Outcome of myringotomy with ventilation tube for otitis media with effusion in Thai children: Ramathibodi experiences.

OBJECTIVE: Study the otologic and audiologic outcome when using a ventilation tube (VT) for the treatment of otitis media with effusion (OME) in Thai children. MATERIAL AND METHOD: The medical records of twenty-three pediatric patients, 17 male and 6 female, aged 4 to 11 (mean age of 6.8 years), with the diagnosis of OME who attended the Department of Otolaryngology, Faculty of Medicine Ramathibodi Hospital, between January 2001 and December 2006 were reviewed. Seventeen (73.9%) patients had associated diseases, 26% with allergic rhinitis (AR), 21.7% with obstructive sleep apnea from chronic hypertrophic tonsillitis and adenoid hypertrophy (OSA), and 26% with cleft palate (CP). The audiometric with tympanometric assessment were done pre- and post-operative with mean of 47.3 and 294.2 days respectively. All children were treated with myringotomy and insertion of VT. Oto-microscopic examinations for tympanic membrane pathologic abnormalities were confirmed Post operative otorrhea cases were identified. The extrusion rates of VT were also recorded after the insertion. RESULTS: Twenty-three patients were enrolled in the present study. Mean air-bone gap was 18.24 (SD = 13.04) and 10.83 (SD = 8.26) before and after the operation respectively, and the difference was statistically significant (p = 0.0013). This could be interpreted that myringotomy with insertion VT could improve hearing by decreasing the air-bone gap dB. Having assessed the effect of associated diseases (i.e., AR, OSA, and CP) on differences of air-bone gap between before and after operation, the authors found that having AR, OSA, and CP did not statistically affect the results of the operation. However the mean differences of air-bone gap between before and after operation were quite different for AR versus non-AR (-11.58 vs. -5.78), and OSA versus the non-OSA group (-12.10 vs. -5.95). This might have the effects of the two factors but with this small sample size and thus low power could not detect the effect. Tympanometric pattern was mainly type B in the pre-operative (79.3%) and post operative (62.5%) period after tympanic membrane closure in both ears. Mucoid fluid in the middle ear cavity of both ears was detected during the operation in all patients. Post operative otorrhoea occurred in 16.7%. The mean of extrusion rate of VT was 307.2 +/- 204.7 days with maximum of 760 days. The mean duration of OME before surgery was 384.1 days. CONCLUSION: The effects of conventional VT in Thai children with OME could improve statistical significant hearing by decreasing the air-bone gap. The associated diseases (i.e., AR, OSA, and CP) did not statistically affect the results of the operation.

Filtration efficiency of the ramathibodi nasal filter evaluated by rhinomanometry in high concentration level of laser smoke particle.

Under conditions with a high concentration level of laser smoke particles, the filtration efficiency of the Ramathibodi nasal filter was studied. Different kinds of filter material in the Ramathibodi nasal filter were evaluated in human adults with an anterior standard rhinomanometric method. The Ramathibodi nasal filter with three-layers of a half-face mask filter and a 4 mm thickness polyurethane foam put inside was applied in a simulated human airway. The experiment was conducted in the Otolaryngology Department, Ramathibodi Hospital from October to December 2001. The amount and size of laser smoke particles were measured by a laser diode portable dust monitor. The amount of residual laser smoke particles in the simulated human airway without the Ramathibodi nasal filter of PM2.5, PM10 and PM15 were 100.91 +/- 7.65, 109.10 +/- 7.87 and 120.18 +/- 14.28 mcg/m3 respectively. The amount of residual laser smoke particles in the simulated human airway with the Ramathibodi nasal filter of PM2.5, PM10 and PM15 were 85.55 +/- 3.42, 92.18 +/- 4.40 and 99.72 +/- 5.02 mcg/m3 respectively. The filtration efficacy of the Ramathibodi nasal filter showed a high statistically significant difference with a p-value of <0.001 for three particle sizes. High concentration of laser smoke particles in an operative room represented suspended particulate matters which are very dangerous for human healths. The Ramathibodi nasal filter as a personal respiratory protective device applied in human nasal vestibules could protect the human airway from atmospheric suspended particulate matter.

Efficacy of the ramathibodi nasal filter in a simulated human airway evaluated by a laser diode portable dust monitor under low laser smoke particle concentration.

The Ramathibodi nasal filter attached to a simulated human airway was proposed to filter laser smoke particles. The simulated human airway composed of nasal and pharyngeal model, airway passage and lung model machine which mimicked the human respiratory system. The laser smoke particles represented a suspended particulate matter in a highly air-pollutted area such as at a main roadside in Bangkok. The experiment was done in the Department of Otolaryngology, Ramathibodi Hospital, from January to March 2000. The simulated human airway got an equal amount of laser smoke particles in a sealed plastic box for 1 min. The residual amount of laser smoke particles in a closed system of the simulated human airway was measured by a laser diode portable dust monitor for 1 min in each cycle and calculated as a mean and standard deviation. Without the Ramathibodi nasal filter of 39 sample pairs, the amounts of PM15, PM10 and PM2.5 were 52.3 +/- 6.8, 43.0 +/- 4.9 and 37.0 +/- 3.5 mcg/m3 respectively. With the Ramathibodi nasal filter of 39 pairs sample, the amounts of PM15, PM10 and PM2.5 were 48.1 +/- 9.9, 39.1 +/- 9.1 and 33.2 +/- 7.2 mcg/m3 respectively. Ramathibodi nasal filter efficacy for all laser smoke particle sizes evaluated statistically using t-test showed significant differences from those without the filter. Filtration efficacy should be tested further in higher concentrations of laser smoke particles and applied in human nasal vestibules under a critical air-polluted condition.

Suspended particulate matter in an office and laser smoke particles in an operating room.

Suspended particulate matter in an office and laser smoke particles in a laser operative room of the Otolaryngology Department, Ramathibodi Hospital were compared. Suspended particulate matter sizes of PM15, PM10 and PM2.5 were selected due to their impact on health. The amount and sizes of the particles were measured by a laser diode portable dust monitor. The mean and standard deviation were measured every hour for 6 periods and calculated by specific computer software. The amount of suspended particulate matters in the office were within the accepted safety level. The amount of suspended particulate matter including laser smoke particles in the operative room before, during and after each laser evaporative procedure was much higher than that of the office. The amount of suspended particulate matter was dangerous for all personnel in the operative room. Risk management for patients in the operative room should be stressed. The ventilation system of the operative room will be assessed further.