Hyperbaric oxygen therapy improved hearing acuity compared to vasodilator therapy with buflomedil in the treatment of idiopathic sudden hearing loss.

Clinical Bottom Line:

1.A 10 day course of hyperbaric oxygen therapy increased the proportion of patients with greater than 50% improvement in hearing, compared with administration of buflomedil.

2. The proportion of patients with little or no improvement in hearing was greater in the buflomedil.

Citation:

Sudden hypoacusis treated with hyperbaric oxygen therapy: a controlled study. Ear, Nose and Throat Journal 2001; 80(9):655-660. Lead author's name and fax: Fattori B. Fax: +39 50 550-307

 Three-part Clinical Question: In patients with idiopathic sudden hearing loss, does hyperbaric-oxygen therapy, compared to treatment with a vasodilator (buflomedil), result in any better improvement in hearing ?

Search Terms:  Hyperbaric oxygenation.      Deafness, sudden.

 

The Study:

Non-blinded randomised controlled trial with intention-to-treat.

The Study Patients:  Patients with idiopathic sudden hearing loss.

Control group (N = 20; 20 analysed): Vasodilator therapy: 10 day course iv 200mg/day buflomedil in 250ml physiological solution. No sham treatment.

Experimental group (N = 30; 30 analysed: 10 once-daily treatments breathing 100% oxygen at 2.2 ATA for 90 mins.

 

The Evidence:

Outcome

Time to Outcome

Vasodilator group

HBO group

Relative risk difference

Absolute risk difference

NNT

>50% increase in PTA

10 days

0.25

0.57

127%

0.32

3

95% CI

 

 

 

23% to 23%

0.06 to 0.58

2 to 17

25 to 50% increase in PTA

10 days

0.30

0.267

11%

0.03

30

95% CI

 

 

 

-74% to 96%

-0.22 to 0.29

NNT 3 to INF    NNH 4 to INF

< 25% increase in PTA

10 days

0.450

0.167

63%

0.283

4

95% CI

 

 

 

6% to 100%

0.03 to 0.54

2 to 37

 

 

Non-Event Outcomes         Time to outcome        Vasodilator          HBOT            P-value

Mean improvement

in PTA                                         10 days                 24% +/- 23%       64% +-34%        0.005

 

Comments:

1. Response to treatment was quantified by audiometry. The relative gain in pure tone average (PTA - average threshold at 4 different frequencies in decibels) was calculated.

2. Other pre-treatment measures were not reported post-treatment, although they were performed (eg tympanometry, auditory evoked potentials). 

3. Lack of blinding and the unexplained imbalance in number of patients in each arm are the principle problems with this paper. 

4. Patients with severe hearing loss benefited more from HBOT than those with mild hearing loss (p=0.05). 

5. HBO was not tested against the usual polypharmacological treatment, nor against no therapy.

  

Appraised by: Juliette Leverment, Mike Bennett and Phil Yeung c/o Dept of Diving and Hyperbaric Medicine, Sydney

+61 2 9382 3882 ; Thursday, 31 October 2002

 Email:  m.bennett@unsw.edu.au

 Kill or Update By:  October 2004