Question | Answer |
hypoxemia | PaO2 <60
failure of respiration/oxygenation |
hypercapnia | PaCO2 >50
failure of ventilation |
state of disturbed gas exchange resulting in abnormal ABGs? | acute respiratory failure |
tidal volume (Vt) | 500 mL air/breath |
anatomic dead space (ADS) | Vt/3
500/3 = 150 mL/breath |
alveolar ventilation volume (AVV) | Vt - ADS
500 - 150 = 350 mL/breath |
alveolar ventilation rate (V) | AVV X RR
350 X 12bpm = 4.2 L/minute |
pulmonary perfusion rate (Q) | volume of blood in the pulmonary circulation per minute
5 L/minute |
V/Q Match | 4.2/5.0 = .8 which is almost 1 |
what are the determinants of adequate alveolar ventilation? | V: adequate air intake
Q: adequate perfusion in pulmonary circulation |
causes of V/Q mismatch? | bronchitis <1 and emphysema >1 |
primary clinical manifestations of ARF? | hypoxemia and hypercapnia |
early clinical manifestations of ARF? | confusion, headache, restlessness, tremors, tachycardia, HTN |
late clinical manifestations of ARF? | coma, bradycardia, hypotension, pulmonary HTN, cyanosis, respiratory arrest |
what is acute respiratory distress syndrome (ARDS)? | -infiltrative lung lesions
-severe refractory arterial hypoxemia
-life threatening respiratory distress |
precipitating events of ARDS (categories)? | -direct injury/physical source
-inhalation or airway source
-blood borne or vascular source |
reason why severe refractory arterial hypoxemia sucks so much? | doesnt respond to oxygen --> ventilator |
top two precipitating events of ARDS? | aspiration and sepsis |
synonymous terms for ARDS? | -septic lung
-wet lung
-white lung
-capillary leak syndrome
-shock lung
-noncardiogenic pulmonary edema |
clinical manifestations of initial ARDS stage? | -insidious (sudden) onset
-dyspnea
-restlessness
-rales
-XRAYS: minimal infiltrates |
primary clinical manifestations of ARDS? | pulmonary edema and decreased lung compliance |
clinical manifestations of second ARDS stage? | -noisy tachypneic breathing
-tachycardia
-diaphoresis
-decreased mentation
-pallor, cyanosis (resp. distress)
-XRAYS: extensive, bilateral infiltrates and cardiomegaly |
clinical manifestations of final ARDS stage? | -intubation and assisted ventilation
-bronchial breath sounds
-severe metabolic acidosis
-death
-XRAYS: white out/white lung |
complications of ARDS? | -disturbances in cardiac rhythm
-secondary to bacterial infections
-sepsis
-stress ulcers
-DIC |
most frequent histopathologic finding of ARDS? | capillary leakage |