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ARDS
Review of Acute Respiratory Distress Syndrome
Question | Answer |
---|---|
What are the names of the phases of ARDS? | Exudative Phase Fibroproliferative (proliferative) Phase Fibrosis Phase |
Which blood cells aggregate after lung injury in the exudative phase of ARDS? | Platelets |
Which inflammatory substances are released in the process of the development of ARDS in the exudative phase of ARDS that inflame and damage the alveolar membrane? | Serotonin, Bradykinin, and Histamine |
One of the most common causes of ARDS is | Sepsis |
What does this describe? Sudden, progressive pulmonary disorder characterized by severe dyspnea, hypoxemia, diffuse bilateral infiltrates, ↓d lung compliance. | ARDS |
How do you treat the disease of ARDS? | Trick question ;0( ARDS is not a disease -- it's a syndrome. You have to identify and treat the underlying cause of ARDS (injury to the lung, sepsis, etc...) ARDS is the result or consequence of injury to the lung. |
What is barotrauma? | Barotrauma—rupture of overdistended alveoli during mechanical ventilation. Patients with ARDS are at a higher risk for this when ventilated due to the fragile state of their alveoli. |
What adjustments are made to Tidal volume for a patient with ARDS in comparison to a patient who does not have as high a risk of barotrauma? | Tidal volumes (Vt) are smaller to minimize the risk of barotrauma in ARDS patients. |
What adjustments are made to allowable CO2 levels in ARDS? | Hypercapnia or higher CO2 levels are allowed in ARDS than in "other" patients. |
What is PEEP? | Positive End Expiratory Pressure. The increase in end-expiratory volume prevents alveolar collapse on exhalation, thereby maintaining ventilation–perfusion ratios and improving oxygenation. necessary to achieve a given change in volume. |
What is tidal volume? | Amount of air breathed in or out per breath. Also utilized as one of the ventilator settings for the amount of air delivered to patient through mechanical ventilation. |
What impact does PEEP have on the amount of oxygen being given to the patient with ARDS on the mechanical vent? | Higher positive end-expiratory pressure (PEEP) levels may reduce atelectrauma, but increase over-distention lung injury. Whether higher PEEP improves clinical outcomes among patients with acute respiratory distress syndrome (ARDS) is unclear. |
What is subcutaneous emphysema? | Subcutaneous emphysema is when gas or air is in the layer under the skin. Subcutaneous refers to the tissue beneath the skin, and emphysema refers to trapped air. |
What causes subcutaneous emphysema in ARDS? | It is a result or consequence of barotrauma in ARDS. There are additional causes of SE in other illnesses. |
Why are the kidneys at risk in ARDS? | ARDS patients are at a higher risk for renal failure because of the lack of adequate oxygen in the bloodstream (hypoxemia) and decreased renal perfusion (hypotension) |
Why would corticosteroids be used in ARDS? | An attempt to suppress inflammation. Keep in mind - the inflammatory process is what starts the damage to the alveoli capillaries. |
Are inotropes and/or vasopressors (PNS drugs used for shock) appropriate for ARDS? and why? | Yes Inotropes (make the heart pump harder and more efficiently) and vasopressors (vasoconstrictors) are used to maintain cardiac output and perfuse the tissues in ARDS. |
List 3 key interventions for maintaining cardiovascular status and therefore tissue/cell perfusion in a patient with ARDS? | 1. Hemodynamic monitoring (more invasive/accurate than just BP) 2. Fluid balance. Prevent dehydration and Pulmonary Edema 3. Inotropes and Vasopressors |
Are antibiotics appropriate treatment for ARDS? | Yes, if the underlying lung trauma involves a bacterial infection. |
In which phase of ARDS is there diffuse scarring and fibrosis that can result in decreased lung compliance? | Fibrotic phase |
Define the fibrotic Phase | Diffuse scarring and fibrosis that can result in decreased lung compliance. |
In which phase of ARDS will you see neutrophils, monocytes, lymphocytes and fibroblasts produced in an attempt to repair the damaged lungs? | Proliferative phase |
What is the effect of pulmonary fibrosis on the lung performance? | lung compliance is worsened due to the "stiffness" caused by the fibrosis. Characteristic of the Proliferative Phase |
What is the effect of thickened alveolar membranes in the proliferative phase of ARDS? | Poor delivery of O2 to the tissues. Hypoxemia. |
Is ARDS caused by direct injury to the lungs are indirect damage caused by a condition elsewhere in the body? | Either! Direct: *Lung contusions, FB aspiration, drowning, smoke inhalation, infection, pneumonia, embolism—fat, thrombus, air. Indirect: *Severe sepsis, multi-system trauma, shock, drug overdose, pancreatitis, ↑ ICP, radiation therapy |
What does this describe? inflames the alveoli, causing them to fill with fluid and collapse. Once the alveoli collapse, gas exchange ceases, and the body becomes starved of oxygen. | ARDS |
Phase of ARDS where long-term ventilator or supplemental oxygen may be required. | Fibrotic phase |
Phase of ARDS that occurs within hours or days of direct or indirect lung injury. | Exudative phase |
Phase of ARDS marked by pulmonary hypertension and increasing pulmonary fibrosis | Fibroproliferative (proliferative) phase |
What impact on compliance is there with the following: 1. Loss of surfactant 2. Damage to alveolar capillaries leading to protein/inflammatory rich liquid leaking into alveoli | Marked reduction in lung compliance. Lung compliance, or pulmonary compliance, is a measure of the lung's ability to stretch and expand (distensibility of elastic tissue). |
Why are greater pressures required for the patient to receive the same volume of air in ARDS than a patient without ARDS? | a greater pressure ( P) than normal is required to give the same increase in volume ( V). Common causes of decreased lung compliance are pulmonary fibrosis (occurs in ARDS and other syndromes/diseases), pneumonia and pulmonary edema. |
As water molecules pull together, they also pull on the alveolar walls causing the alveoli to recoil and become smaller. What keeps the healthy lung from collapsing and what does surfactant do in the lung? | Two factors prevent the lungs from collapsing: surfactant and the intrapleural pressure. Surfactant is a surface-active lipoprotein complex formed by type II alveolar cells. |
Why would a drug like pancuronium or vecuronium be used in the treatment plan for a patient in the proliferative phase of ARDS? | These are neuromuscular blockers that completely paralyze the patient. The patient is unable to voluntarily move any muscles in their body including opening eyes. This minimizes the amount of energy the patient expends to allow for focus on healing. |
If pancuronium or vecuronium is utilized in ARDS why is a sedative necessary? | These are neuromuscular blockers and while the patient is completely paralyzed they are still able to hear and utilize other senses without control of movement which is anxiety inducing in patients. |
When a patient is being treated with neuromuscular blockers - would a BiPap or Cpap be a more effective oxygen delivery method? | Neither! Patients on neuromuscular blockers have paralyzed diaphragms and are unable to breathe independently which requires mechanical ventilation. (ventilator) |