The effects of enhanced formaldehyde clearance in a gross anatomy laboratory by floor plan redesign and dissection table adjustment.

Formaldehyde has carcinogenic properties. It is associated with nasopharyngeal cancer and causes irritation of the eyes, nose, throat, and respiratory system. Formaldehyde exposure is a significant health concern for those participating in the gross anatomy laboratory, but no learning method can substitute cadaver dissection. We performed a formaldehyde level study in 2018, which found that most of the breathing zone (S-level) and environment (R-level) formaldehyde levels during laboratory sessions at the Faculty of Medicine Siriraj Hospital exceeded international ceiling standards. In the academic year 2019, we adapted the engineering rationale of the NIOSH hierarchy of controls to facilitate formaldehyde clearance by opening the dissection table covers and increasing the area per dissection table, then measured formaldehyde ceiling levels by formaldehyde detector tube with a gas-piston hand pump during (1) body wall, (2) upper limb, (3) head-neck, (4) thorax, (5) spinal cord removal, (6) lower limb, (7) abdomen, and (8) organs of special senses dissection sessions and comparing the results with the 2018 study. The perineum region data were excluded from analyses due to the laboratory closure in 2019 from the COVID-19 outbreak. There were statistically significant differences between the 2018 and 2019 S-levels (p < 0.001) and R-levels (p < 0.001). The mean S-level decreased by 64.18% from 1.34 ± 0.71 to 0.48 ± 0.26 ppm, and the mean R-level decreased by 70.18% from 0.57 ± 0.27 to 0.17 ± 0.09 ppm. The highest formaldehyde level in 2019 was the S-level in the body wall region (1.04 ± 0.3 ppm), followed by the S-level in the abdomen region (0.56 ± 0.08 ppm) and the spinal cord removal region (0.51 ± 0.29 ppm). All 2019 formaldehyde levels passed the OSHA 15-min STEL standard (2 ppm). The R-level in the special sense region (0.06 ± 0.02 ppm) passed the NIOSH 15-min ceiling limit (0.1 ppm). Three levels for 2019 were very close: the R-level in the head-neck region (0.11 ± 0.08 ppm), the abdomen region (0.11 ± 0.08), the body wall region (0.14 ± 0.12 ppm), and the S-level in the special sense region (0.12 ± 0.04 ppm). In summary, extensive analysis and removal of factors impeding formaldehyde clearance can improve the general ventilation system and achieve the OSHA 15-min STEL standard.

From a High School Student to an Otolaryngologist-19 Years With a Jugular Foramen Meningioma.

In this essay, an otolaryngologist reflects on the circular journey from patient to physician to patient again over 19 years living with a left jugular foramen meningioma.

Latex-injected, non-decapitated, saturated salt method-embalmed cadaver technique development and application as a head and neck surgery training model.

Published cerebrovascular injection techniques have mostly used decapitated, fresh cadavers or heads embalmed with 10% formaldehyde. There have been no reports using vascular-injected cadavers for head and neck surgical training models or using vascular injections in saturated salt method-embalmed cadavers. Thus, we performed vascular labeling of five saturated salt method-embalmed cadavers without decapitation. Latex mixed with red ink was injected into the common carotid artery via a 3D-printed vascular adapter. The injection force was provided by a peristaltic pump. Thyroidectomy, submandibular gland excision, neck dissection, parotidectomy, and mandibulotomy were performed on both sides of each cadaver (n = 10). The consistency of the cadavers was softer than fresh ones. Subcutaneous tissues were well preserved, and muscles were moist and elastic. Five physicians graded the resemblance of the heads and necks of the latex-injected, saturated salt method-embalmed, non-decapitated of five cadavers compared to living humans using a Likert scale from 0 (no resemblance) to 5 (maximum resemblance). Fifty-two percent of the head and neck region resemblance scale ratings were four or five. Although the cadavers were practical for head and neck surgical simulations, the brain parenchyma was only partially preserved and unsuitable for use. The most distal arterial branches reached by the injected latex were measured. The external caliber of the smallest vessels reached were lacrimal arteries (mean caliber ± SD, 0.04 ± 0.04 mm; 95% CI [0, 0.09]). There were no significant differences in the mean caliber of the smallest vessels reached between the left- and right-sided arterial branches (all p < 0.05).

One academic year laboratory and student breathing zone formaldehyde level, measured by gas-piston hand pump at gross anatomy laboratory, Siriraj Hospital, Thailand.

This study used a formaldehyde detector tube with a gas-piston hand pump to assess ceiling levels of student breathing zone and gross laboratory environment across the 2018 academic year. The room dimension was 28.6 × 55.48 × 5.5 m. It contained 90 cadavers, each placed on a hinged cover table. We measured before and during nine body region dissections. There was a significant difference (p < 0.01) between student exposure and laboratory environment levels. The highest level was student exposure during body wall dissection (2.7 ppm), the first laboratory; students may accidentally enter body cavities. The latter two were in abdominal (1.85 ppm) and lower limb dissections (1.49 ppm). The three highest environment levels were in different regions; spinal cord removal (1.13 ppm), lower limb (0.72 ppm), and thorax (0.71 ppm) dissection. Only the perineum environment level (0.09 ppm) was below the NIOSH ceiling level (0.1 ppm), which may result from the table covers that had been opened for 2 weeks before measurement. This study finding signified the importance of student personal exposure monitoring and encouraged the academic year measurement. Because each laboratory has unique factors, those affect formaldehyde levels; dissection steps, dissection table design, cadaver storage protocol, and heating-ventilation-air conditioning system performance, for instance.

Randomized crossover study of tongue-retaining device and positive airway pressure for obstructive sleep apnea.

PURPOSE: To compare the efficacy of tongue-retaining device (TRD) versus continuous positive airway pressure (CPAP) for treatment of obstructive sleep apnea (OSA). STUDY DESIGN: Randomized crossover study. SUBJECTS AND METHODS: Thirty-six patients with a mean age of 52.7 ± 10.6 years were enrolled. Inclusion criteria were age ≥ 18 years, apnea-hypopnea index (AHI) ≥ 5 events/h, and minimum oxygen saturation (SO2) ≥ 70% from polysomnography (PSG). Exclusion criteria were severe periodontal disease, unstable cardiopulmonary or neurological diseases, and/or total sleep time < 2 h. A 1-week wash-in period was followed by questionnaires and randomization into two groups: TRD/CPAP and CPAP/TRD (18 patients each). After 3 weeks of intervention, questionnaires were re-administered and WatchPAT was performed. After a 1-week wash-out period, patients were switched to the other treatment. Primary outcome was AHI. Secondary outcomes were SO2, Functional Outcomes of Sleep Questionnaire (FOSQ), and Epworth Sleepiness Scale (ESS) scores, treatment side effects, and adherence. RESULTS: Nine patients withdrew, so 27 patients were included in the final analysis. Mean AHI decreased from 38.7 ± 24.0 to 2.5 ± 0.5 and 12.7 ± 2.6 events/h for CPAP and TRD, respectively (95% confidence interval of mean differences 4.65-15.62; p < 0.001). There was no significant difference in ESS and FOSQ scores between treatments. Common adverse effects were drooling, tongue numbness, and pain for TRD; and nasal blockage, mask compression, and difficult portability for CPAP. CONCLUSIONS: CPAP was superior to TRD for resolving PSG parameters; however, both similarly improved QOL and daytime sleepiness. TRD might be considered a short-term alternative treatment for OSA. TRIAL REGISTRATION: NCT02788487.

Diagnostic properties of the STOP-Bang and its modified version in screening for obstructive sleep apnea in Thai patients.

OBJECTIVE: To test the diagnostic properties of the original and a modified STOP-Bang, as well as testing the additional use of a waist-to-height ratio (WHtR) of > or = 0.55 in screening for obstructive sleep apnea (OSA) in Thai patients. MATERIAL AND METHOD: Three hundred and three patients (186 males and 117 females) who underwent anthropometric measurement and standard polysomnography were asked to complete the STOP-Bang questionnaire. Subjects were considered high-risk if their scores were > or = 3. Patients with significant co-morbidities were excluded. RESULTS: Screening for OSA involved measurements of STOP-Bang sensitivity, specificity, positive predictive value, and negative predictive value at several apnea-hypopnea index (AHI) cut-off points. At AHI 5, these values were 87.3%, 48.1%, 82.2%, and 52.2%, respectively. At AHI 15, these values were 92.6%, 36.4%, 58.5%, and 83.6%, respectively. The modified STOP-Bang (using a cut-off of BMI > 30 kg/m2) showed slightly increased sensitivities at the AHI cut-off points of 5 and 15 with values of 88.7% and 93.2%, respectively, with improved area under the curves. Furthermore, by applying the WHtR of > or = 0.55 to those patients who were classified as high-risk by the questionnaires, the specificities for predicting OSA were improved to 85.2% and 76.1% for the aforementioned cut-off points, respectively. CONCLUSION: Both STOP-Bang and its modified version were highly sensitive measures for OSA screening in medical or dental clinics. However, the modified version might be more suitable for Thais and Asians, and the additional use of WHtR > or = 0.55 might be useful for reducing the unnecessary sleep investigation or management in those who were classified as high-risk patients.