ePCR Entonox Gas Therapy

Overview#

Entonox (50% nitrous oxide and 50% oxygen) is an inhaled analgesic gas that ambulance crews record as self-administered therapy. Treating it like a vialled drug with a milligram dose leads crews into the wrong form, skips the clinical safety questions that apply to the gas, and leaves pain scores scattered across narrative notes.

The ePCR Entonox Gas Therapy module gives crews a dedicated Entonox path on the interventions workspace. The gas is recorded without a dose in milligrams, micrograms or millilitres, without a vial scan and without a patient weight. Before the record can be saved, the crew completes a structured contraindication screen that covers every published PHECC Entonox contraindication plus a short set of additional trapped-gas checks. Pain scores from the Entonox record are written into the Pain Scale on Clinical Assessment, while times, self-administration and effect stay in Narrative Notes.

Last Reviewed: 2026-11-09 Last Updated: 2026-11-09

Key Features#

• Dose-Free Gas Recording: Entonox is recorded as an inhaled gas. The form hides vial scan controls and never sends a patient weight, even when the encounter already has a weight on file.
• Dedicated Entonox Path: Entonox is recognised by its own formulary code. Only that code opens the Entonox screen.
• Structured Contraindication Screen: The crew answers every question as explicit Yes or No with nothing pre-selected. A new or cancelled form starts blank. Unanswered questions are omitted from the safety check so the platform blocks until each one is answered.
• Full PHECC Entonox Coverage: The screen covers the published PHECC Medication Formulary contraindications for nitrous oxide 50% and oxygen 50%: impaired consciousness or intoxication, chest injury or pneumothorax (known or suspected, including an open chest wound), shock, recent scuba dive or decompression sickness, bowel obstruction, inhalation injury, carbon monoxide poisoning, known severe adverse reaction, and inability to understand instructions, self-administer or cooperate.
• Additional Trapped-Gas Checks: The same screen covers head injury with impaired consciousness, maxillofacial injuries, recent intraocular gas, air embolism, and other conditions where trapped gas is dangerous.
• Server-Side Formulary Safety Check: Answers are screened by the platform formulary safety check. When blocked, the reason prompt lists what was answered Yes and what was left blank. Answers lock while the check runs and stay tied to its result.
• Fail-Safe When Screening Cannot Run: Any reply without a valid screen (offline, timeout, error or an older server) is treated as not verified and needs a recorded reason. When the check cannot run, the reason-required prompt shows the nine PHECC contraindications as a read-only reference list.
• Pain Score Routing: Entonox messages send pain scores to the Pain Scale in Clinical Assessment. Administration times, self-administration and effect remain in Narrative Notes so assessment scores stay with assessment data.
• Override Audit: When policy allows an override, the saved record and override reason carry the present and unanswered contraindication keys for clinical governance review.

Use Cases#

• On-Scene Analgesia with a Clear Screen: A paramedic selects Entonox for a conscious adult with an isolated limb injury, answers every contraindication question No, passes the formulary safety check, and records the gas without inventing a milligram dose.
• Blocked by an Unanswered Question: A crew member leaves one question blank. The platform blocks Entonox, names the unanswered item, and refuses to save until the screen is complete.
• Blocked by a Present Contraindication: The crew answers Yes to known or suspected pneumothorax. The block lists that condition, and any override that policy allows must carry a recorded reason.
• Pain Scores Stay with Assessment: After Entonox is given, the patient's pain scores appear on the Pain Scale used for clinical assessment, ready for handover and audit.
• Offline or Unreachable Safety Service: Connectivity drops during the check. The record is marked not verified, the crew must give a reason, and the PHECC contraindication list is shown for reference until the check can run again.

Integration#

• Electronic Patient Care Report Clinical Workspace: Entonox is opened from the Interventions path alongside oxygen therapy and other interventions.
• Clinical Decision Support: The formulary safety check applies credential, endorsement and clinical practice guideline rules together with the Entonox contraindication screen.
• Oxygen Therapy Recording: Oxygen therapy stays on its own flow-and-device form. Entonox uses the gas medication path so the two therapies remain distinct on the encounter.
• Mobile Responder Workflows: Field crews complete the same Entonox screen on the responder mobile app, including localised wording for supported languages.
• Immutable Audit Trail: Screen answers, blocks, overrides and the saved gas record are written to the encounter audit trail.

Open Standards#

• PHECC Medication Formulary: contraindication wording follows the published PHECC Entonox (nitrous oxide 50% and oxygen 50%) entries used by Irish pre-hospital practice.
• HL7 FHIR R4 MedicationAdministration: the saved gas record can align with a standard medication administration resource where downstream systems expect one, with dose omitted for this inhaled gas.
• SNOMED CT: clinical conditions named on the screen can align with structured terminology where the tenant maps them.
• ISO 8601: administration and screening timestamps use a standard date-time representation.