Term
| Arterial Blood Gases are performed to determine what 3 things: |
|
Definition
1. Oxygen dissolved in blood
2. Carbon Dioxide dissolved in blood
3. Acid/base balance |
|
|
Term
| ABGs help evaluate metabolic and respiratory problems/status: |
|
Definition
- COPD
- Cardiopulmonary arrest
- Trauma
- Renal Disease
- Medication response
- Multisystem disease monitoring in critical care |
|
|
Term
| Common sampling sites for ABGs: |
|
Definition
- radial
- brachial
- femoral
(all arteries) |
|
|
Term
pH = -log [H+]
Base
pH = pK + log ———
Acid
The more alkalotic, the higher the pH
The more acidotic, the lower the pH |
|
Definition
|
|
Term
| Henderson-Hasselbach equation: |
|
Definition
| H2O + CO2>< H2CO3>< H+ + HCO3- |
|
|
Term
| two organs most involved with acid/base balance: |
|
Definition
|
|
Term
| Normal CO2 is __. Once the CO2 is at 43, you begin to ___ to get more O2. |
|
Definition
- 35-45
- 43, you begin to hyperventilate to get more O2 |
|
|
Term
| ___ is the strongest controller of respiration. |
|
Definition
|
|
Term
| Minute ventilation is how much air you move per minute. Formula is: |
|
Definition
Minute Ventilation= Respiratory Rate X TV
KNOW THIS |
|
|
Term
| O2 has to drop more than CO2 has to rise to cause hyperventilation. thus CO2 has the most control of ventilation. |
|
Definition
|
|
Term
| 2 ways you can increase minute ventilation: |
|
Definition
- breathe faster (hyperventilate)
- breathe deeper |
|
|
Term
| Generally speaking what is avg minute ventilation: |
|
Definition
|
|
Term
| Dead space is the area in lungs not involved with respiration, it is about __ cc. |
|
Definition
|
|
Term
|
Definition
- pH 7.35-7.45 (7.4)
- PaCO2 35-45 mmHg (40)
- PaO2 (102- 0.33age)
- HCO3- 22-26 mEq (24)
- SaO2 905-100% |
|
|
Term
| ABG normal values vary with __. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| __ determines your oxygen saturation. |
|
Definition
|
|
Term
| __ and __ determine your pH. |
|
Definition
|
|
Term
| normal oxygenation status is dependent on age and altitude |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
Mild Hypoxemia PaO2 of 60-80 mmHg
Moderate Hypoxemia PaO2 of 50-60 mmHg
Severe Hypoxemia PaO2 below 50 mmHg |
|
Definition
|
|
Term
|
Definition
1. VQ mismatch
2. Shunting
3. Hypoventilation
4. Decreased FiO2 (high altitidue)
5. Diffusion |
|
|
Term
| With pneumonia, there is decreased __ supply(__), but normal __ supply(__). This results in a __ __ resulting in hypoxemia so __ drops. |
|
Definition
- decreased air supply (ventilation)
- normal blood supply (perfusion)
- VQ mismatch
- paO2 drops |
|
|
Term
|
Definition
- pneumonia: decreased ventilation
- PE: decreased perfusion
- pleural effusion: decreased ventilation |
|
|
Term
| __ causes decreased V/Q ratio. |
|
Definition
| Shunting causes decreased V/Q ratio b/c blockage of bronchus by foreign body or tumor blocks air flow so no ventilation |
|
|
Term
| A __ causes an increased V/Q ratio. |
|
Definition
| PE causes an increased VQ ratio b/c lots of ventilation but no perfusion |
|
|
Term
| With V/Q mismatch and shunting, __ and __ __ while the A-a gradient ___. |
|
Definition
-PO2 and PCO2 decrease
- A-a gradient increases |
|
|
Term
| With hypoventilation __ __, __ __, and __ is normal. |
|
Definition
- PO2 decreases
- PCO2 increases
- A-a gradient is normal |
|
|
Term
| Causes of hypoventilation: |
|
Definition
- narcotics, sedatives
- obesity
- carotid body resection
- kyphoscoliosis
- Myasthenia gravis
- Myotonic dystrophy
- Guillain Barre
- Spinal cord transection/polio
- Medulla infxns, bleeding, trauma, drugs |
|
|
Term
| see slide 16 of PE lecture to see more causes of hypoventilation. look at this. |
|
Definition
|
|
Term
| What is the purpose of having nitrogen in the alveoli? |
|
Definition
| - Nitrogen is an inert gas that prevents the alveoli from collapsing |
|
|
Term
| To get from the alveoli to RBCs, how many layers does oxygen have to go through? Name them. |
|
Definition
- 3 layers
- alveolus
- interstitial
- vessel wall |
|
|
Term
|
Definition
- less than 15 mmHg
OR
(age +10)/4= normal A-a gradient |
|
|
Term
|
Definition
PAO2= [(Pa-PH2O)xFiO2] - [PaCO2/0.8]
which equals
PAO2= 150 - [PaCO2/0.8] |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| __ altitude ___ the FiO2. |
|
Definition
| - High altitude decreases the FiO2. |
|
|
Term
| Pts ABGs show PaO2 75, PaCO2 52. What is her PAO2 and A-a gradient? Is this normal? |
|
Definition
- PAO2= 85
- A-a gradient= 85-75= 10
- this is normal b/c A-a gradient less than 15 is normal |
|
|
Term
| What 2 causes of hypoxemia cause increased A-a gradients? |
|
Definition
|
|
Term
| What cause of hypoxemia has a normal A-a gradient? |
|
Definition
|
|
Term
ABG
PH 7.13, PaCO2 68, PaO2 60
What is the most likely cause of this patient’s respiratory failure? |
|
Definition
- A-a gradient of 5 = normal (don't worry if A-a is low, just high is bad)
- So the cause of this is hypoventilation, possibly from a drug overdose |
|
|
Term
| What would you expect the A-a gradient to do in a pt with pneumonia? What about their PCO2 and PO2? |
|
Definition
- expect A-a gradient to increase
- expect PCO2 and PO2 to decrease
This is b/c penumonia results in V/Q mismatch which results in the above findings. |
|
|
Term
| In a nromal individual what do expect the PaO2 to be in 50% oxygen air instead of room air, big A would be 300, and little a would be close to 300 also. |
|
Definition
|
|
Term
| First question with SOB is whether its acute or chronic (onset), she says it was acute this morning, ask about excaberating and relieving factors, she says its better with rest, worse with exercise, ask about triggers, she says there are not any. Now move on to associated symptoms. Ask about chest pain. She says there was some chest discomfort, she says it is sharp (usually with a PE), what causes the pain? Parietal pleura (lungs themselves don’t feel pain), pleuritic pain is worse with breathing. Coughing is another associated symptom with SOB, not super common with PE but possible. Wheezing is another associated symptom (asthma, congestive heart failure). Pts with PE can also present with palpitations and hemoptysis b/c pulmonary infarcts with PE. |
|
Definition
|
|
Term
|
Definition
- smoking
- recent surgery
- immobility
- cancers (any but esp breast/pancreatic)
- pregnancy
- obesity
- family history
- bcps |
|
|
Term
| In a pt with a PE, you expect her A-a gradient to be __. |
|
Definition
|
|
Term
| What aggravates musculoskeletal chest pain? |
|
Definition
| - taking in a deep breath makes it worse |
|
|
Term
| Types of cyanosis: peripheral vs central. True hypoxemia causes central cyanosis. |
|
Definition
|
|
Term
| MOST COMMON SIGN OF A PE: |
|
Definition
| - TACHYCARDIA (followed by tachypnea) |
|
|
Term
|
Definition
Inspection: tachypnea, tachycardia, cyanosis, accessory muscle use, tractions, large PEs cause hypotension, distressed, possibly dizzy
Percussion: not much
Palpation: not much
Auscultatoin: possibly some crackles if associated infarct with PE |
|
|
Term
| May also see Homan’s sign, Most common site of DVT: lower legs. Can also get a PE from an upper extremity and others. |
|
Definition
|
|
Term
| Most research says elevated D-dimer does not helps. D-dimer helps us most when its negative and there is a low probablity in that pt. If have a high probablity to start out with, whether d-dimer is positive or negative, you still have to work that patient up. But you still order it. |
|
Definition
|
|
Term
| Tmt approach to a pt that is otherwise stable with a PE: |
|
Definition
| - Heparin for a minimum of 5 days and initiate Warfarin (overlap), target INR 2-3. |
|
|
Term
| Pt has elevated A-a gradient and d-dimer. TEST OF CHOICE FOR A PE? |
|
Definition
| - CT angiogram with contrast |
|
|
Term
| Pt is allergic to contrast dye, but you suspect a PE. What test do you do instead? |
|
Definition
|
|
Term
| VQ scans aren't good for pts with pneumonia or COPD if suspect PE, but works well if otherwise normal pt suspicious of PE |
|
Definition
|
|
Term
| Chest x-ray not super helpful with PE, but still do it in the first place to exclude other dxs. |
|
Definition
|
|
Term
| Westermark sign is __lung markings of __ suggestive of a __ __. |
|
Definition
- decreased lung markings of vasculature
- pulmonary embolus |
|
|
Term
| Most common EKG finding with a PE: |
|
Definition
| - sinus tachycardia with non-specific ST-T wave changes |
|
|
Term
A 62-year-old man is admitted for a life threating GI bleed
He is on Warfarin for recurrent DVT’s
You are called because he c/o sudden shortness of breath, pleuritic chest pain, and tachycardia.
A stat CT angiogram confirms the diagnosis of a large pulmonary embolus |
|
Definition
| Inferior Vena cava filter (interruption device) done via catheter, prevents larger clots from going up. Good for pts who are not candidates for anticoagulatns. Problem with this filter is small clots can go through and clots can form above the fitler in upper extremeties. |
|
|
Term
| How long do you keep a PE pt on coumadin? |
|
Definition
|
|
Term
| How long do you keep a DVT pt on coumadin? |
|
Definition
|
|
Term
| Only time you keep someone with PE/DVT on coumadin lifelong is if risk factor is lifelong. |
|
Definition
|
|
Term
| Pt with PE in clear respiratory distress, unstable. How to treat? |
|
Definition
thrombolysis
(If thrombolytics are CI, do embolectomy) |
|
|
Term
| What anticoagulant is CI in pregnancy? |
|
Definition
|
|
Term
| Tmt of pregnant women with pulmonary emboli ? |
|
Definition
| Enoxaparin, 1 mg/kg administered subcu twice daily |
|
|
Term
| Factors during pregnancy that change and increase risk of venous thromboembolism: |
|
Definition
- changes in coagulation system
- venous stasis
- endothelial injury
- prolonged immobilization |
|
|
Term
| Indications for anticoagulation therapy during pregnancy: |
|
Definition
- thromboembolic event
- become pregnant while being treated for VTE
- previous history of unprovoked recurrent VTE (unrelated to trauma/immobilization)
- known hereditary thrombophilia (antithrombin III deficiency, Factor V Leiden mutation, prothrombin G20210A mutation WITH OR WITHOUT personal history of thrombosis
- connective tissue d/o like antiphospholipid syndrome |
|
|
Term
| Pt comes in with Factor V Leiden deficiency. He is on Warfarin and his INR is in the therapeutic range. He presents with PE signs and symptoms and a CT angiogram confirms the PE. Whats the next step? |
|
Definition
| - start heparin, place an inferior vena cava filter |
|
|
Term
| Long bone fractures and pancreatitis increase ones risk for a __ __. |
|
Definition
|
|
Term
| skin findings on a pt with a fat embolus: |
|
Definition
|
|
Term
You are seeing a patient 8 hours after the delivery of her first child.
She is a 24 year old female with the sudden onset of chest pain and difficulty breathing 1 hour ago. She senses a feeling of impending doom.
The delivery was spontaneous and without complications.
Upon examination, the patient is in shock with a BP of 65/40. She has a marked tachycardia. The patients Hgb is 11 grams and her platelets are 25,000.
She demonstrates the presence of fibrin degradation products with a prolonged PT, PTT and decreased fibrinogen |
|
Definition
|
|
Term
| Complicated central line placement> after placed became hypotension and acute shortness of breath> air embolus |
|
Definition
|
|
Term
Air embolus.
Need about 150 cc to be dangerous. Causes death b/c gets stuck in the heart and the heart can’t pump it out.
Treat put them on their side and pray. |
|
Definition
|
|
Term
76 year old male with a 60 pack year history of tobacco use presents to the emergency room with a 2 day history of shortness of breath associated with greenish sputum production and fevers
He is compliant with oxygen and his inhalers
Exam reveals accessory muscle use, retractions, diminished air entry and wheezing
Arterial blood gases on room air PH 7.32, PaO2 45, PaCo2 46. His chest x-ray is normal. Initial management should include: |
|
Definition
| - oxygen and intravenous steroids, you could also do a bi-pap |
|
|
Term
| Patients with asthma should have __ ABGs. |
|
Definition
|
|
Term
| Pt comes in having an asthma attack, what should you do? |
|
Definition
| - intubate and utilize low tidal volumes |
|
|
Term
| Blebs and boli are thin walled cavities that occur with ___. |
|
Definition
|
|
Term
| Hyperresonance to percussion and decreased breath sounds make you think: |
|
Definition
|
|
Term
| pneumothorax after severe cough and URTI: |
|
Definition
|
|
Term
| If a pt has SOB, HTN, blood tinged sputum, what do think? |
|
Definition
| - acute pulmonary edema> SOB> crackles and wheezing |
|
|
Term
| Pt with uncontrolled HTN and acute pulmonary edema. How do you treat? |
|
Definition
| - Lasix and consider bi-pap |
|
|
Term
Your patient comes to the ER with a complaint of dyspnea that developed approximately 6 hours after arriving in the area by airplane from his home in Boston, MA
PMH is negative for cardiopulmonary disease. He does not smoke and takes no medications
Physical examination reveals a thin man in significant respiratory distress. His temperature is 100F, blood pressure is 110/68 mm Hg, pulse is 128/min, and respirations are 28/min
Lung examination reveals scattered wheezes and rales in the bases. The remainder of the physical examination, including cardiac and neurologic examinations, is normal
Initial laboratory studies show: ABG: PH: 7.52, PC02=24 mm Hg, P02 = 40 mm Hg.
CXR shows a normal sized heart, full pulmonary arteries, and patchy infiltrates in the right middle lobe and bilateral lower lobes.
Whats the problem? |
|
Definition
| High altitude> decreased fio2 |
|
|
Term
| How do you treat altitude sickness? |
|
Definition
- oxygen
- acetazolamide
- dexamethasone
- transport pt to lower altitude |
|
|
Term
| CXR of someone with altitidue sickness: |
|
Definition
- normal sized heart
- full pulmonary arteries
- patchy infiltrates in right middle lobe and bilateral lower lobes |
|
|
Term
|
Definition
- gold standard: pulmonary angiogram
- TEST OF CHOICE: CT ANGIOGRAM |
|
|
Term
| Coagulation disorders associated with thrombosis inherited disorders for which there is strong evidence for predisposition to thrombosis: |
|
Definition
- Antithrombin III deficiency
- Factor V Leiden
- Protein C Deficiency
- Protein S Deficiency
- Prothrombin 20210A |
|
|
Term
| Acquired disorders for which there is strong evidence for predisposition to thrombus: |
|
Definition
- Antiphospholipid antibody syndrome
- Heparin induced thrombocytopenia and thrombosis syndrome
- Myeloproliferative disorders (myeloid metaplasia, essential thrombocythemia, polycythemia vera)
- Thrombotic thrombocytopenia purpura
- Malignancy |
|
|
Term
Pulmonary Embolus:
How do you treat? Heparin for 5 days, then do warfarin for 6 months
When to use and contraindications of thrombolytic therapy
Vena caval interruption devices, when to use and limitations |
|
Definition
|
|
