How to flush a saline lock
Other platforms explain it with text and video. In Making Synapses you practice it on the patient.
Flushing keeps the line open and checks it works.
Step by step
Scrub the hub
Alcohol or chlorhexidine for 5 to 15 seconds, let dry. [1]
Use 10 mL syringe
Smaller syringes create higher pressure. [1]
Check
Gentle blood return if policy requires. [1]
Push-pause
Short pushes with pauses. [1]
Never force
Stop if resistance, pain or swelling. [1]
Clamp
Per the connector type (positive pressure). [1]
Common errors
- Not scrubbing the hub.
- Forcing.
- Small syringe.
Practice it in Making Synapses
In Making Synapses you do this on the patient, not on paper: every step goes on the checklist with a score, and in Teach mode Blocky tells you what comes next.
Making Synapses cases that train this skill
- Ectopic pregnancy
- Intussusception
- Sickle cell pain crisis
- Preeclampsia with magnesium toxicity
- Postpartum hemorrhage
- Pain after abdominal surgery
103 Making Synapses cases train this skill: open the case library
Sources
- Open RN, Nursing Skills 2e (Chippewa Valley Technical College) (CC BY 4.0)
- OpenStax, Clinical Nursing Skills (reference)
Steps adapted from Open RN, Nursing Skills 2e (Chippewa Valley Technical College), licensed under CC BY 4.0. Facts and steps also follow OpenStax, Clinical Nursing Skills (reference). Making Synapses is not affiliated with these organizations. Updated: 2026-10-11.