Learning Outcomes
By the end of this section, you should be able to:
- 5.3.1 Describe types of intravenous solutions.
- 5.3.2 Compare and contrast crystalloid and colloid intravenous solutions.
- 5.3.3 Define total parenteral nutrition and its uses.
- 5.3.4 Discuss the importance of blood and blood products in fluid balance.
- 5.3.5 Discuss how intravenous solutions are used to correct fluid imbalances within the body.
Fluid volume replacement is an important part of fluid and electrolyte homeostasis within the body. In this section of the chapter, intravenous fluid therapy, total parenteral nutrition, and blood products will be discussed.
Intravenous Fluid Therapy
Intravenous (IV) fluid therapy is a medical treatment that involves the administration of fluids directly into a person’s veins through an intravenous catheter. The fluids are typically a combination of water, electrolytes, and other nutrients, depending on the specific needs of the client.
IV fluid therapy is used for a wide variety of medical conditions including hypovolemia, electrolyte imbalances, and shock. It is commonly used during and after surgical procedures to help maintain fluid balance and prevent complications.
A health care professional administers IV fluid therapy. The appropriate type and amount of fluid administered is based on the client’s medical history, a thorough physical exam, and laboratory results. The fluids are delivered through an IV catheter, which is inserted into a peripheral vein or via a central venous access device or mediport. The rate and duration of IV fluid therapy will vary depending on the client’s condition and response to treatment. Therapy may last a few hours, several days, or even weeks. Refer to Drug Administration for review of dosage calculation formulas for drops per minute and milliliters per hour as they relate to IV fluid therapy.
Overall, IV fluid therapy is critical in restoring fluid balance, maintaining blood pressure, and preventing complications related to fluid volume deficit. IV fluid therapy usually involves crystalloid solutions, colloid solutions, total parenteral nutrition, and blood and blood products, all of which will be discussed further in the following sections.
Crystalloid Solutions
Crystalloid solutions are a type of IV fluid therapy that consists of electrolytes and fluids that can readily cross the capillary walls. These solutions lack proteins that maintain colloidal oncotic pressure (osmotic pressure exerted by large proteins that holds water within the vascular space) that prevents water from leaving the intravascular space (Epstein & Waseem, 2022). These solutions are commonly used for short-term maintenance of fluids and in treating fluid volume deficits. The three main types of crystalloid solutions are isotonic, hypotonic, and hypertonic, which are discussed in the following sections; examples can be seen in Table 5.1.
Isotonic Solutions
Isotonic solutions have the same concentration of dissolved particles, such as sodium and glucose, as the body’s own fluids. This means they have the same approximate osmolality as ECF or plasma. Because of their osmotic equilibrium, water does not enter or leave the cells. Isotonic solutions are typically used to treat conditions such as dehydration caused by vomiting, diarrhea, or excessive sweating or other conditions that cause fluid volume deficit (Epstein & Waseem, 2022).
Hypotonic Solutions
Hypotonic solutions have a lower concentration of dissolved particles than the body’s own fluids. This means they exert less osmotic pressure than ECF, which allows water to move into the cell or ICF compartment. Hypotonic solutions are often used to treat intracellular fluid volume deficit conditions, such as diabetic ketoacidosis or hyperosmolar hyperglycemic state (Epstein & Waseem, 2022).
Hypertonic Solutions
Hypertonic solutions have a higher concentration of dissolved particles than the body’s own fluid, which means they exert greater osmotic pressure than ECF. This results in a higher solute concentration than the serum, thus pulling water from the interstitial space into the ECF and causing cell shrinkage. They are used to treat conditions such as severe hyponatremia (low sodium levels), cerebral edema (swelling of the brain), or increased intracranial pressure (ICP) (Epstein & Waseem, 2022).
Colloid Solutions
Colloid solutions, also known as volume expanders, differ from crystalloid solutions in that they contain large molecular structures, such as proteins, carbohydrates, and lipids, that increase their osmolality without dissolving in the solution. Due to their large size, colloid solutions cannot cross the semipermeable membrane of capillary walls and remain confined to the intravascular compartment. These solutions increase the colloidal oncotic pressure, which draws fluid from the interstitial space into plasma, resulting in an increase in blood volume.
Commonly administered colloidal solutions are listed in Table 5.1 along with their indications and precautions (Crosignani et al., 2022).
| Crystalloid Intravenous Solutions | |||
| Solution Classification | Common Fluid Names | Indications | Precautions |
| Isotonic | Lactated Ringer’s (LR) 0.9% normal saline (NaCl) 5% dextrose in water (D5W) |
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| Hypotonic | 0.45% normal saline (1/2 NaCl) 0.33% normal saline (1/3 NaCl) |
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| Hypertonic | 3% normal saline (3% NaCl) 10% dextrose in water (D10W) |
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| Colloidal Intravenous Solutions | |||
| Solution Classification | Fluid Names | Indications | Precautions |
| High molecular weight | Dextran 75 Dextran 70 6% in 5% dextrose |
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| Hydroxyethyl starch | Hetastarch 6% Hespan Hextend |
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| Human albumin | Albumin 5% Albumin 25% |
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Safety Alert
Hydroxyethyl Starch (HES) Product Risk
Use of hydroxyethyl starch (HES) products increases the risk of mortality, kidney injury, and coagulopathy. Do not use HES products (such as hetastarch) unless an adequate alternative treatment is unavailable.
Total Parenteral Nutrition
Total parenteral nutrition (TPN), also known as intravenous nutrition, is a medical treatment that involves administering a specialized nutritional formula directly into a person’s bloodstream through a central venous catheter. The nutritional formula is tailored to the specific needs of the client and typically includes amino acids, carbohydrates, proteins, fats, electrolytes, vitamins, and minerals (Hamdan & Puckett, 2022).
TPN is used for clients who are unable to receive adequate nutrition through their digestive system due to illness, injury, or surgery. TPN is administered through a central venous catheter (central line, peripherally inserted central catheter, or an implanted port), which is placed in a large vein that terminates in the superior vena cava. The administration rate and duration of TPN depends on the client’s condition and response to treatment (Hamdan & Puckett, 2022).
Safety Alert
TPN and Peripherally Inserted Venous Catheters
Due to its high osmolality, TPN should not be administered through a peripheral venous catheter because it can cause vein irritation, damage, or thrombus formation (American Society for Parenteral and Enteral Nutrition, n.d.).
Indications for TPN include:
- Severe malnutrition
- Gastrointestinal disorders that prevent the absorption of nutrients
- Severe burns
- Inflammatory bowel disorders or diseases
- Short bowel syndrome
- Cancer or cancer treatments that affect the digestive system
Contraindications for TPN include:
- Intestinal obstruction or perforation
- Hepatic impairment
- Kidney impairment
- Uncontrolled diabetes
Adverse Effects
Adverse effects for TPN include:
- Catheter site infection
- Fluid volume overload
- Hyperglycemia
- Hypoglycemia if discontinued suddenly
- Parenteral-associated cholestasis
- Bleeding
- Refeeding syndrome
- Venous thrombosis
Clients should be monitored closely until they are stable. Monitoring should include (Hamdan & Puckett, 2022):
- Intake and output every 12 hours
- Urine sugar monitoring every 8 hours
- Serum electrolyte levels
- Serum protein levels
- Liver function levels
Blood and Blood Products
As you may recall, blood is a complex bodily fluid that is essential for transporting oxygen, nutrients, and hormones to the body’s tissues and organs as well as removing waste products. Blood products are components of blood that have been separated from whole blood through a process called blood fractionation. This process involves dividing the blood into red blood cells, platelets, and plasma and then processing and storing them separately (American Red Cross, n.d.).
Packed Red Blood Cells (PRBCs)
Packed red blood cells (PRBCs) are a blood product that contains concentrated red blood cells. PRBCs are created by removing most of the plasma from donated blood, leaving behind a concentrated mixture of red blood cells. PRBCs are used to treat conditions such as anemia, blood loss, or other conditions that require a boost in red blood cells. PRBCs are typically stored in a refrigerator unit in a blood bank and have a shelf life of up to 42 days (American Red Cross, n.d.).
Platelets
Platelets are another type of blood cell that plays a crucial role in blood clotting. They help to plug damaged blood vessels and prevent excessive bleeding. Platelets can be separated from donated blood and are used to treat conditions such as thrombocytopenia, which is a low platelet count (American Red Cross, n.d.).
Fat Emulsions (Lipids)
Fat emulsions, also known as lipids, are a substance found in the bloodstream. They include cholesterol, triglycerides, and other types of fatty acids. Lipids are given to clients who have a deficiency of fatty acids. Lipids are commonly administered along with TPN via piggyback or combined into the total TPN formula (Ahmed et al., 2023; American Red Cross, n.d.; Sepulveda & Pak, 2022).
Cryoprecipitated Anti-hemophilic Factor (Cryo)
Cryoprecipitated anti-hemophilic factor (cryo) is a blood product that contains a concentrated mixture of proteins used to treat bleeding disorders such as hemophilia. It is produced by freezing and thawing a unit of plasma and then removing the resulting precipitate. Cryo contains factors such as fibrinogen, von Willebrand factor, and Factor VIII, which are essential for blood clotting (American Red Cross, n.d.; Sachais & Senaldi, 2019).
Blood Typing, Cross-Matching, and Transfusion
Blood and blood products must be compatible with the recipient’s blood type to minimize the risk of transfusion reactions. Blood typing involves determining the blood group and Rh factor of the donor and the recipient. There are four main blood groups: A, B, AB, and O. Each group can be either Rh positive or Rh negative. The donor blood type is determined by testing for the presence of specific antigens on the surface of red blood cells (American Red Cross, n.d.).
Cross-matching involves mixing a sample of the donor’s blood with a sample of the recipient’s blood to check for compatibility. This is done to identify any potential reaction between the donor and recipient’s blood, such as the development of antibodies or agglutination (clumping) of the red blood cells (Harris & Crookston, 2022).
Once the blood has been typed and cross-matched, it can be transfused into the recipient’s bloodstream. An adult client will need a 16–18 gauge IV catheter for rapid transfusions and a 20–22 gauge IV catheter for routine transfusions. A pediatric client will need a 22–25 gauge IV catheter for transfusions. The length of the blood transfusion depends on the amount of blood or blood product being transfused and the rate of infusion. Generally, a unit of PRBCs takes about 2–4 hours to transfuse; other blood products such as platelets may take less time (Lotterman & Sharma, 2022).
During the transfusion, the client’s vital signs should be monitored regularly and per the facility’s protocol. The client should be observed closely for any signs of a transfusion reaction, which can range from mild to severe. Common reactions to blood transfusions include (Harris & Crookston, 2022; Lotterman & Sharma, 2022):
- Febrile reactions: the most common type of transfusion reaction, characterized by a fever and chills
- Allergic reactions: can range from mild itching, hives, and shortness of breath to severe anaphylaxis, which can be life-threatening
- Hemolytic reactions: occur when the body’s immune system attacks the transfused blood cells, causing them to break down
- Transfusion-associated circulatory overload: occurs when the body cannot handle the volume of fluid being transfused, leading to fluid volume excess and/or heart failure
It is important to note that blood transfusions are generally safe and effective when administered properly. Health care providers can take steps to minimize the risk of transfusion reactions, including premedicating with acetaminophen and diphenhydramine. Clients are closely monitored during and after the transfusion to ensure their safety.
Correcting Fluid Imbalance
Fluid imbalance in the body can be corrected by addressing the underlying cause of the imbalance. The goal is to restore the fluid balance through various interventions. The two main types of fluid imbalances are fluid volume deficit and fluid volume excess. Correcting fluid imbalances is critical to promoting normal physiological function.
Correcting Fluid Volume Deficit
As you may recall, fluid volume deficit occurs when the body loses more fluid than it takes in. Correction of fluid volume deficit includes oral rehydration with electrolyte solutions and water and treating the underlying cause, such as vomiting, diarrhea, or excessive sweating. IV fluid therapy may need to be administered by a health care professional after a thorough physical examination and review of laboratory values (Melendez-Rivera & Anjum, 2022). Fluid volume deficit is commonly treated with a crystalloid solution (see Table 5.1); however, it may occasionally require a colloid volume expander and/or blood or blood products to prevent further fluid loss and promote recovery.
Correcting Fluid Volume Excess
Fluid volume excess occurs when the body retains more fluid than it excretes. Correcting fluid volume excess involves restricting fluid and sodium intake, using diuretics to increase urine output, and treating the underlying causes, such as heart failure or kidney disorders, to prevent further accumulation of fluid and to promote healing (Ekinci et al., 2018).