Fluids

Common Abbreviations for Nursing

  • The instructor introduces common abbreviations used in report-taking and charting to streamline communication among nursing professionals:

    • Example Abbreviations:

    • c̅ = with

    • HS = at bedtime

    • R/T = related to

Fluid Management Concepts

Water Sources and Intake

  • Average water consumption: 2 to 2.5 liters daily primarily via the GI tract, which then distributes fluids throughout the body's compartments via osmosis.

Fluid Compartments

  • Intracellular Fluid (ICF)

    • Refers to the fluid contained within cells.

  • Extracellular Fluid (ECF)

    • Comprises plasma and interstitial fluids outside cells.

Fluid Imbalance

  • Discusses the significance of maintaining a balance between fluid intake and excretion.

  • Defines fluid positivity and negativity:

    • Fluid Positive: Intake exceeds output (e.g., ingesting 3 liters while excreting 2 liters).

    • Fluid Negative: Output exceeds intake (e.g., excreting more than one takes in over 24 hours).

Alterations in Fluid Spacing

  • First Spacing

    • Normal distribution of fluids in the body compartments.

  • Second Spacing

    • Fluid accumulation in interstitial spaces leading to edema.

  • Third Spacing

    • Fluid becomes trapped in body cavities or inappropriately relocated (e.g., ascites).

Osmotic and Hydrostatic Pressure

  • Osmotic Pressure: The pressure required to prevent water from flowing across a semipermeable membrane via osmosis.

  • Hydrostatic Pressure: The pressure exerted by fluids within blood vessels, affecting fluid movement between compartments.

Diagnostic Labs for Fluid Imbalance

  • Key labs indicating fluid overload or deficit include:

    • Elevated BUN to creatinine ratio

    • Serum osmolality changes

    • Electrolyte imbalances (potassium, sodium levels, etc.).

Fluid Volume Deficit (Hypovolemia)

Causes and Symptoms

  • Fluid loss through: vomiting, diarrhea, excessive sweating, and inadequate fluid intake.

  • Clinical manifestations include:

    • Hypotension, tachycardia, dry skin, decreased skin turgor, concentrated urine, elevated thirst, and weight loss.

Management

  • First step: identify the underlying cause (e.g., rehydration strategies).

  • Oral rehydration solutions (water, sports drinks) preferred; in severe cases, isotonic IV solutions are used.

  • Standard protocols for fluid replacement:

    • MILD: 50 mL/kg over 4 hours.

    • MODERATE: 100 mL/kg.

    • SEVERE: IV fluids immediately.

Fluid Volume Excess (Hypervolemia)

Symptoms

  • Clinical signs indicating fluid overload:

    • Hypertension, JVD (Jugular Vein Distension), pulmonary edema, abnormal heart sounds (S3), and weight gain.

Management

  • Strategies include:

    • Fluid restriction, diuretics, monitoring vitals closely, adjusting IV fluids as necessary.

    • Aquapheresis for resistant cases.

Intravenous Fluids Overview

  • Crystalloids: Will pass easily in and out of vascular spaces (e.g., saline solutions).

  • Colloids: Large molecules that typically stay in the vascular system (e.g., albumin).

Types of Crystalloid Solutions

  • Hypotonic Solutions: Encourage fluid movement into cells; used carefully, particularly in head injury cases.

  • Isotonic Solutions: Stay in the vascular space; often used for rehydration.

  • Hypertonic Solutions: Pull fluids from cells into blood vessels; used to treat serious issues like cerebral edema.