In medical practice, more often at the prehospital stage, there are urgent conditions that threaten the life of the patient and require intravenous infusion of solutions or administration of drugs. Unfortunately, in some cases, venous access is not possible and it is necessary to use a backup method: intraosseous access. To date, any ambulance is equipped with a set for this type of infusion. In addition to the prehospital stage, this method is actively practiced in pediatrics and intensive care. What is this method? How is intraosseous access performed, what are the indications and contraindications?
Bone circulation
Any bone is supplied with blood and has venous plexuses, which are a draining system into the central circulation. The main plus is that the speed of infusion is approximately equal to the rate of infusion throughcentral vein and even higher. So through the tibia, the rate of administration reaches up to 3 liters per hour, and through the humerus - up to 5 liters. Theoretically, intraosseous access followed by infusion can be performed through any large bone. Modern devices are designed for various access points, including the sternum.
Absolute contraindications
- Injury in the proximal bone in relation to intraosseous access. When conducting an infusion, there is a chance for fluid to exit the vascular bed. This course of events can lead to compartment syndrome.
- Local inflammatory process. If it is present at the access point, there is a risk of infection entering the bone tissue with further inflammation (osteomyelitis).
Relative contraindications
The prosthesis can interfere with intraosseous access. When replenishing the puncture, it may be damaged with a further deterioration of its functions, and the puncture system will also break down.
Access Points
Today, there are major sites that are most commonly infused, as many devices are anatomically limited.
The head of the humerus. The point is one centimeter above the surgical neck and 2 centimeters lateral to the biceps tendon. The needle is inserted at a 45 degree angle
Tibia. The place we need is in the region of the tibial tuberosity. It can be found 1-2 centimeters below the patella and 2 centimeters medially to it. Needleinserted at a 90 degree angle
Bernum. The point is approximately 2 cm below the jugular notch. The needle is inserted at 90 degrees to the sternum
Types of devices
Manual trocar is one of the cheapest and simplest devices in terms of intraosseous access technique. In this case, the puncture is done manually, so this manipulation requires a lot of experience of the practitioner. Insertion of the needle is a twisting motion and requires sufficient physical strength when working with adult patients.
Quick sternal access (thoracic). A system that includes a pistol already equipped with blades and infusion tubes. For intraosseous access, the device is directed to the desired area of the pre-treated skin, helping with the second hand, since there must be sufficient physical strength to pierce the handle of the sternum.
Further, the device is displaced and the intraosseous catheter remains inserted. If blood aspiration is necessary, then 10 ml of physiological saline should be injected into the system before this. To remove the device, disconnect all infusion tubes, remove the protective cowl and pull out the intraosseous catheter perpendicular to the sternum, covering the wound with a sterile gauze pad.
The gun is designed to access the tibia and humerus. The skin is processed immediately before the puncture, the gun is aimed at the access point at an angle of 90 degrees. Once you are sure you are in the correct position, removegun off safety and insert the needle. The appearance of bone marrow in the cannula indicates the correct position of the needle. After puncture, the system should be flushed with 10 ml of isotonic sodium chloride solution. Access is removed by rotating movements, followed by closing the wound with a sterile gauze pad.
Drill is the most common method of all due to the simple technique of intraosseous access. The device consists of a small drill and a needle that is attached to it with a magnet. The kit includes needles of different sizes for all patient groups.
For obese people, there are longer needles to compensate for excess body fat. Access begins with the selection of the puncture site and skin treatment. The limb is fixed with the second hand while providing intraosseous access at the moment the needle passes through the skin and soft tissues.
"Drilling" occurs until the resistance decreases. After that, the drill is unscrewed, the cannula remains in the bone, and the appearance of the bone marrow confirms the correct position of the system.
Next, the infusion set is connected and, as usual, 10 ml of isotonic sodium chloride solution is flushed. It is removed by a strong pulling movement with clockwise rotation. In case of difficulty, you can use a needle holder.
Pain syndrome
Intraosseous access, especially to the tibia, is usually a painful procedure. The bone itselfhas pain receptors, so the puncture in most cases is painful only when the skin and subcutaneous fat are punctured. However, intraosseous receptors react when fluid is injected, and the patient, while conscious, may experience quite severe pain. In the absence of an allergic history, the introduction of a 2% solution of lidocaine is recommended before infusion therapy.
Complications
Complications after intraosseous access most often occur due to improper technique of its implementation: a situation such as bleeding can occur. It can lead to the development of compartment syndrome, which causes an increase in intrafascial pressure, which can subsequently cause a decrease in blood circulation in the tissues.
There is also a high risk of developing osteomyelitis (inflammation of bone tissue). It increases several times when the system is installed for more than a day. The next, more rare, but no less dangerous, is damage to neighboring structures. For example, when making an access in the sternum, it is possible to develop pneumothorax, damage to large vessels with further development of internal bleeding.
This system is quite convenient and easy to carry out, to some extent even easier to set up intravenous access. Many doctors do not recognize this method because of the risk of complications. But, as they say, the winners are not judged, because osteomyelitis is more humane than dooming a patient to death.
