Pneumatic otoscopy makes short work of diagnosing acute otitis media, but it is rarely taught anymore, much less performed. A simple hack using equipment found in every ED, however, could create a renaissance for this procedure.
Plenty of evidence calls for this method: Current guidelines for diagnosing acute otitis media (AOM) in children recommend a combination of otoscopy, which reveals the bulging tympanic membrane (TM), and pneumatic otoscopy, which demonstrates decreased mobility from a middle ear effusion (MEE). (Pediatrics 2013;131:e964.)
The combined features of decreased mobility and bulging are 99 percent and 96 percent sensitive for AOM (Pediatr Infect Dis J 2011;30:822), while other commonly used clinical features like redness, dullness, thickening, retraction, light reflex, or air fluid levels lack sensitivity and specificity. (Int J Pediatr Otorhinolaryngol 1989;17:37; Fam Pract 1999;16:262; Acad Pediatr 2012;12:214; Paediatr Child Health 2016;21:196.) And otoscopy is a must-have for assessing poor mobility of the TM in newborns (where the diagnosis can be vital), which is considered the only reliable indicator of bacterial AOM. (Laryngoscope 1970;80:36; Pediatrics 1972;49:187.)
Of course, pneumatic otoscopy is an obstacle to the accurate diagnosis of AOM if it is rarely performed. Canadian Family Physician called it one of medicine's top 10 forgotten diagnostic procedures (2013;59:962), and numerous studies showed that it is infrequently practiced or taught by the multiple specialties that care for children. (Fam Pract 1999;16:262; Ann Emerg Med 1980;9:634; Pediatrics 1999;104:1251; Can Fam Physician 2013;59:972.)
That's commonly because of a lack of training or unavailability of equipment. (Fam Med 2002;34:598.) The main barrier to teaching pneumatic otoscopy is the educators did not use it themselves. (Can Fam Physician 2013;59:972.)
Learning this, however, is vital because of the many risks inherent in failing to make an evidence-based diagnosis of AOM. Using unsupported criteria promotes premature diagnostic closure and failure to pursue other common causes of fever like urinary tract infections, the most common serious bacterial infection in young children. I have used a simple method for many years to perform pneumatic otoscopy quickly and easily, and best of all, no bulb is required.
Pneumatic otoscopy refers to the visual examination of the tympanic membrane in response to induced pressure changes. Otoscopes with insufflation ports are ubiquitous in health care settings. The addition of an insufflator bulb and tube permits the application of small-volume, intermittent suction and compression to the eardrum to assess tympanic membrane mobility visually. (Image 1.)
The mechanical difficulties of making the diagnosis of AOM are well known and well-described. (Pediatr Ann 2013;42:485.) Standard pneumatic otoscopy includes first finding an insufflator bulb, then assessing the mobility of the TM while simultaneously holding the otoscope and the bulb (Image 2), manipulating the pinna, safely controlling the patient's head, and alternately and consistently compressing and releasing the insufflator while maintaining a seal between the speculum and the external auditory canal. This is a process repeatedly and correctly described as difficult—at best. (Pediatrics 1999;104:1251; Pediatrics 2002;109:993; BMC Fam Pract 2014;15:181.) But there is a better way.
From Difficult to Easy
There is a remarkably simple but forgotten means of avoiding the insufflator bulb when performing pneumatic otoscopy: Replace the unavailable and difficult-to-manipulate insufflator bulb with a piece of readily available IV connector tubing. (Image 2.) One can then generate the required positive and negative pressure by alternately applying gentle insufflation and suction by mouth. (Image 3.)
The simplified pneumatic otoscopy in the emergency department helps answer two key clinical questions in diagnosing AOM: Is there a middle ear effusion? Is the tympanic membrane bulging? This is also the only means of diagnosing MEE for any age. Pneumatic otoscopy is the only reliable examination feature to detect AOM in newborns (Laryngoscope 1970;80:36; Pediatrics 1972;49:187) or in infants younger than 7 months. (Am Fam Physician 2004;70:1713.)
No bulb is required, and the IV connector tubing is easy to come by and carry. It takes just seconds to perform during routine otoscopy, and requires no additional training or eye-hand coordination. Applied pressures are more easily regulated, lower, and potentially safer and more comfortable than with a bulb. The pressure required to induce visible movement of the TM in a normal ear ranged from 10 to 15 mm H2O. (Otolaryngol Head Neck Surg 1987;96:119.)
Gentle application of positive and negative pressure with a bulb generated pressures as high as 1134 mm H2O (the mean was 748 mm H2O) in healthy pediatric patients. The lowest pressure was generated by using a mouthpiece (338 mm H2O; the mean was 502 mm H2O). (Pediatrics 1989;84:362.) This simpler method is also intuitive, easy to do, and simple to teach. The barriers to routine pneumatic otoscopy are no bulb and no training. Manipulating the bulb, otoscope, and patient simultaneously can be a challenge, but nearly everyone can inhale and exhale through a plastic tube.
The tubing that best replaces the otoscope bulb ends is a slip tip or Luer slip fitting. Luer Lock connectors are more common but more difficult to attach. A search through ambulance cabinets, clinic closets, and ED IV carts will usually unearth the required item. Failing that, online sources offer slip tip IV infusion sets or female Luer lock and male Luer slip connectors.Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.