Sedation with dexmedetomidine is associated with transient gallbladder wall thickening and peritoneal effusion in some dogs undergoing abdominal ultrasonography

Abstract

Background Dexmedetomidine often is used for sedation before or during abdominal ultrasonography. The effect of dexmedetomidine on gallbladder wall thickness is unknown. Hypothesis/Objectives To investigate the relationship between dexmedetomidine administration and gallbladder wall thickening in dogs. The hypothesis was that sedation with dexmedetomidine will cause transient gallbladder wall thickening. Gallbladder wall thickness will be associated with duration of sedation and recumbency position. Animals Seventy‐nine client owned dogs and 10 healthy research dogs. Methods A prospective observational study (n = 79) was used to establish the prevalence of gallbladder wall thickening (> 2.0 mm) after sedation with dexmedetomidine. A randomized, crossover study (n = 10) was used to evaluate the effect of time and recumbency position on the development of gallbladder wall thickening. Linear mixed models were used. Results The proportion of client‐owned dogs that developed gallbladder wall thickening was 24.05% (19/79; 95% confidence interval [CI], 15.1%‐35.0%) with a median dose of dexmedetomidine of 5.0 μg/kg (range, 2.0‐12.5 μg/kg). After sedation, the proportion of research dogs that developed gallbladder wall thickening in left lateral (5/10, 50%; 95% CI, 18.7%‐81.3%) and dorsal (7/10, 70%; 95% CI, 34.8%‐93.3%) recumbency did not differ significantly (P = .45). Gallbladder wall thickening developed within 20 to 40 minutes. Duration of sedation was significantly associated with thickening of the gallbladder wall (P < .001). Five dogs developed 9 instances of peritoneal effusion in both lateral (5) and dorsal (4) recumbency. Conclusions and Clinical Importance Sedation with dexmedetomidine is associated with gallbladder wall thickening (> 2.0 mm) and peritoneal effusion that could be confused with pathologic etiologies.

Ultrasonographic measurement of gallbladder wall thickness in fasted dogs without signs of hepatobiliary disease

“…Another important consideration is the sedation protocol used before imaging. Because dexmedetomidine has been documented to result in significant increases in gallbladder wall thickening in normal dogs, 16 alpha‐2 agonists should be avoided or used judiciously, avoiding high doses, before gallbladder measurement, as was the case in our study.…”

“…The normal gallbladder wall appears as a thin echogenic line during ultrasound examination, and may be difficult to identify in its entirety when not diseased 5,7 . Gallbladder wall thickening can occur either diffusely or focally, and may reflect gallbladder disease, systemic illness, iatrogenic causes, or be artifactual in nature 5,15,16 . Artifactual increases in wall thickness primarily relate to imaging technique or increases that can occur when free fluid surrounding the gallbladder mimics diffuse wall thickening 4,5 .…”

“…5,7 Gallbladder wall thickening can occur either diffusely or focally, and may reflect gallbladder disease, systemic illness, iatrogenic causes, or be artifactual in nature. 5,15,16 Artifactual increases in wall thickness primarily relate to imaging technique or increases that can occur when free fluid surrounding the gallbladder mimics diffuse wall thickening. 4,5 The type of transducer used, orientation of the sound beam relative to the gallbladder wall, and the extent of gallbladder distension all impact wall thickness.…”

Ultrasonographic features of gallbladder wall thickening in dogs with hypoalbuminemia

“…In the present study, most of the dogs received some kind of sedation during the ultrasound study, including dexmedetomidine, which is known to cause gallbladder wall edema (Seitz et al. 2021 ; Bini et al. 2022 ).…”

“…acute hepatitis, pancreatitis, or peritonitis), right-sided heart failure, renal failure, neoplasia, adenomyomatosis, sedation-induced (Seitz et al. 2021 ; Bini et al. 2022 ) or hypoalbuminemia (Fiske et al.…”