Comparison of therapeutic results in sudden sensorineural hearing loss with/without additional hyperbaric oxygen therapy: a retrospective review of 465 audiologically controlled cases.

OBJECTIVE: To investigate the necessity of routine application of hyperbaric oxygen therapy for sudden sensorineural hearing loss. DESIGN/SETTING AND PARTICIPANTS: A retrospective chart review looked at 465 patients, with 353 of them receiving pharmacologic treatments alone. Among these patients, 76 underwent systemic steroid treatment only (steroid group) and 277 received systemic steroids and dextran (steroid-dextran group). The remaining 112 patients were treated with hyperbaric oxygen in addition to pharmacologic agents (steroid-dextran-hyperbaric oxygen group). MAIN OUTCOME MEASURES: The outcome was determined by comparing the difference of pure-tone thresholds and absolute hearing gains after treatment calculated at each audiometric octave frequency or grouped frequencies of audiograms. On the basis of the severity of initial hearing loss, patients were classified at three scales of hearing impairments measured in decibels hearing level (dBHL): ≦ 70 dBHL, less severe; 71-90 dBHL, severe; and ≧ 91 dBHL, profound. The outcomes of their hearing recovery were classified into three recovery grades: good, fair and poor. RESULTS: In those patients with initial hearing loss >90 dBHL, the addition of hyperbaric oxygen to steroid-dextran gave a significant hearing gain difference (P = 0.030) by showing a greater hearing gain of 24.5 ± 2.7 dB compared with steroid only (12.9 ± 3.7 dB) or steroid-dextran (15.6 ± 2.7 dB). This outcome was confirmed when we compared the outcome using the recovery grading; steroid-dextran-hyperbaric oxygen group showed that more patients with initial profound (≧ 91 dBHL) hearing loss responded to hyperbaric oxygen treatment by exhibiting good and fair recoveries (2% and 70%) as compared with steroid only (0% and 42%) or steroid-dextran (8% and 46%) groups (P = 0.043), while the patients with initial severe (71-90 dBHL) and less severe (≦ 70 dBHL) hearing loss responded to the addition of hyperbaric oxygen treatment with less favourable recoveries. Furthermore, the addition of dextran in steroid-dextran group showed no significant benefit compared with the steroid group (P = 0.435). CONCLUSIONS: When applied as an adjuvant to pharmacologic agents, hyperbaric oxygen benefits patients with initial profound sudden sensorineural hearing loss. Therefore, we recommend the routine application of hyperbaric oxygen in conjunction with pharmacologic agents for those patients. The addition of dextran to steroid has no benefit and cannot be recommended.

Comparison of effects of pyronaridine, amodiaquine, mefloquine and qinghaosu on rodent malaria.

Blood schizontocidal effect of antimalarials were compared by 4-day suppressive test with an extended observation period of 31 days. On a drug-sensitive Plasmodium berghei ANKA strain, pyronaridine (PND) exhibited the best effect, followed by amodiaquine (ADQ), mefloquine (MFQ), and qinghaosu (QHS). On a moderately chloroquine-resistant P. berghei NS line, the order of effects was the same, PND greater than ADQ greater than MFQ greater than QHS. On a highly pyronaridine-resistant P. berghei RP line, ADQ, MFQ and QHS showed cross resistance with PND.

[The blood schizontocidal effects of pyronaridine, amodiaquine, mefloquine and qinghaosu on mice infected with Plasmodium berghei].

The asexual stages of P. berghei ANKA were completely eliminated as revealed in a "4-day suppressive test" with the daily dose of pyronaridine 12.5 mg base/kg or amodiaquine 25 mg base/kg. Mefloquine 25 mg base/kg and qinghaosu 100 mg/kg though exerted obvious suppressive effect, the cure rates were only 50% and 0%, respectively. In treating chloroquine-sensitive P. berghei ANKA strain pyronaridine exhibited the best therapeutic activity, which was followed by amodiaquine, mefloquine and quinghaosu. In treating moderately chloroquine-resistant P. berghei NS line the cure rate of pyronaridine 12.5 mg/kg.d x 4 was 70%, but none of the 10 infected mice from any group was cured by amodiaquine 100 mg/kg.d, mefloquine 100 mg/kg.d or qinghaosu 200 mg/kg.d. Though the latter 3 drugs showed prominent suppressive effects, parasitemia remained positive or recrudesced after dosing. We demonstrate that parasites resistant to chloroquine had cross resistance to amodiaquine, mefloquine and inghaosu at various degrees. Amodiaquine 100 mg/kg.d, mefloquine 100 mg/kg.d and qinghaosu 200 mg/kg.d exhibited no obvious suppressive activity on highly pyronaridine-resistant line of P. berghei, indicating the existence of cross resistance to pyronaridine.