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Original Article

The role of hyperbaric oxygen therapy in SuddenSensorineural Hearing Loss: A retrospective reviewof 50 patients

Tarun Sahni a,*, Rachin Aggarwal b, Anil Kumar Monga c, Rajeev Puri d,Pavithra Shivkumar e, Shweta Gupta f, Sapna Verma f

a Senior Consultant, Department of Internal and Hyperbaric Medicine, Indraprastha Apollo Hospital, Sarita Vihar,

Delhi-Mathura Road, New Delhi 110076, Indiab Department of Internal and Hyperbaric Medicine, Indraprastha Apollo Hospital, Sarita Vihar, Delhi-Mathura Road,

New Delhi 110076, Indiac Department of ENT, Sir Ganga Ram Hospital, New Delhi 110060, Indiad Prof., Department of ENT, Indraprastha Apollo Hospital, Sarita Vihar, Delhi-Mathura Road, New Delhi 110076,

Indiae Department of Genetics, Dr.ALM Post Graduate Institute of Basic Medical Sciences, University of Madras,

Chennai 600113, Indiaf Research Associate, Department of Hyperbaric Medicine, Indraprastha Apollo Hospital, Sarita Vihar,

Delhi-Mathura Road, New Delhi 110076, India

a r t i c l e i n f o

Article history:

Received 11 July 2014

Accepted 19 July 2014

Available online xxx

Keywords:

Hearing loss

Hyperbaric oxygen

Sensorineural

Inner ear

* Corresponding author. Tel.: þ91 981003801E-mail addresses: aimhu@live.in, sshwet

Please cite this article in press as: Sahni Tretrospective review of 50 patients, Apol

http://dx.doi.org/10.1016/j.apme.2014.07.0060976-0016/Copyright © 2014, Indraprastha M

a b s t r a c t

Background: Sudden Sensorineural Hearing Loss (SSNHL) is a hearing impairment of more

than 30 dB occurring within a period of upto 3 days in three consecutive pure tone fre-

quencies. Hyperbaric oxygen therapy (HBOT) in recent years has gained relevance for

treating SSNHL in combination with other agents. The aim of this study is to review the

outcomes in patients with SSNHL treated with HBOT at our centre.

Materials & methods: Records of 50 patients with SSNHL who received HBOT with conven-

tional management were retrospectively reviewed. They were treated in a multiplace hy-

perbaric chamber at 2.4 ATA, for 90 min once a day. Pre and post treatment audiograms at

500, 1000, 2000, 4000 and 6000 Hz were compared to assess improvement. Hearing gain in

relation to severity, age of patients, therapeutic delay and coexisting symptoms in prog-

nosis was evaluated.

Results: 94% patients had overall hearing improvement. 82% patients of severe hearing loss

presenting to us within 2 weeks of onset showed maximum gain. Those who received

treatment within 14 days showed highest gain from 76 ± 20.06 dB to 51.9 ± 17.1 dB as

compared to other patients. The hearing gain was greater at frequencies above 500 Hz.

Patients younger than 50 years showed greater gain of 25 ± 13.2 dB as compared to those

older than 50 years with gain of 19 ± 10.2 dB.

0; fax: þ91 (0)11 26823629.aa0186@gmail.com (T. Sahni).

, et al., The role of hyperbaric oxygen therapy in Sudden Sensorineural Hearing Loss: Alo Medicine (2014), http://dx.doi.org/10.1016/j.apme.2014.07.006

edical Corporation Ltd. All rights reserved.

a p o l l o m e d i c i n e x x x ( 2 0 1 4 ) 1e52

Please cite this article in press as: Sahni Tretrospective review of 50 patients, Apoll

Conclusion: Addition of HBOT to standard treatment significantly improves outcome of

SSNHL in a subset of patients. We recommend additional multicentric, prospective studies

be carried out to define the role of HBOT in SSNHL.

Copyright © 2014, Indraprastha Medical Corporation Ltd. All rights reserved.

Table 1 e Clinical profile of patients with sudden

1. Introduction

Sudden Sensorineural Hearing Loss (SSNHL) is hearing

impairment of more than 30 dB of three consecutive pure tone

frequencies developing within 3 days or less.1e3 It is a clinical

manifestation with proposed diverse aetiologies such as viral

infection, vascular compromise, intra-cochlear membrane

rupture or inner ear disease among others.3e5 It is more

common in young and middle aged people with unilateral ear

involvement in more than 90% cases.1,5e8

Due to lack of definite cause of SSNHL, its treatment is

largely empirical and includes use of a wide variety of thera-

pies like systemic and intratympannic steroids, vasodilators,

osmotic drugs, antiviral and anticoagulants to counteract

possible inflammatory mechanism, modify hydrostatic pres-

sure and improving cochlear blood flow.8e12 The possible final

goal of any treatment modality of SSNHL has been the resto-

ration of oxygen tension in the cochlea to encourage healing

and return of hearing to normal levels.

Hyperbaric oxygen therapy (HBOT) is a treatment modality

involving the intermittent inhalation of 100% oxygen in

chambers pressurized above 1 atmosphere absolute (ATA).

HBOT has been used as an adjunctive therapy for SSNHL as it

raises the amount of oxygen in the inner ear by diffusion

which activates cell metabolism leading to restoration of ionic

balance and electrophysiological functions of cochlea.2,13e16

This study aims to analyse retrospective data of this

centre to evaluate the efficacy of addition of HBOT to con-

ventional treatment in patients with SSNHL and identify

specific groups of patients likely to benefit from the addition

of this therapy.

sensorineural hearing loss.

Variables n ¼ 50 %

Gender Male 28 56

Female 22 44

Age �50 yrs 34 68

>50 yrs 16 32

Affected ear Right 37 74

Left 13 26

Time lag �14 days 26 52

15e30 days 17 34

>30 days 07 14

Severity Mild 06 12

Moderate 12 24

Severe 32 64

Presence of associated complaints Tinnitus 13 26

Vertigo 04 08

Coexisting illnesses Hypertension 05 10

Diabetes 08 16

CAD 04 08

Smoking 11 22

2. Materials and methods

In this retrospective studywe reviewed records of 150 patients

with SSNHL who presented to our unit during the period

2006e2011. 50 Patients who met the following inclusion

criteria were taken for the study: unilateral onset of SSNHL of

30 dB or greater in atleast three contiguous frequencies, un-

known cause of hearing loss and no previous surgery in the

affected ear. These patients received HBOT in addition to

conventional treatment as prescribed by the referring ENT

Surgeon. The conventional treatment however was not stan-

dardized for patients in our study. HBOT was administered in

a multiplace chamber at 2.40 ATA for 90 min once daily for

atleast 10 days. The data collected included demographics,

initial symptoms of hearing loss, tinnitus, vertigo or any other

coexisting symptom, pure tone audiogram (PTA) and duration

of onset of hearing loss from starting of HBOT.

, et al., The role of hypero Medicine (2014), http:

The patient's audiograms were reviewed before starting

treatment and after 10 sessions of HBOT. If the audiogram

showed improvement after 10 treatments, patients were

advised for additional 10 sessions of HBOT, this process was

repeated after further 10 sessions and a maximum of 30

sessions were given if they continuously showed improve-

ment. All patients were assessed with PTA at 500, 1000, 2000,

4000 and 6000 Hz and hearing gain at these frequencies was

calculated separately. The level of hearing loss at these 5

frequencies was evaluated in 3 groups: <40 dB (mild), be-

tween 41 and 70 dB (moderate), >70 dB (severe). The average

of mean hearing gain of patients according to age group and

therapeutic delay along with presence of associated com-

plaints as contributory factors to prognosis of SSNHL was

assessed.

Data of study was evaluated using descriptive statistical

methods i.e. mean and standard deviation.

3. Results

The clinical profile of the patients in our study is shown in

Table 1. The 50 subjects in our study were in the age range of

18e75 (28 males and 22 females). The co-morbid factors in

them were hypertension (8% cases), Diabetes Mellitus (16%

cases) and coronary artery disease (8%). There was history of

smoking in 22% of cases and 34% additionally complained of

tinnitus and vertigo.

baric oxygen therapy in Sudden Sensorineural Hearing Loss: A//dx.doi.org/10.1016/j.apme.2014.07.006

Table 3 e Change in mean hearing level before and aftertreatment on basis of intensity.

Intensity(db)

Pre MHL Post MHL % Of patients withhearing

improvementa

<40 35.5 ± 6.40 27.50 ± 3.53 16

41e70 60.55 ± 10.46 43.27 ± 11.6 33

>70 86.50 ± 11.90 58.75 ± 13.0 81

a Hearing improvement denotes >30 db gain in audiometry.

a p o l l o m e d i c i n e x x x ( 2 0 1 4 ) 1e5 3

The initial and final mean hearing levels at 500, 1000, 2000,

4000 and 6000 Hz of patients are presented in Table 2. The

mean hearing gain was highest at frequencies above 1000 Hz.

Themean hearing gain after treatment is shown in Table 3.

The average hearing gain at the five frequencies was signifi-

cantly higher in patients with initial level of >70 dB in com-

parison to patients with hearing levels of <70 dB.

Table 4 shows the mean hearing gain according to thera-

peutic delay of starting HBOT. Time of presentation ranged

between 1 and 60 days. The patients who received treatment

within 14 days had higher hearing gain

(76 ± 20.06 dBe51.9 ± 17.1 dB) as compared to patients with

therapeutic delay of 15e30 days

(77.85 ± 29.12 dBe59.85 ± 22.50 dB) and in patients who started

therapy after 30 days (77.8 ± 23.81 dBe64.5 ± 21.82 dB).

Table5showsacorrelationbetweenthe time lagandseverity

on the improvement in mean hearing gain in patients. 82% pa-

tients presenting to us within 14 days showed maximum

improvement as compared to other subset of patients.

Average hearing gain of patients according to age group is

presented in Table 6 and was significantly high in patients

younger than 50 years.

No statistically significant difference was found among

patientswith coexisting complaints of hypertension, diabetes,

smoking and presence of tinnitus or vertigo.

The hearing gain were 30 dB or more in 40%, between 20

and 30 dB in 20% and upto 20 dB in 34% of patients. There was

no response to HBOT in 6% patients (n ¼ 3).

The average number of hyperbaric sessions ranged from 10

to 25 with maximum number of patients showing improve-

ment after 10 exposures. Only one patient was given 25 ses-

sions of HBOT; however the patient did not show additional

improvement. In all patients the treatment was well tolerated

and no patient complained of any side effects. Hearing loss did

not worsen in any case.

4. Discussion

SSNHL is a loss of hearing greater than 30 dB in three contig-

uous frequencies occurring in less than 3 days.1e3 Most sud-

den hearing loss occurs within minutes to several hours. It is

considered as a clinical manifestation of possible several un-

derlying causes such as viral infection, vascular compromise,

intra-cochlearmembrane rupture or inner ear disease.2e7 This

diversity demonstrates the prevailing uncertainty in aetiol-

ogies and an inability to predict the prognosis.

The high spontaneous recovery rate of SSNHL and its low

incidence make validation of empirical treatment modalities

Table 2 e Mean hearing levels (MHL) at differentfrequencies before and after treatment.

Frequency (Hz) Initial MHL Final MHL % Of patients

500 66.12 ± 22.0 49.16 ± 23.12 25

1000 64.68 ± 24.60 48.0 ± 20.46 40

2000 68.17 ± 21.90 52.83 ± 24.30 45

4000 74.0 ± 23.32 52.16 ± 21.00 65

6000 74.83 ± 19.76 54.83 ± 21.11 55

Please cite this article in press as: Sahni T, et al., The role of hyperbretrospective review of 50 patients, Apollo Medicine (2014), http:

difficult. Many treatment regimens have been proposed such

as antiviral agents, vasodilators, anti-inflammatory and oral

and intratympannic steroids. Hyperbaric oxygen therapy in

recent years has gained relevance for treating SSNHL in

combination with other agents.8e13 The Undersea & Hyper-

baric Medicine Society (UHMS) has approved the use of HBOT

in SSNHL in October 2011.

HBOT increases oxygen tension (pO2) in blood by dissolving

in the plasma and diffuses into tissue fluids such as those

surrounding the sensory and neural elements of the coch-

lea.14e17 Gills showed oxygen induced osmosis as the mech-

anism for healing property of HBOT in such cases.11

Aslan et al and Bennett et al demonstrated that earlier the

treatment received, better is the prognosis.17 This was

confirmed in our study. The maximum recovery was in the 26

cases which received HBOT within 14 days after onset. They

showed significantmean hearing gain from 75.93 ± 20.06 dB to

51.90 ± 17.19 dB.

Topuz et al reported HBOT as more effective in severe

hearing loss.14 In our study, 64% cases had hearing loss of

>70 dB and 81% of these patients showed improvement of

>30 dBwithmean hearing gain of 86 ± 11.9 dBe58.75 ± 13.0 dB.

We observed a significant correlation between patients with

severe hearing loss presenting to us within 2 weeks of onset.

82% of patients in this subset showed maximum

improvement.

Presence of tinnitus and vertigo has been reported to affect

reversibility of hearing loss in various studies.14,15 In our

study, 34% cases (n ¼ 17) with hearing loss had accompanied

tinnitus and vertigo but no significant differencewas observed

between cases with and without these complaints.

Age has been found to be a prognostic factor for improve-

ment.18 In our study, patients in <50 year age group showed

better hearing gain as compared to patients with age of >50years. Presence of diabetes, hypertension and other associ-

ated complaints in this age group might have been the

contributory factors to poor prognosis; however we were not

able to establish any correlations.

Table 4 e Change in mean hearing level before and aftertreatment on basis of therapeutic delay.

Days ofonset

Pre MHL Post MHL % Of patients withhearing improvement

<14 75.93 ± 20.06 51.90 ± 17.19 56.25

14e30 77.85 ± 29.12 59.85 ± 22.50 42.10

>30 77.8 ± 23.81 64.5 ± 21.82 25

aric oxygen therapy in Sudden Sensorineural Hearing Loss: A//dx.doi.org/10.1016/j.apme.2014.07.006

Table 5 e Correlation between hearing improvement onbasis of severity and time lag.

Time lag Severity (% of patients showing improvement)

Days Mild Moderate Severe

<14 45 50 82

15e30 35 43 50

>30 0 33 25

Table 6 e Comparison of mean hearing level according toage group.

Age group (yr) Pre MHL Post MHL % Patients withhearing

improvement

<50 77.0 ± 19.30 52.0 ± 13.70 32

>50 68.4 ± 17.22 49.4 ± 17.34 26

a p o l l o m e d i c i n e x x x ( 2 0 1 4 ) 1e54

There is no consensus on the right number of treatments

with HBOT in the treatment of SSNHL.While some cases show

improvement within a few days other cases might need it

longer to achieve good results, however few studies report the

optimum number of sessions. In our study, maximum pa-

tients showed improvement after 10 exposures and

maximum improvement was seen on an average of 20 ses-

sions.19,20 We recommend that 20 sessions of HBOT may be

optimum for recovery in a majority of patients.

While the number of cases in this study is small, 94% of

patients in the study group showed statistically significant

improvement in hearing, when HBOTwas administered along

with conventional therapy. While all patients were on oral

steroids the conventional treatment was not standardized in

our patients.

There appears to be a scientific rationale for use of HBOT in

SSNHL and our results are encouraging. We recommend

additional multicentric, prospective trials be carried out with

a standardized protocol to establish role of HBOT in SSNHL

patients.

5. Conclusion

This retrospective study reveals that the addition of HBOT to

conventional therapysignificantly improvesoutcome inpatients

of SSNHL if started within 14 days. Improvement is best at fre-

quencies above 500 Hz and in hearing loss of above 70 dB. HBOT

wasmore effective in patients younger than 50 years of age.

Conflicts of interest

All authors have none to declare.

Acknowledgement

The Hyperbaric Oxygen Therapy Unit acknowledges the sup-

port given by the Department of ENT namely Dr Sindhu, Dr

Please cite this article in press as: Sahni T, et al., The role of hyperretrospective review of 50 patients, Apollo Medicine (2014), http:

Kishore, Dr Soni, Dr Raheja, Dr Nagpal, Dr Dhingra, Dr Prakash

& Dr Ansari in this hospital and other clinicians from within

and outside Delhi.

r e f e r e n c e s

1. Korpinar S, Alkan Z, Yigit O, et al. Factors influencing theoutcome of idiopathic sudden sensorineural hearing losstreated with hyperbaric oxygen therapy. Eur ArchOtorhinolaryngol. 2011;268(1):41e47.

2. Liu S-C, Kang B-H, Lee, et al. Comparison of therapeuticresults in sudden sensorineural hearing loss with/withoutadditional hyperbaric oxygen therapy: a retrospective reviewof 465 audiologically controlled cases. Clin Otolaryngol.2011;36:121e128.

3. O’Malley MR, Haynes DS. Sudden hearing loss. Otolaryngol ClinNorth Am. 2008;41:633e649.

4. Muzzi E, Zeenaro B, Visetin R, Soldano F. Hyperbaric oxygentherapy as salvage treatment for sudden sensorineuralhearing loss: review of rationale and preliminary report. JLaryngol Otol. 2010 Feb;124(2).

5. Agarwal L, Pothier DD. Vasodilators and vasoactivesubstances for idiopathic sudden sensorineural hearing loss.Cochrane Database Syst Rev. 2009 Oct 7;(4).

6. Kanzaki J, Inoue Y, Ogawa K, et al. Effect of single-drugtreatment on idiopathic sudden sensorineural hearing loss.Auris Nasus Larynx. 2003;30:123e127.

7. Conlin AE, Parnes LS. Treatment of sudden sensorineuralhearing loss: I. A systemic review. Arch Otolaryngol Head NeckSurg. 2007;133:573e581.

8. Plontke SK, Bauer M, Meisner C. Comparison of pure toneaudiometry analysis in sudden hearing loss studies: lack ofagreement for different outcome measures. Otol Neurotol.2007;28:753e763.

9. Racic G, Maslovara S, Roje Z, Dogas Z, Tafra R. Hyperbaricoxygen in treatment of sudden hearing loss. ORL JOtorhinolaryngol Relat Spec. 2007;65:317e320.

10. Gill AL, Bell CN. Hyperbaric oxygen: its uses, mechanisms ofaction and outcomes. QJM. 2004;97:385e395.

11. Fattori B, Berrettini S, Casani A, et al. Sudden hypoacusistreated with hyperbaric oxygen therapy: a controlled study.Ear Nose Throat J. 2001;80:655e660.

12. Satar B, Hidir Y, Yetiser S. Effectiveness of hyperbaric oxygentherapy in idiopathic sudden hearing loss. J Laryngol Otol.2004;120:665e669.

13. Cekin E, Cincik H, Ulubil SA, et al. Effectiveness of hyperbaricoxygen therapy in management of sudden hearing loss. JLaryngol Otol. 2009;123:609e612.

14. Topuz E, Yigit O, Cinar U, et al. Should hyperbaricoxygen be added to treatment in idiopathic suddensensorineural hearing loss? Eur Arch Otorhinolaryngol.2004;261:393e396.

15. Lamm K, Lamm H, Arnold W. Effect of hyperbaric oxygentherapy in comparison to conventional or placebo therapy orno treatment in idiopathic sudden hearing loss, acoustictrauma, noise-induced hearing loss and tinnitus. A literaturesurvey. Adv Otorhinolaryngol. 1998;54:86e99.

16. Aslan I, Oysu C, Veyseller B, et al. Does the addition ofhyperbaric oxygen therapy to the conventional treatmentmodalities influence the outcome of sudden deafness?Otolaryngol Head Neck Surg. 2002;126:121e126.

17. Bennett M, Kertesz T, Yeung P. Hyperbaric oxygen therapy foridiopathic sudden sensorineural hearing loss and tinnitus: asystemic review of randomized controlled trials. J LaryngolOtol. 2005;119:791e798.

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a p o l l o m e d i c i n e x x x ( 2 0 1 4 ) 1e5 5

18. Desloovere C, Knecht R, Germonpr�e. Hyperbaric oxygentherapy after failure of conventional therapy for suddendeafness. ENT. 2:69e73.

19. Bennett MH, Kertesz T, Yeung P. Hyperbaric oxygen foridiopathic sudden sensorineural hearing loss and tinnitus.Cochrane Database Syst Rev. 2007:CD004739.

Please cite this article in press as: Sahni T, et al., The role of hyperbretrospective review of 50 patients, Apollo Medicine (2014), http:

20. Uzun G, Yildiz S. Therapeutic window for the use ofhyperbaric oxygen therapy in idiopathic suddensensorineural hearing loss. Auris Nasus Larynx. 2008;35:318.

aric oxygen therapy in Sudden Sensorineural Hearing Loss: A//dx.doi.org/10.1016/j.apme.2014.07.006

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