Evaluation of transabdominal ultrasound as a tool for predicting the success of abdominocentesis in horses

Abstract

The aim of this study was to evaluate the transabdominal ultrasonography as a tool for predicting the success of abdominocentesis in horses. Patients were included in the study if a complete transabdominal ultrasonography examination and abdominocentesis were performed as part of the clinical work-up. Ultrasonographically, the amount of peritoneal fluid was assessed using a 4-point grading system, as well as the amount of peritoneal fluid collected. A χ(2) or Fischer exact test was performed to test for an association between the ultrasonography findings and fluid retrieved, and between the two grading scales. Interobserver and intraobserver agreement values were calculated using k statistics. Values of P<0.05 were considered significant; 109 horses met the inclusion criteria. Peritoneal fluid was identified ultrasonographically in 72 per cent of horses, and it was collected from 93 per cent of these cases. In horses with no peritoneal fluid identified at ultrasonography (28 per cent), fluid was collected in 70 per cent of cases. There is a significant association between transabdominal ultrasonography detection of peritoneal fluid and the likelihood to obtain a diagnostic amount of peritoneal fluid at abdominocentesis; however, even when peritoneal fluid is not detected during abdominal ultrasonography examination, an amount of peritoneal fluid useful for gross, clinicopathological and cytological evaluation can frequently be obtained.

Clinical and diagnostic findings, treatment, and short‐ and long‐term survival in horses with peritonitis: 72 cases (2007‐2017)

“…Exclusion of peritonitis is possible only on the basis of cytological evaluation of peritoneal fluid, and abdominocentesis is usually successful even without ultrasonographic evidence of free peritoneal fluid. 19 In this study, culture of the peritoneal fluid was performed in 65 cases, with only 25 (38%) yielding positive growth. The proportion of positive culture results is comparable to the results in a recently published retrospective report 11 of peritonitis cases in Sweden, in which a positive culture was obtained in only 41% of the cases.…”

“…It is important that clinicians be aware that a lack of peritoneal fluid does not rule out the presence of peritonitis. Exclusion of peritonitis is possible only on the basis of cytological evaluation of peritoneal fluid, and abdominocentesis is usually successful even without ultrasonographic evidence of free peritoneal fluid 19 …”

Ultrasonographic Findings in 13 Horses With Lymphoma

“…The amount of peritoneal fluid had been assessed subjectively during the real‐time US examination using a grading system proposed elsewhere . Anechoic fluid was considered normal, while homogeneous increased echogenicity or presence of floating echoic debris were recorded and considered significant of increased cellularity or presence of fibrin.…”

Abdominocentesis techniques in horses

“…In one study, fluid was successfully collected from 70% of horses in which no free peritoneal fluid was identified ultrasonographically prior to the tap. 7 Therefore, although there are some benefits to using ultrasound guidance to perform this procedure, abdominocentesis should still be attempted even if fluid is not visualized on ultrasound.…”