Should sedation be used to reduce a child’s discomfort and possible movement when performing a Tc-99 dimercaptosuccinic acid (DMSA) renal scan? Opinion is mixed. But a multispecialty team of researchers conducted a study of the practices of 19 radiology facilities and determined that routine sedation did not appear to be particularly beneficial, except for children under three years of age.
Lead author Nader Shaikh, MD, of the Division of General Academic Pediatrics at the Children’s Hospital of Pittsburgh, and co-authors compared the discomfort levels experienced by children during a DMSA scan to the discomfort level they experienced when undergoing other frequently performed uroradiologic tests. They also wanted to determine whether sedation during a DMSA scan modified levels of discomfort, and if there was a correlation between sedation and image quality.
A DMSA renal scan is performed to evaluate the presence or absence of pyelonephritis, inflammation of the kidney and upper urinary tract, and renal scarring in children with urinary tract infections. A DMSA scan consists of three phases: an intravenous injection, its distribution to the tissues—which takes 90 minutes to three hours, during which the patient leaves the radiology suite—and the imaging acquisition phase, which takes 30 minutes to an hour. During the imaging acquisition phase, children may be sedated.
For the study, whose findings were published in Pediatric Radiology, the authors examined parent-perceived degrees of discomfort experienced during a variety of uroradiologic imaging tests performed in 607 children enrolled in the Randomized Intervention for children with Vescoureteral Reflux (RIVUR) trial and 195 children enrolled in the Careful Urinary Tract Infection Evaluation (CUTIE) study. All of the children had sonography, a voiding cystourethrogram (VCUG), and a DMSA scan.
The researchers determined that on a scale of 0 to 10, the VCUG caused the most discomfort, followed by the DMSA, and then the ultrasound exam. They determined that discomfort levels were not significantly different between sedation centers and selective centers. As might be expected, very young patients had less discomfort if sedated, and if not sedated, the percentage of exams producing images of interpretable quality were higher for these very young patients.
A total of 1,215 DMSA scans were performed, 67% of which were performed on children aged two months to two years. The remainder of the patients were under six years of age. Patients were sedated for 32% of the procedures.
The authors categorized centers as either being “sedation centers” (using sedation for more than 90% of DMSA scans performed), “selective sedation centers” (determining whether to use sedation based on established policies based on a child’s age) or “non-sedation centers”(using sedation for 10% or fewer DMSA scans performed).
The authors concluded that sedation is more appropriate for very young children, and may be appropriate for older, uncooperative children on a selective basis.
Value of sedating young children having DMSA scans. Appl Radiol.