The equipment used for the subcutaneous infusion is same which is used for intravenous infusions. The subcutaneous infusions may be given in two places, using a ‘Y’ connection to help in the maximum absorption of the fluid. To start the subcutaneous infusions, pick up a fold of subcutaneous tissue with the left hand and with a right hand, insert the needle at an angle into the subcutaneous tissue in the direction of venous blood flow.
The rate of flow is determined by the individual’s rate of absorption. In all cases, the rate at which the fluid is given, should be such that the tissue around the needle stay nearly normal in tension and appearance. Hyaluronidase injected into the tissues at the site of infusion or added to the infusion fluid, will increase absorption. When swelling occurs, the infusion should be stopped completely.
The solutions used for the subcutaneous infusion should be isotonic. Sugar solutions that are electrolyte free are contraindicated, as it may produce oedema at the injection site. Hypertonic solutions are not absorbed. On the contrary, they may attract body fluids into the injection site.
COMPLICATIONS OF I.V. INFUSIONS
1. Circulatory Overload
Circulatory overload means that the intravascular fluid compartment contains more fluid than the normal. It occurs when the fluids are administered too rapidly or the fluid administered is more than what is necessary. Circulatory overload results in cardiac failure and pulmonary oedema. Signs of pulmonary oedema are dyspnoea, cough, red frothy sputum, gurgling sounds on respiration etc. puffiness of the face, generalized oedema and engorged neck veins etc indicate the cardiac failure.
Prevention of circulatory over load is achieved by carefully regulating the flow rate over 24 hours; e.g. if 3000 ml of fluid is ordered in 24 hours, the flow rate can be calculated as follows:
Flow rate = Total volume infused in ml × drops/ml ÷ Total time of the infusion in minutes.
Total volume infused = 3000 ml in 24 hours.
Drops per ml = 15 (this depends upon the bore of the needle)
Total time in minutes = 24 × 60 = 1440 minutes.
Flow rate = 3000 × 15 /1440 = 31 drops per minute.
Infiltration is the escape of fluid into the circulatory tissues due to dislodgement of needle. It can be easily detected by observing the following signs and symptoms.
The infusion rate slows or stops completely, development of swelling, hardness and pain around the needle site, a feeling of numbness and coldness around the injection site, a feeling of blood to return to the tubing when the bottle is lowered. Early recognition of the infiltration can prevent unnecessary discomfort to patient. When infiltration has taken place, stop the infusion immediately and apply warm towels over the side of infusion. Restart the infusion at another site.
3. Damage to the walls of blood vessels and extravasation of blood (hematoma)
The walls of blood vessels may be damaged due to careless introduction of the needle into the body. The needle may puncture the blood vessels in more than one place and the blood my flow into the tissues causing sudden swelling (hematoma formation) at the site of the puncture.
Withdraw the needle immediately and apply pressure to control bleeding. Apply cold compress over the injured site.
Thrombophlebitis is caused by mechanical trauma to the vein or the chemical irritation of some substances introduced into the veins such as potassium chloride. Patients may complain of burning pain along the veins or a nurse may notice redness, swelling and increased skin temperature over the course of the vein. There can be generalized symptoms such as fever, rapid pulse, malaise etc.
The treatment is to stop the infusions immediately and restart it at another site. Apply warm moist compress. Do not massage or rub the area. This may dislodge any clot and it may cause pulmonary embolism.
5. Pyrogenic Reactions
Symptoms generally appear in 30 minutes after the infusion is started. This is characterized by temperature elevation and chills, headache, nausea, vomiting and circulatory collapse in severe cases. The pyrogenic reactions are caused by pyrogens (usually the fungus) present in the I.V. fluids or due to the contaminated I.V. tubings and needles used for infusions.
To prevent pyrogenic reactions, check the I.V. fluids in good light before they are infused. Any solution that is cloudy or containing suspended particles, or with a color change should not be used. The I.V. tubings and needles used for infusion should be thoroughly cleansed and autoclaved to destroy the pathogens.
When the patient develops the pyrogenic reactions, stop the infusion immediately. Change the I.V. fluid and I.V. tubings. Administer antiallergic drugs. Apply cold therapy to lower the body temperature. Restart the I.V. infusion.
AUTHOR: STEPHEN STE
SUBCUTANEOUS INFUSIONS AND COMPLICATIONS OF I.V. INFUSIONS – Prevention and Treatment
6. Air Embolism
The main problem is the vascular collapse due to occlusion of the vessel by embolism. As a result, the tissues which are normally supplied with blood by the involved vessel, will not receive adequate oxygen. The signs of pulmonary embolism are dyspnoea, cyanosis, low blood pressure, shock and collapse, tachycardia, and unconsciousness.
To prevent this complication, make sure that the air is completely expelled from the tubing and the needle, before introducing the needle into the vein. Do not elevate the arm or leg receiving the infusions above the level of the heart, if so, a negative pressure will be created in the veins and air will be drawn into the vein, should there be any leak in the infusion apparatus. Never allow the I.V. drip to run dry. There should be a little fluid left in the tubing when the infusion is discontinued.
Air embolism and the subsequent pulmonary embolism is an emergency situation. No time should be lost to save the patient. Report to the doctor immediately. Give oxygen. Check the vital signs.
7. Infection at the Needle Site
The needle may become contaminated during the insertion or infection may be developed at the needle site when it is left exposed for a long period.
To prevent infection, follow strict aseptic technique during the procedure. Cover the needle with a sterile dressing so that there is no chance for the infection to get into the puncture site.
8. Allergic Reaction
This may be due to certain drugs administered along with the I.V. fluids.
9. Serum Hepatitis
Infectious hepatitis has been attributed to improperly disinfected syringes and needles. Inoculation of 0.0004 ml of infected blood may transmit serum hepatitis.
10. Osmotic Diuresis
If dextrose solutions are administered too rapidly, the patient develops a glucose overload and will consequently undergo an excessive diuresis. If diuresis remains unchecked, extreme dehydration followed by shock and collapse will ensure.
To prevent this, it is essential to make observations of vital signs frequently on all patients receiving I.V. infusions. The nurse should observe the vital signs, urinary output, body weight, urine test for sugar and acetone etc.
11. Nerve Damage
Nerve damage may occur from tying the arm too tight with the splint.
The introduction of a large amount of fluid into body via veins is termed as I.V. infusions.
1. Restore the fluid volume
2. To meet the patient’s basic requirements
3. To prevent and treat shock and collapse
4. To supply the body with adequate amount of fluids (electrolytes and other nutrients)
SUBCUTANEOUS INFUSIONS (HYPODERMOCLYSIS)
In medical practice, the term subcutaneous infusion or hypodermoclysis is used to designate an injection of a large amount of fluid into the subcutaneous tissues, by means of a needle for the purpose of supplying the body with fluids. In this method, the fluid is absorbed principally by the lymphatics. It is given in a part where the tissue is loose. The purpose of subcutaneous infusions is same as that of intravenous infusions. This route is seldom used now-a-days due to increased facilitates available for the intravenous infusions. However, this route may be useful under emergency conditions.
The Sites used for Subcutaneous Infusions are:
1. Anterior and outer aspect of the thigh, midway between the knee and hip
2. Under and outer margins of the breast
3. Abdominal wall halfway between the umbilicus and the flank
4. Back, just below the scapula