Maintenance of Homeostasis: This involves the regulation of bodily fluids and electrolytes within narrow limits to ensure optimal function.
Composition and Volume of Fluids and Electrolytes: The body maintains a specific composition and volume of fluids, crucial for physiological processes.
Water Content: Water content in the body is variable and depends on age, gender, and fat content. For example, newborns have a higher percentage of body water, while the elderly have less.
Fluid Compartments
Intracellular Fluid (ICF): Fluid found inside the cells, which constitutes approximately 2/3 of body water.
Extracellular Fluid (ECF): Fluid outside the cells, further divided into multiple compartments:
Interstitial Fluid: Fluid that surrounds the cells.
Intravascular Fluid (Plasma): Fluid that is found in the blood vessels.
Transcellular Fluid: Includes fluids found in specific compartments such as cerebrospinal fluid, pleural fluid, and synovial fluid.
Fluid Shifts
Edema: Defined as the accumulation of excess fluid in the interstitial spaces of tissues.
Causes of Edema:
Shifts of Plasma to Interstitial Fluid: Fluid moves from blood vessels to surrounding tissues.
Elevation of Venous Hydrostatic Pressure: Increased pressure in veins leads to fluid leakage into interstitial spaces.
Decrease in Plasma Oncotic Pressure: Lower protein levels in plasma result in a decreased ability to retain fluid in the intravascular space.
Elevation of Interstitial Oncotic Pressure: Increased pressure draws fluid from plasma into the tissues.
Calculation of Fluid Gain or Loss
Weight of Water: 1 liter of water weighs approximately 2.2 pounds (1 kg).
Body Weight Change: Noticed weight changes effectively indicate overall fluid volume gain or loss. For instance, consuming 240 mL of fluid can lead to about a 0.5 lb gain.
Diuretic Example: A patient losing weight on diuretics may lose 4.4 lbs (2 kg) correlating to a fluid loss of approximately 2 liters.
Hypovolemia
Definition: A condition characterized by an abnormal loss of body fluids, inadequate intake, or shifting of fluids from plasma to interstitial space.
Causes:
Conditions like hemorrhage, vomiting, diarrhea, burns, pancreatitis, and diuretics can lead to hypovolemia.
Clinical Manifestations: Symptoms include:
Restlessness, lethargy, and confusion
Thirst, dry mucous membranes, cold clammy skin
Decreased skin turgor, delayed capillary refill time
Postural hypotension, tachycardia, and tachypnea
Decreased urine output or concentrated urine
Weakness, dizziness, weight loss, and seizures.
Interprofessional Care for Hypovolemia
Treatment Goals: Address the underlying cause and restore lost fluids and electrolytes.
Interventions:
Oral rehydration or intravenous fluid therapies including blood products or balanced IV solutions like Normal Saline (NSS) and Lactated Ringer's (LR).
Monitoring: Daily weights, strict input/output tracking, and relevant lab tests.
Fluid Volume Excess (Hypervolemia)
Causes: Due to excess intake of fluids, abnormal retention, or shifting of fluid from interstitial to plasma compartment.
Common Conditions: Heart failure, renal failure, excessive intravenous fluids, long-term corticosteroid use, and polydipsia.
Clinical Manifestations:
Most notably weight gain, distended neck veins, and jugular venous distension (JVD).
Edema, crackles in the lungs, liver enlargement.
Headaches, confusion, lethargy, murmurs, hypertension, increased urination, dyspnea, and potential for seizures or coma.
Interprofessional Care for Hypervolemia
Treatment Goals: Remove excess fluid without altering the electrochemical balance or osmolality of extracellular fluid.
Interventions:
Administration of diuretics, fluid restrictions, and sodium intake reductions.
Specialized treatments can involve removal of fluid to address ascites or pleural effusion.
Continuous monitoring of cardiac and pulmonary systems, along with pertinent lab tests.
Normal Range: Sodium levels in the body should be between 136–145 mEq/L.
Functions: Sodium is crucial in regulating fluid balance, nerve impulses, and muscle contractions and is primarily maintained by the kidneys.
Elderly Patients: Often cannot maintain adequate fluid intake leading to complications.
Hypernatremia: Characterized by sodium levels greater than 145 mEq/L.
Causes: Insufficient water intake (fever, diarrhea, excessive sweating), excessive sodium intake (hypertonic IV solutions, tube feeds without water).
Symptoms: Include thirst, dry mouth, confusion, agitation, and can progress to seizures and coma. High fluid volume presents with symptoms such as swelling and hypertension, while low fluid volume may manifest as low blood pressure and weakness.
Treatment: Administer IV fluids or oral water and preferably sodium-free solutions (like D5W). Important to lower sodium levels gradually to avoid brain edema.
Hyponatremia (Na⁺ < 136)
Causes: Often results from sodium loss due to vomiting, diarrhea, nasogastric suction, and diuretics, or excessive water gain through intravenous fluids or conditions like heart failure.
Mechanism: This can lead to water influx into brain cells resulting in cerebral edema and neurological symptoms.
Symptoms: The manifestation varies based on fluid volume status:
Dry patients present with dizziness, cold skin, and low BP.
Overloaded patients exhibit weight gain, edema, and hypertension.
Treatment: Restrict fluids in cases of excess water; replace sodium through IV or oral means for sodium losses, while holding diuretics. Correction should be achieved slowly to prevent irreversible brain damage.
Normal Range: Potassium levels should remain between 3.5–5.0 mEq/L.
Functions: Vital for nerve function, muscle contractions, and regulating heart rhythm. Excretion largely governed by the kidneys.
Hyperkalemia: Signified by potassium levels exceeding 5.0 mEq/L.
Causes: Excessive intake, shifts of potassium from cells during states of acidosis, renal insufficiency (inability to excrete), and certain medications.
Symptoms: Patients may have dysrhythmias, muscle cramps, fatigue, and GI distress like diarrhea.
Treatment: Immediate cessation of potassium intake, enhancing its excretion, shifting potassium into intracellular space via agents like insulin and glucose, and utilizing calcium gluconate IV to safeguard cardiac function. Continuous monitoring of cardiovascular parameters is essential.
Hypokalemia (K⁺ < 3.5 mEq/L)
Causes: Commonly due to loss from vomiting, diarrhea, nasogastric suction, excessive diuretics, or inadequate intake.
Symptoms: Patients may experience arrhythmias, fatigue, proximal muscle weakness, and respiratory complications.
Treatment: Replenishing potassium orally or IV formulation (never as a push), ensuring proper dilution, with the maximum infuse rate typically capped at 10 mEq/hr and using a pump for administration. Monitoring of urine output is critical prior to administration.
Calcium (Ca²⁺) Basics & Hypercalcemia
Normal Range: The normal ionized calcium range is 9.0–10.5 mEq/L.
Functions: Critical for bone density, cardiac function, muscle contraction, and neurotransmission - dependent on vitamin D for proper absorption.
Causes: Included are hyperparathyroidism, malignancies, prolonged immobilization, and excess vitamin D.
Symptoms: Patients may show dysrhythmias, weakness, fatigue, and possible confusion or hallucinations, alongside renal complications like stones.
Treatment: Involves dietary management, increased fluid intake, and the use of bisphosphonates or calcitonin.
Hypocalcemia
Causes: Typically arises from hypoparathyroidism, vitamin D deficiency, or certain medications.
Symptoms: Manifestations include dysrhythmias, confusion, cramps, and tetany.
Treatment: Involves addressing the root cause with calcium and vitamin D supplementation, the application of IV calcium gluconate in severe scenarios, and anxiety management techniques to lessen transitions toward respiratory alkalosis.
Phosphate (Phos⁻) Basics & Hyperphosphatemia
Normal Range: Phosphate levels range from 3.0–4.5 mEq/L.
Functions: Integral to energy production (ATP), red blood cell function, and nervous system health; impacts calcium metabolism reciprocally.
Hyperphosphatemia: Identified when levels exceed 4.5 mEq/L.
Causes: Renal failure and dietary excess, leading to minimal symptomatic presentation until severe.
Symptoms: Can reflect calcium and pose risks for tissue calcification.
Treatment: Based on management of underlying causes and phosphate binders.
Hypophosphatemia (Phos⁻ < 3.0)
Causes: Leading causes include malabsorption, hormonal shifts, and deficient nutrition.
Symptoms: Potentially grave situations of respiratory failure, arrhythmias, and bone integrity issues can occur.
Treatment: Administration of potassium phosphate supplements and careful lab monitoring.
Magnesium (Mg²⁺) Basics & Hypermagnesemia
Normal Range: Magnesium regular values are 1.3–2.1 mEq/L.
Functions: Essential for cellular metabolism, protein synthesis, and vital for muscle and nerve function.
Hypermagnesemia: Levels exceed 2.1 mEq/L, typically linked to renal impairment.
Causes: Excess intake or renal dysfunction.
Symptoms: Include lethargy, cardiac irregularities, and severe respiratory depression.
Treatment: Consists of ceasing magnesium intake, ensuring the heart is stable via calcium supplementation, and further diuresis through IV fluid management.
Hypomagnesemia (Mg²⁺ < 1.3)
Causes: Often results from GI loss or inadequate intake.
Symptoms: Range from neuromuscular irritability to gastrointestinal distress.
Treatment: Involves correction of the reason for deficiency alongside magnesium supplementation, thoroughly observing the patient during administration.
Chloride (Cl⁻) Basics & Hyperchloremia
Normal Range: Typical chloride levels range from 96–106 mEq/L.
Functions: Plays a fundamental role in maintaining osmotic pressure and aiding digestion via hydrochloric acid production in gastric fluids.
Hyperchloremia: Denotes a chloride level greater than normal.
Causes: Primarily dehydration and excessive saline use.
Symptoms: Patients may experience rapid breathing and changes in blood pressure.
Treatment: Addressing hydration through IV fluids and monitoring laboratory values.
Causes: Often due to excessive loss (vomiting, sweating).
Symptoms: Include neuropsychological manifestations as well as muscle irritability.
Treatment: Involves replacing chloride through electrolyte solutions and maintaining acid-base balance.
Intravenous Insertion Selection
Important veins for IV insertion include the:
Cephalic vein
Brachial artery
Basilic vein
Metacarpal plexus
Median cubital vein
Dorsal venous arch
Common Problems with IV Catheters
Occlusion: Blockage that can prevent fluid entry or exit, requiring immediate evaluation.
Leakage: Noted when infused fluids exit the vein and cause discomfort or swelling at the insertion site.
Intermittent Saline Lock
An Intermittent Saline Lock is used to maintain vascular access for medications while also minimizing discomfort for the patient.
Alaris IV Pump System
The Alaris IV pump system utilizes a variety of components including a roller clamp, safety clamp, check valve, and injection port to ensure precise fluid delivery.
Primary VS Secondary Infusion
Primary Infusion: The main line connected to the IV.
Secondary Infusion: Additional lines (often referred to as piggyback) that can be intermittently attached to the primary line.
Venipuncture Complications
Infiltration: Occurs when the needle moves out of the vein, causing fluid to leak into surrounding tissues.
Treatment: Stop the infusion, remove the needle, elevate the area, and apply cold compress initially.
Extravasation: Leakage of caustic solutions that can lead to tissue damage.
Treatment: Cease the infusion and possibly consult for specific antidotes.
Phlebitis: Involves vein inflammation with characteristic tenderness.
Treatment: Networked with catheter removal and warm compresses.
Infection: Local infection at the venipuncture site which may necessitate antibiotic treatment.
Treatment: Remove catheter and manage care actively.
Hypersensitivity Reactions: Allergic responses can range from mild to severe.
Treatment: Cessation of the infusion and allergy management, potentially with epinephrine needed in severe reactions.
Blood Transfusion Protocols
Order Verification: Ensure a legitimate order for the transfusion exists. Conduct physical assessments and confirm patient consent procedures.
Patient Education: Inform the patient about the transfusion process and potential reactions, ensuring they know when to alert staff.
Vascular Access: Use a large gauge IV line (at least #18 gauge) for administering blood products alongside normal saline fluid (only IVF used).
Double-check Protocols: Always verify patient identifiers against the blood product with another healthcare professional before the transfusion begins.
Infusion Timings: Infusion rates must be adjusted based on the patient's tolerance and clinical status—rapid for trauma and slower for frail older patients.
Monitoring: Closely observe the patient for the first 15 minutes for any adverse reactions during the blood transfusion process and be prepared to respond appropriately.