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Recurrent Airway Obstruction (view source)
Revision as of 12:59, 26 August 2010
, 12:59, 26 August 2010→Laboratory Tests
Routine haematology and biochemistry are usually within normal limits, and there is little evidence to support the use of serum and intradermal allergy testing in the diagnosis of RAO<sup>allen</sup>.
Routine haematology and biochemistry are usually within normal limits, and there is little evidence to support the use of serum and intradermal allergy testing in the diagnosis of RAO<sup>allen</sup>.
Fluids obtained from bronchoalveolar lavage or tracheal wash may be useful in the diagnosis of RAO. The presence of greater than 20% neutrophils in BALF confirms the presence of lower airway inflammation, thus and differentiates horses with RAO from those with eosinophilic pneumonitis, fungal pneumonia, or lungworm infestation. Normal horses have fewer than 10% neutrophils in BALF. Cytology of bronchoalveolar lavage fluid may also reveal Curschmann’s spirals , which represent inspissated mucus/cellular casts from obstructed small airways<sup>1</sup>. BAL should not be performed if the horse is markedly dyspnoeic and should be postponed until the dyspnoea is controlled. There
Fluids obtained from bronchoalveolar lavage or tracheal wash may be useful in the diagnosis of RAO. The presence of greater than 20% neutrophils in BALF confirms the presence of lower airway inflammation, thus and differentiates horses with RAO from those with eosinophilic pneumonitis, fungal pneumonia, or lungworm infestation. Normal horses have fewer than 10% neutrophils in BALF. Cytology of bronchoalveolar lavage fluid may also reveal Curschmann’s spirals , which represent inspissated mucus/cellular casts from obstructed small airways<sup>1</sup>. BAL should not be performed in markedly dyspnoeic horses, and instead should be postponed until the dyspnoea is controlled. Aspiration of tracheal mucus or a tracheal lavage can also be used to evaluate lung inflammation but it is less reliable than BALF.
Aspiration of tracheal mucus or a tracheal lavage can also be used to evaluate lung inflammation but it is less reliable than BALF. Because there can be increased numbers of neutrophils in the tracheal wash but not in BALF [52], it is wiser to base evaluation of peripheral lung inflammation on the cytology of BALF. Presumably increased numbers of neutrophils in the tracheal secretions reflect local tracheal inflammation that does not extend deeper into the lung. Mixed populations of bacteria are common in a tracheal wash and usually are of no significance.
===Other Tests===
===Other Tests===