Q4h
Formal Definition
Every four hours (quaque 4 hora): a dosing or monitoring frequency indicating that a medication, vital sign check, neuro exam, or other assessment should occur once every four hours.
How It's Used on the Ward
"Vitals q4h" or "neuro checks q4h" — one of the standard nursing frequency orders for stable but monitored patients.
Example
""Post-op thyroidectomy: neuro checks and neck circumference q4h for the first 24 hours — watching for hematoma formation causing airway compression.""
Clinical Context
Common nursing frequencies: q1h (ICU, unstable), q2h (turn schedule for pressure ulcer prevention), q4h (stable monitored), q6h, q8h, q12h, qd (daily). Vital sign frequency drives nursing workflow and patient sleep disruption — a patient on q2h vitals overnight cannot sleep. Order the appropriate frequency: not everything needs to be q4h. Ask yourself: how often do I actually need this data?