Effects of inhaled amikacin in bacterial tr-IAD affected racehorses and comparison with intravenous administration
Contributo in Atti di convegno
Data di Pubblicazione:
2013
Citazione:
Effects of inhaled amikacin in bacterial tr-IAD affected racehorses and comparison with intravenous administration / F. Ferrucci, L. Stucchi, M. Salvadori, G. Stancari, B. Conturba, V. Bronzo, E. Zucca - In: XIX CONGRESSO SIVE-FEEVA[s.l] : SIVE-FEEVA, 2013 Feb 01. - pp. 357-358 (( Intervento presentato al 19. convegno XIX CONGRESSO SIVE-FEEVA tenutosi a Arezzo nel 2013.
Abstract:
Purpose of the work. Inflammatory Airway Disease (IAD) is a syndrome characterized by inflammation
of lower airways without systemic implication such as fever or dyspnea. The abbreviation
“tr” indicates IAD diagnosed by tracheal wash (TW)[1]. IAD is defined as “bacterial” when more
than 100 Colony Forming Units (CFU) are isolated from TW[2]; in this case antibiotic therapy is
recommended. Efficacy of antibiotic therapy in respiratory disease is directly correlated with the
minimal inhibitory concentration (MIC) reached in the respiratory tract[3]. Studies have shown
that inhaled antibiotics, used at lower dosage, could reach higher concentration in horses respiratory
fluids than systemic administration[3]. A recently published study reports the clinical efficacy
of inhaled amikacin in human patients[4].
Aim of the present work is to evaluate the effect of inhaled amikacin, compared to systemic administration,
on TW cytology and bacteriology and on clinical scoring in bacterial tr-IAD affected
racehorses.
Materials and used methods. Thoroughbred racehorses, aged between 3 to 4 years old, affected
with bacterial tr-IAD with a sensitivity testing positive for amikacin, were selected.
In all horses a clinical evaluation was performed and, using a modified respiratory clinical scoring
system[5], a score was assigned to each horse at the beginning and the end of the trial.
TW was endoscopically (Olympus) performed into the thoracic portion of trachea and 60 ml of
saline at 37°C was flushed, through a sterile Teflon catheter passed into the biopsy channel, and
then immediately collected.
The sample was cytocentrifuged (Rotofix 32, Hettich Zentrifugen) and stained with May Grumwald
Giemsa for differential cell count and also cultured on blood agar plate for CFU/ml count and agar
diffusion amikacin sensitivity test.
Horses were then randomly divided in 2 groups; the horses of group A were treated with 3,3 mg/Kg
of amikacin (Amikavet® Merial), diluted in 0,45% NaCl solution at 50 mg/ml, administered by a jet
nebulizer (Fiac F3000) and Equine Aeromask®, q24h for 10 days, while horses of group B received
10 mg/Kg of amikacin (Amikavet® Merial) intravenously q24h for 10 days.
Clinical scoring and TW cytology and bacteriology were performed in all horses at the end of the
treatment.
Values of clinical score, TW neutrophils count and CFU/ml before and after the treatment in both
groups were compared by Student-T test. Rate of recurrence of bacteria isolation after therapy between
the two groups was compared with chi-squared test.
Outcomes. In group A, a statistically significant decrease in clinical score (p<0.01), TW neutrophils
count (p<0.05) and CFU (p<0.01) was found after inhaled amikacin treatment. In group B a statistically
significant decrease in clinical score (p<0,05) and CFU (p<0.01) was recognized after intravenous
amikacin administration. Although, no significant difference was found in TW neutrophils
count for group B, a decrease in their count was evident.
No statistically significant difference in bacteria isolation after the treatment was found between the
two groups.
358
Conclusions. Inhaled amikacin at dosage of 3,3 mg/Kg q24h for 10 days administered by jet nebulizer
and Equine Aeromask® seems to be effective in the reduction of clinical signs, TW neutrophils
count and bacterial CFU.
The absence of a significant difference between the two groups in the isolation of bacteria after
treatment suggests that, despite a lower inhaled dose, amikacin may be equally effective for both
routes of administration. However, inhaled amikacin in group A, seems to be able to induce a lower
chemotactic action on neutrophils, less damage of the lower respiratory tract mucosa, and consequ
Tipologia IRIS:
03 - Contributo in volume
Elenco autori:
F. Ferrucci, L. Stucchi, M. Salvadori, G. Stancari, B. Conturba, V. Bronzo, E. Zucca
Link alla scheda completa:
Titolo del libro:
XIX CONGRESSO SIVE-FEEVA