Essential Knowledge for Microsuction Practitioners
In 2021, we conducted an experiment to provide guidance on the safe utilisation of the Lateral Air Hook, a tool designed by audiologists to enhance patient comfort and efficiency of earwax removal during aural microsuction procedures.
We concluded that the Lateral Air Hook significantly improves the removal process of earwax, especially in canals that are tightly occluded, by using a larger-diameter tube. This innovation is crucial for practitioners performing microsuction, as it offers a combination of increased patient comfort due to improved practitioner efficiency that was previously unattainable.
The results below show the Real Ear Measurements (REMs) that were taken during the experiment, showing the amount of 'noise' across the frequency range at two ear canal depths with a standard Zoellner suction tube and a Lateral Air Hook. In this article, we are going to look at the implications of these results on the safety of aural microsuction in regards to noise. We used the most powerful suction unit regularly used for aural microsuction, the CAMI New Hospivac 400.
Noise Exposure and Hearing Safety
It's imperative for practitioners to grasp the following critical information, which, unfortunately, many may not know. According to the U.S. Environmental Protection Agency, Office of Noise Abatement and Control, exposure to sounds at 85 dB(A) is permissible for up to 8 hours. However, the noise level during microsuction will exceed this threshold at certain frequencies as soon as the suctioning Zoellner tube enters the ear canal.
Sounds above 85 dB(A) can accelerate hearing damage, with safe listening durations halving for every 3-dB increase in noise level above 85 dB(A). For instance, at 88 dB(A), the safe exposure time is reduced to 4 hours, and at 91 dB(A), it further decreases to 2 hours. Beyond the second bend of the ear canal with a standard tube, noise levels exceed 100 dB SPL at 2.5 kHz, equating to about 103 dB for our purposes. This level of exposure reduces safe listening time to just 7.5 minutes, heightening the risk of tinnitus and permanent hearing loss.
NB: While understanding the logarithmic relationship between dB(A) and dBSPL might be useful, it is not mandatory or necessary. You can consider them the same for these purposes at 2.5 kHz.
Length (time), depth and skill. It all matters.
Aural microsuction training with The Hearing Lab Store has always advised that standard Zoellner tubes without fine ends should only reach the second bend of the ear canal, while lateral air hooks should not go beyond the first bend. Additionally, a microsuction session should not involve more than 10 minutes of actual suctioning per ear.
Experienced practitioners who can better control the air flow within an ear canal during a procedure may be able to perform for longer durations, and their are other factors to consider too, such as a fully occluded ear, and where significant wax is against the eardrum, the patient can’t hear much anyway.
If you go longer than advised, then your patient is at risk. If you go deeper than advised, then your patient is at risk. If you have the fine ends and the skills to go longer and deeper, do you have the best vision with sufficient magnification available to not put your patient at risk? Be careful out there, folks. Don't take unnecessary risks; reappoint and refer when appropriate because their hearing is literally in your hands.
U.S. Environmental Protection Agency, Office of Noise Abatement and Control. (1974, March). Information on levels of environmental noise requisite to protect public health and welfare with an adequate margin of safety. Retrieved from EPA Document [PDF].