In medical practice, more often at the prehospital stage, there are urgent conditions that threaten the patient's life, and requiring intravenous infusion of solutions or administration of drugs. Unfortunately, in some cases it is impossible to carry out venous access and you have to use the backup method: intraosseous access. To date, any ambulance is equipped with a kit for this type of infusion. In addition to the prehospital stage, this method is actively practiced in pediatrics and resuscitation. 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 drained system in the central blood circulation. The main plus is that the speed of infusion is approximately equal to the rate of infusion through the central 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 through any large bone. Modern devices are designed for various access points, including the sternum.
Absolute contraindications
- Injury to the proximal bone in relation to the intraosseous access. During the infusion, there is a chance of fluid exit from the vascular bed. This variant of the 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 its further inflammation (osteomyelitis).
Relative contraindications
A prosthesis may interfere with intraosseous access. When replenishing the puncture, it can be damaged with a further deterioration in its functions, and the system for puncture will also break down.
Access points
Today, there are the main places where infusion is most often carried out, since many devices are anatomically limited.
- The head of the humerus. The point is a centimeter above the surgical neck and 2 centimeters lateral to the bicep tendon. The needle is inserted at an angle of 45 degrees.
- Tibia. The place we need is located in the area of the tibial tuberosity. It can be found 1-2 cm below the patella and 2 cm medial to it. The needle is inserted at an angle of 90 degrees.
- Sternum. The point is approximately 2 cm below the jugular notch. The needle is inserted at 90 degrees to the sternum.
Types of devices
A manual trocar is one of the cheapest and easiest devices in terms of technique for intraosseous access. In this case, the puncture is done manually, therefore, to perform this manipulation, a lot of practitioner experience is required. The needle is inserted by twisting movements and requires sufficient physical strength when working with adult patients.
Rapid sternal access (thoracic). A system that includes a gun already equipped with blades and infusion tubes. For intraosseous access, the device is sent to the desired area of pre-treated skin, helping with the second hand, since there must be sufficient physical strength to pierce the sternum handle.
Further, the device is displaced and the intraosseous catheter remains inserted. If blood aspiration is necessary, then 10 ml of physiological saline should be introduced into the system before this. In order to remove the device, all the infusion tubes should be disconnected, the protective cowl should be removed, and the intraosseous catheter should be pulled out perpendicular to the sternum, covering the wound with a sterile gauze cloth.
The gun is designed to access the tibia and humerus. The skin is processed immediately before the puncture, at a 90-degree angle the gun is pointed at the access point. With confidence in the correct position, remove the gun from the fuse and insert the needle. The appearance of bone marrow in the cannula indicates the correct position of the needle. After the puncture, the system should be rinsed with 10 ml of isotonic sodium chloride solution. Access is removed by rotating movements, followed by closing the wound with a sterile gauze cloth.
Drill is the most common method of all because of 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 set includes needles of different sizes for all groups of patients.
For obese people, longer needles exist to compensate for excess body fat. Access begins with the choice of puncture site and skin treatment. The limb is fixed with the second hand while providing intraosseous access at the time the needle passes through the skin and soft tissues.
“Drilling” occurs until a decrease in resistance occurs. After this, the drill is unscrewed, the cannula remains in the bone, and the appearance of the bone marrow confirms the correct position of the system.
Then the infusion system is attached and, as usual, washed with 10 ml of isotonic sodium chloride solution. Removed by strong pulling movement with clockwise rotation. In case of difficulty, a needle holder can be used.
Pain syndrome
Intraosseous access, especially to the tibia, is usually a painful procedure. The bone itself does not have pain receptors, so the puncture in most cases is painful only with a puncture of the skin and subcutaneous fat. However, when fluid is injected, intraosseous receptors react and the patient, being conscious, may experience quite severe pain. In the absence of an allergic history, the introduction of a 2% solution of lidocaine before infusion therapy is recommended.
Complications
Complications after intraosseous access are most often due to the improper technique of its implementation: a situation such as bleeding may occur. It can lead to the development of compartment syndrome, which causes an increase in intrafascial pressure, which in the future can cause a decrease in blood circulation in the tissues.
There is also a high risk of developing osteomyelitis (inflammation of bone tissue). It increases many times when setting up the system for more than a day. The next, rarer, but no less dangerous, is damage to neighboring structures. For example, when conducting access in the sternum, a variant of the development of pneumothorax, damage to large vessels with the further development of internal bleeding is possible.
This system is quite convenient and easy to carry out, to some extent even easier to administer 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 condemning a patient to death.