Pulmonary rehab

--Benefits of pulmonary rehab: increases arterial venous oxygen (AVO2) difference for improved oxygen extraction from arteries, improved exercise tolerance, reduced dyspnea, improved ambulation, decreased hospitalizations

--Moser classification of functional pulmonary disability:
1. Normal at rest, dyspnea with stenuous exertion
2. Normal ADLs, dyspnea on stairs
3. Dyspnea with some ADLs, able to walk 1 block
4. Dependent with some ADLs, dyspnea with minimal exertion
5. Housebound, dyspnea at rest

--Patients who would benefit most from pulmonary rehab:
• Respiratory limitation of exercise at 75% max O2 consumption
• Irreversible airway obstruction with FEV1 < 2000ml or FEV1/FCV < 60%
• Restrictive lung disease with CO diffusion capacity < 80% predicted

--Maximal oxygen consumption (VO2 max) = (HR x SV) x AVO2 diff (Fick’s equation)
*dependent on body weight, age, sex, natural endowment, pathological conditions, endurance exercise training

--Obstructive Pulmonary Disease:
• increased airway resistance due to bronchospasm
• air trapping
• increased compliance
• impaired blood oxygenation (hypoxia) 2/2 perfusion/ventilation mismatch
• Flattening of diaphragm
• Causes: chronic bronchitis, emphysema, cystic fibrosis, asthma
--Emphysema: distention of air spaces distal to terminal bronchioles with destruction of alveoli --> airway collapse on exhalation, decreased gas exchange --> severe mulmonary artery HTN and RV failure
--Cystic fibrosis: generalized disease of exocrine glands, respiratory failure due to inadequate removal of secretions from bronchioles
*aerobic exercise helps increase sputum expectoration, improves mucous transport, and reduces airway resistance
--Impairment develops when FEV1 falls below 3 L/sec
--Increased RV, TLC

--Restrictive lung disease: impaired lung ventilation as a result of mechanical dysfunction of the lungs or chest wall --> stiffness of the chest wall or lung tissue
--Causes of restrictive lung disease: neuromuscular disease, thoracic deformities (kyphoscoliosis), scoliosis > 90 deg, ank spond, cervical SCI, interstitial lung disease, pleural disease, surgical removal of lung
--Respiratory complications of Duchenne’s MD: atelectasis, pna, chronic alveolar hypoventilation, ventilatory failure
--Decreased VC, TLC, RV, but normal FEV1

--Aging --> decreased VC, FEV1 (rate of 30 cc/yr), PO2, increased RV and FRC
--In smokers, FEV1 decrease will be 2-3 times as fast

--Pulmonary changes in C5 quad: 60% inspiratory capacity, weak cough, difficulty clearing secretions, decreased VC, increased RV

--Duchenne’s MD: initiate vent support when pt has dyspnea at rest, VC 40% predicted, maximal inspiratory pressure < 30% predicted, hypercapnea

--ALS: monitor PFTs, functional VC is best prognostic indicator

--Asthma: for reversible bronchospasm, can try methylxanthines, beta-2 agonists, anticholincholinergics
*young patients with moderate asthma may benefit from theophylline
--O2 recommended for pts who desat below 90% during exercise
--Benefits of home O2: reduced polycythemia, improved pulm HTN, reduced perceived effort during exercise, prolonged life expectancy, improved cognition, reduced hospital needs
--Benefits of diaphragmatic breathing: incr TV, decr FRC, incr max oxygen uptake
--Benefits of pursed-lip breathing: prevents air trapping, greater gas exchange in alveoli, incr TV, reduced dyspnea and work of breathing in COPD
--Benefits of preoperative and postoperative chest therapy: decreased pna, decreases atelectasis
--Aerobic exercises for CF: trunk exercises (sit-ups), swimming, jogging

--Glossopharyngeal breathing: can be used in restrictive lung disease in the case of ventilator equipment failure for up to 4 hours, improves volume of voice and rhythm of speech, prevents micro-atelectasis, allows deeper breaths for better cough, improves pulmonary compliance

--Intermittent abdominal pressure ventilator (pneumobelt): abdominal corset which created forced expiration by moving diaphragm cephalad, works only in sitting position, liberates hands and mouth for other activities
*contraindicated in obesity, scoliosis, and patients with decreased pulmonary compliance or increased airway resistance
--Rocking bed: rocks patient along vertical axis, using gravity to assist ventilation --> useful in diaphragm paralysis
*benefits include preventing venous stasis, improved clearance of secretions, prevents decubs, benefits bowel motility
*disadvantages: not portable, not useful in patients with decreased pulmonary compliance or increased airway resistance

--Fenestrated trach tubes: used in pts who can speak and require only intermittent vent assist  when inner unfenestrated cannula is out and tube is plugged, pt may speak
--Nonfenestrated trach: for pts who require continueous vent or are unable to protect their airway during swallowing
*one-way talking valve may be installed
--Speaking trach tubes: used in alert pts who require inflated cuff for ventilation, and have intact vocal cords
*need to speak in short sentences, quality of speech altered
*manual dexterity and strength required to occlude external port
--One-way speaking valves (Passy-Muir): air directed through trachea and up through vocal cords
*requires less work
*cannot be used in COPD patients because lung has lost elasticity so air can’t be forced out