Case Answers:

Answer 1

  1. Sharp chest pain with radiation to left shoulder, pleuritic
  2. Shortness of breath
  3. Hemoptysis
  4. Swelling, tender calf

Answer 2

  1. DVT/PE, MI, pneumothorax.

Answer 3

  1. Oral contraceptives + smoking

Answer 4

  1. The diagnosis of DVT/PE is difficult to make with the exam and is often not sensitive or specific. 
  2. Pertinent positives: tachycardia with increased P2, tachypnea, respiratory distress, dullness to percussion/decreased breath sounds (suggestive of pleural effusion)
  3. Pertinent negatives: no rhonchi, no crackles, no bronchophony (increased voice transmission over area of consolidation due to solidification of lung tissue around bronchi), egophony or tactile fremitus, lack of fever (all argue against infectious etiology – pneumonia). Dullness to percussion suggests effusion or consolidation.  PTX also less likely given bilateral breath sounds and would sound hyperresonant on exam
  4. There is no tracheal deviation.  If there was tracheal deviation to the right – this would suggest left sided tension  pneumothorax or massive pleural effusion.  Deviated to the left would suggest left-sided tension pneumothorax or massive pleural effusion. Deviation to the left would suggest left-sided volume loss due to atelectasis or tumor causing volume loss
  5. Physical exam findings for DVT (calf swelling, erythema, tenderness, warmth, palpable cord, Homan’s sign) have poor sensitivity and specificity and are of no value in ruling a DVT in or out.

Answer 5

  1. Dullness to percussion and decreased breath sounds indicates pleural effusion.  Pleural effusion associated with decreased voice transmission. 
  2. Accentuated P2 suggests pulmonary hypertension

Answer 6

  1. Acute respiratory alkalosis.  Note that for a 10 torr change in pCO2 there is an associated predicted 0.08 change in the pH.  If a chronic respiratory alkalosis, would be expect a 0.03 change in pH for every 10 torr change in pCO2
  2. PE → increased CO2 → increased minute ventilation → resp alkalosis

Answer 7

The gradient on room air is the best use of the alveolar-arterial oxygen gradient.
PAO2 = FiO2(PATM – PH20)– (PaCO2/0.8)
PATM = 760mmHg
PH20 = 47mmHg
PAO2 = .21 (760-47) – (30/0.8) = 150-37.5 = 112.5

PAO2 – PaO2 = 112.5 – 80 = 32.5


Normal predicted alveolar-arterial oxygen gradient is:  4 + (Age/4)
Age 20 yr = 4 + (20/4) = 9
Age 80 yr = 4 + (80/4) = 24

Answer 8

  1. The EKG shows sinus tachycardia.  EKG is neither sensitive nor specific for PE.  Most common EKG finding for PE is sinus tachycardia.
  2. You can also see signs of right-heart sided strain patterns including axis deviation and right bundle branch block.   S1Q3T3 (S wave in lead 1, Q wave and flipped T wave in lead 3) is a sign of acute cor pulmonale (PE, pneumothorax, bronchospasm). It is a manifestation of acute pressure and volume overload of right ventricle

Answer 9 
You need to calculate your pre-test probability with the modified Well’s criteria

Clinical symptoms of DVT (leg swelling, pain with palpation)


Other diagnosis less likely than pulmonary embolism


Heart rate >100


Immobilization (>3 days) or surgery in the previous four weeks


Previous DVT/PE






Dichotomized score:                                                        0-1: Low

PE likely >4                                                                    2-6: Intermediate
PE unlikely </= 4                                                            >7: High
Our patient’s score is 8.5

Answer 10
Based on her pre-test probability of 8.5, the next test should be a CTPA.

  1. a)      Chest xray should be ordered if the PERC tool is zero (d-dimer not even indicated) and you want to workup the patient’s symptoms of dyspnea.

    The PERC (PE rule-out criteria) tool was designed to help guide clinicians in identifying low-risk patients (patients in whom the physician has a genuine concern about PE and whose initial risk stratification identifies them as being low risk).  Should decrease the use of d-dimer testing. 




    Age< 50



    Initial HR <100 bpm



    Initial O2 sat >94% on RA



    No unilateral leg swelling



    No hemoptysis



    No surgery or trauma within 4 weeks



    No hx of VTE



    No estrogen use



    Pretest probability with score of 0 is <1%


    b)   D-dimer would be checked if the pre-test probability is intermediate or if the pretest prob is low but the PERC is +.  Remember to age adjust the d-dimer (500 + ((age-50) * 10) is cutoff for normal) if the patient is older than 50.

    c)   CT-PE protocol would be appropriate for our patient (high risk) or intermediate risk with a + d-dimer

                                                               i.CTA is very specific for PE (80-97%) but sensitivity can vary (53-100%). 

                                                             ii.The primary limitation of CTA is that it can miss distal emboli (but clinical significance of peripheral clots is unknown). 

                                                           iii.Therefore, if CTA is negative or non-diagnostic for PE, think of your pre-test probability. 

                                                           iv.If PTP is high, get an additional study to rule out VTE such as LE Doppler or a VQ scan 

    d)  LE Doppler would be appropriate if the patient is having signs or sx of a DVT. If this is positive, you will treat with anticoagulation and avoid any additional imaging. 

    e)   VQ scan is appropriate for a high risk or intermediate risk with a + d-dimer who has a contraindication to CT (history of reactions to contrast agents, pregnancy, radioactive iodine treatment for thyroid disease, metformin use, and chronic or acutely worsening renal disease)

    f)    If pt is too hemodynamically unstable for CTA or if CTA is not available, start anticoagulation and get TTE to look for RV dysfunction or TEE to look for emboli in the main pulmonary arteries.

Answer 11


a.       High probability scan: >2 large segmental defects without corresponding ventilation or CXR abnormalities or any perfusion defect substantially larger than radiographic abnormality

b.      Intermediate (indeterminate) probability: borderline high or borderline low, not falling into normal, low or high prob

c.       Low probability:

                                                              i.      any perfusion defect with substantially larger radiographic abnormality

                                                            ii.      matched ventilation and perfusion defects with normal chest radiograph

                                                          iii.      small subsegmental perfusion defects

d.      Normal scan: normal perfusion, normal ventilation (very good sens and spec)


Again, think about pre-test probability!

a.                If PTP is high and you have a high probability VQ scan, specificity is very good (88-96%)

b.               If PTP is low and you have a low or normal VQ scan, sensitivity is very good (94-100%)

c.                BUT, if PTP is low and you have a high prob scan, sensitivity drops to 55%


Answer 12

    1. There is a small left sided pleural effusion.  CXR is often normal with PE but one can also see diminished lung volumes, atelectasis, pleural effusions, infarct that appears as wedge-shaped infiltrate (Hampton’s Hump) or Westermark’s sign (prominent central pulmonary artery with local oligemia 


Answer 13

  1. Referred pain from the diaphragm results from any inflammatory process (e.g., pleural effusion) that affects the diaphragm.

Answer 14

Age >80

Hx of cancer

Hx of chronic cardiopulmonary disease



O2 sat <90%

       Her simplified PESI score is 1 (based on her HR of >110) and she should be monitored in an inpatient setting.

      If her score was zero, her risk of death is low and she can be discharged home. 



Answer 15

    1. Heparin drip – concern for bleeding; able to turn this off quickly.  Also used after thrombolytics
    2. Low molecular weight heparin – cancer patients, pregnancy, liver disease or coagulopathy

                                                              i.      For VTE associated with cancer, LMWH is recommended over VKA or any direct oral anticoagulants

                                                            ii.      NOACs contraindicated if INR raised because of liver disease; VKA difficult to control and INR may not reflect antithrombotic effect.

    1. Warfarin – severe renal disease or poor compliance (INR can help determine if patient is taking the medication)

                                                              i.      NOACs and LMWH contraindicated with severe renal impairment.

    1. Rivaroxaban (Xarelto) – good choice for our patient
    2. Dabigatran (Pradaxa) – also a good choice for our patient
    3. Aspirin – Aspirin is not a treatment option for VTE. 


Based on less bleeding with NOACs and greater convenience for patients and health-care providers, we now suggest that a NOAC (dabigatran, rivaroxaban, apixaban, or edoxaban) is used in preference to VKA for the initial and long-term treatment of VTE in patients without cancer. 



Preferred Anticoagulant





Once daily oral therapy preferred

Rivaroxaban; edoxaban; VKA


Liver disease and coagulopathy


NOACs contraindicated if INR raised because of liver disease; VKA difficult to control and INR may not reflect antithrombotic effect.

Renal disease and creatinine clearance <30 mL/min


NOACs and LMWH contraindicated with severe renal impairment. Dosing of NOACs with levels of renal impairment differ with the NOAC and among jurisdictions.

Coronary artery disease

VKA, rivaroxaban, apixaban, edoxaban

Coronary artery events appear to occur more often with dabigatran than with VKA.

Dyspepsia or history of GI bleeding

VKA, apixaban

Dabigatran increased dyspepsia. Dabigatran, rivaroxaban, and edoxaban may be associated with more GI bleeding than VKA.

Poor compliance


INR monitoring can help to detect problems. However, some patients may be more compliant with a NOAC because it is less complex.

Thrombolytic therapy use

UFH infusion


Reversal agent needed



Pregnancy or pregnancy risk




a.       For VTE associated with cancer, LMWH is recommended over VKA (Grade 2B) or any direct oral anticoagulants (all Grade 2C).

b.      Start warfarin on day of starting anticoagulation and overlap at least 5 days (even if INR >2 earlier than that)




Answer 16

She has a VTE provoked by a nonsurgical reversible risk factor (estrogen + smoking) and                      should be treated for 3 months












Risk of recurrence after 1 year

Risk of recurrence after 5 years

Recommended duration of anticoagulation

VTE provoked by surgery:



3-6 months

VTE provoked by nonsurgical reversible factor (estrogen, pregnancy, leg injury, flight >8hrs):






3-6 months



Unprovoked VTE







If low/mod bleeding risk, indefinite **

If high bleeding risk: 3 months

Provoked VTE with persistent risk factor (antiphospholipid syndrome or other inherited thrombophilias)



VTE in setting of cancer

15% annual risk





Unprovoked isolated distal DVT




Serial U/S or

3 months of a/c if risk factors for extension of clot


** In the unprovoked VTE group with low risk of bleeding, patient sex and Ddimer level measured about 1 month after stopping a/c therapy can help further stratify the risk of recurrent VTE.


For isolated distal DVT, you can either start A/C or do serial u/s.  RF for extension of distal DVT and would therefore favor starting a/c include:



Answer 17

  1. Systemic Thrombolysis
  2. Catheter-directed thrombolysis
  3. Anticoagulation with Lovenox or DOAC (Apixiban)


  • BP 140/85, HR 100, RR, 30, O2 sat 92% on room air, mild respiratory distress.  Saddle embolus found on CTA chest. 


  • BP 70/45, HR 140, RR 32, O2 sat 90% on NRB.  PE noted in subsegmental branch of pulmonary artery on right


  • BP 70/45, HR 140, RR 32, O2 90% on NRB.  PE noted in subsegmental branch of pulmonary artery on right.  Hx of multiple GI bleeds requiring ICU stay, most recently 2 weeks ago.


  • BP 120/80, HR 90, RR 25, O2 93% on RA.  Multiple PEs noted bilaterally on CT.  Troponin +, BNP elevated, right heart strain on echo. 


  • BP 128/70, HR 95, RR 22, O2 92% on RA on admission.  Large PE in R main pulmonary artery.  Patient started on lovenox and admitted.  On hospital day #2, patient is more hypoxic with BP now 100/70, HR 110, RR 30 and O2 sat 92% on NRB. 



·         In most patients with acute PE NOT associated with hypotension, thrombolytics are NOT recommended

o   PE + no shock = 2% mortality

·         In patients with acute PE and hypotension (Massive PE) but have a higher risk of bleeding with systemic thrombolytic therapy, catheter-directed therapy is recommended over no such intervention. 

·         Submassive PE is defined as PE plus RV dysfunction on echo +/- increase in cardiac biomarkers (troponin or BNP) but NO hypotension.

o   ACCP does not recommend thrombolytic therapy routinely for patients with submassive PE

·         Deterioration that has not resulted in hypotension (progressive increase in heart rate, a decrease in systolic BP (which remains >90 mm Hg), an increase in jugular venous pressure, worsening gas exchange, signs of shock (eg, cold sweaty skin, reduced urine output, confusion), progressive right heart dysfunction on echocardiography, or an increase in cardiac biomarkers) may also prompt the use of thrombolytic therapy.


Answer 18

a.       As mentioned in above table, her risk of recurrent VTE is 5% within 1 year and 15% within 5 years.  It is important to consider reducing all possible risks factors which includes smoking cessation.

Answer 19

a.       IVC filter.  Indications for IVC filter include:

                                                              i.      Major contraindication to anticoagulation therapy

                                                            ii.      Recurrent VTE despite therapeutic anticoagulation

                                                          iii.      Chronic recurrent VTE with pulmonary HTN


b.      Note that insertion of IVC filter does not eliminate the risk of PE and increases risk for DVT.  Therefore, IVC filter should be “removable” and anticoagulation should be initiated once bleeding risk resolves.