CHAPTER 28 Toxicologic Considerations in the Young Patient*
Relevant Physiologic Differences in Pediatric Patients Relative to Adults
TABLE 28-1 Altered xenobiotic disposition in pediatric patients
Alteration | Impact |
---|---|
Increased intestinal permeability | Increased oral uptake, toxic plasma concentrations |
Increased gastric pH | Increased oral uptake of weak bases and acid-labile compounds, prolonged and elevated plasma levels, toxic plasma concentrations |
Altered peristalsis (decreased gastric emptying time) | Decreased absorption, lower plasma levels of toxin |
Decreased plasma proteins | Toxin may accumulate, leading to more unbound compound and thus a potentially longer half-life |
Decreased body fat | Increased plasma levels; decreased accumulation of lipid-soluble toxins |
Increased total body water (more extracellular fluid) | Decreased plasma concentrations, longer half-life |
Increased uptake of volatile gases | High plasma concentrations, increased response and toxicity |
Increased dermal absorption | Higher or prolonged plasma exposure levels, toxicity increased |
Immature P-glycoprotein system | Poor ability to clear toxins with this system |
Management of Toxicosis
Toxicologic History
There is an art to acquiring a good toxicologic history. If the history is to provide any type of working diagnosis, the veterinarian’s interview must be meticulous, caring, and thorough in scope. The veterinarian must be a calming influence if a reliable account of events is to be obtained. Specific criteria characteristic of a toxicologic history include what poison or poisons are involved, when the exposure occurred, how much poison the animal was exposed to, and the route of the exposure It is particularly relevant to inquire about the entire litter, particularly if they are still together. Additionally, what is the mother’s condition and is there a possibility that she has been exposed to a compound that could be a problem for her offspring (regardless of whether she is exhibiting clinical signs of toxicosis)? Obtaining packaging containers for known exposures is significant in identifying the compounds involved and quality available to be ingested. Some aids in obtaining an organized history are outlined in Boxes 28-1 and 28-2.