Peripheral IVs (Figure 13.1) come in various sizes, referred to as gauges. Don’t ask us why, but the bigger the IV, the smaller the number. A good size for an IV in an adult is at least an 18 or 20 gauge, because red blood cells fit through that size. You can place an IV in any vein, but typical sites are the hands and forearms. A lot of IVs that get placed in the emergency department go into the antecubital vein, which ICU nurses hate because the patient inevitably bends his or her arm, causing the IV pump to go off repeatedly. Peripheral IVs should be placed using aseptic technique, and most hospitals have an IV care protocol for nursing. Fluid, blood, and blood products and many medications can be administered intravenously through a peripheral IV. There are many drugs that cannot be given through a peripheral IV, including chemotherapy drugs and very strong antibiotics that can damage the vein. For these IV medications, central venous access is preferred.
An intraosseous catheter (IO) is a great way to gain access for fluids and medications very quickly. This is a good tool if your patient is a difficult stick with a regular peripheral IV. The IO might be an option in the obese patient, pediatric patient, the elderly patient (who may have tortuous veins that roll), and the burn patient. An IO is drilled directly into the bone using a device that looks like a hot glue gun. While this sounds pretty awful, patients say it’s not as painful as you would expect. A common place to put in an IO is the tibial plateau. Placing one of these gives you 24 hours to place a peripheral or central line and is a great tool in an emergency setting.
A midline catheter is an 8- to 20-cm small diameter tube that is inserted into a vein in the upper arm and terminates in the axillary vein. It is inserted with ultrasound guidance under sterile conditions. It is used to deliver fluids, antibiotics, and other medications to patients. This device does not provide central access but it can be left in for an indefinite time period, in contrast to a regular peripheral IV that needs to be changed every few days.
Arterial lines (Figure 13.2) provide a continuous blood pressure reading and allow for blood to be drawn directly from an artery. Arterial lines are particularly useful in a critically ill patient where organ perfusion is a concern and accurate measurement of blood pressure is essential for titration of pressors. They are typically inserted into a radial or femoral artery and hooked to a pressure bag and a transducer that transmits information to a monitor to get a waveform reading of systolic, diastolic, and mean arterial pressures. Also, it is extremely easy to draw blood gases and other labs from an arterial line without the patient needing to be stuck with a needle. Blood gases can be drawn frequently on ventilated patients with minimal blood waste and no additional pain to the patient, which allows us to monitor oxygenation and ventilation in patients with respiratory failure.
CENTRAL VENOUS CATHETER
A central venous catheter (CVC), or central line (Figure 13.3), is a small diameter tube placed into the venous system and terminates in a central vessel that delivers blood directly to the heart, either the superior or inferior vena cava. The three usual sites of insertion are the jugular, subclavian, or femoral vein. The size of the vessel and volume of blood at the terminal site allows a CVC to safely carry chemotherapy medications or fluids of extreme pH that can be harmful to the smaller peripheral vessels. The body then distributes the fluid systemically through the circulatory system. CVCs can have single or multiple lumens (up to five) for noncompatible infusions and drawing blood for laboratory sample.
PERIPHERALLY INSERTED CENTRAL CATHETER
The peripherally inserted central catheter (PICC line) (Figure 13.4) is a special type of central venous catheter that is inserted into the basilic or brachial vein and terminates in the superior vena cava. PICC lines may have a single, double, or triple lumen. Each lumen can be utilized for noncompatible medications or drawing blood for laboratory samples. PICC lines provide central venous access in patients who require it without the risks associated with placing a central line.