Pneumothorax/PE Flashcards

Question

# hemothorax complications

Answer 1

Impaired ventilation on the affected side Leads to respiratory distress May require intubation Empyema Retained blood collection develops a bacterial infection 5% of cases Fibrothorax Formation of scar tissues within the lungs due to blood irritation 1% of cases

Answer 2

Intraluminal obstruction of a main pulmonary artery or any of its branches Common, potentially fatal condition Epidemiology: Incidence: approximately 112 per 100,000 in the United States Slight male predominance Relationship of PE with DVT **> 90% of PEs are due to DVTs of the lower leg 50% of untreated proximal DVTs lead to PE within 3 months**

Answer 3

**Virchow’s triad** Venous stasis Hypercoagulability Vascular endothelial damage

Answer 4

Any condition that worsens 1 (or more) of the 3 factors increases the risk of PE as well as DVT Dislodged DVT is the most common cause for PE **Rare causes**: fat embolism (long bone fractures), tumor embolism, infected clots (right-sided endocarditis), sickle cell disease

Answer 5

**Genetic**: Factor V Leiden mutation (most common genetic) Prothrombin gene mutation Protein C and Protein S deficiencies **Acquired:** (most are aquired) Immobilization Recent surgery (especially orthopedic surgery) Malignancy Trauma Obesity Smoking (with Birthcontrol is very high risk) Estrogen exposure: Pregnancy Hormonal contraception Hormone replacement therapy **Medical conditions:** Hypertension Congestive heart failure Autoimmune disease Nephrotic syndrome Covid-19 ## Footnote never prescribe birth control to a smoker for this reason.

Answer 6

Most emboli move beyond the bifurcation to smaller branches of a pulmonary artery: Lobar branches Segmental branches Subsegmental branches Saddle embolus: At the bifurcation of the main pulmonary trunk May extend into the right or left main pulmonary artery ## Footnote Usually have multiple emboli, with bilateral involvement in the lower lobes more frequently than the upper lobes

Answer 7

PE causes impaired gas exchange due to obstruction of the pulmonary vascular bed → ventilation/perfusion (V/Q) mismatch Alveolar ventilation remains the same Pulmonary capillary blood flow decreases Decreased blood flow leads to dead space and hypoxemia; decreases oxygen signals the brain to increase breathing Blood pumped from the RV to the pulmonary arteries cannot pass the clot → increased pulmonary artery pressure (PAP) and increased pulmonary vascular resistance (PVR) = **right heart strain and potential right-sided heart failure**

Answer 8

Ventilation/Perfusion (V/Q) mismatch ↑ PAP ↑ PVR **Right** heart strain

Answer 9

Pulmonary infarction: Occurs in about 10% of patients Associated with small emboli in the segmental and subsegmental branches, causing ischemia of lung tissue Produces: -An intense inflammatory response which leads to: -Vasoconstriction and bronchoconstriction in unaffected nearby areas → further decreases blood flow (Q) and air flow (V) -Decreased surfactant production + atelectasis → shunting (perfusion without ventilation) → worsens V/Q mismatch -Intra-alveolar hemorrhage is possible (hemoptysis)

Answer 10

Presentation varies significantly High suspicion must be maintained given the risks of complications and mortality Can be asymptomatic (incidentally found on imaging) Massive PE presents with hemodynamic instability/shock Symptom: **Dyspnea** at rest and/or during exertion (most common tachycardia **Pleuritic chest pain** Cough Hemoptysis Near syncope/Syncope-rare **Symptoms of DVT** Calf pain and/or tenderness Extremity swelling Palpable cord Erythema Warmth

Answer 11

Physical exam findings Tachypnea **Tachycardia** Rales and/or decreased breath sounds Hypoxia Hypotension *Loud second heart sound (P2) Jugular vein distension* - evidence of R heart strain more chronic

Answer 12

Made through imaging studies Decision to obtain imaging is based on: Clinical suspicion Pretest probability assessment (Modified Wells criteria) D-dimer levels

Answer 13

if high probability straight to imaging intermediate start with D dimer low probability do PERC score, then D dimer

Answer 14

Pulse oximetry: room-air oxygen saturation (O2 sat) < 95%- the lower it gets the higher the suspicion. Electrocardiography (ECG) may show: Arrhythmia: **Sinus tachycardia** (anything over 100) Atrial fibrillation Right heart strain pattern:- not on boards New right bundle branch block Right axis deviation Dominant R wave in leads V1 and V2 **S1Q3T3 pattern (rare):** Prominent S wave in lead I Q wave in lead III Inverted T wave in lead III

Answer 15

## Footnote score > 4 : PE likely (intermediate/high) Score <= 4 : PE unlikely (low)

Answer 16

Byproduct of crosslinked fibrin degradation → indicating thrombus breakdown **> 95% sensitivity when negative** A negative test effectively rules out VTE in low-risk and moderate-risk cases **Low specificity** → a positive test (elevated value) does not confirm VTE since any condition that causes clots to form can elevate D-dimer levels (recent surgery, cancer, or sepsis) Specificity of d-dimer decreases steadily with age; use age-adjusted cut-offs for patients over 50 years

Answer 17

Created to reduce testing in patients who have a very low probability of PE Pre-test probability < 15% Includes 8 components that must be absent to rule out PE Interpretation If the patient is deemed low risk and **all criteria are absent, then there is no need for further PE workup** If the patient is deemed low risk but is **positive for ANY criteria, a d-dimer should be considered** If a d-dimer is positive, further investigation such as CTPA or V/Q scan may be indicated

Answer 18

PE probability assessment and D-dimer levels guide diagnostic workup If PE is unlikely (Modified Wells Score ≤ 4): D-dimer normal (< 500): PE excluded D-dimer elevated: Order computed tomographic angiography (CTA) of the chest with contrast or V/Q scan If PE is likely (Modified Wells Score > 4): Order **CTA** of the chest **with contrast**

Answer 19

Current “**gold standard**” in diagnosing PE Best initial test if modified Wells score > 4 Shows filling defects in the pulmonary vasculature

Answer 20

for people with **poor renal function(cant handle contrast),** or if CTA is inconclusive. Used if CTA of the chest is contraindicated, not available, or inconclusive Compares distribution of air in the lungs via inhalation of radioactive xenon gas (the ventilation scan) and perfusion via labeled serum markers (the perfusion scan) PE shows areas of perfusion defects with normal ventilation Scored as normal, low-, intermediate-, or high-probability of PE Major limitation: most individuals have indeterminate scans

Answer 21

## Footnote V/Q mismatch

Answer 22

**Anticoagulation:** initial treatment Medication is selected based on patient comorbidities and patient preferences Administered for **3‒6 months** to prevent recurrence (some patients may require **lifelong** therapy) Options: Low molecular weight heparin (LMWH) Enoxaparin (Lovenox): 1 mg/kg every 12 hours or 1.5 mg/kg daily Unfractionated heparin (UFH) - *preferred in patients with renal failure or pregnancy and it costs less than DOACs * Follow hospital protocol Indirect factor Xa inhibitor: fondaparinux (Arixtra) - not commonly used < 50 kg: 5 mg daily 50–100 kg: 7.5 mg daily > 100 kg: 10 mg daily **Direct factor Xa inhibitors/DOAC** - no monitoring required Rivaroxaban (Xarelto): 15 mg 2 times daily (with food) for 21 days, followed by 20 mg daily (with food) Apixaban (Eliquis): 10 mg 2 times daily for 7 days, followed by 5 mg 2 times daily Direct thrombin inhibitor: dabigatran (Pradaxa) Can be administered after 5–10 days of initial treatment with LMWH or UFH 150 mg 2 times daily

Answer 23

Contraindications: Active bleeding Acute intracranial hemorrhage Major trauma Severe bleeding disorders

Answer 24

Assess and treat any hemodynamic instability Address the ABCs **Airway Breathing/respiratory support:** Supplemental oxygen therapy to improve O2 sat > 95% **Circulation/hemodynamic support:** **Small** amount of IV fluids (avoid fluid overload, which worsens the effects of right-sided heart failure) Vasopressors- if hypotensive Cardiac medications based on the presence and severity of heart failure and hemodynamics

Answer 25

lifelong treatment if unprovoked or multiple clot incedents 3-6 months if provoked

Answer 26

Infusion of a lytic agent - **tissue plasminogen activator (tPA)** Routes: Systemic therapy Catheter directed: a catheter tip directed at the embolus in an attempt to lyse the thrombus Indications: Hemodynamically unstable patients with a massive embolus Hemodynamically stable patients with adverse outcomes (RV dysfunction) **Individuals unresponsive to systemic anticoagulants with clear deterioration** good for people who cant take anticoags and large clots

Answer 27

Embolectomy consists of removal of the embolus: Catheter-based or surgical procedure Indications: Hemodynamically unstable patients with massive emboli, who are not suitable candidates for thrombolytic therapy (e.g., active bleeding) In cases of failed thrombolytic therapy

Answer 28

Anticoagulation: secondary prevention of VTE Options: LMWH Vitamin K antagonists: warfarin (Coumadin) Requires regular monitoring of the prothrombin time (PT) Numerous drug interactions Contraindicated in pregnancy (teratogenic) Direct factor Xa inhibitors: rivaroxaban, apixaban, edoxaban Monitoring generally not required More expensive Thrombin inhibitors: dabigatran Requires monitoring of the activated partial thromboplastin time (aPTT) Often used in patients with a history of HIT Depending on the initial and secondary therapies, “**bridging**” may be required to ensure full anticoagulation during transition of therapy (continuing LMWH until warfarin is effective based on the PT)

Answer 29

Used to prevent recurrent PE in patients with DVT in the lower extremities Barrier placed within the IVC to prevent passage of the migratory thrombus into the pulmonary arterial system Indications: Contraindications to anticoagulants Complications from or failed systemic anticoagulants

Answer 30

Lifestyle/other options Exercise Weight loss Smoking cessation Control of hypertension Avoid estrogen (combined oral contraceptive pills) in high-risk patients Compression stockings

Answer 31

Prognosis Estimated mortality Untreated PE: approximately 30% Treated PE: 2%‒11% Poor prognostic indicators RV dysfunction Shock during presentation Recurrence More likely in patients with unresolved risk factors (cancer) Highest in the 1st 2 weeks after presentation

Pneumothorax/PE Flashcards

(58 cards)