Background. Sensorineural hearing loss after procedures including extracorporeal circulation and hypothermia is greater than general population. Mild hypothermia has a protective role on cochlea; however, deep hypothermia may result in cochlear injury. This research aimed at assessing auditory function in children after open heart surgery in relation to different hypothermic techniques. Subjects and Methods. Forty children with acyanotic heart diseases who underwent open heart surgery were included: group I: twenty patients subjected to mild hypothermia (33° to 37°C), group II: twenty patients subjected to moderate hypothermia (28° to 32°C). Audiological assessment included basic evaluation and otoacoustic emissions. Results. Both groups had distortion-product otoacoustic emissions (DPOAEs) amplitude >3？dB SPL at all frequencies. However, group II showed lower amplitude at overall and at high frequencies (4.416–8.837？KHz) than group I. Transient evoked otoacoustic emissions (TEOAEs) showed partial pass in three patients of group I (15%) and in 15 patients of group II (75%). Moreover, group II showed statistical significant reduction in overall TEOAEs amplitude as well as at high frequencies (2–4？KHz). Conclusions. Patients exposed to moderate hypothermic technique had subtle cochlear dysfunction. Otoacoustic emissions should be used for early detection of subtle cochlear dysfunction in operated cardiac children. 1. Introduction The risk of sensorineural hearing loss after surgical procedures including extracorporeal circulation and hypothermia is estimated at 0.14% in the literature, a rate six times greater than the risk in general population [1]. In cardiopulmonary bypass most patients are subjected to one of two techniques regarding body temperature either mild (normothermic) technique in which body temperature ranges from 32° to 37°C or moderate hypothermic technique in which body temperature ranges from 28° to 32°C [2]. Few studies revealed that hypothermia has a protective role on the cochlea and could prevent its damage during long-lasting operations performed in extracorporeal circulation [3]. However, extracorporeal circulation with deep hypothermia may result in cochlear cells injury [4]. Otoacoustic emissions (OAEs), described by Kemp in 1978 [5], arise apparently in the outer hair cells (OHCs) and possibly represent the rapid contractions of this cell group. They are acoustic phenomena of cochlear nature, which reverberate through the ossicles in the middle ear and are transmitted to the ear canal, where they can be captured through a
References
[1]
J. A. Ness, J. A. Stankiewicz, T. Kaniff, R. Pifarre, and J. Allegretti, “Sensorineural hearing loss associated with aortocoronary bypass surgery: a prospective analysis,” Laryngoscope, vol. 103, no. 6, pp. 589–593, 1993.
[2]
A. Harry, J. R. Wellons, and R. K. Zacour, “Adult cardiac surgery (Part A-General Considerations)-cardiopulmonary bypass,” in Mastery of Cardiothoracic Surgery, L. R. Kaiser, I. L. Kron, and T. L. Spray, Eds., pp. 305–314, Lippincott Williams & Wilkins Companies, 2007.
[3]
G. Namys？owski, K. Morawski, I. Urban, G. Lisowska, and J. Skalski, “Influence of hypothermia and extracorporeal circulation on transiently evoked otoacoustic emission (TEOAE) in children operated on for various heart defects (I),” Otolaryngologia Polska, vol. 57, no. 2, pp. 263–269, 2003.
[4]
E. Veuillet, M. Gartner, G. Champsaur, J. Neidecker, and L. Collet, “Effects of hypothermia on cochlear micromechanical properties in humans,” Journal of the Neurological Sciences, vol. 145, no. 1, pp. 69–76, 1997.
[5]
D. T. Kemp, “Stimulated acoustic emissions from within the human auditory system,” Journal of the Acoustical Society of America, vol. 64, no. 5, pp. 1386–1391, 1978.
[6]
J. H. Sabes, “Audiologic testing,” in Current Otolaryngology, A. K. Lalwani, Ed., pp. 596–706, The McGraw-Hill, 2007.
[7]
T. J. Glattke and M. S. Robinette, “Transient evoked otoacoustic emissions,” in Otoacoustic Emissions – Clinical Applications, R. M. Robinette and T. J. Glattke, Eds., pp. 95–115, Thieme, New York, NY, USA, 2nd edition, 2002.
[8]
M. P. Gorga, S. T. Neely, and P. A. Dorn, “Distortion product otoacoustic emissions in relation to hearing loss,” in Otoacoustic Emissions–Clinical Applications, R. M. Robinette and T. Glattke, Eds., pp. 243–272, Thieme, New York, NY, USA, 2nd edition, 2002.
[9]
R. Khvoles, S. Freeman, and H. Sohmer, “Effect of temperature on the transient evoked and distortion product otoacoustic emissions in rats,” Audiology and Neuro-Otology, vol. 3, no. 6, pp. 349–360, 1998.
[10]
E. Seifert, A. Lamprecht-Dinnesen, B. Asfour, H. Rotering, H. G. Bone, and H. H. Scheid, “The influence of body temperature on transient evoked otoacoustic emissions,” British Journal of Audiology, vol. 32, no. 6, pp. 387–398, 1998.
[11]
E. Seifert, K. Brand, K. Van de Flierdt, M. Hahn, M. Riebandt, and A. Lamprecht-Dinnesen, “The influence of hypothermia on outer hair cells of the cochlea and its efferents,” British Journal of Audiology, vol. 35, no. 1, pp. 87–98, 2001.
[12]
R. A. Rhoads, “Gas transfer and transport,” in Medical Physiology–Principles for Clinical medicine, R. A. Rhoads and D. R. Bel, Eds., pp. 348–361, Lippincott Williams & Wilkins, Philadelphia, Pa, USA, 3rd edition, 2009.
[13]
A. B. Maxon, K. R. White, B. R. Vohr, and T. R. Behrens, “Using transient evoked otoacoustic emissions for neonatal hearing screening,” British Journal of Audiology, vol. 27, no. 2, pp. 149–153, 1993.
[14]
M. A. Padula and A. M. Ades, “Neurodevelopmental implications of congenital heart disease,” NeoReviews, vol. 7, no. 7, pp. e363–e369, 2006.
[15]
W. J. Greeley, F. H. Kern, R. M. Ungerleider et al., “The effect of hypothermic cardiopulmonary bypass and total circulatory arrest on cerebral metabolism in neonates, infants, and children,” Journal of Thoracic and Cardiovascular Surgery, vol. 101, no. 5, pp. 783–794, 1991.
[16]
A. Marelli, K. Gauvreau, M. Landzberg, and K. Jenkins, “Sex differences in mortality in children undergoing congenital heart disease surgery: a United States population-based study,” Circulation, vol. 122, no. 11, pp. S234–S240, 2010.
[17]
N. K. Shrestha and S. Padmavati, “Congenital heart disease in Delhi school children,” Indian Journal of Medical Research, vol. 72, no. 3, pp. 403–407, 1980.
[18]
V. M. Vashishtha, A. Kalra, K. Kalra, and V. K. Jain, “Prevalence of congenital heart disease in school children,” Indian Pediatrics, vol. 30, no. 11, pp. 1337–1340, 1993.
[19]
S. L. Chadha, N. Singh, and D. K. Shukla, “Epidemiological study of congenital heart disease,” Indian Journal of Pediatrics, vol. 68, no. 6, pp. 507–510, 2001.
[20]
J. W. Cameron, A. Rosenthal, and A. D. Olson, “Malnutrition in hospitalized children with congenital heart disease,” Archives of Pediatrics and Adolescent Medicine, vol. 149, no. 10, pp. 1098–1102, 1995.
[21]
B. Varan, K. Tokel, and G. Yilmaz, “Malnutrition and growth failure in cyanotic and acyanotic congenital heart disease with and without pulmonary hypertension,” Archives of Disease in Childhood, vol. 81, no. 1, pp. 49–52, 1999.
[22]
I. K. Arenberg, G. W. Allen, and A. Deboer, “Sudden deafness immediately following cardiopulmonary bypass,” Journal of Laryngology and Otology, vol. 86, no. 1, pp. 73–77, 1972.
[23]
H. M. Plasse, F. C. Spencer, M. Mittleman, and J. O. Frost, “Unilateral sudden loss of hearing. An unusual complication of cardiac operation,” Journal of Thoracic and Cardiovascular Surgery, vol. 79, no. 6, pp. 822–826, 1980.
[24]
R. J. Brownson, M. H. Stroud, and W. F. Carver, “Extracorporeal cardiopulmonary bypass and hearing,” Archives of Otolaryngology, vol. 93, no. 2, pp. 179–182, 1971.
[25]
M. J. Shapiro, J. M. Purn, and C. Raskin, “A study of the effects of cardiopulmonary bypass surgery on auditory function,” Laryngoscope, vol. 91, no. 12, pp. 2046–2052, 1981.
[26]
H. M. Ibrahim, T. B. Kamel, N. M. S. Abdel-Salam, and S. R. Abu-Ata, “Study of auditory function in children with chronic lung diseases,” International Journal of Pediatric Otorhinolaryngology, vol. 75, no. 1, pp. 39–42, 2011.
[27]
A. Borin and O. L. M. Cruz, “Study of distortion-product otoacoustic emissions during hypothermia in humans,” Brazilian Journal of Otorhinolaryngology, vol. 74, no. 3, pp. 401–409, 2008.
[28]
S. Meri, M. Aronen, and M. Leijala, “Complement activation during cardiopulmonary bypass in children,” Complement, vol. 5, no. 1, pp. 46–54, 1988.
[29]
F. Watanabe, K. Koga, N. Hakuba, and K. Gyo, “Hypothermia prevents hearing loss and progressive hair cell loss after transient cochlear ischemia in gerbils,” Neuroscience, vol. 102, no. 3, pp. 639–645, 2001.
[30]
J. Hyodo, N. Hakuba, K. Koga et al., “Hypothermia reduces glutamate efflux in perilymph following transient cochlear ischemia,” Neuroreport, vol. 12, no. 9, pp. 1983–1987, 2001.
[31]
S. Takeda, N. Hakuba, T. Yoshida et al., “Postischemic mild hypothermia alleviates hearing loss because of transient ischemia,” Neuroreport, vol. 19, no. 13, pp. 1325–1328, 2008.
