Audiologic monitoring of multi-drug resistant tuberculosis patients on aminoglycoside treatment with long term follow-up

<p>Abstract</p> <p>Background</p> <p>Multi-drug resistant tuberculosis has emerged as a significant problem with the resurfacing of tuberculosis and thus the need to use the second line drugs with the resultant increased incidence of adverse effects. We discuss the effect of second line aminoglycoside anti-tubercular drugs on the hearing status of MDR-TB patients.</p> <p>Methods</p> <p>Sixty four patients were put on second line aminoglycoside anti-TB drugs. These were divided into three groups: group I, 34 patients using amikacin, group II, 26 patients using kanamycin and group III, 4 patients using capreomycin.</p> <p>Results</p> <p>Of these, 18.75% of the patients developed sensorineural hearing loss involving higher frequencies while 6.25% had involvement of speech frequencies also. All patients were seen again approximately one year after aminoglycoside discontinuation and all hearing losses were permanent with no threshold improvement.</p> <p>Conclusion</p> <p>Aminoglycosides used in MDR-TB patients may result in irreversible hearing loss involving higher frequencies and can become a hearing handicap as speech frequencies are also involved in some of the patients thus underlining the need for regular audiologic evaluation in patients of MDR-TB during the treatment.</p

Stability of far field R wave signals in different conditions

Aims The presence of far field R wave sensing (FFRS) is usually evaluated in patients with dual chamber pacemakers in supine position. To check if this approach is valid, we tested whether FFRS is consistent both in terms of amplitude threshold and timing characteristics in different daily life conditions. Methods and Results In 42 patients with a DDD pacemaker. the presence. amplitude threshold and timing parameters of FFRS were therefore determined. with patients supine. standing and at peak exercise. Measurements were made of paced and sensed R waves in unipolar and bipolar sensing configurations (at peak exercise only paced R waves and bipolar sensing). After paced R waves (bipolar sensing) amplitude thresholds/time of FFRS after Vpace were 0.32 +/- 0.18 mV/119-139 ms (supine). 0.32 +/- 0.16 mV/114-130 ms (upright) and 0.27 +/- 0.13 mV/121-136 ms (exercise) - with unipolar sensing. this was 0.49 +/- 0.27mV/101-150 ms (Supine). 0.51 +/- 0.29 mV/100-144 ms (upright). After sensed R waves (bipolar sensing) amplitude thresholds/time of FFRS after Vsense were 0.27 +/- 0.18 mV/ 24-42 ms (Supine). 0.29 +/- 0.16 mV/18 to 41 ms (upright) - with unipolar sensing. thresholds were 0.59 +/- 0.32 mV/3-50 ins (supine). 0.59 +/- 0.36 mV/2-58 ms (upright). Conclusion given the lower FFRS thresholds with bipolar sensing. bipolar sensing is superior in avoiding FFRS compared with Unipolar sensing. No differences were found in terms of amplitude thresholds and timing characteristics with patients supine. standing and at peak exercise. Thus. measurements made in the supine position Lire basically sufficient to predict the presence/absence of FFRS under different conditions