Subcutaneous Infusion and Access Devices

Purpose and Scope

This guideline establishes evidence-based standards for subcutaneous infusion therapy, including hypodermoclysis and medication administration. It is intended for use by clinical professionals across acute care, ambulatory, and home care settings. The subcutaneous route represents a valuable alternative to intravenous access and should be integrated into comprehensive vessel health and preservation strategies.

1. Patient Assessment and Selection Criteria

1.1 Fundamental Standards

Prior to initiating subcutaneous infusion therapy, clinicians must conduct a comprehensive patient assessment addressing three key domains: compatibility of the prescribed medication or solution with subcutaneous delivery, the patient’s overall clinical status and treatment goals, and verification of adequate subcutaneous tissue depth at potential infusion sites.

1.2 Tissue Assessment Requirements

Appropriate candidates for subcutaneous infusion should demonstrate intact skin integrity and subcutaneous tissue depth of approximately 1.0 to 2.5 centimeters at the intended infusion site. Clinical evaluation should include inspection and palpation to confirm tissue adequacy before device placement.

2. Hypodermoclysis for Fluid Replacement

2.1 Clinical Indications

Subcutaneous administration of isotonic fluids — commonly termed hypodermoclysis — is an established intervention for treating mild-to-moderate dehydration in adult and pediatric populations. This approach is particularly valuable when oral hydration is not feasible and venous access presents challenges. Published evidence demonstrates favorable outcomes across multiple domains including clinical effectiveness, patient safety, acceptability, and resource efficiency.

The technique offers several practical advantages over intravenous hydration. Subcutaneous access is typically easier to establish and maintain, requires less technical expertise, and demonstrates cost-effectiveness. Patient satisfaction rates are generally high, particularly in palliative care and geriatric populations. For home-based care, hypodermoclysis can be safely administered by trained caregivers with minimal equipment requirements and technical support infrastructure.

2.2 Contraindications

Clinicians must avoid hypodermoclysis in patients presenting with severe dehydration requiring rapid volume replacement, severe malnutrition with inadequate subcutaneous tissue, significant electrolyte disturbances requiring precise correction, decreased tissue perfusion states, compromised skin integrity or active skin infection at potential sites, bleeding disorders or coagulation abnormalities, and generalized edema that would impair fluid absorption.

2.3 Local Site Reactions

Anticipated local reactions include transient swelling at the infusion site, localized erythema, and discomfort during needle insertion. These reactions are typically self-limiting and can be minimized through careful attention to infusion rate regulation and proper needle placement technique.

2.4 Infusion Rate Parameters

Evidence from clinical studies demonstrates considerable variation in appropriate infusion rates based on patient population:

Adult Patients: Infusion rates ranging from 5 to 167 mL per hour have been reported as safe and effective. Alternatively, bolus administration of 500 mL delivered over 2 to 6 hours may be employed based on clinical circumstances.

Pediatric Patients: Weight-based dosing at approximately 15.4 mL per kilogram per hour has demonstrated safety and efficacy in published trials.

Palliative Care Settings: Infusion rates of 42 to 72 mL per hour are commonly utilized for symptom management in end-of-life care.

3. Subcutaneous Medication Administration

3.1 Pharmaceutical Characteristics for Subcutaneous Delivery

Medications demonstrating optimal characteristics for subcutaneous administration share several pharmacological properties: high aqueous solubility, neutral pH values, low viscosity formulations, and relatively low molecular weight. These properties facilitate absorption from subcutaneous tissue while minimizing local irritation.

Systematic review evidence supports strong safety and efficacy profiles for ten medication categories delivered via subcutaneous infusion:

Opioid Analgesics: Hydromorphone, morphine, and ketamine demonstrate reliable subcutaneous absorption and predictable pharmacokinetics through this route.

Antimicrobial Agents: Ceftriaxone and ertapenem possess pharmacological profiles suitable for subcutaneous delivery, including longer half-lives that support once-daily or twice-daily dosing regimens.

Other Agents: Hydrocortisone, trastuzumab, immunoglobulin preparations, treprostinil, and deferoxamine have established evidence supporting subcutaneous administration.

3.2 Antimicrobial Therapy Considerations

Antibiotics selected for subcutaneous administration should possess longer serum half-lives that support practical dosing intervals, demonstrate good absorption characteristics from subcutaneous tissue, and exhibit acceptable local tolerability. Ceftriaxone and ertapenem meet these criteria and have been successfully used in outpatient subcutaneous antimicrobial therapy programs. Documented adverse events associated with subcutaneous antibiotic delivery include localized pain, hematoma formation, tissue induration, and erythema at the infusion site.

3.3 Diuretic Therapy

Systematic review evidence indicates that subcutaneous diuretic administration achieves comparable symptom relief to intravenous delivery in heart failure management, with a low incidence of adverse effects. A subcutaneous furosemide formulation received regulatory approval in 2022, specifically designed to facilitate home-based treatment of volume overload in heart failure patients. This represents an important option for disease management outside acute care settings.

3.4 Infusion Rate Guidelines for Medications

For most subcutaneous medication infusions, rates should not exceed 5 mL per hour unless the manufacturer’s prescribing information specifically recommends higher rates. Subcutaneous immunoglobulin preparations represent a notable exception, as these products are formulated and approved for higher-volume infusion rates as specified in product labeling.

4. Adjunctive Use of Hyaluronidase

Recombinant human hyaluronidase may be considered as an adjunct for both adult and pediatric patients to enhance subcutaneous hydration therapy and facilitate absorption of compatible medications. This enzyme temporarily increases tissue permeability by depolymerizing hyaluronic acid in the interstitial matrix, thereby improving dispersion and absorption of the infusate.

Before administering any medication with hyaluronidase, clinicians must consult current pharmaceutical references to verify stability and compatibility. Not all medications maintain chemical and physical stability when combined with hyaluronidase, and incompatibility may compromise therapeutic efficacy or patient safety.

5. Continuous Subcutaneous Insulin Infusion

5.1 Overview

Continuous subcutaneous insulin infusion via external insulin pump devices represents standard therapy for many patients with diabetes mellitus. Healthcare organizations must establish clear policies and procedures addressing safe management of these devices across all care settings, including during hospitalization.

5.2 Inpatient Management Principles

Healthcare facilities should implement structured processes to assess whether individual patients are appropriate candidates for self-management of their insulin pump therapy during hospitalization. Patients who routinely manage their diabetes with pump therapy often possess detailed knowledge of their individual glucose patterns, insulin sensitivity factors, and correction algorithms that may exceed what can be readily determined by inpatient clinical staff unfamiliar with the patient’s baseline management.

However, hospitalized patients require appropriate supervision and support to ensure safe insulin dose adjustments in the acute care environment. Multiple factors common during hospitalization — including active infection, administration of corticosteroids or other glucose-altering medications, reduced mobility, variations in nutritional intake, and acute illness states — can significantly alter insulin sensitivity and glycemic response. Clinical protocols should balance patient autonomy and expertise with appropriate oversight to maintain glycemic safety.

6. Site Selection and Preparation

6.1 Anatomical Site Considerations

Selection of the subcutaneous infusion site should incorporate patient comfort preferences, impact on mobility and daily activities, and individual site preferences when clinically appropriate. Anatomical regions suitable for subcutaneous infusion include the abdomen (maintaining a minimum distance of four finger-widths from the umbilicus), anterior chest wall, anterior and lateral aspects of the upper extremities, flank regions, hips, and anterior thighs. Drug manufacturers may specify preferred or required sites for particular products, and these recommendations should be followed.

6.2 Sites to Avoid

Clinicians must avoid placing subcutaneous access devices in proximity to bony prominences, over or adjacent to joints, near previous surgical incisions, in areas that have received radiation therapy, over damaged or compromised skin, over the intercostal spaces in cachectic patients (due to elevated pneumothorax risk with minimal subcutaneous tissue), on the affected side following mastectomy, over or near tumor sites, in areas of ascites or lymphedema, on the inner thigh when an indwelling urinary catheter is present, and on the thigh in patients with peripheral vascular insufficiency.

6.3 Aseptic Technique and Skin Antisepsis

All subcutaneous access device insertions and subsequent infusion procedures must adhere to established aseptic technique principles. Appropriate skin antisepsis using approved antiseptic agents must be performed prior to device insertion to reduce microbial colonization and infection risk.

7. Device Selection and Insertion

7.1 Recommended Device Specifications

For subcutaneous infusions, clinicians should select small-gauge devices — typically 24- to 27-gauge — with short cannula length appropriate for the patient’s tissue depth. Non-metal (soft) cannulas with integrated luer-lock connections are preferred for infusion therapy due to reduced risk of tissue trauma during extended dwell times.

Metal-winged (butterfly) needles are not recommended for subcutaneous infusions due to increased risk of tissue injury and infiltration. However, specialized subcutaneous needles designed and labeled for high flow rates may be indicated when required by specific drug manufacturer recommendations.

7.2 Multiple Site Utilization

For high-volume hydration requirements, two or more simultaneous infusion sites may be established. Each individual site can accommodate up to approximately one liter of isotonic fluid per day, allowing total daily volumes of two liters or more when multiple sites are utilized.

7.3 Blood Return Management

If blood return is observed during device placement, the device should be removed and discarded. A new device must be inserted at an alternative anatomical site to ensure proper subcutaneous positioning and avoid intravascular administration.

For subcutaneous immunoglobulin therapy specifically, manufacturer guidance regarding blood return assessment varies among products. Given the low likelihood of cannulating a significant blood vessel during subcutaneous access and the relatively low risk profile of immunoglobulin products, some manufacturers do not mandate aspiration for blood return prior to each infusion.

8. Site Dressing and Maintenance

8.1 Dressing Application

A transparent semipermeable membrane dressing should be applied over the subcutaneous access site following device insertion. Transparent dressings allow continuous visual assessment of the site for early detection of complications including erythema, swelling, or leakage.

8.2 Dressing Changes

The dressing should be replaced each time the subcutaneous site is rotated to a new location. Additionally, immediate dressing change is required whenever dressing integrity becomes compromised — including edge lifting, moisture accumulation, soiling, or loss of occlusive seal.

9. Site Assessment and Rotation

9.1 Assessment Parameters

Regular assessment of the subcutaneous access site is essential throughout therapy. Clinicians should evaluate for signs and symptoms indicating the need for site rotation, including localized erythema, abnormal swelling not attributable to the infusion itself, fluid leakage from the insertion site, local bleeding or bruising, burning sensation, abscess formation, or patient-reported pain.

9.2 Rotation Intervals by Therapy Type

Hydration Solutions: Published evidence supports site dwell times of 24 to 48 hours for hypodermoclysis, or site rotation after 1.5 to 2.0 liters of solution have infused through a single site — whichever occurs first.

Continuous Medication Infusions: Sites may be maintained for 2 to 7 days when delivering continuous medication infusions, provided regular assessment demonstrates no complications.

Intermittent Infusions: For intermittent therapies such as subcutaneous immunoglobulin, the site should be changed with each infusion session.

9.3 Managing Immunoglobulin Site Reactions

Local site reactions are common during subcutaneous immunoglobulin therapy, particularly during initial treatment. Typical reactions include localized swelling, erythema, discomfort, and pruritus at infusion sites. These reactions characteristically decrease in frequency and severity over subsequent infusion cycles as patients develop tolerance.

For patients experiencing persistent or problematic site reactions, clinical interventions include reducing the infusion rate, decreasing the volume administered per site, utilizing longer needle lengths to ensure appropriate tissue depth, or changing to an alternative anatomical site.

10. Flow Rate Regulation

10.1 Delivery Systems for Hypodermoclysis

Multiple delivery systems have demonstrated safety and efficacy for subcutaneous hydration therapy. Gravity-based infusion sets offer simplicity and may provide inherent safety advantages, as the infusion rate naturally decreases when tissue pressure increases from fluid accumulation — potentially reducing the risk of localized edema. Electronic infusion pumps provide precise rate control when consistent delivery is required.

10.2 Delivery Systems for Medication Infusions

Medication infusions may be administered via mechanical infusion devices (including elastomeric pumps) or electronic infusion pumps depending on clinical requirements and care setting. Contemporary “on-body” delivery systems represent an emerging technology category — these devices incorporate miniaturized pump mechanisms within an adhesive housing that attaches directly to the patient’s skin and delivers programmed subcutaneous doses without external tubing or traditional infusion sets.

11. Ongoing Monitoring

Continuous monitoring of both the patient’s clinical status and the subcutaneous access site is required throughout therapy. Assessment frequency should be determined by the patient’s condition, the infusion being administered, and the care setting. Monitoring parameters include site integrity, infusion progress, patient comfort, and early recognition of local or systemic complications.

12. Patient and Caregiver Education

12.1 Essential Education Topics

Comprehensive education must address recognition of access site complications including signs and symptoms of infection, infiltration, or adverse reactions. Patients and caregivers must understand the appropriate process and contact information for reporting complications to healthcare providers.

12.2 Activity and Site Protection

Education should include guidance on activity modifications necessary to protect the subcutaneous access device, appropriate measures to maintain dressing integrity, and any specific precautions relevant to the prescribed therapy.

References

American Diabetes Association Professional Practice Committee. Diabetes technology: Standards of medical care in diabetes — 2022. Diabetes Care. 2022;45(Suppl 1):S97-S112.

Arthur AO. Innovations in subcutaneous infusions. J Infus Nurs. 2015;38(3):179-187.

Broadhurst D, Cooke M, Sriram D, Gray B. Subcutaneous hydration and medications infusions (effectiveness, safety, acceptability): A systematic review of systematic reviews. PLoS ONE. 2020;15(8):e0237572.

Broadhurst D, Cooke M, Sriram D, et al. International consensus recommendation guidelines for subcutaneous infusions of hydration and medication in adults: An e-Delphi consensus study. J Infus Nurs. 2023;46(4):199-209.

Caccialanza R, Constans T, Cotogni P, Zaloga GP, Pontes-Arruda A. Subcutaneous infusion of fluids for hydration or nutrition: A review. J Parenter Enteral Nutr. 2018;42(2):296-307.

Canadian Vascular Access Association. Canadian Vascular Access and Infusion Therapy Guidelines. Pappin Communications; 2019.

Danielsen MB, Worthington E, Karmisholt JS, et al. Adverse effects of subcutaneous vs intravenous hydration in older adults. Age and Ageing. 2022;51(1):afab193.

Ferry T, Lodise TP, Gallagher JC, et al. Outpatient subcutaneous antimicrobial therapy (OSCAT) as a measure to improve the quality and efficiency of healthcare delivery. Front Med. 2020;7:585658.

Institute for Safe Medication Practices. Recommendations for the safe management of patients with an external subcutaneous insulin pump during hospitalization. ISMP Medication Safety Alert. 2016;21(21):1-5.

Payne D. Intravenous diuretic administration in the home environment. Br J Community Nurs. 2021;26(12):599-603.

Schleis T, Clarke AE, Vaughan L. Immunoglobulin Therapy Standards of Practice. 2nd ed. Immunoglobulin National Society; 2019.

Spandorfer PR, Mace SE, Okada PJ, et al. A randomized clinical trial of recombinant human hyaluronidase-facilitated subcutaneous versus intravenous rehydration in mild to moderately dehydrated children. Clin Ther. 2012;34(11):2232-2245.

Vidal M, Hui D, Williams J, Bruera E. A prospective study of hypodermoclysis performed by caregivers in the home setting. J Pain Symptom Manage. 2016;52(4):570-574.

Wierda E, Dickhoff C, Handoko ML, et al. Outpatient treatment of worsening heart failure with intravenous and subcutaneous diuretics. ESC Heart Failure. 2020;7(3):892-902.

Zubairi H, Nelson BD, Tulshian P, et al. Hyaluronidase-assisted resuscitation in Kenya for severely dehydrated children. Pediatr Emerg Care. 2019;35(10):692-695.