An infusion pump is a machine that infuses the drugs, or nutrients into the body of the patient in a precise volume for a fixed period of time.
Types of Infusion
1. Continuous Infusion
It usually consists of small pulses of infusion. The volume of a single pulse of infusion can normally range between 500 Nano liters to 10 milliliters. This value can depend upon the design of the pumps, the rate of flow of the pulses, etc.
2. Intermittent Infusion
This kind of infusion allows to simultaneously alter the infusion rate from high to low with the main purpose of keeping the cannula open. This mode is suitable for the administration of the drugs such as antibiotics that can irritate a blood vessel.
3. Patient-Controlled Infusion
The patient can control the infusion with the help of the pressure pad or the button. This is mainly suitable to avoid the intoxication of the drugs administered into the body. For example, in patient-controlled analgesia (PCA), the patient can manually infuse the drug whenever he/she feels pain.
4. Total Parental Nutrition
In this method, all the required nutrients are fed to the patient intravenously.
Types of Infusion Pump
An infusion pump is a type of machine that uses different types of pumps for infusion. So based on the type of pump used in the machine, they are mainly of two types.
1. Large Volume Pumps
Large volume pumps are useful for infusing large volumes of fluid (about 500 ml). It can be a nutrient solution, saline solution, medications such as antibiotics, etc.
Usually, a peristaltic pump is present in this type of infusion pump. The technology can also be a finger type of pump in which fingers like projections press the tubing in sequence.
An iv infusion pump is a type of large volume pump. It can hold around 500 ml of fluid.
2. Small Volume Pumps
Small volume pumps are useful in infusing a small volumes of fluids (about 50 ml) such as insulin.
Usually, it consists of a computer-controlled motor, that turns the screws around. This pushes the plunger of the syringe. A syringe pump is an example of a small volume pump.
Another method is the use of the osmotic pump. The inner layer of the pump is a drug reservoir. The middle is the osmotic layer filled with constituents such as salt. Finally, the outer layer is a semi-permeable membrane. The osmotic pressure causes the absorption of water into the middle layer. This causes an expansion of the middle layer causing a contraction of the inner layer. Thus the drug will be squeezed out of the reservoir.
The rate of release of the drug depends upon factors such as concentration of the salts, the volume of the pump, etc.
Parts of Infusion Pump
(Block Diagram of Infusion Pump)
The infusion pump consists of the following major components.
- Power Supply Unit:- The power supply can be through an AC or DC supply. Nowadays, the rechargeable battery is mostly used.
- Detector Unit:- Consists of sensors such as door sensor, pressure sensor, bubble sensor, etc.
- Motor Unit:- Can be pumping unit such as peristaltic pump, syringe pump, osmotic pump, etc.
- Control Unit:- Made up of processing, controlling, analyzing, recording, and storing units.
- Alarm Unit
- Display Unit
Working of Infusion Pump
Different manufacturing companies have developed different types of infusion pumps. These pumps can differ from one another on the basis of technology, applications, size, shape, etc. Thus, here I am going to explain the general working principle of the infusion pump.
On getting the signal from the control unit, the pump gets activated. Thus, the activated pump pumps or draws the fluid from the reservoir to the patient. The reservoir can be an IV bag, bottle, syringe, etc.
In case of any abnormalities in the pumping process, the detectors will send the message to the controlling unit. The controlling unit will inform this error in the form of an alarm or text message in the display unit.
Applications of Infusion Pump
- An infusion pump is useful in the management of patients during and after surgery, treating burns, and treating the dehydration of pediatric patients.
- It allows to intravenously supply nutrients to pediatric patients for growth, development, and survival.
- It is also useful for providing anesthetics during surgery, chemotherapy to cancer patients, oxytocin hormone for the induction of labor, anti-arrhythmic drugs for patients in the coronary units, etc.
Handling of Infusion Pump
The infusion pump should be handled properly. Here are few things that you need to take care of while handling the unit.
- Place the machine on a fixed, solid surface.
- Do not place the machine near the water supply.
- Use a proper power supply. Use a voltage stabilizer, if there is voltage fluctuation.
- Do not use the machine near the source of strong electromagnetic field such as radiation equipment (X-ray, CT- Scan. etc.), NMR equipment, microwave generating devices, etc.
- Keep the machine away from the high-frequency surgical equipment such as electrode feeder plate.
- If the batteries are damaged, dispose of them properly.
- Avoid direct sunlight, vibration, bumps, etc.