| Question | Answer |
| Causes of low lung compliance | Pneumonia, pulmonary edema, pulmonary fibrosis(silicosis), atelectasis |
| What is RV? | Residual Volume. Gas remaining in lungs following a maximum expiratory effort. |
| If surface tension goes up, then ... | Pressure goes up |
| What is IC? | Inspiratory Capacity. Vt + IRV |
| Airway resistance is approximately __% of breathing resistance in healthy adults. | 80 |
| What is Specific Compliance? | Used to compare adults & children |
| Low values of Conductance indicate: | Asthma, Chronic Bronchitis |
| What is TLC? | Total Lung Capacity. Sum of all lung volumes. |
| What is surfactant? | Dipalmityl Lecithin - a phospholipid that dramatically reduces alveolar surface tension; keeps alveoli from collapsing. |
| Define Time Constants | The time required for a lung unit to empty approx. 65% of a tidal volume of breath |
| Es (Elastic static) equation: | Plat - Peep / Vt |
| Explain Alveolar Dead space | Non-perfused alveoli - alveoli that aren't receiving enough blood flow. |
| Chest wall resistance is approximately __% of breathing in healthy adults. | 20 |
| What is LaPlace's Law? | P=4ST/r (P=pressure, ST=surface tension, r=radius) |
| What is the BOHR Equation? | PaCO2 - PeCO2 / PaCO2 = Vd/Vt |
| There is a direct correlation between respiratory rate & ... | Vd/Vt |
| What are the accessory muscles of inspiration? | Scalenes, sternocleidomastoid, pectoralis major, & trapezius |
| Low values of elastance indicate: | Emphysema |
| If radius goes up, then ... | Pressure goes down |
| If the difference between PaCO2 & PeCO2 is greater than 20, then ... | Lots of dead space. (#1 cause is pulmonary emboli) |
| Raw equation: | Peak - Plat / flow |
| What is Elastance? | Opposite of Compliance = how easy air is pushed out. |
| Small radius = ____ distending pressure | Increase |
| What is VC? | Vital Capacity. Vt + IRV + ERV. Maximum inspiration follwed by maximum expiration. 70ml/kg. |
| A horizontal curve = | Low lung compliance. |
| A horizontal reflection on a compliance curve denotes ... | Low compliance; little V for lots of P. |
| What is FRC? | Functional Residual Capacity. RV + ERV. Volume of gas in the lungs following a passive expiration. |
| Specific causes of Surfactant Deficiancy | ARDS, IRDS, pulmonary edema, drowning, oxygen toxicity |
| Explain Anatomic Dead space | Conducting airways. Ideal body weight x 1 = approx dead space. |
| What is ERV? | Expiratory Reserve Volume. Maximum breath out from bottom of tidal volume (Vt). |
| What is an Anatomic Shunt? | Anatomic channel that bypasses the pulmonary capillary bed & empties venous blood into the L Atrium. (Ex: Thebesian, Broncial, Pulmonary, & Pleural veins) |
| Long Time Constant = | Long amount of time to empty O2 from the lungs |
| C dyn equation: | Vt / Peak - Peep |
| Reynold's Number | 2rvd / n. # >2000 establishes turbulent flow. |
| Normal Conductance | 0.5 - 1.5 L/sec/cmH2O |
| Never allow Plat to hit ... | 30 - or puppies die & Sarah McLachlan cries. |
| What is Alveolar Dead Space? | Ventilation w/o perfusion |
| What is the #1 dead space disease? | Pulmonary Embolism (blood clot) |
| Time Constant equation | Kt = Cl x Raw |
| General causes of Surfactant Deficiency | Acidosis, hypoxia, hyperoxia(high FiO2), atelectasis, prematurity |
| What are the accessory muscles of expiration? | Rectus abdominus, transverse abdominus, external oblique, internal oblique, internal intercostals |
| What is Conductance? | Ease of flow - opposite of Raw. |
| What are some resistance factors? | Bronchospasm, secretions, mucosal edema, low elastance, artificial airway(ET & Trach tubes) |
| What is surfactant produced by? | Type II pneumocytes |
| A vertical reflection on a compliance curve denotes ... | High compliance; lots of V for little P. |
| Explain Physiologic Dead space | Anatomic + Alveolar dead space (Vd/Vt) |
| What is airway resistance? | Impedance to movement of gas through the airways |
| If Surface tension goes down, then Distending Pressure ... | Goes down |
| What is the normal Time Constant? | .2 seconds |
| If Surface Tension goes up, then Distending Pressure ... | Goes up |
| Surface Tension & Distending Pressure are ... | Directly proportional |
| Normal Airway Resistance | 1-2 cmH2O/L/sec |
| High value of Raw indicates: | Asthma, Chronic Bronchitis |
| What is Resistance? | Chest wall tissue resistance; impedance to motion caused by the thorax & abdomen. |
| What is the normal Vd/Vt range? | .20 - .40 |
| WOB Calculation: | Diameter x 16 |
| Never allow Peak to hit ... | 50 |
| Rapid, shallow breathing = | Increase in Vd/Vt |
| What is the major muscle of inspiration? | Diaphragm. (R & L hemidiaphragms) |
| What is normal Specific Compliance? | 0.080 L/cmH2O/L |
| C stat equation: | Vt / Plat - Peep |
| Too much lung compliance can cause ... | Emphysema(due to low elastance) |
| What nerve innervates the diaphragm? | Phrenic nerve |
| What is the purpose of low density gases? | To decrease turbulence & WOB |
| What is FVC? | Forced Vital Capacity; maximum inhale followed by maximum exhale. Ideal Body Weight x 6 = FVC |
| What is IRV? | Inspiratory Reserve Volume. Maximum breath in on top of tidal volume (Vt). |
| Short Time constant indicate: | 0.1 sec = Pneumonia, IRDS, ARDS, cardiogenic pulmonary edema |
| Low lung compliance diseases | Pneumonia, Pulmonary Edema |
| What is a capillary shunt caused by? | Atelectasis & Alveolar Fluid |
| Explain airway tethering | The more alveoli in contact w/ other airways, the less likely they are to collapse. |
| Indications for use of low density gases: | Stridor, croup(post extubation), foreign body aspiration, upper airway masses |
| Ed (Elastic dynamic) equation: | Peak - Peep / Vt |
| Long Time constant indicate: | 2.0 sec = asthma, bronchitis; 4.0 sec = emphysema |
| Large radius = ____ distending pressure | Decrease |
| What is normal Elastance? | 5cmH2O/L |
| Short Time Constant = | Short amount of time to empty O2 from the lungs |
| What is the Specific Compliance equation? | Cl / FRC. (Lung Compliance / Functional Residual Capacity) |
| Poiseuille's Law | Flow ~ P x r(to the 4th power) Addresses laminar flow, occurs in the small airways <2mm in diameter. WOB increases when Diameter decreases. |
| A vertical curve = | High lung compliance. |
| Low thoracic compliance caused by: | Kyphoscoliosis, Ascites, Gross Obesity |
