Emergency Medical Services. Группа авторов
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1. Preparation
Wash hands, don the appropriate personal protective equipment (PPE), and prepare the equipment (Figure 8.6)
2. Identify the landmarks and site
Humeral head – Keep the arm adducted with the palm pronated. Palpate the proximal humerus and locate the greater tuberosity, which will be the site of insertion.
Proximal Tibia – Identify the tibial tuberosity. The site of insertion should be two finger breadths below and just medial to this landmark.
Distal tibia – Abduct and externally rotate the hip. Palpate the flat portion of bone just proximal to the medial malleolus.
3. Clean the site
Cleanse the targeted area with alcohol prep, betadine, chlorhexidine, or other antiseptic. Allow the site to dry.
4. Insert the IO
Insert the IO needle into the skin overlying the desired location until bone is reached. Insert the needle through the cortex into the marrow either manually or per device‐specific instructions. The needle should be relatively stable and freestanding in the bone if inserted appropriately.
Figure 8.6 Intraosseous equipment.
5. Assess IO patency
Remove the trocar and dispose of it in a sharps container. Attach a syringe or IO‐specific tubing and assess for patency of the IO. Monitor the extremity for extravasation. Attach IV fluids if indicated; use a pressure bag or manually push fluids via syringe to achieve desired infusion rates.
6. Secure the IO needle
Stabilize the IO needle in place with gauze and tape or a commercially available device.
In a non‐urgent setting, lidocaine or other anesthetic drugs may be injected into the area of the proposed IO insertion.
Central intravenous access
Prehospital central venous access is a procedure sometimes performed by advanced‐level paramedics, nurses, and EMS physicians. Usually in the form of a large 8.5 French single lumen catheter, the route provides rapid access to the central venous circulation for fluid resuscitation, blood product administration, and medications. Central venous access may be the preferable option when attempts at peripheral and IO lines have failed or are contraindicated, but its prehospital use is sparsely reported (Figure 8.7). Central venous line placement by air medical transport teams has been reported [22]. Similarly, one report documented the performance of 115 prehospital central lines placed by field‐response EMS physicians over a 3‐year period [23]. Another describes central venous catheters being placed in the prehospital setting quickly and safely by EMS physicians in systems that employ this model, such as those in Europe [24]. Critical care teams are often responsible for maintenance of these lines during interfacility transport, so familiarity with this form of vascular access is important.
The internal jugular, subclavian, and femoral veins are options for central venous access. Traumatic injuries above the diaphragm often dictate a femoral location. Attempts for access in the internal jugular and subclavian veins have a risk of pneumothorax, which should be considered if the patient acutely decompensates during the procedure. Placement of a central line, especially in the upper body, often causes an interruption of CPR efforts [21]. Risks of bleeding from venous or inadvertent arterial puncture, infection, thrombosis, and nerve damage also exist [19]. The prehospital environment makes it nearly impossible to preserve sterile technique. Given that these lines are performed as “code” lines under emergency, semisterile (similar to a peripheral IV line) conditions, it should be expected that the line would be removed and another one placed if the patient survives to the ED.
Figure 8.7 Central venous catheter kit.
Special considerations
Accessing dialysis catheters and indwelling catheters
In the prehospital setting, dialysis catheters, infusion ports, and other long‐term artificial structures should not be considered as first‐line options for gaining vascular access unless carefully considered by the medical director and other relevant consultants. The health of these difficult access patients often depends on frequent IV access and medication administration. Improper use of these routes may result in serious consequences. Alternative forms of vascular access or medication routes should be considered. In the case that the EMS clinician must access these types of catheters, special attention must be paid to the specific technique for accessing each device found in the community, as subtle but important differences exist across a range of device types and manufacturers. The most important tenets of accessing an existing device revolve around maintaining a sterile procedure, as line infection often leads to substantial morbidity. Additionally, many indwelling catheters are filled with a fluid such as saline or heparin when not in use. Care must be taken to properly remove and discard this solution to avoid contamination of blood samples or systemic administration of an active medication.
Other Alternative Vascular Access Points
Saphenous vein cutdown is a last‐resort access method. In a direct comparison with cadaveric models, paramedic students performed IO access more rapidly, successfully, and with less complications than venous cutdown [25].
Hypodermocyclis is the interstitial or subcutaneous administration of fluids into the body. This method is much slower than an intravenous infusion, but it is safe and effective as an alternative method of hydration in the geriatric population [26]. Hyaluronidase‐facilitated subcutaneous infusion can also be used in a mass casualty incident or disaster response scenario where there may be a limited number of practitioners treating a large number of patients [27].
Pediatric