Term
| definition of ARDS/Acute Respiratory Distress Syndrome |
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Definition
| acute onset, bilateral infiltrates, and no clinical evidence of left sided heart failure or capillary wedge pressure <18mmHg. has to happen within a week of known clinical insult of new or worsening respiratory symptoms. chest imaging has to show bilateral opacities not fully explained by effusions, collapse, or nodules, and the origin of the edema has to be respiratory failure not fully explained by cardiac failure, or a fluid overload. needs to be pulmonary compliant w a non-cardiac cause for this |
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Term
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Definition
| pneumonia, aspiration of gastric contents, contusion, near drowning, or inhalation injury |
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Term
| Indirect lung injury ARDS |
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Definition
| more common, sepsis, severe trauma, multiple fractures, flail chest, multiple transfusions, drug overdose (opiod/aspirin), pancreatitis, post-cardiopulmonary bypass |
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Term
| ~60% of cases of ARDS due to |
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Definition
| pneumonia, infection, or sepsis |
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Term
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Definition
| starts to white out over time (diffuse alveolar involvement) |
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Term
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Definition
| direct and indirect injury to alveolus causing alveolar macrophages to release their cytokines that are pro-inflammatory causing an inflammatory process -> neutrophils attracted to area and cause more damage to alveolar capillary membrane -> area fills with fluid made of protein and surfactant and can no longer support the alveoli -> lung starts to collapse and fill with fluid -> whiting out |
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Term
| consequences of the injury to lungs in ARDS |
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Definition
| impaired gas exchange (V/Q mismatch, alveoli filling w fluid), decreased compliance, increased pulmonary arterial pressure, shunting -> hypoxia, increased dead space -> impairs carbon dioxide elimination, stiffness of poorly or non-aerated lung due to loss of surfactant, takes more pressure to deliver a tidal ventilation (work hard to pop open alveoli), increase in pulmonary arterial pressure due to hypoxic nasal constriction, get pos airway pressure causing vascular compression resulting in right ventricular failure |
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Term
| initial management of ARDS |
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Definition
| oxygenate, minimize acidosis and diuresis |
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Term
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Definition
| low tidal volume ventilation to avoid over distention of the normal alveoli and repeated opening and closing of damaged alveoli (every time they pop open and closed leads to more damage), use PEEP (positive end-expiratory pressure), 70 mL per kilo, conservative fluid management, prone positioning (greater expansion of ventral alveoli than dorsal alveoli- recruits and opens alveoli that have collapsed), pH goal 7.30-7.45, treat the underlying issue |
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Term
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Definition
| positive end-expiratory pressure, goal is to maximize alveolar recruitment and prevent injury. higher levels of PEEP and FiO2 can have a negative effect |
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Term
| benefits of prone positioning |
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Definition
| improves bloodflow and cardiac output, alveoli remain open even when returning to supine position |
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Term
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Definition
| rarely give sodium bicarb, usually help maintain BP by controlling respiratory rate, inc RR to blow off CO2 and raise pH, may also have to inc tidal volume |
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Term
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Definition
| decrease RR to retain CO2 |
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