Children’s (Paediatric) Renal Ultrasound
Dr Timothy Cain What are the prerequisites for having a paediatric renal ultrasound done? Renal ultrasound examination is the initial…Read more
Prior imaging is required to confirm the presence and accessibility of any intra-abdominal collection, free fluid or ascites before requesting an ascitic tap. This is usually via ultrasound or CT, and most often this will be ultrasound as this is better for showing small amounts of fluid and any loculation or solid material (e.g. tumour) within the fluid that may influence needle placement.
Patients undergoing the procedure should have normal clotting parameters. Hence, coagulation studies and full blood examination should be carried out for all patients with ascites in the setting of liver disease.
Although aspirin does not need to be ceased, patients must cease warfarin for 5 days or Clopidogrel/Asasantin for 10 days before the procedure. If the risks of ceasing these medications are considered too high, such as in patients with recently inserted stents or other cardiac intervention, this should be discussed with the radiologist before requesting the procedure. Alternate anticoagulation or antiplatelet cover may be necessary. If the patient is on warfarin, an INR is required before the procedure, preferably on the same day.
There are no absolute contraindications to an ascitic tap.
Relative contraindications are:
Complications are uncommon. Infection typically produces pain and/or fever several days after the procedure, or localised pain, erythema or discharge at the injection site.
Ongoing ascitic leak more than 48 hours post-procedure is uncommon, but should result in discussion with the radiology facility carrying out the procedure. Sometimes a suture and removal of more fluid can stop the leak.
Hypotension occurs infrequently, only after drainage of several litres of ascitic fluid. It may occur as late as 12 hours after the paracentesis. This may be prophylactically or actively treated at the time of the procedure with intravenous volume expanders. The recommended treatment regimen for this varies widely in the literature, with some studies showing no improvement in morbidity or mortality.
Inadvertent injury of bowel, vessels or solid organs in the path of the needle is uncommon. Internal haemorrhage and visceral trauma/perforation usually manifest at the time of the procedure with worsening abdominal pain or shock. However, haematuria from bladder perforation may present later.
Intra-abdominal fluid may be drained without ultrasound guidance in the cases of large volume ascites, or surgically if the collection is too complex, multiloculated or inaccessible by percutaneous means.
Page last modified on 29/3/2017.
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