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Respiratory Cheat Sheet by

Adult Health 2


All body systems depend on adequate O2
Purpose of breathing: + O2 & - CO2


- Ventil­ation
- Hgb & RBC transport

- Gas exchange
ATP production is vital for cell activity & life
Cellular hypoxemia impairs the cell's energy produc­tion, disrupts cell function
Acute lung tissue is at the alveol­ar-­cap­illary membrane level

Mechanics of Breathing

Concepts of airway resist­ance, lung compli­ance, opposing lung forces
Inspir­ation: chest wall muscles contract, inc. intrap­leural pressure = lung expands
Expiration: lung deflates passively
Blood flow through the lungs:
- Bronchial
- Pulmonary: highly vascular capill. network
Pulse ox: measures O2 bound to Hgb (3% plasma, 97% Hgb)
Smoking = carboxyHgb binds faster to Hgb
Ventil­ati­on-­Per­fusion Ratios
V/Q Scans: r/o pulmonary embolus
Dead space: lung area has V/Q mismatch
- Do not partic­ipate in gas exchange
- Enough O2 but not enough blood flow
Shunt: blood bypasses alveoli w/o getting O2
Silent unit: pt can have dead space & shunt
Hypoxemia: not enough O2 in the blood
Hypoxia: not enough O2 in the tissues

Oxygen­-He­mog­lobin Dissoc­iation Curve

Hgb saturation = oximetry
O2 partial pressure (mm Hg) = paO2
Don't just get SpO2 when acute, get ABG's!
- pH is important
- Aerobic anaerobic metabolism lactic acid buildup
Oximetry has a +/- 2 margin of error

Personal History Assessment

Smoking (#1) - how long, how much might not be ready to hear it but respon­sible to inform about risks & compli­cations
Allergies - year round, don't have to be allergic for things to affect breathing
- Breathing in cold air is a very powerful irritant! (at least a cough)
Drug use - ACEI (cough), amiodarone (cough), beta-b­lockers (compete for B2 sites)
Travel - TB, outside country, soil
SES - what's in home enviro­nment, pet hair, heating system in fall/w­inter
Family Hx - genetics (recur­r./­chr­onic, acute)
Occupation - if mask required, ventil­ation

Respir­atory Changes w/ Aging

Chest wall: stiffer, m/s issues dec. compliance
Pharynx & larynx: muscles atrophy, airways lose cartilage, vocal cords start to slack
Lungs: lose elasticity dec. compliance
Alveoli: lose starting at 35yo but breathing not impacted unless chronic disease present
Pulmonary vascul­ature: alveol­ar-­cap­illary membrane thickens impairs gas exchange
Ciliary action: move mucus & filter grunge (mucoc­iliary exhalade)
- Cilia paralyzed for 4 hr after every cigarette

Subjective & Objective Data Assessment

Cough - cardinal symptom of respir­atory disease (6-8 wk = chronic)
Sputum - color? odor? changes? (normal = clear)
CP - assoc. w/ other things (GI, MI, etc.)
Dyspnea: length? onset? what helps? rate?
General appearance: visibly dyspneic? using accessory muscles (stern­ocl­eid­oma­stoid, trapezius, interc­ost­als)? position to breathe?
Vital signs: (later) all affected w/ work of breathing
Physical assessment: inspec­tion, palpit­ation, percus­sion, auscul­tation
- Always want extent to which you hear advent­itous breath sounds

Diagnostic Evaluation

Laboratory Assessment
- RBC (r/t Hgb transport)
- Hgb
- Sputum (sample for antibi­otics, C&S)
- ABG's (pH, CO2 hypo-/­hyp­erv­ent­ila­ting; acidic­/ac­idotic; bicarb.)
CT scan
Pulse ox
Lung biopsy
V/Q scan


X-rays: air = black / everything else = white
CXR - infilt­rates, infusions, masses
- Daily in ICU for changes

CT Scan

Thin slices, more specific than radiog­raphy
Often w/ contrast (more detailed)
- Assess allergies (shell­fish, iodine), kidney function

Pulse Oximetry

Measure of O2 attached to Hgb; SpO2 or SaO2
Normal value: 95-100%
Value affected by...
- Poor peripheral perfus­ion­/cold
- Nail polish
- Same arm as BP cuff
- Applied correctly?
Don't diagnose with value!


Measure of CO2 in exhaled air, which correlates w/ arterial CO2
Normal value = 20-40
Now checking capnog­raphy w/ PCA pumps

Pulmonary Function Tests (PFTs)

R/t volume and flow
Good way to track and trend where pts are


Insert scope to examine upper & lower airway
Invasive, need consent time-out!
Therap­eutic vs. diagnostic
Labs: platelets (CBC), PT/INR (clotting)
NPO 4-8 hr before
Premed­icate: sedation, topical to paralyze cords
VS & Assessment: pre- & post-s­cope, infection, bleeding
- May cause perfor­ation or pneumo­thorax
- Accessory muscles
- Asymme­tical expansion & breath sounds
- Acutely dyspneic
- Tachypneic
- Hypert­ensive


Therap­eutic (remove fluid) vs. diagnostic
Need consent, comfort pt
Sterile procedure!
Pre & Post: CXR, check puncture site, s/s of infection, VS, incentive spir. & deep breathe
Assessment: pneumo­thorax, pain on affected side, medias­tinal shift insert chest tube?
Upright, leaning permits better access

Lung Biopsy

Purpose: to obtain tissue sample for eval.
Various approa­ches:
- Transb­ron­chial Bx (TBB)
- Endobr­onchial Bx (EBB)
- Medias­tin­oscopy
- Open lung Bx (general anesth­esia)
Conscious sedation
Pre: CT for depth and density of mass
Post: gag reflex, VS (infec­tion), pneumo­thorax, bleed, hemoptysis

Ventil­ati­on-­Per­fusion (V/Q) Scan

Does ventil­ation match perfusion?
- Mismatch = ventilated not always perfused
Low/mo­der­ate­/high probab­ility for risk of pulmonary embolus
Procedure: pt gets inhaled nucleotide

Mixed Venous O2 Saturation (SVO2)

Get from pulmonary arterial line
Purpose: to eval. O2 supply­-demand balance
Normal value = 60-80%
Venous gas (60-80%) < arterial (80-100%)
- Easier sample, less painful
- What's going on at peripheral level

Pulmonary Embolism

A collection of matter that enters venous circul­ation and into the lungs
DVT's is a big risk!
1) Alveolar dead space inc. as blood shunted away
2) Vasoactive & bronch­oco­nst­rictive substances released vasoco­nst­riction dec. bood flow to lungs worsens PE
3) Pulmonary vascular resistance inc.
4) Pressure in pulmonary artery inc.
5) R ventricle workload inc.
6) CO dec. systemic blood pressure dec.
7) Deoxyg­enated blood moves into arterial circul­ation hypoxia & hypoxemia
Depends on SIZE of blood clot!

PE Risk Factors

Anything causing venous stasis - vericose veins, inactivity (spinal cord/hip surgery), restri­ctive clothing, prolonged travel, obesity
Hyperc­oag­ulable - obesity, trauma, cancer, factor defici­encies, birth control (estrogen)
Venous endoth­elial disease - vericose veins, trauma, surgery, vascular vein disease
Smoking - inc. fibrinogen = inc. viscosity
Change in aging
(1) venous stasis
(2) hyperc­oag­ula­bility
(3) venous endoth­elial damage­/injury
80-90% come from venous

PE Clinical Manife­sta­tions & Physical Assessment

SOB/dy­spnea (worse­ning) - tachyp­neic, cyanotic, use of accessory muscles, cough, restless, panicky, confused
Early/late HTN
Pleuritic CP
EKG changes
S3 or S4 (pooling, R-sided workload inc.)
paCO2 inc. = acidotic

PE Management Goals

1. Improve gas exchange
2. Improve lung perfusion
3. Dec. risk for further clot formation
4. Prevent compli­cations


Admini­stered ASAP for therap­eutic effect
Length of time-v­ariable
Heparin - usually autely (unless massive)
- -Kinases (antit­hro­mbo­lytic)
- Bridge w/ Warfarin (Coumadin) - treat 3-6 months but depends on size & risk factors
Other agents:
- Enoxaparin (Lovenox)
- Fondap­arinux (Arixtra)
Newer agents:
- Rivaro­xaban (Xarelto)
- Dabigatran (Pradaxa)
- Apixaban (Eliquis)
- Endoxaban (Savaysa)
Pro: infrequent labs / Con: no quick reversal

PE Diagnostic Evaluation

Sugges­tive, not definitive
Diagnosed w/ diagnostic tests, Sx, & labs
Labs - CK, CRP, ESR, D-Dimer
Radiol­ogy/CT, TEE (cardiac assess)
V/Q scan - now more pulm. angiog­raphy
D-Dimer: protein fragment active w/ clots

PE Treatment

O2 therapy - fix hypoxemia (vent/­mas­k/NC)
Anti-c­oag­ulation, Thromb­olytic agents
Surgery (embol­ectomy) & Filters (break up traveling clots; temporary or permanent)
Ekos: endo catheter through blood vessels to deliver clot-b­usting med &/or break up clot

Strategies to Prevent PE's

Early mobili­zation, Freq. position changes
Active­/pa­ssive ROM
Avoid tight clothes - esp. popliteal area
Lifestyle changes - obesity/wt loss, smoking, birth control, activity, diet (salads), hydration, medic alert bracelets
Anti-c­oag­ulation therapy - PT/INR, UFH
Avoid valsalva maneuver laxatives
Assess­men­t/eval of peripheral circul­ation - color, temp., & sensation in extrem­ities
Bleeding precau­tions - electric razors, hold pressure, scissors & knives
Hepari­n-I­nduced Thromb­ocy­topenia (HIT): heparin antibodies develop bind to pH & activate thrombin ( develop clots)


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