Pulmonology Review for Rotation Exams

Pulmonology for Rotation Exams
Peak Expiratory Flow - use a peak flow meter

• If <350 L/min, perform PFTs to screen for obstruction

Pulmonary Function Testing

• FEV1: amount of air that can be forced out of the lungs in 1 second
• Airway obstruction diagnosed by: normal/increased TLC with decreased FEV1
• FEV1/FVC < 0.7

Disease	FEV1	FVC	FEV1/FVC	FEF25-75	FET	Peak Exp Flow
Obstructive	Decreased <80%	Normal <80%	Decreased < 0.7	Decreased <60%	Increased	Low
Restrictive	Normal or Decreased <80%	Decreased <80%	Normal or Increased 0.7	Normal >60%	Normal	Normal
Mixed	Decreased <80%	Decreased <80%	Decreased < 0.7	Decreased or Normal <60%	Increased or Normal

• Tiffeneau index (FEV1/FVC x 100): % of FVC expired in one second
• FET = Forced Expiratory Time
• Pay Attention Here: The important thing to know about how to differentiate an obstructive vs. restrictive lung disease is based on their TLC, not the vital capacity, which will be decreased in obstructive lung diseases (this can be misleading).

Disease	TLC	FRC	TV	RV	VC
Obstructive	Increased	Increased	N	Increased	Decreased
Restrictive	Decreased	Decreased	N	Decreased	Decreased

• Total Lung Capacity: volume of air in lungs after maximum inspiration
• Functional Residual Capacity: volume of air in lungs after normal expiration
• Residual Volume: volume of air in the lungs at maximal expiration
• Tidal Volume: volume of air breathed in and out of lungs during quiet breathing
• Vital Capacity: volume of air expelled from the lungs during a maximum expiration