Changes

==Introduction==

==Introduction==

Thoracocentesis is a procedure which has both diagnostic and therapeutic value.  

Thoracocentesis is a valuable '''diagnostic''' and '''therapeutic''' procedure.  

 

 

When the findings from either thoracic auscultation or percussion suggest a pleural effusion, thoracocentesis can both confirm its presence and provide a specimen for examination.

The horse may show more discomfort if a significant amount of fluid is drained because the fluid had previously provided a 'cushion' effect in the pleural cavity. However the removal of this fluid is beneficial as it '''relieves dyspnoe'''a and '''removes infectious material''' from the pleural space, which aids resolution. The placement of '''chest drains''' following thoracocentesis may be necessary in cases of thoracic neoplasia and severe pleural effusion.

Drainage of pleural effusion via thoracocentesis is beneficial in removing large volumes of fluid from the thorax.

Immediately following this drainage, some horses show increased pain, associated with loss of the ‘cushion’ of fluid in the pleural space.

Removal of this fluid decreases respiratory effort and is beneficial in the resolution of an infectious process in the thorax.

In horses with thoracic neoplasia and large volumes of pleural effusion, thoracocentesis and chest drainage may resolve signs of dyspnoea and respiratory distress.

==Equipment==

==Equipment==

==Procedure==

==Procedure==

The site for thoracocentesis can be identified using anatomical landmarks; 7-8th intercostal space on the left or 6-7th intercostal space on the right midway between the shoulder and the elbow. For more reliable identification of the correct position for thoracocentesis ultrasound can be used. As there are vessels and nerves running along the caudal aspect of each rib, the cannula should aim for the cranial border of the rib in order to avoid damage to these structures.

The site for thoracocentesis can be identified using anatomical landmarks; '''7-8th intercostal space''' on the '''left''' or '''6-7th intercostal space''' on the '''right''' '''midway between the shoulder and the elbow'''. For more reliable identification of the correct position for thoracocentesis '''ultrasound''' can be used. As there are vessels and nerves running along the caudal aspect of each rib, the cannula should aim for the '''cranial border of the rib''' in order to avoid damage to these structures.

* The horse should be sedated and the area clipped and scrubbed

* The horse should be sedated and the area clipped and scrubbed

==Complications==

==Complications==

Iatrogenic pneumothorax

Iatrogenic '''pneumothorax'''

==Peritoneal Fluid Analysis==

==Peritoneal Fluid Analysis==

Analysis of the pleural fluid may in turn help you to determine the underlying disease process and develop a therapeutic plan.  

Analysis of the pleural fluid may in turn help you to determine the underlying disease process and develop a therapeutic plan.  

Pleural fluid from healthy horses may contain up to 10,000 nucleated cells/l and 35g/l total protein.

Pleural fluid in healthy horses normally contains '''less than 5,000 nucleated cells/l''' and '''less than 25g/l total protein'''. Levels greater than 10,000 nucleated cells/l and 35g/l total protein should be considered abnormal.

Most horses have less than 5,000 nucleated cells/l and less than 25g/l total protein.

=Small Animal Thoracocentesis=

=Small Animal Thoracocentesis=

Thoracocentesis is a procedure which has both diagnostic and therapeutic value.  

Thoracocentesis is a procedure which has both diagnostic and therapeutic value.  

When the clinical history, presenting signs, thoracic auscultation and percussion of the animal suggest a pleural effusion, thoracocentesis can both confirm its presence and provide a specimen for examination. Ideally radiography (minimum of two views - lateral and dorsoventral) or ultrasound should be performed to confirm pleural space disease prior to thoracocentesis. However it can be particularly useful in the emergency patient (the dyspnoeic cat in particular) who is too unstable to undergo radiography or similar diagnostic tests as drainage of pleural fluid will both provide a preliminary diagnosis and improve clinical signs.

When the '''clinical history''', '''presenting signs''', '''thoracic auscultation''' and '''percussion''' of the animal suggest a pleural effusion, thoracocentesis can both '''confirm''' its presence and provide a '''specimen''' for '''examination'''. Ideally '''radiography''' (minimum of two views - lateral and dorsoventral) or '''ultrasound''' should be performed to confirm pleural space disease prior to thoracocentesis. However it can be particularly useful in the emergency patient (the dyspnoeic cat in particular) who is too unstable to undergo radiography or similar diagnostic tests as drainage of pleural fluid will both provide a preliminary diagnosis and improve clinical signs.

==Equipment==

==Equipment==

* EDTA tube for cytology and plain tube for biochemistry and culture

* EDTA tube for cytology and plain tube for biochemistry and culture

Sedation is not generally required, especially in the dyspnoeic patient (however it can be used if necessary to prevent further stress to an excitable animal). The patient should be handled gently and the procedure performed in a quiet environment. It may be necessary to place the animal in an oxygen cage prior to the procedure as they often have a poor oxygen reserve.

Sedation is not generally required, especially in the dyspnoeic patient (however it can be used if necessary to prevent further stress to an excitable animal). The patient should be '''handled gently''' and the procedure performed in a '''quiet environment'''. It may be necessary to place the animal in an '''oxygen cage''' prior to the procedure as they often have a poor oxygen reserve.

==Procedure==

==Procedure==

The site for thoracocentesis is between the 7th and 8th intercostal space. If fluid is suspected in the pleural space then the needle should be inserted 2/3rds of the way down the chest. If pneumothorax is suspected then the needle should be inserted more dorsally, approximately 1/3rd down the chest. Local anaesthetic can be used if necessary.

The site for thoracocentesis is between the '''7th and 8th intercostal space'''. If fluid is suspected in the pleural space then the needle should be inserted '''2/3rds of the way down the chest'''. If '''pneumothorax''' is suspected then the needle should be inserted more '''dorsally''', approximately '''1/3rd of the way down the chest'''. Local anaesthetic can be used if necessary.

* Clip and scrub a generous area around the 7-8th rib space on both sides of the chest.  

* Clip and scrub a generous area around the 7-8th rib space on both sides of the chest.  

* The fluid or air should then be aspirated. The needle may need redirecting to access pockets of fluid.

* The fluid or air should then be aspirated. The needle may need redirecting to access pockets of fluid.

Up to 100mls of fluid per side can be expected in the cat. Removal of fluid should see an improvement in clinical signs.

Up to 100mls of fluid per side can be expected in the cat. '''Removal of fluid should see an improvement in clinical signs'''.

==Complications==

==Complications==

==Peritoneal Fluid Analysis==

==Peritoneal Fluid Analysis==

Analysis of the pleural fluid may in turn help you to determine the underlying disease process and develop a therapeutic plan.

Analysis of the pleural fluid may in turn help you to determine the underlying disease process and develop a therapeutic plan.

The following can be analysed: cytology, total cell count, differential cell count, total protein, bacterial culture ans sensitivity, gram stain and triglyceride and cholesterol levels (if [[Chylothorax|chylothorax]] is suspected).  

The following can be analysed: '''cytology, total cell count, differential cell count, total protein, bacterial culture ans sensitivity, gram stain and triglyceride and cholesterol levels''' (if [[Chylothorax|chylothorax]] is suspected).  

The types of fluid that may cause pleural space disease are:  

The types of fluid that may cause pleural space disease are:  

These can be identified by the protein and cellular content of the sample.  

These can be identified by the protein and cellular content of the sample.  

The fluid fluid can give an indication of prognosis; in the cat prognosis is generally poor for all diagnosis except [[Pyothorax|pyothorax]] (an exudate with degenerate neutrophils and intracellular bacteria). Therefore it is often useful to perform in-house cytology to give a preliminary diagnosis, which allows the owners to make an informed decision before proceeding with further treatment. Differential diagnosis in the cat include [[Heart Failure|congestive heart failure]], [[Feline Infectious Peritonitis|FIP]], [[Pyothorax|pyothorax]], [[Neoplasia - Pathology|neoplasia]], [[Haemothorax|haemothorax]] and [[Chylothorax|chylothorax]]. It should be noted that any pleural effusion may produce bizarre mesothelial cells which could be mistaken for neoplastic cells.

The fluid fluid can give an indication of '''prognosis'''; in the cat prognosis is generally poor for all diagnosis except [[Pyothorax|pyothorax]] (an exudate with degenerate neutrophils and intracellular bacteria). Therefore it is often useful to perform in-house cytology to give a preliminary diagnosis, which allows the owners to make an informed decision before proceeding with further treatment. Differential diagnosis in the cat include [[Heart Failure|congestive heart failure]], [[Feline Infectious Peritonitis|FIP]], [[Pyothorax|pyothorax]], [[Neoplasia - Pathology|neoplasia]], [[Haemothorax|haemothorax]] and [[Chylothorax|chylothorax]]. It should be noted that any pleural effusion may produce bizarre mesothelial cells which could be mistaken for neoplastic cells.

=References=

=References=