Hair analysis is a well-established and important tool in both forensic and clinical context. When it comes to the interpretation of positive hair analysis results, reliable and comprehensive reference data is essential. Such data on opioids, especially novel synthetic ones (such as fentanyl and its analogues (fentalogs)) is currently highly limited. This applies especially to hair with pediatric origin, due to differences in the metabolism and hair anatomy in children compared to adults.

Investigators hypothesize that opioids, both traditional and novel synthetic ones exhibit detectable concentrations and distinct metabolite ratios within the hair matrices of pediatric patients. Thus, this observational, prospective research study provides 150 hair and sweat samples from children who received opioids as part of surgery or pain management. The samples will be consecutively extracted and analyzed using a sensitive targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, enabling the quantitative determination of the opioid and metabolite concentrations. The study thereby contributes valuable reference data for both forensic and clinical applications, addressing challenges in interpreting hair analysis results in especially pediatric populations. Further, a deeper understanding of the mechanisms (e.g. via sweat) and pharmacokinetic processes involved in the opioid incorporation to hair will be achieved. The study has received ethical approval from the Swiss Ethics Board (approval number: 2022-01693 / amendment approval date: 09.01.2024).

Inclusion Criteria:

• Obtained written informed-consent from legal representatives (and oral consent from the patient).
• Patient's age must be within date of birth irrespective of gestational age to completed 13th year of life
• Patients that received single or multiple treatment (either with single doses or continuous infusion) of fentanyl, remifentanil or sufentanil either during surgery or during stay in the pediatric intensive care unit

Exclusion Criteria:

• Patient's age of 14 or older
• Inability to understand the study procedure due to language or cognitive reasons (applies to legal representatives and elder children)
• Denied or missing informed consent
• Insufficient amount of head hair to obtain hair sample
• Cosmetic hair treatment, like coloring, bleaching and dying

The study population consists of patients (newborns, infants, children and adolescents up to 13 years of age) from the pediatric intensive care unit from the Children's Hospital Zurich. Patients in focus are exposed to fentanyl and fentalogs (remifentanil, sufentanil and alfentanil) or other more traditional opioids (such as morphine, oxycodone and methadone) either during surgery or as part of post-operative pain management for up to three months prior to study inclusion.

The outcomes of the research will be published in peer-reviewed journals. Data will be strictly anonymized.

starting after publication

upon request via e-mail