When you or a loved one is facing dehydration , intravenous fluids are not the only medical option. There is a less invasive, more comfortable, and equally effective alternative : subcutaneous hydration, also known as hypodermoclysis .
If this method seems unfamiliar, you should know that it has been used for decades in geriatric and palliative care units , where its effectiveness has been widely demonstrated. Contrary to popular belief, rehydrating a patient does not always require puncturing a vein. Subcutaneous tissue has a physiological capacity to gradually absorb and release the fluids the body needs.
Hypodermoclysis is an ideal therapeutic alternative for elderly patients with weakened veins, for end-of-life patients seeking maximum comfort, or when venous access becomes complex.
In this article, we offer you a detailed look at this medical practice, its indications, its procedure, and the benefits it offers to patients who need it.
What is subcutaneous hydration?
Definition and principle of hypodermoclysis
Subcutaneous hydration , or hypodermoclysis, is a medical technique that allows for the administration of solutions into the space between the skin and muscles, called the subcutaneous tissue or hypodermis. This procedure relies on the natural ability of this tissue to gradually absorb the injected fluids and then diffuse them into the bloodstream.
The solutions used are generally isotonic , most often physiological saline or glucose solution . The infusion is administered either by gravity alone or with the aid of an infusion pump.
This route of administration has the advantage of being simple to implement , while guaranteeing comparable effectiveness to conventional intravenous infusion .
Difference between subcutaneous and intravenous hydration
The difference lies mainly in the route of administration , the speed of action and the context of use .
With intravenous hydration , the healthcare professional inserts a catheter directly into one of your veins. The fluids immediately enter the bloodstream . According to a clinical review published in Reviews in Clinical Gerontology , this is the standard method in emergency situations or cases of severe dehydration . However, it requires good venous access, closer monitoring , and a higher risk of local complications .
In subcutaneous hydration , fluids are injected into the subcutaneous tissue, which acts as a temporary reservoir . Absorption is slower , but clinically sufficient to correct mild to moderate dehydration . This technique is less invasive , better tolerated, and simpler to implement .
In what cases should subcutaneous hydration be used?
Medical indications
Subcutaneous hydration is particularly indicated in cases of mild to moderate dehydration , especially if you are unable to drink enough orally. It is suitable for terminally ill patients , those with swallowing difficulties , or those experiencing persistent nausea and vomiting .
Healthcare professionals favor this technique as a relevant alternative when venous access is difficult or when maintenance hydration is required over a prolonged period.
Its use also facilitates the administration of certain medications , particularly analgesics such as morphine or hydromorphone , in palliative care patients who can no longer absorb their treatments orally.
Subcutaneous hydration also plays a role in preventing dehydration in at-risk individuals, particularly during fever or gastroenteritis. In geriatrics , it helps avoid unnecessary hospitalizations.
Populations concerned
The elderly are among the population most frequently affected. Indeed, with age, venous access decreases and the risk of dehydration increases because the sensation of thirst diminishes.
Patients in palliative care also benefit from this technique, which offers them comfort and dignity during their final moments.
In an oncological context, hypodermoclysis makes it possible to treat patients with advanced cancer while avoiding repeated invasive procedures.
How does subcutaneous hydration work?
Choice of injection site
The preferred areas have sufficiently developed subcutaneous tissue. The abdominal region , particularly the flanks , is the most commonly used area due to its good tolerability. The anterior thighs, the subclavicular region, and the outer aspect of the arms are good alternatives.
Before choosing the injection site, the healthcare professional assesses the condition of the skin and verifies the presence of sufficient adipose tissue. The skin surface must be healthy, without edema, lipodystrophy, or hematoma.
In malnourished patients, the choice is more limited and requires special attention. The interscapular region, located in the back between the shoulder blades , can be used for confused patients who might try to remove the device.
The equipment used
As described in detail by Shvartzman and Sasson , intravenous infusion equipment is most often used, with adaptations for the subcutaneous route. It includes a specific subcutaneous needle (24-26 G gauge), a tubing system connected to an infusion bag, a flow regulator, and skin disinfection equipment.
The steps of the application protocol
The protocol for administering subcutaneous hydration follows several specific steps:
- Preparation : verification of the medical prescription, preparation of sterile equipment, hand hygiene by hydro-alcoholic friction and wearing of non-sterile gloves.
- Disinfection : the injection area is carefully disinfected using an antiseptic solution.
- Insertion : The needle is inserted into the subcutaneous tissue at an angle of approximately 45 degrees, then secured with a transparent dressing.
- Setting : the infusion is set to a flow rate of 1 to 2 millilitres per minute.
- Monitoring : The site is regularly monitored for any signs of inflammation, edema, redness or infection.
Duration and rate of the infusion
The recommended flow rate is between 1 and 3 milliliters per minute , or approximately 40 to 125 milliliters per hour. A standard infusion allows for the administration of 500 to 1500 millilitres per site over 24 hours . With two injection sites, it is possible to administer up to 3000 millilitres per day .
The injection site can remain in place for three to seven days in the absence of complications. This extended duration is an advantage compared to the intravenous route, which requires more frequent changes.
The infusion can be continuous over 24 hours or programmed over time slots , including nighttime, in order to preserve the patient's mobility and autonomy during the day .
The benefits of subcutaneous hydration
Subcutaneous hydration offers numerous benefits that explain its increasing use in geriatrics and palliative care :
- Ease of implementation : quick administration without advanced technical skills.
- Patient comfort : preservation of mobility and limitation of constraints related to venous access.
- Reduced risk of complications : absence of phlebitis, almost zero risk of systemic infection and less venous trauma compared to the intravenous route.
- Moderate cost : possibility of performing the procedure at home, avoiding costly hospitalizations.
- Versatility : also allows the administration of certain medications.
Subcutaneous hydration at home: how does it work?
Home subcutaneous hydration requires coordination between your doctor and a nursing service . A detailed medical prescription specifies the type of solution, volume, flow rate, and frequency of administration.
A trained nurse will come to your home to provide care according to the established protocol. This arrangement ensures continuity of patient care in a familiar environment , while guaranteeing high-quality treatment.
Frequently asked questions about subcutaneous hydration
Is it painful?
Subcutaneous hydration is usually only slightly painful. You may feel a slight pricking sensation when the needle is inserted. A feeling of local tightness may occur during the infusion, but it is generally well tolerated.
How long does a session last?
The duration varies depending on the volume prescribed by the doctor, generally between two and eight hours. The flow rate is adjusted to your needs and tolerance. In certain specific clinical situations, particularly in palliative care or to maintain constant hydration, it may be administered continuously over 24 hours.
Can it be used on children?
Subcutaneous hydration is rarely used in children , with intravenous administration generally preferred. However, it may be considered in certain specific situations at the doctor's discretion.
What is the cost of subcutaneous hydration?
Subcutaneous hydration is covered by French National Health Insurance (Assurance Maladie) when prescribed by a doctor. At home, as part of home hospitalization, coverage is generally complete. Check the details with your health insurance provider and supplemental health insurance company.
Bibliography
Remington, R., & Hultman, T. (2007). Hypodermoclysis to treat dehydration: a review of the evidence. Journal of the American Geriatrics Society , 55 (12), 2051–2055. https://doi.org/10.1111/j.1532-5415.2007.01437.x
Duems Noriega, O., & Ariño Blasco, S. (2014). Efficiency of the subcutaneous route compared to intravenous hydration in the elderly hospitalized patient: a randomized controlled study]. Revista espanola de geriatria y gerontologia , 49 (3), 103–107. https://doi.org/10.1016/j.regg.2013.12.003
Barreto Annes, LM, Andrade, RGADC, Pontes, IEA, Sena, GR, Telles, J., & de Orange, FA (2020). Subcutaneous Versus Intravenous Rehydration in Hospitalized Older Adults: A Meta-Analysis. Journal of infusion nursing: the official publication of the Infusion Nurses Society , 43 (5), 283–291. https://doi.org/10.1097/NAN.0000000000000388
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Gill, S., Dasgupta, M., & Rochon, P. (2001). Hypodermoclysis in the treatment of dehydration. American family physician, 64(9), 1516–1519. https://www.aafp.org/pubs/afp/issues/2001/1101/p1516.html
Caccialanza, R., Constans, T., Cotogni, P., Zaloga, GP, & Pontes-Arruda, A. (2018). Subcutaneous Infusion of Fluids for Hydration or Nutrition: A Review. JPEN. Journal of parenteral and enteral nutrition , 42 (2), 296–307. https://doi.org/10.1177/0148607116676593
