Effects of Oral Administration of a Commercial Activated Charcoal Suspension on Serum Osmolality and Lactate Concentration in the Dog

Abstract

The purpose of this investigation was to determine the effects of an activated charcoal (AC) suspension containing propylene glycol and glycerol on serum osmolality, osmolal gap, and lactate concentration in dogs. Six healthy adult dogs were administered 4 g/kg AC in a commercially available suspension that contained propylene glycol and glycerol as vehicles. Blood samples were taken before and 1, 4, 6, 8, 12, and 24 hours after the administration of the test suspension. Samples were analyzed for osmolality, blood gases, and concentrations of lactate, sodium, potassium, serum urea nitrogen, and glucose. Osmolal gaps were calculated for each time point. Mean serum osmolality, osmolal gap, and lactate concentration were significantly increased after suspension administration compared to baseline. Serum osmolality increased from 311 mOsm/kg at baseline to 353 mOsm/kg, osmolal gap increased from 5 to 52 mOsm/kg, and lactate concentration increased from 1.9 to 4.5 mmol/L after suspension administration (all P < .01). Three of the 6 dogs vomited between 1 and 3 hours after the administration of the test suspension, and 4 of 6 dogs were lethargic. All dogs drank frequently after AC administration. Commercial AC suspension administered at a clinically relevant dose increases serum osmolality, osmolal gap, and lactate concentration in dogs. These laboratory measures and the clinical signs of vomiting, lethargy, and increased frequency of drinking might complicate the diagnosis or monitoring of some intoxications (such as ethylene glycol) in dogs that have previously received AC suspension containing propylene glycol, glycerol, or both as vehicles.

Use of the advanced micro‐osmometer model 3300 for determination of a normal osmolality and evaluation of different formulas for calculated osmolarity and osmole gap in adult dogs

“…The reference value for osmolality in the dog has been reported to be 301, 7 311, 8 309, 9 and 303 mOsm/kg 10 . These studies reported results as a pretreatment value before measuring the effects of another intervention on osmolality.…”

Approach to Drug Overdose

“…4 Samples were also evaluated for acid-base status and concentrations of sodium, potassium, blood urea nitrogen (BUN), and glucose. 4 Samples were also evaluated for acid-base status and concentrations of sodium, potassium, blood urea nitrogen (BUN), and glucose.…”

“…4 Samples were also evaluated for acid-base status and concentrations of sodium, potassium, blood urea nitrogen (BUN), and glucose. 4 All six dogs drank frequently after AC administration, but water intake or urine output was not recorded. 4 In this study, mean serum osmolality, osmolal gap, and lactate concentration were significantly increased after suspension administration compared with baseline, typically increasing at 1 hour after AC administration, peaking at 4 hours, and returning to baseline by 24 hours.…”

“…In this study, dogs (n = 6) were given 4 g/kg of AC and samples were taken before and 1, 4, 6, 8, 12, and 24 hours post-AC. 4 Although this study was important in evaluating complications from AC, this particular AC did not contain sorbitol or a cathartic (Actidose with Sorbitol). Hypernatremia was not detected in any of the study dogs; however, mild hypokalemia was seen (p < .05).…”

“…4 This raised the concern that the use of AC could confuse the diagnosis of intoxication of substances that can increase the osmolal gap such as ethylene glycol. A study evaluating a commercial AC, Actidose-Aqua, in healthy dogs reported increases in serum osmolality, osmolal gap, and lactate after administration.…”