Abstract
Objective
Patient and equipment safety has become increasingly scrutinized in today’s medical care. Routine otolaryngologic evaluation often involves suctioning with Frazier-type suction devices in the ear canal for improved visualization, but data are limited on the potential acoustic trauma from ear canal suction devices. This study intends to document the objective and subjective effects of ear canal suctioning to identify any risk for hearing threshold shifts or other potential negative effects.
Patients and Methods
Prospective study on 21 healthy volunteers enlisted for evaluation. Presuctioning tympanogram, audiogram, and otoacoustic emissions data were obtained. Spectrum analyses were recorded during ear canal suctioning with a probe microphone placed lateral to the tympanic membrane. Subjective data were recorded, and a follow-up audiogram and otoacoustic emissions were obtained to identify any temporary threshold shifts.
Results
Spectrum analyses revealed a high degree of variability between subjects. A peak intensity of 111 dB sound pressure level was recorded. All patients tolerated suctioning, and none reported hearing loss. No threshold shifts were observed. Subjective data failed to correlate with the objective recorded intensities.
Conclusions
Clinicians and patients need to be acutely aware of potential risks and benefits from any medical intervention. Routine ear canal suctioning can be extremely loud and uncomfortable for patients. This study failed to document objective proof of hearing detriment from ear canal suctioning, although the possibility exists during office and surgical intervention. Further study and potential alternative suctioning methods deserve attention.
1
Introduction
As patient safety has become more of a priority, routine procedures such as ear suctioning should be scrutinized for potential deleterious effects. As otolaryngologists work in and around the ear, powered instrumentation may create sound levels that potentially could cause damage to hearing. Although there have been no known documented noise-induced hearing loss cases from routine ear suctioning, anecdotal cases have been described . Some reports imply that there may be a cause-effect relationship between suction noise and acoustical trauma, but there are limited data detailing this potential side effect .
Routine otolaryngologic evaluation involves direct visualization of the external auditory canal and tympanic membrane. Impacted cerumen and/or other materials are often removed using small ear curettes, irrigation, or suctioning with Frazier-type suction devices to thoroughly examine the canal and tympanic membrane. Healthy volunteers were enlisted to participate in hearing tests, ear suctioning under the otomicroscope, and an immediate follow-up postsuctioning hearing evaluation to document if there are temporary threshold shifts from such routine ear canal suctioning.
Otolaryngologists may not be aware of the potential for current diagnostic and therapeutic interventions to cause discomfort and to even put patients at risk for noise-induced hearing loss. This study attempts to clearly document the acoustic parameters of ear canal suctioning and associated subjective perceptions experienced by patients. All diagnostic and therapeutic interventions in medicine should have established safety records.
2
Patients and methods
Twenty-one healthy volunteers were enrolled to participate in this series and underwent suctioning and testing of the right ear only. Informed consent was obtained through the standard process approved our institutional review board. Inclusion criteria required subjects to be older than 18 years, without recent ear infection/trauma/perforation in the last 4 weeks, and no history of ear surgery (except ventilation tubes) within last 2 months. Exclusion resulted if the subject was unable to lay still and flat on their back for at least 10 minutes. The subjects completed a questionnaire of their ear and hearing history. Conventional handheld otoscopy was completed on the right ear to rule out impacted cerumen. Any significant obstructing wax or debris was removed with a curette before an audiogram or suctioning.
Each patient then underwent a right ear tympanogram (primarily to define external auditory canal volume), pure tone air conduction audiogram, and distortion product-evoked otoacoustic emissions (DPOAEs) in a single-walled sound suite. Presuction and postsuction testing was performed by a licensed audiologist, and all equipment was calibrated in accordance with ANSI standards. Testing was completed with a Welch-Allyn Microtymp 2 (Skaneateles Falls, NY), Grasen-Stadler GSI 1716 clinical audiometer (Milford, NH), TCH-49 circumaural earphones (Eden Prairie, MN), AudX distortion product-evoked otoacoustic emissions analyzer with ototoxic protocol (Mundelein, IL), and Audioscan real ear analyzer (Etymonics, Dorchester, Ontario, Canada) with probe microphone assembly.
After recording the presuctioning data, the subject was taken to the examination table and instructed to lie supine with the head turned slightly to the left. Calibration sound measurements were taken outside the ear canal to obtain a baseline for background ambient sound levels. Then a flexible microphone probe was placed through an appropriately sized metal ear speculum in the anterior-superior portion of the ear canal near the tympanic membrane under direct visualization with the otomicroscope. The microphone was again calibrated to account for individual ear canal resonance characteristics and to confirm that the probe was functional. With the microphone probe in place, initial spectrum analyses were obtained in the dry canal to document the sound from the suction itself placed near the tympanic membrane with the thumb hole occluded. Next, approximately 0.5 mL of a warm dilute hydrogen peroxide/normal saline was instilled into the ear canal. With the number 5 Frazier-type suction instrument (Miltex 19-580 stainless made in Germany) attached to 3.6 m (12 ft) of standard nonconductive suction tubing with an inner diameter of 6 mm and the wall suction set at approximately 100 mm Hg (13.5 kPa), the fluid was slowly suctioned for approximately 20 to 40 seconds while recording spectrum analyses.
After data acquisition, a short questionnaire to subjectively quantity the sound levels was given. They were also briefly asked to describe if they experienced hearing loss, dizziness, or tinnitus. Finally, pure tone audiograms, followed by otoacoustic emission measures were repeated within 5 minutes.
2
Patients and methods
Twenty-one healthy volunteers were enrolled to participate in this series and underwent suctioning and testing of the right ear only. Informed consent was obtained through the standard process approved our institutional review board. Inclusion criteria required subjects to be older than 18 years, without recent ear infection/trauma/perforation in the last 4 weeks, and no history of ear surgery (except ventilation tubes) within last 2 months. Exclusion resulted if the subject was unable to lay still and flat on their back for at least 10 minutes. The subjects completed a questionnaire of their ear and hearing history. Conventional handheld otoscopy was completed on the right ear to rule out impacted cerumen. Any significant obstructing wax or debris was removed with a curette before an audiogram or suctioning.
Each patient then underwent a right ear tympanogram (primarily to define external auditory canal volume), pure tone air conduction audiogram, and distortion product-evoked otoacoustic emissions (DPOAEs) in a single-walled sound suite. Presuction and postsuction testing was performed by a licensed audiologist, and all equipment was calibrated in accordance with ANSI standards. Testing was completed with a Welch-Allyn Microtymp 2 (Skaneateles Falls, NY), Grasen-Stadler GSI 1716 clinical audiometer (Milford, NH), TCH-49 circumaural earphones (Eden Prairie, MN), AudX distortion product-evoked otoacoustic emissions analyzer with ototoxic protocol (Mundelein, IL), and Audioscan real ear analyzer (Etymonics, Dorchester, Ontario, Canada) with probe microphone assembly.
After recording the presuctioning data, the subject was taken to the examination table and instructed to lie supine with the head turned slightly to the left. Calibration sound measurements were taken outside the ear canal to obtain a baseline for background ambient sound levels. Then a flexible microphone probe was placed through an appropriately sized metal ear speculum in the anterior-superior portion of the ear canal near the tympanic membrane under direct visualization with the otomicroscope. The microphone was again calibrated to account for individual ear canal resonance characteristics and to confirm that the probe was functional. With the microphone probe in place, initial spectrum analyses were obtained in the dry canal to document the sound from the suction itself placed near the tympanic membrane with the thumb hole occluded. Next, approximately 0.5 mL of a warm dilute hydrogen peroxide/normal saline was instilled into the ear canal. With the number 5 Frazier-type suction instrument (Miltex 19-580 stainless made in Germany) attached to 3.6 m (12 ft) of standard nonconductive suction tubing with an inner diameter of 6 mm and the wall suction set at approximately 100 mm Hg (13.5 kPa), the fluid was slowly suctioned for approximately 20 to 40 seconds while recording spectrum analyses.
After data acquisition, a short questionnaire to subjectively quantity the sound levels was given. They were also briefly asked to describe if they experienced hearing loss, dizziness, or tinnitus. Finally, pure tone audiograms, followed by otoacoustic emission measures were repeated within 5 minutes.
3
Results
Ten male and 11 female subjects completed informed consent and are included in all analyses. All had unremarkable otoscopic examination without tympanic membrane perforation, obstructing lesions, or pneumatization tubes. Twenty subjects had equivalent external auditory canal volumes within 90% ranges for adult norms (0.63–1.46 cm 3 ) ( Table 1 ).
