Table 1 The MeSH terms and keywords according to the modified PICO

Patient (children)

Child or infant or adolescent or pediatrics

Child or juvenile or infant or preschool child or school child or toddler or adolescent or newborn or pediatrics or pediatric emergency medicine

Child or infant or adolescent or pediatrics

Child or infant or adolescence or pediatrics

Child or adolescent or infant or pediatrics

Only key word

Infant* or newborn* or child* or "preschool child*" or juvenile* or preschool* or adolescent* or pediatric* or paediatric* or "young people" or "young person"

AND

AND

AND

AND

AND

AND

AND

Population (prehospital)

Ambulances or emergency medical services or advanced trauma life support care or transportation of patients or emergency medicine or emergency responders or emergency medical technicians or emergency nursing

Ambulance or emergency health service or rescue personnel or emergency nursing or emergency medicine or pediatric emergency medicine

Emergency medical services or emergency medicine or emergency medical technicians

Prehospital care or emergency medical services or transportation of patients or ambulances or emergency medicine or emergency medical technicians

Emergency medical services or ambulances or emergency medicine or emergency medical technicians or emergency nursing

Only key word

Ambulance* or "transportation of patient*" or "emergency service*" or "emergency medical service*" or ems or "emergency health service*" or "prehospital care" or prehospital* or pre-hospital* or "out of hospital" or "out of hospital care" or "emergency medicine" or "pediatric emergency medicine" or "paediatric emergency medicine" or "emergency responder*" or "first responder*" or "emergency medical technician*" or "emergency technician*" or "emergency practitioner*" or " emergency medical practitioner*" or "emergency care practitioner*" or emt or "rescue personnel*" or "emergency nurse*" or paramedic*

AND

AND

AND

AND

AND

AND

AND

Intervention (pharmacologic pain management) or Outcome (pain reduction/ adverse event)

Analgesia or analgesics or nerve block or fentanyl or ketamine or morphine or acetaminophen or drug administration routes or pain measurement

Analgesia or analgesic agent or nerve block or fentanyl or ketamine or morphine or paracetamol or drug administration route or pain measurement or numeric rating scale or pain assessment

Pain management or analgesia or analgesics or nerve block or fentanyl or ketamine or morphine or acetaminophen or drug administration routes or pain measurement

Pain management or analgesia or analgesics or nerve block or acetaminophen or drug administration routes or pain measurement

Pain management or analgesia or analgesics or nerve block or fentanyl or ketamine or morphine or acetaminophen or drug administration routes or pain measurement

Only key word

"Pain management*" or "pain treatment*" or "pain intervention*" or analgesi* or analgaesi* or "analgetic agent*" or "analgesic drug*" or anodynes or antinociceptive or nsaids or paracetamol or ketamine or fentanyl or "nitrose oxide" or methoyloxine or morphine or opoid or non-opoid or narcotics or non-narcotics or "regional nerve block*" or "per oral" or peroral or intravanous or "intra venous" or iv or intramuscular or "intra muscular" or "intra nasal" or intranasal or inhalational or "pain reduction" or "pain relief" or oligoanalgesia or "pain intensity" or "pain assessment" or "pain measurement" or effectiveness or "effect management" or "side effect*" or "adverse effect*" or "adverse event*"

Limit

Publication year (the past 20 years from 2000 to 2020), language (English, Danish, Norwegian, and Swedish)