Subcutaneous Infusion (Hypodermoclysis): What to Expect

Most people are familiar with IV lines that go into veins. But for some patients — particularly those in palliative care, hospice, older adults with difficult venous access, or patients needing gentle hydration at home — there is another option: subcutaneous infusion, also called hypodermoclysis.

In subcutaneous infusion, fluids or medications are delivered under the skin (into the subcutaneous tissue — the layer of fat and connective tissue beneath the skin surface) rather than directly into a blood vessel. The body then absorbs the fluid or medication gradually from the tissue into circulation.

Who Is Subcutaneous Infusion For?

Subcutaneous infusion is particularly useful when:

• Venous access is difficult or impossible. In older adults, patients with extensive prior IV use, or those with fragile veins, finding a usable vein is painful and often unsuccessful. Subcutaneous tissue is accessible almost anywhere on the body.
• Long-term IV access (PICC, port, central line) is not appropriate. When a patient’s overall condition or goals of care make the burden of a central catheter unacceptable, subcutaneous access is far simpler.
• Gentle hydration is needed at home or in hospice. Subcutaneous fluid delivery can maintain comfort and prevent dehydration without the complexity of intravenous hydration.
• Regular symptom-control medications are needed without repeated injections. A small needle under the skin can stay in place for days, providing a route for pain medication, anti-nausea drugs, and other comfort medications without repeated needle sticks.
• The patient or caregiver can manage at home. Subcutaneous infusion setups are simple enough to be managed in home, hospice, or nursing home settings with basic training.

Common clinical situations where subcutaneous infusion is used:

• Palliative care and hospice — symptom management and comfort hydration
• Older adults with dehydration who have poor venous access
• Pediatric patients requiring hydration when IV access is difficult
• Post-surgical patients with nausea preventing adequate oral intake and difficult veins
• Patients on chronic subcutaneous medications (such as some chemotherapy agents, teriparatide, or biologic agents administered subcutaneously)

What Can Be Given Subcutaneously?

Not all IV medications can be given subcutaneously — some would cause tissue irritation or damage, and some are absorbed too slowly or erratically this way. The following are commonly given via subcutaneous infusion:

Fluids for hydration

• Normal saline (0.9% sodium chloride)
• 0.45% sodium chloride (half-normal saline)
• 5% dextrose in water (D5W) — used in some protocols
• With or without added electrolytes (potassium, magnesium) at low concentrations

Rates are slower than IV hydration (typically 60–120 mL/hour maximum at a single site), but adequate for maintenance hydration or gentle rehydration.

Medications — commonly used

• Morphine and hydromorphone — for pain management
• Haloperidol — for nausea and agitation
• Midazolam — for anxiety and seizure control
• Metoclopramide — for nausea
• Hyoscine butylbromide (buscopan) — for secretion management
• Dexamethasone — for inflammation, nausea, and other indications
• Furosemide — for fluid management in some protocols

Your care team will confirm which medications are appropriate for subcutaneous delivery in your specific situation. Not all formulations of a given drug are suitable — concentration and pH matter.

What cannot be given subcutaneously

• Concentrated potassium — causes tissue damage
• Chemotherapy drugs that vesicants (cause blistering/necrosis if outside a vein) — must be given IV
• Blood products — cannot be given subcutaneously
• Medications that require rapid peak levels — absorption is too slow
• Some antibiotics (limited by irritancy and required concentrations)

The Equipment: What a Subcutaneous Infusion Setup Looks Like

A subcutaneous infusion requires minimal equipment:

The needle or cannula: A small, fine needle (often called a butterfly needle or Teflon cannula) is inserted at a shallow angle (typically 45 degrees) into subcutaneous tissue. The needle is very short — typically 24–27 gauge (thinner than most standard IV needles). Some setups use a soft plastic cannula rather than a metal needle, which is more comfortable for extended use.

Securing the device: The needle or cannula is secured with a transparent dressing (similar to a PICC dressing), taped gently to keep it from moving.

The tubing and pump: Extension tubing connects the needle to a syringe driver (a small electronic device that delivers medication at a controlled rate), a portable infusion pump, or a gravity infusion set for fluids.

Syringe drivers: In palliative care, a syringe driver or continuous subcutaneous infusion (CSCI) device is commonly used to deliver one or more medications continuously over 24 hours from a small syringe. This allows multiple symptom-control medications to be mixed and given together around the clock.

Where Is the Site?

Subcutaneous needles can be placed at multiple body locations. The most common sites:

How long does a site last?

A single subcutaneous infusion site can typically remain in place for 48–72 hours before being changed. Sites should be changed sooner if:

• Redness, swelling, or firmness develops at the site
• The patient reports increasing discomfort or a burning sensation
• Fluid is leaking back along the needle track
• The needle appears dislodged

Multiple sites can be used if continuous infusion is needed long-term, rotating between them to allow recovery.

What the Procedure Feels Like

Insertion

• A brief sting or sharp sensation as the needle goes in — similar to a blood draw but typically milder because the needle is finer and the angle is more superficial
• Most patients tolerate insertion well; topical anesthetic cream can be applied 45–60 minutes beforehand if desired

During infusion

• Fluids infusing subcutaneously may cause a noticeable lump (swelling) at the infusion site — this is expected and is the fluid collecting in the subcutaneous tissue before being absorbed. It is soft and usually not painful.
• Mild warmth or fullness at the site — normal
• Faster infusion rates or more irritating solutions may cause discomfort — tell your nurse if the site becomes painful

At the end of a session or site change

• Needle removal is quick and typically painless
• The small puncture closes immediately; a small adhesive bandage may be applied

Site Care: What You Do at Home

If you are managing subcutaneous infusion at home (or your caregiver is managing it), site care is straightforward:

Daily checks

• Inspect the site around the dressing each day: look for redness, swelling beyond the expected small lump of fluid, hardness, or warmth
• If the site looks inflamed, discolored, or feels painful, the site needs to be changed — call your nurse

Keeping the site secure

• Avoid tension or pulling on the tubing; coil and tape excess tubing near the site
• When moving or repositioning, keep the syringe driver or pump at the same level as the site to avoid accidental needle movement
• Do not submerge the site in water (bathtub, swimming) — keep it covered and protected during showering with a waterproof cover if your nurse advises

Site changes

• Sites are changed by your nurse or specifically trained caregiver every 48–72 hours or sooner if needed
• A new site is selected with each change, rotating systematically around available sites

Advantages and Limitations

Advantages over IV access

• No need for venous access — avoids the difficulty, pain, and risk of repeated IV insertions
• Simpler to maintain — no flushing protocols, no locked needleless connectors, no dressing changes as complex as PICC care
• Lower infection risk — subcutaneous tissue infection risk is much lower than bloodstream infection risk from a central catheter
• Manageable at home — patients, families, and community nurses can learn to manage subcutaneous infusion with basic training
• Comfortable — many patients find subcutaneous needles less obtrusive than IV lines

Limitations compared to IV access

• Slower absorption — subcutaneous medication absorption is slower and less predictable than direct IV delivery; not suitable when rapid drug effects are required
• Volume limits — maximum infusion rates are lower than IV (typically 1 mL/minute maximum; 60–120 mL/hour for hydration)
• Not all medications are compatible — more restricted formulary than IV
• Site reactions — some medications cause more local irritation than others; the site may swell, become uncomfortable, or need more frequent changes
• Not for emergencies — subcutaneous infusion cannot replace IV access in acute emergencies

Subcutaneous Infusion in Palliative and Hospice Care

Subcutaneous infusion is particularly well-suited to the palliative and hospice setting, where:

• Comfort, not cure, is the goal. The simplicity and comfort of subcutaneous access aligns with the goals of care.
• Home care is preferred. Most people prefer to die at home or in a familiar setting. Subcutaneous infusion allows medications for pain, breathlessness, nausea, and restlessness to be given continuously at home without hospitalization.
• Venous access may be failing. As patients near the end of life, peripheral veins often become impossible to cannulate. Subcutaneous access remains available.
• Round-the-clock symptom control. A continuous subcutaneous infusion (CSCI) via a syringe driver provides steady medication levels throughout the day and night, preventing peaks and troughs in symptom control.

If you are in a palliative or hospice setting and have questions about whether subcutaneous infusion is appropriate for your situation, ask your palliative care nurse or physician.

Talking with Your Care Team

Questions worth asking:

• Is subcutaneous infusion appropriate for my situation?
• Which medications or fluids would be given this way?
• How will the site be monitored and by whom?
• Who do I call if the site looks wrong or the infusion seems to stop?
• Can I or my caregiver learn to change the site?
• How does this fit with my overall goals of care?

Related Guides in This Series

• Vascular Access and Goals of Care
• Living Well with Long-Term IV Therapy
• Mental Health and Emotional Adjustment During IV Therapy
• Keeping Your IV Safe: Infection Prevention
• Recognizing Complications: When to Call for Help

This guide is for educational purposes. Subcutaneous infusion protocols, compatible medications, and site management vary by institution and individual patient situation. Always follow the guidance of your palliative care team, home infusion nurse, or hospice nurse.