IO

115 study guide

  • Ideal Body Weight Calculation

    • Be prepared to calculate ideal body weight based on height and gender.

    • Ideal body weight is initially provided in kilograms; convert by multiplying by 2.2 to get pounds.

  • Alveolar Ventilation Calculation

    • Formula: Alveolar Ventilation (Va) = (Tidal Volume - Dead Space) x Respiratory Rate.

    • Understanding how tidal volume, dead space, and respiratory rate are interconnected is crucial for this calculation.

  • Partial Pressure of Oxygen (PaO2)

    • Know how to calculate the partial pressure of oxygen in the alveoli as part of the exam scenario.

  • Total Oxygen Content

    • Be familiar with calculating the total oxygen content (CaO2) as this is a necessary component of the exam questions.

  • Static vs Dynamic Compliance

    • Understanding the definitions and differences is crucial for the related calculations.

    • Remember to subtract any peak end-expiratory pressure (PEEP) from peak pressures when calculating compliance.

  • Blood Circulation through the Heart

    • Review the blood flow and be prepared to identify the heart valves even if not asked to label them.

  • Sympathetic vs Parasympathetic Nervous System

    • Know that the parasympathetic nervous system is associated with rest and digest (neurotransmitter: acetylcholine).

    • The sympathetic nervous system corresponds to fight or flight (neurotransmitter: norepinephrine/adrenaline).

  • Breathing Mechanism

    • Understand how inhalation and exhalation processes change pressure dynamics (decreased pressure during inhalation and increased pressure during exhalation).

  • Minute Ventilation Calculation

    • Review the formula for Minute Ventilation to ensure accuracy in calculations during the exam.

  • Dead Space Ratio

    • Be aware of how to calculate dead space ratio (VD/VT) as it will be included in the exam.

    • Remember the formula: VD = (Paco2 - Petco2) / Paco2.

  • V/Q Ratio

    • Understand how to calculate the ventilation/perfusion (VQ) ratio and what the individual components (V = Ventilation, Q = Cardiac Output) stand for.

    • Be prepared to analyze VQ ratio problems presented in the exam.

  • Volume and Capacity Definitions

    • Know the definitions of lung volumes and capacities, including Total Lung Capacity, Residual Volume, Tidal Volume, and Vital Capacity.

  • Normal Values and Conditions

    • Memorize regular ranges and normal values for alveolar-arterial gradient (A-a gradient) and airway resistance, as well as what changes indicate normal versus pathological conditions.

  • Oxygen Cost of Breathing

    • Be aware of the metabolic cost of breathing, outlined as 55% oxygen cost in adults.

  • Gas Laws and Disassociation Curves

    • Review the Law of Partial Pressures and be able to calculate using atmospheric pressure, with specific focus on the Oxyhemoglobin Dissociation Curve (normal p50 is 26).

    • Understand what shifts in this curve imply about hemoglobin's affinity for oxygen.

  • Restrictive Lung Diseases

    • Know which lung diseases can cause decreased lung compliance (restrictive conditions).

  • Bohr Effect and Haldane Effect

    • Familiarize yourself with these physiological effects and be able to explain their relation to oxygen and carbon dioxide transport during assessment scenarios.