Nursing Management of the Patient Receiving IV Therapy
Venipuncture, or the ability to gain access to the venous system for administering fluids and medications, is an expected nursing skill in many settings. This responsibility includes selecting the appropriate venipuncture site and type of cannula and being pro-ficient in the technique of vein entry.
Before performing venipuncture, the nurse carries out hand hy-giene, applies gloves, and informs the patient about the proce-dure. Next the nurse selects the most appropriate insertion site and type of cannula for a particular patient. Factors influencing these choices include the type of solution to be administered, the expected duration of IV therapy, the patient’s general condition, and the availability of veins. The skill of the person initiating the infusion is also an important consideration.
Many sites can be used for IV therapy, but ease of access and po-tential hazards vary. Veins of the extremities are designated as pe-ripheral locations and are ordinarily the only sites used by nurses. Because they are relatively safe and easy to enter, arm veins are most commonly used (Fig. 14-7). The metacarpal, cephalic, basilic, and median veins as well as their branches are recommended sites be-cause of their size and ease of access. More distal sites should be used first, with more proximal sites used subsequently. Leg veins should rarely, if ever, be used because of the high risk of thromboembolism. Additional sites to avoid include veins distal to a previous IV infil-tration or phlebitic area, sclerosed or thrombosed veins, an arm with an arteriovenous shunt or fistula, or an arm affected by edema, in-fection, blood clot, or skin breakdown. The arm on the side of a mastectomy is avoided because of impaired lymphatic flow.
Central veins commonly used by physicians include the sub-clavian and internal jugular veins. It is possible to gain access to (or cannulate) these larger vessels even when peripheral sites have collapsed, and they allow for the administration of hyperosmolar solutions. Hazards are much greater, however, and may include inadvertent entry into an artery or the pleural space.
Ideally, both arms and hands are carefully inspected before choosing a specific venipuncture site that does not interfere with mobility. For this reason, the antecubital fossa is avoided, except as a last resort. The most distal site of the arm or hand is gener-ally used first so that subsequent IV access sites can be moved pro-gressively upward. The following are factors to consider when selecting a site for venipuncture:
· Condition of the vein
· Type of fluid or medication to be infused
· Duration of therapy
· Patient’s age and size
· Whether the patient is right- or left-handed
· Patient’s medical history and current health status
· Skill of the person performing the venipuncture
After applying a tourniquet, the nurse palpates and inspects the vein. The vein should feel firm, elastic, engorged, and round, not hard, flat, or bumpy. Because arteries lie close to veins in the antecubital fossa, the vessel should be palpated for arterial pulsa-tion (even with a tourniquet on), and cannulation of pulsating vessels should be avoided. General guidelines for selecting a can-nula include:
· Length: 3⁄4 to 1.25 inches long
· Diameter: narrow diameter of the cannula to occupy mini-mal space within the vein
· Gauge: 20 to 22 gauge for most IV fluids; a larger gauge for caustic or viscous solutions; 14 to 18 gauge for blood ad-ministration and for trauma patients and those undergoing surgery
Hand veins are easiest to cannulate. Cannula tips should not rest in a flexion area (eg, the antecubital fossa) as this could in-hibit the IV flow.
Equipment used to gain access to the vasculature includes can-nulas, needleless IV delivery systems, and peripherally inserted central catheter or midline catheter access lines.
Most peripheral access devices are cannulas. Theyhave an obturator inside a tube that is later removed. “Catheter” and “cannula” are terms that are used interchangeably. The main types of cannula devices available are those referred to as winged infusion sets (butterfly) with a steel needle or as an over-the-needle catheter with wings, indwelling plastic cannu-las inserted over a steel needle, and indwelling plastic cannulas inserted through a steel needle. Scalp vein or butterfly needles are short steel needles with plastic wing handles. These are easy to insert, but because they are small and nonpliable, infiltration occurs easily. The use of these needles should be limited to ob-taining blood specimens or administering bolus injections or in-fusions lasting only a few hours, as they increase the risk for vein injury and infiltration. Insertion of an over-the-needle catheter requires the additional step of advancing the catheter into the vein after venipuncture. Because these devices are less likely to cause infiltration, they are frequently preferred over winged in-fusion sets.
Plastic cannulas inserted through a hollow needle are usually called intracatheters. They are available in long lengths and are well suited for placement in central locations. Because insertion requires threading the cannula through the vein for a relatively long distance, these can be difficult to insert. The most com-monly used infusion device is the over-the-needle catheter. A hol-low metal stylet is preinserted into the catheter and extends through the distal tip of the catheter to allow puncture of the ves-sel, in an effort to guide the catheter as the venipuncture is per-formed. The vein is punctured and a flashback of blood appears in the closed chamber behind the catheter hub. The catheter is threaded through the stylet into the vein and the stylet is then re-moved. There are many safety over-the-needle catheter designs available with retracting stylets to protect health care workers from needlestick injuries.
Many types of cannulas are available for IV therapy. Some of the variations in these cannulas include the thickness of the cannula wall (affects rate of flow), the sharpness of the insertion needles (determines needle insertion technique), the softening properties of the cannula (influences the length of time the can-nula can remain in place), safety features (minimizes risk of needlestick injuries and blood-borne exposure), and the number of lumens (determines the number of solutions that can be infused simultaneously). Cannula systems that help prevent needlesticks and transmission of blood-borne diseases are discussed below. Most standard peripheral catheters are composed of some form of plastic. Teflon (polytetrafluoroethylene)–coated catheters have less thrombogenic properties and are less inflammatory than polyurethane or PVC. Catheter size for steel needles can range from 3⁄8 to 1.5 inches in length and 27 to 13 gauge. Plastic catheters range in length from 5⁄8 to 2 inches or as long as 12 inches. The size of the catheter ranges from 27 to 12 gauge.
To select the ideal product for use, consideration should be given to which product provides the greatest patient satisfaction and offers quality, cost-effective infusion care. All devices should be radiopaque to determine catheter location by x-ray, if indicated. All catheters are thrombogenic and differ only in their degree of thrombus occurrence. Biocompatibility, another characteristic of a catheter, ensures that inflammation and irritation do not occur. Silicone catheters are the most bioinert catheter available today.
In an effort to decrease needle-stick injuries and exposure to HIV, hepatitis, and other blood-borne pathogens, agencies have implemented needleless IV delivery systems. These systems have built-in protection against needle-stick injuries and provide a safe means of using and disposing of an IV administration set (which consists of tubing, an area for in-serting the tubing into the container of IV fluid, and an adapter for connecting the tubing to the needle). Numerous companies produce needleless components. IV line connectors allow the si-multaneous infusion of IV medications and other intermittent medications (known as a piggyback delivery) without the use of needles (Fig. 14-8). Technology is advancing and moving away from use of the traditional stylet. An example is a self-sheathing stylet that is recessed into a rigid chamber at the hub of the catheter when its insertion is complete. Other designs have placed the stylet at the end of a flexible wire to avoid needlesticks.
Many examples of these devices are on the market. Each insti-tution must evaluate products to determine its own needs based on OSHA guidelines and the institution’s policies and procedures.
Patients who need moderate- to long-termparenteral therapy often receive a peripherally inserted central catheter or a midline catheter. These catheters are also used for patients with limited peripheral access (eg, obese or emaciated patients, IV/injection drug users) who require IV antibiotics, blood, and parenteral nutrition. For these devices to be used, the median cephalic, basilic, and cephalic veins must be pliable (not sclerosed or hardened) and not subject to repeated puncture. If these veins are damaged, then central venous access via the sub-clavian or internal jugular vein, or surgical placement of an im-planted port or a vascular access device, must be considered as an alternative. Table 14-9 compares peripherally inserted central and midline catheter lines.
The principles for inserting these lines are much the same as those for inserting peripheral catheters; however, their insertion should be undertaken only by those who are experienced and spe-cially skilled in inserting IV lines.
The physician prescribes the line and the solution to be in-fused. Insertion of either line requires sterile technique. The size of the catheter lumen chosen is based on the type of solution, the size of the patient, and the vein to be used. The patient’s consent is obtained before use of these catheters. Use of the dominant arm is recommended as the site for inserting the can-nula into the superior vena cava to ensure adequate arm move-ment, which encourages blood flow and reduces the risk of dependent edema.
Except in emergency situations, a patient should be prepared in advance for an IV infusion. The venipuncture, the expected length of infusion, and activity restrictions are explained. Then the pa-tient should have an opportunity to ask questions and voice con-cerns. For example, some patients believe they will die if small bubbles in the tubing enter their veins. After acknowledging this fear, the nurse can explain that usually only relatively large vol-umes of air administered rapidly are dangerous.
Before preparing the skin, the nurse should ask the patient if he or she is allergic to latex or iodine, products commonly used in preparing for IV therapy. Excessive hair at the selected site may be removed by clipping to increase the visibility of the veins and to facilitate insertion of the cannula and adherence of dressings to the IV insertion site. Because infection can be a major com-plication of IV therapy, the IV device, the fluid, the container, and the tubing must be sterile. The insertion site is scrubbed with a sterile pad soaked in 10% povidone–iodine (Betadine) or chlorhexidine gluconate solution for 2 to 3 minutes, working from the center of the area to the periphery and allowing the area to air day. The site should not be wiped with 70% alcohol be-cause the alcohol negates the effect of the disinfecting solution. (Alcohol pledgets are used for 30 seconds instead, only if the pa-tient is allergic to iodine.) The nurse must perform hand hygiene and put on gloves. Nonsterile disposable gloves must be worn during the venipuncture procedure because of the likelihood of coming into contact with the patient’s blood.
Guidelines and a suggested sequence for venipuncture are pre-sented in Chart 14-2. For veins that are very small or particularly fragile, modifications in the technique may be necessary. Alter-native methods can be found in journal articles or in specialized textbooks of IV therapy. Institutional policies and procedures determine whether all nurses must be certified to perform venipuncture. A nurse certified in IV therapy or an IV team can be consulted to assist with initiating IV therapy.
Maintaining an existing IV infusion is a nursing responsibility that demands knowledge of the solutions being administered and the principles of flow. In addition, patients must be assessed care-fully for both local and systemic complications.
The flow of an IV infusion is governed by the same principles that govern fluid movement in general.
• Flow is directly proportional to the height of the liquid col-umn. Raising the height of the infusion container may im-prove a sluggish flow.
• Flow is directly proportional to the diameter of the tubing. The clamp on IV tubing regulates the flow by changing the tubing diameter. In addition, the flow is faster through large-gauge rather than small-gauge cannulas.
• Flow is inversely proportional to the length of the tubing. Adding extension tubing to an IV line will decrease the flow.
• Flow is inversely proportional to the viscosity of a fluid. Vis-cous IV solutions, such as blood, require a larger cannula than do water or saline solutions.
Because so many factors influence gravity flow, a solution does not necessarily continue to run at the speed originally set. There-fore, the nurse monitors IV infusions frequently to make sure that the fluid is flowing at the intended rate. The IV container should be marked with tape to indicate at a glance whether the correct amount has infused. The flow rate is calculated when the solu-tion is originally started, then monitored at least hourly. To cal-culate the flow rate, the nurse determines the number of drops delivered per milliliter; this varies with equipment and is usually printed on the administration set packaging. A formula that can be used to calculate the drop rate is:
gtt/mL of infusion set/60 (min in hr) × total hourly vol = gtt/min
Flushing of a vascular device is performed to ensure patency and prevent the mixing of incompatible medications or solutions. This procedure should be carried out at established intervals, ac-cording to hospital policy and procedure, especially for intermit-tently used catheters. Most manufacturers and researchers (LeDuc, 1997) suggest the use of saline for flushing. The volume of the flush solution should be equal to at least twice the volume capacity of the catheter. The catheter should be clamped before the syringe is completely empty and withdrawn to prevent reflux of blood into the lumen, which could cause catheter clotting.
A variety of electronic infusion devices are available to assist in IV fluid delivery. These devices allow more accurate administration of fluids and medications than is possible with routine gravity-flow setups. A pump is a positive-pressure device that uses pressure to infuse fluid at a pressure of 10 psi. Newer models use a pressure of 5 psi. The pressure exerted by the pump overrides vascular resis-tance (increased tubing length, low height of the IV container).
Volumetric pumps calculate the volume delivered by measur-ing the volume in a reservoir that is part of the set and calibrated in mL/h. A controller is an infusion assist device that relies on gravity for infusion; the volume is calibrated in drops/min.
A controller uses a drop sensor to monitor the flow. Factors essential for the safe use of pumps include alarms to signify the presence of air in the IV line and occlusion. The standard for the accurate delivery of fluid or medication via an electronic IV infusion pump is plus or minus 5%. The manufacturer’s directions must be read care-fully before using any infusion pump or controller, because there are many variations in available models. Use of these devices does not eliminate the need for the nurse to monitor the infusion and the patient frequently.
The removal of an IV catheter is associated with two possible dan-gers: bleeding and catheter embolism. To prevent excessive bleed-ing, a dry, sterile pressure dressing should be held over the site as the catheter is removed. Firm pressure is applied until hemostasis occurs.
If a plastic IV catheter is severed, the loose fragment can travel to the right ventricle and block blood flow. To detect this complication when the catheter is removed, the nurse compares the expected length of the catheter with its actual length. Plastic cathe-ters should be withdrawn carefully and their length measured to make certain that no fragment has broken off.
Great care must be exercised when using scissors around the dressing site. If the catheter clearly has been severed, the nurse can attempt to occlude the vein above the site by applying a tourni-quet to prevent the catheter from entering the central circulation (until surgical removal is possible). As always, however, it is better to prevent a potentially fatal problem than to deal with it after it has occurred. Fortunately, catheter embolism can be prevented easily by following simple rules:
• Avoid using scissors near the catheter.
• Avoid withdrawing the catheter through the insertion needle.
• Follow the manufacturer’s guidelines carefully (eg, cover the needle point with the bevel shield to prevent severance of the catheter).
IV therapy predisposes the patient to numerous hazards, includ-ing both local and systemic complications. Systemic complica-tions occur less frequently but are usually more serious than local complications. They include circulatory overload, air embolism, febrile reaction, and infection.
Overloading the circulatory system with excessiveIV fluids causes increased blood pressure and central venous pres-sure. Signs and symptoms of fluid overload include moist crack-les on auscultation of the lungs, edema, weight gain, dyspnea, and respirations that are shallow and have an increased rate. Possible causes include rapid infusion of an IV solution or hepatic, cardiac, or renal disease. The risk for fluid overload and subsequent pul-monary edema is especially increased in elderly patients with car-diac disease; this is referred to as circulatory overload.
The treatment for circulatory overload is decreasing the IV rate, monitoring vital signs frequently, assessing breath sounds, and placing the patient in a high Fowler’s position. The physician is contacted immediately. This complication can be avoided by using an infusion pump for infusions and by carefully monitoring all infusions. Complications of circulatory overload include heart failure and pulmonary edema.
The risk of air embolism is rare but ever-present.It is most often associated with cannulation of central veins. Man-ifestations of air embolism include dyspnea and cyanosis; hypo-tension; weak, rapid pulse; loss of consciousness; and chest, shoulder, and low back pain. Treatment calls for immediately clamping the cannula, placing the patient on the left side in the Trendelenburg position, assessing vital signs and breath sounds, and administering oxygen. Air embolism can be prevented by using a Luer-Lok adapter on all lines, filling all tubing completely with solution, and using an air detection alarm on an IV pump. Complications of air embolism include shock and death. The amount of air necessary to induce death in humans is not known; however, the rate of entry is probably as important as the actual volume of air.
Pyrogenic substances in eitherthe infusion solution or the IV administration set can induce a febrile reaction and septicemia. Signs and symptoms include an abrupt temperature elevation shortly after the infusion is started, backache, headache, increased pulse and respiratory rate, nausea and vomiting, diarrhea, chills and shaking, and general malaise. In severe septicemia, vascular collapse and septic shock may occur. Causes of septicemia include contamination of the IV product or a break in aseptic technique, especially in immunocompromised patients. Treatment is symptomatic and includes culturing of the IV cannula, tubing, or solution if suspect and establishing a new IV site for medication or fluid administration.
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