Trauma can significantly affect a patient's acid-base balance.
Fluid Functions in the Body
Water as a transport medium:
Transports nutrients, hormones, enzymes, and platelets.
Facilitates cellular metabolism.
Acts as a solvent for biochemical reactions.
Importance of fluid intake and output balance:
Fluid intake should equal output.
Insufficient intake or excessive output can lead to complications.
Fluid Compartments
Total Body Water Breakdown:
Intracellular Fluid (ICF):
Comprises approximately 75% of total body water.
Represents about 40% of an adult's body weight.
Extracellular Fluid (ECF):
Accounts for about 30% of total body water.
Around 20% of body weight.
Includes:
Vascular (intravascular) fluid
Interstitial fluid
Fluid Output and Losses
Types of Fluid Losses:
Sensible Losses:
Measurable losses (urine, vomit, diarrhea, etc.).
Insensible Losses:
Non-measurable losses (sweat, respiration).
Total Fluid Output Analysis:
Kidneys: 1,500 mL
Skin: 600 mL
Lungs: 400 mL
GI Tract: 300 mL
Total: 2,600 mL
Clinical Implications:
Excessive fluid loss can lead to dehydration; visible signs include moist beds in sweating patients.
Dehydration Indicators and Urine Characteristics
Symptoms of Dehydration:
Darker, concentrated urine.
Scant amounts of urine output.
Elevated specific gravity (indicates higher solute concentration).
Specific Gravity Contextualization:
Increased specific gravity likened to sugar concentrated in coffee where there's not enough fluid to dissolve it adequately.
Physical Symptoms:
Dry mucus membranes and sticky lips as examples of dehydration symptoms.
Understanding Fluid Mechanisms in the Body
Key Concepts in Physiology:
Osmosis:
Movement of water molecules from areas of low solute concentration to high solute concentration.
Analogy: "The good party is over there, let's go!"
Diffusion:
Solutes moving from an area of high concentration to an area of low concentration until equilibrium is achieved.
Active Transport:
Energy-requiring movement across a concentration gradient (low to high concentration).
Capillary Filtration:
Passage of fluids through permeable membranes.
pH Maintenance in the Body
Normal pH Range:
Human body maintains a pH of 7.35 to 7.45.
Minor pH changes can lead to compensatory mechanisms.
Acid-Base Definitions:
Acidosis: pH below 7.35 (excess hydrogen ions or loss of bicarbonate).
Alkalosis: pH above 7.45 (loss of hydrogen ions or gain of bicarbonate).
pH Examples:
Gastric juices: pH 2 (acidic)
Tomato juice: pH 4
Urine: pH 5
Water: pH 7 (neutral)
Blood: pH 7.4
Effects of Acidosis and Alkalosis on Patients
Response to Acidosis: Excess hydrogen ions or insufficient bases lead to a panel
Treatment Mechanisms: Sodium bicarbonate, protein buffers adjust pH levels.
Respiratory System Role:
Primary regulator of pH by controlling carbon dioxide levels in the blood.
Relationship between Respiratory Functioning and Acid-Base Balance
Consequences of CO2 Retention:
Hypoventilation leads to acid retention; respiratory rate must increase to expel CO2.
Hyperventilation:
Excessive breathing leads to increased loss of CO2, resulting in alkalosis.
Practical approach: breathing in a brown bag will recapture CO2.
Arterial Blood Gas (ABG) Values Explained
Critical ABG Values:
pH: 7.35-7.45
PaO2: 80-100 mmHg
PaCO2: 35-45 mmHg
HCO3: 22-26 mEq/L
Oxygen Saturation: 95-100%
Indications of ABG:
Determining a patient's respiratory or metabolic acid-base status.
Fast vs. Slow Compensation:
Respiratory compensation is immediate, kidneys take 2-3 days to respond.
Clinical Scenario Breakdown
Clinical Cases Examples:
Patient scenarios illustrating different acid-base imbalances were reviewed and analyzed in depth, demonstrating the correlating ABG values.
Key Output Indicators:
Respiratory Acidosis with corresponding low pH and high CO2.
Metabolic Acidosis with low pH and low bicarbonate; considerations for respiratory compensation.
Compensation Mechanism in Acid-Base Balances
Understanding Compensation:
Partial compensation indicated by changes in ABG values that lead to attempts at normalization without achieving it completely.
Full compensation occurs when pH is normalized even if CO2 or bicarbonate are still outside normal ranges.
Immune System Overview
Components of the Immune System:
Two major types:
Bone marrow: Produces white blood cells (Lymphocytes).
Lymphoid tissues: Including spleen and lymph nodes, which filter and destroy antigens, viruses, and bacteria.
Prednisone and Corticosteroids Effects:
Immunosuppressive risks, increased likelihood of infections, and impaired wound healing post-surgery.
Types of Immunity
Natural/Innate Immunity:
Broad spectrum, first line of defense without prior exposure memory.
Acquired/Adaptive Immunity:
Develops from previous infection or vaccination, can be active (body produces its own antibodies) or passive (temporary immunity through other sources).
Age-Related Changes in Immune Function
T and B lymphocyte production declines with age.
Risks for older adults: decrease in gastric acidity, reduced kidney function, and deteriorating pulmonary capacity, leading to increased risks for infections and slow recovery.