Equine Health Update EHU Vol 20 Issue 03 - Page 39

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 • 39