Term
| what is the definition of respiratory failure (RF)? (*exam question*) |
|
Definition
| *PO2 less than 50 mm Hg, PCO2 greater than 50 mm Hg* |
|
|
Term
| what are the physiologic disorders that lead to RF? |
|
Definition
| impaired ventilation, impaired diffusion/gas exchange, ventilation/perfusion (V/Q) abnormalities, and venous admixture |
|
|
Term
| what leads to impaired ventilation? |
|
Definition
| obstructive defects: COPD and chronic asthma, restrictive defects: decreased lung expansion (interstitial fibrosis, PE, pneumothorax), limited thoracic expansion (kyphoscoliosis, ankylosing spondylitis, mult rib fractures, throacic sx), decreased diaphragmatic movement (abdominal sx, ascites, peritonitis, severe obesity), neuromuscular defects (phrenic nerve): guillain-barre, MS, myasthenia gravis, and respiratory center: drug OD, CVA, high flow/uncontrolled O2 therapy (severe COPD pts bodily sensors reset to base breathing rate on O2, not CO2, so when O2 is given, they stop breathing) |
|
|
Term
| what leads to impaired diffusion/gas exchange? |
|
Definition
| anything that disrupts the alveoli from functioning properly; pulmonary fibrosis (due to sarcoidosis, hammon-rich, pneumoconiosis - occupational), pulmonary edema (cardiogenic, uremia, drowning, smoke, ARDS), obliterative pulmonary vascular disease (thromoembolism), anatomic loss of tissue function (pneumonectomy) |
|
|
Term
| how does interstitial fluid or fibrosis cause impaired diffusion/gas exchange? |
|
Definition
| the capillary bed pulls away so that CO2/O2 have more difficulty/take a longer time to cross the membrane gap |
|
|
Term
| what is the V/Q ratio supposed to be? |
|
Definition
| V is supposed to be in the 400 cc range and Q in the 500 cc range, so the V/Q ration should be: .8 |
|
|
Term
| how does RF present in pts? should a blood gas performed? |
|
Definition
| restlessness, tachycardia, confusion, diaphoresis, jerking tremors, headaches, varying degrees of stupor. a blood gas should be performed if RF is suspected/diagnosed. |
|
|
Term
| what are the common bacteria that can cause COPD? |
|
Definition
| diplococci and haemophilus |
|
|
Term
| what is the common etiology for ARDS? (*exam question*) |
|
Definition
| *shock, trauma, infection, aspiration, drug OD, inhaled toxin, metabolic disorders, hematologic disorders* |
|
|
Term
| what conditions can predispose someone for ARDS? |
|
Definition
| infection (bacterial/viral/fungal), multisystem trauma (car accidents etc), aspiration of foreign bodies (big problem w/elderly w/GERD - test for gag reflex on these people, rotten teeth can cause anaerobic pneumonia) |
|
|
Term
| what are complications associated with ARDS? |
|
Definition
| PE (laying on their back), barotrauma (due to ventilator set too high, causes pneumothorax), infection (nosocomial staph/pseudomonas due to variety of lines going into the pt), GI complications (these pts have more subcutaneous acid, have to prevent bleeds), renal insufficiency, cardiac complications (decreased CO, arrhythmias - due to electrolyte problems), hematologic consequences (anemia, thrombocytopenia, DIC), consequences of endotracheal intubation (laryngeal/tracheal ulceration, tracheal malacia, stenosis) |
|
|
Term
| what happens histologically in ARDS w/the alveolus? how does it sound on auscultation? what is this a form of? |
|
Definition
| normal alveoli are flush against the capillary, but in ARDS, there is fluid around the alveolus that pushes it away from the endothelium - increasing the distance and difficulty of diffusion. on auscultation, this will sound like rales. as this problem continues, the capillary endothelium can be damaged due to leakage of ROSs and PMNs, which lead to fibrosis and death of the type II pneumocytes (no surfactant). this is a form of atelectasis, and the non-oxygenated blood coming down the pulm vein causes the pt to hyperventilate though they still can't drop the excess CO2. |
|
|
Term
| what are the signs of ARDS? (*exam question*) |
|
Definition
| *CXR: diffuse alveolar infiltrates (whiteout), severe hypoxemia despite FIO2, low compliance (stiff lungs), and rales (discontinous sounds)* |
|
|
Term
| how are cardiac and non-cardiac edema differentiated? |
|
Definition
| in cardiac pulmonary edema, the pulmonary capillary wedge pressure will be elevated - in non-cardiac shock lung edema, the pulmonary capillary wedge pressure will be normal. also, CO (cardiac output) is low in cardiac edema, but elevated in non-cardiac edema. |
|
|
Term
| how is a ADRS pt managed? |
|
Definition
| an arterial line to check ABG, electrolyte consistently. swan-ganz catheter to monitor wedge pressure (if wedge pressure is low, give colloids and fluids; if high, diurese pt & have them go through peritoneal dialysis), prevent infection/tx infections intelligently (gram stain) |
|
|
Term
| what is CPAP and what is it used for? |
|
Definition
| CPAP is continous airway pressure which is used if a pt has decreased O2, as it delivers a steady continuous pressure of O2. it is not given on a ventilator. |
|
|
Term
| what is PEEP and what is it used for? |
|
Definition
| positive expiratory end pressure is given to pts with pO2 and pCO2 problems. the purpose of PEEP is to increase the volume of gas remaining in the lungs at the end of expiration in order to decrease the shunting of blood through the lungs and improve gas exchange. it is given through a ventilator. to start a pt on it, adjust pCO2 FIRST, measure best PEEP, and “shunt chart” |
|
|
Term
| what are the best ways of determining the right PEEP for a pt? (*exam question*) |
|
Definition
| *the compliance measurement or the opicath system* |
|
|
