Difference between revisions of "Thoracocentesis"

Revision as of 14:10, 24 July 2011

Introduction

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

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. 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

Sedation as necessary
Clippers and materials to perform a surgical scrub
Ultrasonography if available
Local anaesthetic and a 23G 3cm needle
Sterile gloves
Number 15 scalpel blade
Cannula, 3-way tap and extension set
EDTA tube, plain tube and sterile vial for culture

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 horse should be sedated and the area clipped and scrubbed

Local anaesthetic should be administered into the subcutis, intercostal musculature and parietal pleura using a 23 gauge, 3 cm needle

A stab incision using a number 15 scalpel blade should be made through the skin

Prior to inserting the cannula, a three-way tap and extension set should be attached to it

Using moderate pressure, the cannula should be pushed through first the intercostal muscles and secondly through the parietal pleura in order to enter the thoracic cavity. Passage of the cannula through the parietal pleura is extremely painful to the horse if the area has not been fully desensitised by the local anaesthetic

A release in pressure should be felt when the cannula enters the thoracic cavity. The cannula can be manipulated and moved to collect as much fluid as possible

Complications

Pneumothorax

Peritoneal Fluid Analysis

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

@@ Line 1: / Line 1: @@
+==Introduction==
+Thoracocentesis is a procedure which has both diagnostic and therapeutic value.
-Also known as: '''''Pleurocentesis'''''
+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.
+Drainage of pleural effusion via thoracocentesis is beneficial in removing large volumes of fluid from the thorax.
-==Equine Thoracocentesis==
+Immediately following this drainage, some horses show increased pain, associated with loss of the ‘cushion’ of fluid in the pleural space.
-===Introduction===
+Removal of this fluid decreases respiratory effort and is beneficial in the resolution of an infectious process in the thorax.
-Thoracocentesis is a valuable '''diagnostic''' and '''therapeutic''' procedure.
+In horses with thoracic neoplasia and large volumes of pleural effusion, thoracocentesis and chest drainage may resolve signs of dyspnoea and respiratory distress.
-When the findings of thoracic auscultation or percussion are suggestive of pleural effusion, thoracocentesis can be performed to:
-* '''Confirm''' the '''presence''' of pleural effusion
-* Provide a '''specimen''' for '''examination''' which provide a diagnosis or guide the therapeutic plan
-* '''Therapeautically drain''' a large volume of pleural fluid
-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 dyspnoea''' 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.
-===Equipment===
+==Equipment==
 * Sedation as necessary
 * Clippers and materials to perform a surgical scrub
@@ Line 23: / Line 18: @@
 * EDTA tube, plain tube and sterile vial for culture
-===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'''. '''[[Local Anaesthetics|Local anaesthetic]]''' should be administered into the subcutis, intercostal musculature and parietal pleura using a 23 gauge, 3 cm needle. A '''stab incision''' using a number 15 scalpel blade should be made through the skin. Prior to inserting the cannula, a '''three-way tap''' and extension set should be attached to it. Using moderate pressure, the cannula should be pushed through first the intercostal muscles and secondly through the parietal pleura in order to enter the thoracic cavity. Passage of the cannula through the parietal pleura is extremely painful to the horse if the area has not been fully desensitised by the local anaesthetic. A release in pressure should be felt when the cannula enters the thoracic cavity. The cannula can be manipulated and moved to collect as much fluid as possible.
-===Complications===
-Iatrogenic '''[[pneumothorax]]'''
-===Pleural Fluid Analysis===
+* The horse should be sedated and the area clipped and scrubbed
-Analysis of the pleural fluid may in turn help you to determine the underlying disease process and develop a therapeutic plan.
-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.
+* Local anaesthetic should be administered into the subcutis, intercostal musculature and parietal pleura using a 23 gauge, 3 cm needle
-==Small Animal Thoracocentesis==
-===Introduction===
-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.
-===Equipment===
-* Clippers and materials to perform a surgical scrub
-* Ultrasonography if available
-* Sterile gloves
-* Butterfly needle with incorporated extension set or sterile needle (1 inch with the smallest possible gauge) with extension set
-* 20ml sterile syringe
-* 3-way tap - if large volumes of fluid are anticipated, as this allows for multiple syringes of fluid to be removed safely under a closed system
-* 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.
+* A stab incision using a number 15 scalpel blade should be made through the skin
-==Procedure==
+* Prior to inserting the cannula, a three-way tap and extension set should be attached to it
-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. Advance the needle slowly at a '''45 degree angle''' in the middle of the 7th or 8th intercostal space into the pleural space. A small amount of '''negative pressure''' should be applied as the needle passes through the thoracic wall. The needle should be angled downward, '''parallel to the body wall'''. The fluid or air should then be aspirated. The needle may need redirecting to access pockets of fluid.
+* Using moderate pressure, the cannula should be pushed through first the intercostal muscles and secondly through the parietal pleura in order to enter the thoracic cavity. Passage of the cannula through the parietal pleura is extremely painful to the horse if the area has not been fully desensitised by the local anaesthetic
-Up to 100mls of fluid per side can be expected in the cat. '''Removal of fluid should see an improvement in clinical signs'''.
+* A release in pressure should be felt when the cannula enters the thoracic cavity. The cannula can be manipulated and moved to collect as much fluid as possible
 ==Complications==
-Iatrogenic [[pneumothorax]]
+Pneumothorax
-===Pleural 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.
-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:
-#[[Exudate]]
-#[[Modified Transudate]]
-#[[Transudate]]
-#[[Chylous Effusion|Chyle]]
-These can be identified by the protein and cellular content of the sample.
-The fluid can give an indication of '''prognosis'''; in the cat prognosis is generally poor for all diagnoses 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.''
-{{Learning
-|flashcards = [[Equine Internal Medicine Q&A 18]]<br>[[Equine Internal Medicine Q&A 19]]<br>[[Cytology Q&A 03]]<br>[[Small Animal Emergency and Critical Care Medicine Q&A 03]]
-}}
-==References==
-Adamantos, S (2011) '''Feline Respiratory Emergencies''' RVC Emergency Medicine and Critical Care Elective, ''Royal Veterinary College''
-Mair, TS & Divers, TJ (1997) '''Self-Assessment Colour Review Equine Internal Medicine''' ''Manson Publishing Ltd''
-RVC staff (2009) '''Respiratory System''' RVC Intergrated BVetMed Course, ''Royal Veterinary College''
-Rutgers, C H (1989) '''Thoracocentisis in the dog and cat''' ''In Practice'' 1989 11: 14-1
-Copas, V (2011) '''Diagnosis and treatment of equine pleuropneumonia''' ''In Practice'' 2011;33:155-162
-RVC staff (2011) '''A logical approach to clinical problem solving''' RVC Feline Medicine Elective, ''Royal Veterinary College''
-{{review}}
-==Webinars==
+Pleural fluid from healthy horses may contain up to 10,000 nucleated cells/l and 35g/l total protein.
-<rss max="10" highlight="none">https://www.thewebinarvet.com/surgery/webinars/feed</rss>
+Most horses have less than 5,000 nucleated cells/l and less than 25g/l total protein.
-[[Category:Clinical Techniques]]
+[[Category:To Do - Siobhan Brade]]
-[[Category:Expert Review]]