What is an IV Drip?
An intravenous or IV drip is a way of delivering fluids and medications into the bloodstream through a vein. This can be done as a continuous or timed infusion, or as a short IV ‘bolus’ or push injection, which rapidly delivers a single dose of medicine directly into the bloodstream.
How do IV drips work?
A hollow-bore needle is inserted through the skin into a vein to allow specially prepared sterile liquid medication to be administered into the bloodstream. Usually, rather than leaving a sharp needle in the vein, a specially designed IV cannula is used. A needle is used to insert it, but once the cannula is in the vein, the needle is withdrawn, leaving a soft plastic tube in the vein with a port that is affixed to the skin with a dressing. The port has a cover or valve through which the IV fluids can be administered while preventing blood loss or infection.
A drip is a bag of sterile fluid attached to the IV cannula by a long thin tube. A simple IV tube usually consists of a roller clamp which is used to vary the rate of administration and a drip chamber where the rate of dripping can be monitored to help administer the fluid over a specific period of time. A more precise way to administer IV fluids is by running an IV tube through an infusion pump for carefully-measured administration volumes and rate. The fluid which goes into the vein mixes with the normal blood circulation directly, allowing the medication to be distributed around the body quickly.
What is an IV drip used for?
Different medications can be administered by different routes. Medications administered via intravenous injections are generally more bioavailable – that is, they are absorbed and used better by the body.
The intravenous route is used to deliver medications, fluids, nutrients and blood transfusions. IV fluids can be used to treat dehydration, electrolyte imbalance, kidney injury and clinical shock.
Transfusions of donated blood components are also administered intravenously for various conditions, including blood loss, some forms of anaemia, and some clotting disorders.
Are IV drips good for me?
Intravenous fluids and medications must be prescribed and are only given when there is a clinical need. As with almost any medical treatment, there are benefits and risks which need to be considered. If the medical team involved in your care recommends intravenous therapy, it is because they believe there is a medical need for the treatment.
Some private clinics offer their clients a choice of intravenous administration of vitamins or hormones as an alternative or complementary medicine. There is little evidence to support the use and benefit over the risk of IV treatments for purposes other than medical need, so this is generally not recommended by legitimate health authorities.
How long does it take for an IV to drip?
IV drip rates are controlled and a prescription will usually include a rate or volume and duration – for example, a litre of fluid over 10 hours will run at 100ml per hour. In some circumstances, IV fluids need to be given rapidly, while in other cases, infusions of fluids or medications need to be given continuously for an undetermined length of time.
What’s in an IV Formula?
There are a wide range of prepared sterile fluids which can be given via drip, and there are medical indications for choosing which one is best on an individual basis. The most common simple rehydration fluid is ‘normal saline’, a 0.9% solution of sodium chloride (salt) which is isotonic, meaning that it should allow the body to maintain a normal balance between the fluids within the cells and tissues.
When someone in the hospital requires IV fluids, they should get regular blood tests to monitor their kidney function and make sure the fine balance of electrolytes – the essential salts and minerals in the blood – stays within a healthy range. Different formulations of IV fluids can be chosen to maintain this balance – ‘Ringer’s’ or ‘Hartmann’s’ solution is a sterile liquid which contains small amounts of sodium, potassium, and calcium salts and is commonly given for fluid and electrolyte replacement.
Some medications come in a sterile injectable form either as a liquid or a powder that needs to be dissolved in a sterile liquid. Some can then be given neat (undiluted) or need to be diluted into a bag of fluid and given as a drip.
Blood transfusions are given via an IV line and may take the form of red cells, plasma, platelets, albumin or other components of blood.
Total Parenteral Nutrition
Some people require nutritional input which totally bypasses the digestive system. This can be for a variety of reasons and may be either short- or long-term. Sterile liquid ‘feed’ is available, known as total parenteral nutrition, or TPN. This contains a mixture of essential vitamins, minerals, proteins carbohydrates and fats.
IV Drips vs Oral Treatment
Intravenous drips are given for medication that can be absorbed and used by our body better than if taken orally. Some medications are only available in intravenous form, whereas some medicines can come in multiple forms, and the medical team has to decide which is the best for each person and situation. Having IV treatment is usually more time-consuming, costly, less convenient for the patient, and associated with more risk than oral treatment, so a switch to oral treatment is usually considered wherever possible.
Intravenous therapy may also be used when someone is unconscious or unable to swallow for any other reason, or when immediate uptake of medications or fluids is essential. IV fluids are used to rehydrate in a measurable and efficient way, with the benefit of being able to correct electrolyte imbalances at the same time.
Types of IV Therapy
IV treatments can be given as a drip, continuous infusion or a bolus (‘push’), depending on the type of treatment. Lots of different medications can be given intravenously.
Some medications can be given as a ‘push’ or bolus. If they’re given through an existing IV cannula, it should be cleaned with antiseptic wipes designed specifically for that purpose, and flushed, usually with normal saline, before and after administration. This ensures that the line is clean and patent, so that the medication is able to go all the way through the tube and into the vein.
An IV drip traditionally refers to a fluid infusion of a set amount and duration. We call it a drip because there is a chamber at the top of the line where fluid drips through, and we can measure the drip rate to monitor the speed of administration. IV infusions which require a specific set rate more commonly go through an IV administration pump, which can be programmed to deliver a certain amount over a set period of time.
Both fluids and medications can be delivered by drip, and some medications need to be diluted in specific sterile fluids before they can be given.
Some medications need to be continuously infused at a certain rate without a set endpoint. These should go through an infusion pump or a programmable syringe driver for accurate administration. Some continuous infusions can have a short gap while fresh medications are set up. Other medications need to be continuously infused without any break, and medical staff may need to ensure you have multiple points of IV access; this is to allow for a rapid changeover, and in case one IV cannula fails.
Types of IV Access
The locations and types of access points vary depending on the type of medication needed, the expected duration of treatment, and the individual. Some people have more difficult-to-access veins than others. Sometimes, ultrasound scans are used to help find a suitable vein. Occasionally, IV access may need to be gained in an operating theatre setting.
Peripheral Venous Cannula
An intravenous cannula is most commonly located in a vein in the hand or forearm, or occasionally the foot. This is known as a peripheral venous cannula, as it is in a peripheral vein; smaller and further from the heart. These types of cannulae are usually only kept in for up to around three days, and so other options may be considered for people who require longer-term IV therapy.
A longer-term option for intravenous treatment is a midline – these can stay in much longer than standard peripheral IV lines.
Central Venous Catheter
A central venous catheter (CVC), also known as a ‘central line’ is an IV line inserted into a much bigger central blood vessel. These can stay in longer than standard peripheral lines and therefore are often used when people need to have repeated IV therapy over a longer period of time, such as in some chemotherapy treatments, or in certain conditions where long-term IV antibiotic therapies are expected.
Central lines can also be used when access to peripheral veins is impossible. They can have multiple access lines within a single device so different medications can be administered simultaneously.
Central lines are also often used for administering medications that are likely to cause damage to smaller veins – the greater lumen and amount of blood pumping through big blood vessels means that there is a much lower concentration of the medication within a single vessel and reduces the risk of irritation and leakage.
Another type of central line is called a peripherally-inserted central catheter (PICC) line – this is a long line so the port is usually situated on the upper arm, but the medications administered still go into the large central vein.
Central lines can be used to take blood samples as well as deliver treatment.
Are there any risks involved in IV drips?
Almost all medical treatments carry some risk, including IV therapy, and this should be explained by your medical team.
Getting intravenous access means that a fine needle will be pushed through the skin. This usually hurts a little, with some areas of the body being more sensitive than others. When the needle is removed and the cannula left in, it shouldn’t continue to be painful, though it may feel a little awkward and uncomfortable, especially if it’s in a place where it can be knocked or caught on clothes. Having a bandage over the port when it isn’t being used can help prevent this.
Inserting a peripheral venous cannula is a clean/sterile procedure; your skin will be cleaned before it is punctured, all the equipment is sterile, and the healthcare professional gaining access and administering medication or fluids through the IV site will have clean hands and gloves and will use a ‘no touch’ technique to avoid touching anything that will be connected to the vein. However, there is still a risk of getting an infection whenever anything punctures the skin, and you and your medical team should watch out for signs of a problem, such as redness, heat, pain and swelling around the site of the cannula. Infected cannula sites can cause serious illness.
Some medications can be irritating to the vein and cause pain when they’re administered. Veins can also be irritated simply by the movement of a foreign body within them, and may become inflamed. This is known as phlebitis.
Sometimes, a cannula can become misplaced or start to seep fluids into the tissues around the vein. This is known as extravasation, which can cause swelling, irritation, or – in the case of certain particularly irritant medications – serious damage to the tissues around the vein.
There are some circumstances where blood products or fluids must be given cautiously – particularly in patients with kidney disease or heart failure who can quickly develop fluid overload and respiratory problems.
Going Home With Intravenous Therapy
If you have a plan for regular IV therapy such as chemotherapy or sustained courses of antibiotics, you may be able to go home with a long-term IV access port such as a midline of a PICC line. Medication can then be administered in your own home, either by specialist nurses from your hospital care team or by experienced qualified nurses from a trusted home care provider. If you do go home with more care needs, having a care plan from an organisation with a wide multi-disciplinary team means seamless medical and nursing provision, whatever your needs. Doctors are available for house calls as and when needed, and nurses and caregivers can provide help around the house, personal care, and medication administration or prompts.
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