Pulmonary System & Response to Exercise Flashcards
Pulmonary Ventilation
- what is it driven by?
gas exchange from high partial pressure to low partial pressure
Fick’s Law of Diffusion: amt of gas that can move across a sheet of tissue is proportional to the thickness & area
- increased thickness = decreased diffusion
- increased area (# of alveoli) = increased diffusion
Minute ventilation (VE)
amount of air you can breath in per minute (L/min) - tidal volume x breaths per minute
Increases w/ exercise linearly until reaching AT (then increased due to increased respiratory rate)
controlled by CO2 levels
- normal PCO2 = 40
Respiratory Pattern & Exercise
- light exercise
- > 80% intensity
During light exercise…
- increased tidal volume & increased RR
- tidal volume generally plateaus at 50-60% of vital capacity
> 80%, tidal volume will decrease & RR will increase
- less O2
ventilation tends to match the rate of energy metabolism during mild steady-state activity
Tidal volume
amount of air inhaled and exhaled in one NORMAL breath
Vital Capacity
max inspiration to max expiration
IRV + TV + ERV
Pulmonary function & regulation of acid-base balance
respiration will increase as H+ increases allowing more C)2 to be released into the blood and transported to the lungs for exhalation
-bicarbonate is responsible for buffering a rise in H+ (due to lactate accumulation or CO2)
Best to do an ACTIVE cool down to reduce blood lactate levels
Dyspnea
shortness of breath
often caused by inability to readjust the blood PCO2 and H+ due to poor conditioning of respiratory muscles
Hyperventilation
increase in ventilation that exceeds metabolic need for O2
reduces ventilatory drive by increasing blood pH
Valsava Maneuver
breathing technique to trap and pressurize air in the lungs; often used during heavy lifting
dangerous, can reduce cardiac output
ESPECIALLY if patient has HTN
Respiratory limitations to exercise
respiratory muscles use 15% of O2 during heavy exercise
- more resistant to fatigue
pulmonary ventilation, airway resistance & gas diffusion NOT a limiting factor
Can be limited if abnormal or obstructive respiratory disorders
…aka COPD (@ risk for hyperventilation & O2 desaturation) due to reduced max ventilation, diminished lung volumes & increased physiologic dead space
Objectives of exercise training for those w/ Pulmonary disease
- increase functional capacity & functional status
- reduce severity of dyspnea
- improve QOL
Pulmonary Function Test
Spirometry - purpose - classify lung function into 4 categories
- normal
- restrictive
- obstructive
- combination of restrictive/obstructive
based on patient’s effort, can be challenging
Contraindications to pulmonary function test
pneumothorax thoracic aneurysm recent eye surgery recent abdominal or thoracic surgery recent MI or unstable angina
Forced Vital Capacity
FVC
- maximal volume of air that can be forcefully exhaled after deepest possible inspiration
- Restriction = decreased
- obstruction is normal
Forced Expiratory Volume in 1 second
FEV1
- normal value should be >80% of predicted
- indicator for large airway obstruction & asthma
- obstruction = decreased
FEV1/FVC
ratio used to classify lung function
BEST INDICATOR of obstruction - below 80% of predicted
Forced Expiratory Flow or Midflows
FEV25-75%
Represents the small airway function
- Obstruction = decreased
- normal value: > 60-70% of predicted
Exercise induced SOB - spirometry protocol
- Pre-exercise PFT
- Brief warm up
- Exercise: elevate HR to 160-180 bpm & sustain that intensity for 6-8 minutes
- Post-exercise PFT @ 5, 10, & 15 min
Obstruction Pulmonary Diseases
any disease affecting the diameter of the airways
i.e. mucous production, inflammation, bronchoconstriction (asthma)
Characterized by low flow rates relative to lung volume
- Diagnosed by FEV1/FVC or FEV1 alone
Classifications of Asthma
based on FEV1
Mild = 65-80% predicted
Moderate = 50-65%
Severe =
Restrictive Pulmonary Disease
restriction of lung tissue or capacity of the lungs to expand & hold predicted volumes of air
i.e. sarcoidosis, insterstitial fibrosis, scoliosis
Characterized by low volumes & normal flow rates
Obs + Rest Pulmonary Disease
main example = cystic fibrosis - excessive mucous production & damage to lung tissue
3 most common causes of chest pain (in pediatrics)
- Asthma
- Vocal Cord Dysfunction
- GERD
Others:cardiac (ischemia, anomalies), pericarditis, mitral valve prolapse, esophagitis, costochondritis, sickle cell disease
Asthma
- symptoms
- parameters & response to PFT
Symptoms usually begin 5-20 min after exercise
- coughing, wheezing, chest tightness, SOB
Parameters for PFT:
- FEV1: primary value - increase of 200mL or 12% is positive
- FVC: increase of 10% or more is positive
- FEV25-75: increase of >20% is positive
if 2/3 parameters are positive after given albuterol (or other short acting beta agonist) then the patient has reversible airway obstruction & should be prescribed an inhalor
Vocal Cord Dysfunction
- what is it
- symptoms
- treatment
parodoxical closure or adduction of vocal cords during INSPIRATION which causes partial to severe air way obstruction
Symptoms mimic EIA:
- tightness, suffocation, choking , stridor, chronic cough or hoarseness, tingling in arms/legs, feeling faint, SOB
- abrupt onset & resolution in 2-3 min W/O meds
More common in females (2:1)
Treatment by respiratory therapist - education, recognition, breathing techniques, etc
Gastroesophageal Reflux Disease
GERD
2/3 of patients w/ asthma have underlying reflux & GERD that provokes their asthma;
therefore anti-reflux medications may help asthma symtpoms
95% of athletes w/ VCD also have GERD
Dehydration increases incidence
Treatment of Asthma
have an asthma action plan!
For EIA:
- use prescribed medications 10-20 min prior to exercise
2-4 puffs w/ 1 min in between
