CPD Article | EQUINE
gentamicin or NSAID therapy as these are potential
nephrotoxic medications 7 8 . Often intravenous fluid
supportive therapy is required during the first few
days 8 to address dehydration. Additional monitoring of
creatinine levels and urine output are recommended
to assess renal function.
NSAIDs are indicated 3 to reduce pain, pyrexia
and fibrin deposition 6 . Flunixin is also indicated
in the treatment of a developing septicaemia or
endotoxaemia 3 6 and can be administered at 0.5mg/kg
IV q 6-8hr 6 . Opioids 3 should be considered especially
for patients with severe pleurodynia (pleural pain).
An indwelling chest drain should be placed with
detection of continuous large pleural fluid volume
production 3 , pleural fluid with a pH less than 7.2, a
high pleural fluid lactate level or glucose less than
40mg/dl 3 or if the patient shows a poor response to
intermittent drainage 11 . Intermittent drainage can be
performed after ultrasound evaluation and in low
pleural fluid production cases is usually required
every 2 -3 days 2 . Lavaging of the pleural cavity can
be performed with approximately 5 L of warmed
sterile isotonic fluid 3 to aid removal of fibro-necrotic
material 11 . The additional use of diluted intrapleural
fibrinolytics, such as alteplase or tenecteplase, in an
attempt to improve treatment response still requires
additional research before the efficacy and safety of
the medications can be guaranteed 3 . Should the horse
start coughing or develop a nasal discharge during
lavage, a bronchopleural fistula should be suspected
and the lavaging should immediately be stopped.
Nasal insufflation of oxygen 10 -15L/min can be
administered to hypoxic horses or horses showing
respiratory distress 10, 11 .In severely affected horses,
preventative laminitic measures, such as distal limb
cryotherapy 3 should be instituted 11 .
Nebulization of drugs has been suggested 3 , however
plugging of lower airways with mucous and exudate
and poor patient compliance may limit the success of
this treatment 3 .
The patient should not be stressed at all. All food
should be fed from the floor to improve drainage of
respiratory secretions 3 . Short hand walks with hand
grazing may encourage appetite and recovery 11 but
should not be considered for severely ill or dyspnoeic
patients 3 . Should the horse become severely
hypoproteinaemic , synthetic colloid or plasma
transfusion should be considered 3 .
It is recommended that during the course of therapy,
additional TTA samples are collected for culture
and sensitivity to monitor whether the infection is
responding to the medication 3 . Refractory cases will
require repeated re- evaluations with ultrasound,
thoracocentesis and TTA sampling as resistant bacteria
may develop11 or new infections and complications
arise 3 11 .
At referral centres, thoracoscopy can be performed
understanding sedation to allow direct assessment
of the lung and pleura 3 . Thoracotomy can also be
performed for manual debriding of necrotic lung
tissue and removal of fibrin deposits 11 .
In summary the treatment aims are to reduce the
pleural effusion volume, inhibit further bacterial
growth, minimise secondary complications and to
render supportive care 11 .
Prognosis
Early identification of affected horses with rapid and
aggressive treatment is paramount in affecting the
successful outcome of the case 5, 7 . Survival rates are
quite varied with 43 – 88% cited 3 .
• Volume 20 Issue 3 | October 2018 •
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