Gas Laws in Respiratory Therapy

Flashcards covering key gas laws and their relevance in the field of respiratory therapy.

Boyle’s Law

At constant temperature, pressure and volume are inversely related; Formula: P1V1 = P2V2; Pressure up, Volume Down, etc.

Charles’s Law

At constant pressure, volume is directly proportional to absolute temperature; Formula: V1/T1 = V2/T2; Relevant for understanding how gas expands and contracts with temperature.

Gay-Lussac’s Law

At constant volume, pressure is directly proportional to absolute temperature; Formula: P1/T1 = P2/T2; Significant for ensuring safety in storage of gas cylinders in hot conditions.

Dalton’s Law of Partial Pressures

Total pressure is equal to the sum of the partial pressures of gases in a mixture; Formula: Ptotal = P1 + P2 + P3 …; Useful for calculating alveolar oxygen and fraction of inspired oxygen.

Henry’s Law

The amount of gas dissolved in a liquid is proportional to the partial pressure of the gas above it; Formula: C = k × P; Important for understanding therapies like HBOT in carbon monoxide poisoning.

Fick’s Law of Diffusion

Rate of gas transfer is proportional to surface area times pressure gradient divided by membrane thickness; Formula: Vgas = (A × D × (P1 - P2)) / T; Explains diffusion efficiency and impairment in respiratory conditions.