Diagnostic Value of the Morphometric Model and Adjusted Neck Circumference in Adults with Obstructive Sleep Apnea Syndrome.

BACKGROUND: Obstructive sleep apnea syndrome is a major public health problem. The morphometric model and the Sleep Apnea Clinical Score are widely used to evaluate adults; however, neither of these tools has been validated in a Mexican population. OBJECTIVE: To determine the diagnostic value of the morphometric model and the Sleep Apnea Clinical Score and compare them with conventional clinical instruments. METHODS: A total of 97 individuals were recruited prospectively. Initial screening excluded 36, of whom nine were subjects without apnea; the remaining 52 were consecutive patients with obstructive sleep apnea syndrome diagnosed by nocturnal polysomnography. Diagnostic values of each test were calculated. RESULTS: Obstructive sleep apnea syndrome patients had significantly higher scores with both instruments than controls: morphometric model: 61.3 (95% CI: 45.5-75.3) vs. 41.0 (95% CI: 35.6-45.6); Sleep Apnea Clinical Score: 45.3 (95% CI: 39.5-40.3) vs. 36 (95% CI: 34.0-36.5), respectively. For severe cases, the best cutoff point for morphometric model was 46, with a sensitivity of 81% (95% CI: 62.5-92.6) and specificity of 46.7% (95% CI: 66.4-100), while for Sleep Apnea Clinical Score it was > 48, with a sensitivity of 61% (95% CI: 46.1-74.2) and specificity of 80.4% (95% CI: 66-90.6). CONCLUSIONS: A morphometric model value of ≥ 46 or an adjusted neck circumference (Sleep Apnea Clinical Score) > 48 were adequate for diagnosing obstructive sleep apnea syndrome.

Comparison of lyophilized glutaraldehyde-preserved bovine pericardium with different vascular prostheses for use as vocal cords implants: experimental study.

This study compared the use of lyophilized glutaraldehyde-preserved bovine pericardium (LGPBP), polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), and Teflon felt (TF) as implants for vocal cords (VC) medialization and aimed to assess the endoscopic, macroscopic, and microscopic VC changes after medialization in a canine model. In 18 mongrel dogs, the right VC were medialized with LGPBP and the left were implanted as follows: Group I (n = 6): LGPBP and PTFE; Group II (n = 6): LGPBP and PET; Group III (n = 6): LGPBP and TF. Surgical handling of the implants was compared. Three months after surgery, macroscopic and microscopic changes of VC and implants were evaluated. LGPBP offered the best surgical handling (p = 0.005, Kruskal-Wallis). TF implants showed extrusion (p = 0.005, Kruskal-Wallis) and severe inflammation. All VC formed fibrous capsules around the implants; the ones developed by LGPBP implants were thinner (p = 0.001, ANOVA, Tukey). VC implanted with synthetic materials showed eosinophilic infiltration (p = 0.01, Kruskal-Wallis). We concluded that the LGPBP could be used as an implant for VC medialization because it is biocompatible, easy to handle and remove during surgical procedures, and nonabsorbable or extrudable and produces an inflammatory reaction similar to PTFE and PET.

Accuracy and linearity of positive airway pressure devices: a technical bench testing study.

STUDY OBJECTIVES: To analyze the accuracy and linearity of different CPAP devices outside of the manufacturers' own quality control environment. METHODS: Accuracy (how well readings agree with the gold standard) and linearity were evaluated by comparing programmed pressure to measured CPAP pressure using an instrument established as the gold standard. Comparisons were made centimeter-by-centimeter (linearity) throughout the entire programming spectrum of each device (from 4 to 20 cm H2O). RESULTS: A total of 108 CPAP devices were tested (1836 measurements); mean use of the devices was 956 hours. Twenty-two of them were new. The intra-class correlation coefficient (ICC) decreased from 0.97 at pressures programmed between 4 and 10 cm H2O, to 0.84 at pressures of 16 to 20 cm H2O. Despite this high ICC, the 95% agreement limit oscillated between -1 and 1 cm H2O. This same behavior was observed in relation to hours of use: the ICC for readings taken on devices with < 2,000 hours of use was 0.99, while that of the 50 measurements made on devices with > 6,000 hours was 0.97 (the agreement limit oscillated between -1.3 and 2.5 cm H2O). "Adequate adjustments" were documented in 97% of measurements when the definition was +/- 1 cm H2O of the programmed pressure, but this index of adequate adjustment readings decreased to 85% when the +/- 0.5 cm H2O criterion was applied. CONCLUSIONS: In general, the CPAP devices were accurate and linear throughout the spectrum of programmable pressures; however, strategies to assure short- and long-term equipment reliability are required in conditions of routine use.