The RAMER Reviews: Pediatric Edible Ingestion
Written by: John Lin, MD; Edited by: Timothy Khowong, MD, MSEd
Background:
Since the legalization of marijuana in the United States, there has also been an increase in THC edible ingestions, especially in the pediatric population. Pepin et al recently published a study in September 2023 in the Journal of Pediatrics looking at these trends (Figure 1). They aim to study the effects of tetrahydrocannabinol (THC) in the pediatric population and to discern a dose-dependent effect of THC toxicity in terms of severity and duration.
The Study:
The authors performed retrospective chart review looking at ingested doses of THC in children less than 6 years old from January 1, 2015 to October 25, 2022 . The patient population was from the Colorado health care system. Children who had witnessed ingestions, positive urine drug screen, regional poison control documentations, and associated ICD10 codes with known THC dose were included. In cases where doses were unknown or not documented or non-edible intoxication / medical prescriptions were excluded. Ultimately they had about 80 children (n), equal numbers of males and females, with an average age of 2.9 years old (Table1). The results were both qualitative and quantitative: qualitative descriptions of symptoms at a weight-based dose increment were described while quantitative statistical analysis helped determine toxicity weight-based threshold.
Results Summary:
For the qualitative results, the authors described symptom progression in different weight based increments (<1 mg/kg, 1-2 mg/kg, 2-4 mg/kg, >4-6 mg/kg, 6 mg/kg). The symptoms were summarized in Table 2 and severity of symptoms were described as critical neuro, cardiovascular, or pulmonary manifestations. Generally reviewing the trends, one can recognize an increase in the percentages of patients with higher dose exposure (e.g. more patients were lethargic, requiring painful stimuli to get a response; more patients required O2 supplement).
For the quantitative analysis, the authors were able to demonstrate with statistical significance that between severe and prolonged toxicity at higher weight-based doses than in absence of severe toxicity or prolonged duration. Table 3A and 3B provides a summary with P value < 0.0001. The median mg/kg dose of severe toxicity was 5.4 (IQR 3.2-8.2) while absence of toxicity was 0.9 mg/kg (IQR 0.6-1.9). The median mg/kg dose of prolonged toxicity was 3.7(IQR 1.7-5.7) while absence of toxicity was 0.7 mg/kg (IQR 0.5-1.4). They also highlighted the median duration of symptoms. Finally, in Figure 2, the authors also plotted a Receiver Operating Characteristic Curve with Area Under the Curve analysis to provide a weight-based threshold for severity and prolonged toxicity with their respective sensitivity and specificity. Sensitivity and specificity were maximized at a dose of 2.3 mg/kg of THC with a sensitivity of 89.2% and specificity of 86.1%. Sensitivity and specificity were maximized at a dose of 1.7 mg/kg of THC with a sensitivity of 75.4% and specificity of 90%.
Strengths and Weaknesses:
The study provides a lot of detail in terms of how to manage a pediatric THC ingestion. Given that randomized controlled trials would be difficult to perform, this paper provides insight into the clinical course such as severity and duration of symptoms at a measured mg/kg dose. The authors selected patients with known dose ingestions and also mentioned how the state laws require proper labeling on the packages to ensure the dose. They were not only able to provide a table with qualitative results, but also provided statistically significant results to determine a threshold for THC toxicity. This can help guide emergency room management. Kids who ingest less than 1.7 mg/kg may not experience severe and prolonged toxicity and an observation of 6 hours may suffice while higher doses may warrant an admission. During the observation, Table 2 offers the key symptoms to watch out for as higher doses may have neurological or cardiopulmonary compromise.
On the other hand the study also has weaknesses. It is hard to replicate such a study as marijuana laws are different and the amount of THC in edibles is not regulated. The study population also only has kids less than 6 years old, which may not be generalizable to adolescents or adults. Finally, this is a retrospective chart review which is subject to recall bias. Information is only as accurate as it originally documented.
Conclusion:
The THC dose of edible cannabis correlates to the degree of toxicity in children <6 years old. The threshold of 1.7 mg/kg of THC may guide medical management and preventive regulations.