy was positive in two patients and scintigraphy in four. Human leukocyte antigen DR4 was found in 68.75% of VKH cases and in 83.3% of the cases with Schirmer test less than 3 mm. CONCLUSIONS: The incidence of keratoconjunctivitis sicca was higher in VKH syndrome patients than in controls. Two patients satisfied the criteria for Sj?gren syndrome, and two others had scintigraphy indicative of salivary gland involvement. The association of these two autoimmune disorders is suggested by the low incidence of VKH syndrome in Italy and might be related to HLA DR4.