Abdominocentesis

Introducción

La extracción y análisis del líquido peritoneal del caballo es útil en la valoración del estado del paquete intestinal. La abdominocentesis se convierte así en una herramienta diagnóstica útil para decidir si un paciente con cólico es o no intervenido quirúrgicamente. Debe practicarse siempre que estemos ante situaciones de cólicos recurrentes o persistentes; también en situaciones de pérdidas de peso crónicas y diarreas. Se recomienda realizar en instalaciones clínicas bien comunicadas ante la posibilidad de que el análisis recomiende referir al animal urgentemente para su intervención. Para acceder al análisis del líquido peritoneal en caballos accede aquí.

Material

Buena sujección y sedación en caso de ser necesario
Peladora y material necesario para una buena limpieza y desinfección del área
Ecógrafo, en caso de disponer de él, para hacer la punción eco-guiada
Guantes estériles
Jeringas estériles de calibre 18 a 20g. Puede ser necesario una aguja de bisturí en caso de utilizar una cánula mamaria.
Jeringuilla estéril
Tubos de recogida de muestras: 1)Tubo con EDTA; 2)Tubo sin anticoagulante; y 3)Viales estériles para cultivos bacterianos (hisopos, placas de petri, etc.)

Procedure

The best site for abdominocentesis is the most dependent part of the abdomen, midline and usually around 5 cm caudal to the xiphoid. The use of ultrasound for selecting the pockets of peritoneal fluid within the abdomen is ideal as it not only indicates how thick the body wall is but the location of viscera to be avoided. However, peritoneal fluid can still be extracted even if it is not apparent on ultrasound. A right paramedian approach at the most dependent area of the abdomen is the best site if ultrasound is not available. This approach should avoid accidental puncture of the spleen. The selected area should be generously clipped and a sterile scrub performed. At minimum a twitch, or sedation if the horse is more fractious, should be used for restraint. Sterile gloves should be worn to maintain sterility. The veterinarian should stand next to the horse and insert the needle with a quick action through the skin. Then the needle can be gently and carefuly advanced through the linea alba, into the peritoneal cavity. If fluid is present, then drops should be seen in the needle hub. If this is not the case, reposition and twist the needle. Alternatively, a sterile syringe can be attatched and the fluid can be aspirated. Once the fluid is noted, it should be allowed to drop freely into the EDTA and plain tubes for analysis. The fluid may also be submitted for microbiological culture and sensitivity, peritoneal lactate and glucose concentrations if necessary.

Complications

Accidental splenic puncture will contaminate the sample and make analysis difficult. The fluid will be blood-tinged and have a PCV greater than that of the peripheral blood. Accidental puncture and aspiration of the bowel and its contents commonly occurs but does not often cause complications. The risk of this can be minimized using a blunt-tipped cannula. The risk of both scenarios can be minimized by the use of ultrasound guidance. If sterility is broken during the procedure or purulent and septic fluid is removed then there is a risk of cellulitis and abscess formation in the body wall.

Peritoneal Fluid Analysis

For normal and abnormal peritoneal fluid analysis, see peritoneal fluid analysis in horses.

References

Edwards B. (2009), Diagnosis and Pathophysiology of Intestinal Obstruction, in Equine Gastroenterology courtesy of the University of Liverpool, pp 8-9
Meuller E, Moore J. N, (2008) Classification and Pathophysiology of Colic, Gastrointestinal Emergencies and Other Causes of Colic, in Equine Emergencies- Treatments and Procedures, 3rd Edition, Eds Orsini J. A, Divers T.J, Saunders Elsevier, pp 102 - 105, 111