USMLE Step 3 Question #487

487) 57-year-old male with a history of mild COPD has been using albuterol as needed to manage his COPD without any other maintenance medications. Recently he has been experiencing a greater degree of shortness of breath, wheezing and a productive cough. Pulmonary function tests demonstrate a FEV1 that is 60% of predicted. What is the next best step for management of his COPD?

A. Add budesonide to treatment regimen

B. Add rofilumast to treatment regimen

C. Add tiotropium to treatment regimen

D. Add tiotropium plus fluticasone to treatment regimen

E. Add carbocystine to treatment regimen


Question of the Week # 190

190) A 45 year old man presents to your office for follow up of his dyslipidemia that was diagnosed 6 month. His lipid panel at that time was consistent with high Total cholesterol , Low HDL and high triglyceride levels. He was instructed on dietary modification. He presents for a follow up visit today and reports that he had been strictly compliant with reduced fat diet. His social history is significant for smoking 1 pack per day for the past 25 years . He reports drinking about 1 pint vodka per day for past 10 years. He read on an online magazine  that drinking alcohol would boost his “Good” cholesterol. At this time, a repeat fasting lipid profile reveals:

Total Cholesterol : 250mg%

HDL cholesterol : 35mg%

Triglycerides: 500mg%

The most important step at this time to address his lipid abnormalities:

A) Niacin

B) Gemfibrozil

C) Fenofibrate

D) Alcohol cessation

E) Smoking cessation

Question of the Week # 189

189) A 38 year old woman presents for follow up visit of right leg weakness. Her history is significant for episodes of diplopia and right sided weakness that recurred thrice in the last 3 months. These presentations were also associated with concomitant urinary incontinence and ataxia. Her most recent hospitalization for such an episode was three weeks ago. She was discharged after her symptoms improved upon using intravenous steroids. An MRI brain taken during the initial episode revealed multiple white matter lesions in the peri-ventricular area. Today, she feels well except for minimal weakness in her right leg. Most appropriate drug that should be administered to this patient to reduce the frequency and severity of these recurrences?

A) Methyl dopa

B) Interferon Beta

C) Methyl Prednisolone

D) Interferon Alpha

E) Intravenos Immunoglobulin ( IVIG)

Question of the Week # 188

188) A 24 year old woman is evaluated for a history of chronic anemia. Her history is significant for anemia for the past 7 years. She has been treated with oral iron supplements in the past with out any response. She denies any  gastrointestinal bleeding. Her menstrual cycle is 3 days in duration and her menses have been scant for the past 5 years. There is no family history of anemia or bleeding disorder or cancer. Physical examination is unremarkable. Laboratory investigations reveal :

Hemoglobin : 10.6gm%

MCV: 68fl ( normal 80 to 100)

WBC : 8.8K/μl

Platelets: 230k/μl

Red Cell Distribution Width : 12.8% ( 10.2 to 14.5%)

Reticulocyte count : 6% ( normal 0.5% to 1.5%)

Which of the following are most helpful in diagnosing this patient’s anemia?

A) Serum ferritin

B) Bone marrow biopsy

C) Direct Coombs’ test

D) Hemoglobin Electrophoresis

E)  Anti-endomysial antibodies

Question of the Week # 187

187) A 34 year old obese man presents with complaints of cough of 3 months’ duration. His cough is non-productive and occurs daily. It is worse in the night. He also reports a need to clear his throat constantly. He denies any nasal congestion. He denies smoking or alcohol. He also reports a chronic history of heart burn for which he uses over the counter antacids intermittently. He works as a nurse in a health care facility. He denies any fever or night sweats or weightloss. On examination, throat is normal in appearance with out any exudate or eythema. Lungs are clear to auscultation. A Chest X-ray is normal. The most appropriate initial diagnostic step in evaluating his cough is :

A) Tuberculin skin test

B) Methacholine challenge

C) Albuterol trial

D) Omeprazole trial

E) 24 Hour esophageal  pH monitoring

Question of the Week # 186

186) A 65 year old woman is evaluated in your office for lower extremity swelling and weakness. She has difficulty speaking for the past 3 months. Her past medical history is significant for renal insufficiency and hypertension that was diagnosed 6 months ago. A TSH level that was obtained 3 weeks ago was normal. She smokes cigarettes, about 1 pack per day for the past 35 years. Her medications include Lisinopril and Hydrochlorthiazide. On physical examination, her heart rate and rhythm are regular. Lungs are clear to auscultation. She has gross edema of the lower extremities. There is no extremity weakness. Head and neck examination reveals findings as shown below:

Most appropriate next step in management of this patient:

A) Stop Lisinopril

B) Start Levothyroxine

C) Intubation

D) Abdominal fat pad biopsy

E) Serum immunoelectrophoresis

Question of the Week # 185

185) A 65 year old woman is evaluated in your office for lower extremity swelling and weakness. She reports difficulty speaking for the past three months. Her past medical history is significant for renal insufficiency and hypertension that was diagnosed 6 months ago. A TSH level that was obtained 3 weeks ago was normal. She smokes cigarettes, about 1 pack per day for the past 35 years. Her medications include Lisinopril and Hydrochlorthiazide. On physical examination, her heart rate and rhythm are regular. Lungs are clear to auscultation. She has gross edema of the lower extremities. There is no extremity weakness. Head and neck examination reveals findings as shown below:

Which of the following is most likely to be abnormal in this patient?

A) Free thyroxine

B) Serum immunoelectrophoresis

C) Rheumatoid factor

D) ACE Level

E) Bradykinin level

Question of the Week # 183

183) A 65 year old woman  presents  with a white plaque on her vulva. It is associated with occasional itching. She has no other hypo-pigmented lesions on her body.  She denies any post-coital bleeding. Physical examination reveals a white colored plaque on the vulva. The lesion is atrophic, thin with a crinkled surface and is well-demarcated. There is atrophy of the labia minora. Most appropriate next step in managing this patient?

A) Topical Corticosteroids

B) Fluconazole

C) Vulvar Biopsy

D) HPV testing

E) Topical Testosterone

Question of the Week # 163

163) A 62 year old man with past medical history significant for Congestive Heart Failure presents with progressively increasing shortness of breath over the past 2 months. He denies any chest pain on exertion or at rest. He was recently started on furosemide for management of peripheral edema and is compliant with low salt diet. An Echocardiogram obtained 3 months ago revealed an Ejection Fraction of 32% (Normal = above 55%) at which time he was started on Enalapril. On physical examination, there is trace ankle edema. There are no lung crackles on auscultation. Rest of the examination is normal. An EKG reveal changes of left ventricular hypertrophy with normal QRS duration. The most important intervention at this time that would most improve his survival is

A) Start Losartan

B) Start Carvedilol

C) Start Isosorbide and Hydralazine

D) Add Digoxin

E) Biventricular Pacing

Question of the Week # 161

161) A 42 year old man is evaluated in your office for pain in his left hand. He has a chronic history of biciptal tendinopathy in his left upper extremity and Gastro-esophageal Reflux disease. He denies any history of recent trauma. He reports sudden onset of pain in his left hand that is associated with burning sensation. On physical examination, the left hand is swollen, pal, cool and tender to touch. Radial and ulnar pulses are intact. The image of his hands is shown below:







Most likely diagnosis of this patient’s presentation

A)     Scleroderma

B)      Raynaud’s phenomenon

C)      Complex regional pain syndrome

D)     Acute arterial occlusion

E)      Carpal Tunnel Syndrome

F)      Compartment Syndrome

Question of the Week # 159, 160

159) A 65 year old man with history of Diabetes Mellitus Type II and Hypertension is evaluated for a one month history of numbness in bilateral hands and feet. He has been feeling excessively tired lately. His medications include Glyburide, Metformin and Enalapril for the past 5 years. Physical examination reveals loss of position sensation in bilateral lower extremities.  He reports good control of blood pressure and Diabetes. His recent HgBA1C was 6.0% 1 month ago. His laboratory tests reveal a Hemoglobin of 9.0gm%; WBC of 8.0k/µl, MCV of 103 and Platelets of 200k/µl. Once the diagnosis is confirmed, the most important therapeutic step in addressing this patient’s presentation:

A) Stop Metformin

B) Switch to insulin

C) Vitamin b12 and Calcium supplementation

D) Start Gabapentin

E) Start Thyroid Supplements

160) In Question above, the most likely underlying cause of this patient’s presentation:

A) Diabetes related complications

B) Chronic Metformin Use

C) Poor Glycemic Control

D) Myelodysplastic Syndrome

E) Hypothyroidism 

Question of the Week # 158

158) A 55 year old man comes to the Emergency Room complaining of left upper quadrant discomfort. His physical examination reveals Splenomegaly. Laboratory investigations were sent but there was a significant delay in sending the specimen to the laboratory after collection. Laboratory investigations reveal a WBC count of 110,000/µl with neutrophilia,  basophilia and eosinophilia and Serum potassium of  3.0/µl. Leucocyte Alkaline Phosphatase level is low. A bone marrow biopsy is obtained and the results are pending. The most likely explanation of the patients hypokalemia :

A) Delay in specimen transport to lab

B) Marked Leucocytosis and Delay in specimen transport

C) Tumor Lysis

D) Splenomegaly

E) Renal loss

Question of the Week # 157

157) A 25 year old woman presents to your office with complaints of muscle cramps and weakness. She smokes 1 pack cigarettes per day and chews tobacco and flavored gum. She also has history of alcoholism and ingests about one pint of vodka every day for the past 2 years. She also uses “Ecstasy”  during weekend parties. She has a history of snoring in the night. On examination,  afebrile,  heart rate is 88/min and blood pressure is 150/98.  Laboratory investigations reveal a Sodium of 144 meq/L, potassium of 3.0meq/L, Chloride 98meq/L , Bicarbonate of 34meq/L and Creatinine of 0.8mg%. Urinary chloride is 45meq/L. Which of the following points in the patient’s history is most helpful in diagnosing her condition?

A) Alcohol use

B) Chewing tobacco and flavored gum

C) Snoring in the night

D) Smoking

E) Use of Ecstasy

Question of the Week # 156

156) A 25 year old woman presents to your office with complaints of muscle cramps and weakness. On examination, she is afebrile,  heart rate is 88/min and blood pressure is 150/98.  Ophthalmoscopic examination shows the following :

Laboratory investigations reveal a Sodium of 144 meq/L, potassium of 3.0meq/L, Chloride 98meq/L , Bicarbonate of 34meq/L and Creatinine of 0.8mg%. Urinary chloride is 45meq/L. The most likely diagnosis that explains this patient’s clinical features :

A) Gitelman’s syndrome

B) Chronic Laxative abuse

C) Diuretic Abuse

D) Primary Hyperaldosteronism

E) Bartter’s syndrome

Question of the Week # 154

154) A 68 year old man presents to the clinic for progressive right hip pain.  He reports pain in the right hip when walking more than 1 block and also, has difficulty putting shoes on his right foot. On examination, the range of motion is significantly limited in the right hip. An X-ray of the right hip reveals significant loss of cartilage, subchondral sclerosis and sub-chondral cysts. The patient is diagnosed with Right Hip Osteoarthritis and is started on Acetaminophen. Which of the following exercises should not be recommended to this patient at this time:

A) Stair climbing

B) Quadriceps strtengthening

C) Tai-Chi

D) Swimming

E) Bicycling

Question of the Week # 153

153) A 68 year old man presents to the clinic for progressive right hip pain. He has a history of hearing impairment. He reports pain in the right hip when walking more than 1 block and also, has difficulty putting shoes on his right foot. On examination, the range of motion is significantly limited in the right hip. An X-ray of the right hip reveals significant loss of cartilage, subchondral sclerosis and sub-chondral cysts. X-ray also reveals pagetoid changes in the right liac wing and right femoral neck. Serum alkaline phosphatase level is normal. The most appropriate initial step in managing this patient is:

A) Bisphosphanates

B) Acetaminophen, Quadriceps strtengthening and Tai-Chi

C) Bisphosphanates and Acetaminoiphen

D) Calcitonin

E) Oral prednisone

Question of the Week # 151

151) A 65 year old man is evaluated in the Emergency room for Shortness of breath and mild chestpain. On examination, he has dullness to percussion in the left lung base. The breath sounds are bronchial in nature. Vocal and tactile fremitus is increased in this area. Most likely lung abnormality that can explain this patient’s physical examination findings:

A) Consolidation

B) Pneumothorax

C) Pleural Effusion

D) Lung Collapse

E) Hydropneumothorax

Question of the Week # 149

149) A 29 year old internal medicine resident physician has been exposed to a patient with cavitary pulmonary tuberculosis 1 month ago. He denies any symptoms. His physical examination is normal. A tuberculin skin test reaction is positive now at 6mm. His Skin test one year ago was negative. A chest X-ray is within normal limits and chemistry panel is normal. The most appropriate management optiuon for this patient is :

A)     Isoniazid, Pyrazinamide, Rifampin and Ethambutol for 9 months

B)      Observation as  ≥ 10mm is considered positive in health care workers

C)      Isoniazid for 9 months

D)     Rifampin for 9 months

E)      Isoniazid for 6 months

Question of the Week # 148

148)  A 55 year old nurse has recently been exposed to an in-patient with active Tuberculosis about 2 months ago. Her tuberculin skin test was negative a year ago however; the skin test reveals an 12 mm induration at this time. A chest x-ray is normal. She denies any cough or fever or weightloss. A comprehensive metabolic panel is within normal limits. She is started on Isoniazid for the treatment of latent tuberculosis. Two weeks after the therapy, patient develops edema in the face and neck, maculopapular rash, lymphadenopathy, asthenia, and a fever of 38°C. Laboratory tests reveal a WBC count 20k/µl with a differential showing neutrophils of 50%, eosinophils of 30% and lymphocytes 20%. The most appropriate next step in management:

A)     Start antifungal therapy

B)      Discontinue Isoniazid and re-administer after de-sensitization

C)      Discontinue Isoniazid and administer Rifampin for four months

D)     Start Metronidazole

E)      Change to multi-drug therapy,  Isoniazid , Pyrazinamide, Rifampin and Ethambutol

Archer – Critical Care

Topic I Pulmonary Embolism

Pulmonary embolism is a highly questioned topic on USMLE Step 2 and Step 3. Many students have questions and concerns regarding :
1. Stable vs. Unstable PE. Diagnosis/ clinical scenarios
2. Acute management of stable vs. unstable Pulmonary embolism
3. Indications for IVC filter ( Greenfield filter)
4. Duration of anticoagulation
5. Hypercoagulability work-up

We will discuss these here in three parts and self assessment questions will follow after the discussion.

Chapter I – Clinical scenarios – Acute PE.

1. Pulmonary embolism can manifest in several ways. You need to familiarize yourself with various clinical scenarios associated with PE that can be often tested on the exam. Commonest symptoms would be chestpain and/ or shortness of breath. But other scenarios that can be tested are : ( You should consider and rule out the possibility of PE in the following scenarios)

a) Acute onset atrial fibrillation in an immobilized hospitalized patient.
b) Shock with no other obvious causes in a patient with risk factors for PE
( Obstructive shock – understand that the embolus can be massive and occlude the right ventricular outlet i.e; pulmonary artery there by preventing filling of the left heart leading to shock)
c) Persistent tachycardia in a patient with risk factors for PE.
d) Hypoxemic respiratory failure with increased A-a ( alveolar-arterial gradient)
e) Sudden right ventricular strain pattern on the EKG ( Typical S1Q3T3 pattern on EKG -sudden onset).
f) Pumonary Hypertension ( If chronic and no other etiology, suspect and rule out chronic thromboembolism in patients with risk factors for PE)

There are several other scenarios a PE can present in a hospitalized patient. However, the above scenarios are commonly asked on the exam. In the self-assessment questions at the end of the section, we will give you sample questions for some of these scenarios.

a) In an inpatient with acute onset atrial fibrillation – you need to control the rate with drugs like beta blocker or diltiazem but you must also consider the differential diagnosis regarding the etiology of afib such as hypoxia, electrolyte abnormalities, acute MI, valvular diseases, accelerated hypertension, hyperthyroidism and congestive heart failure. It is important to know the etiology so that you can treat the underlying issue that led to afib. Controlling the rate alone in afib is not enough , you must also address the reversible etiology so as to prevent recurrence of afib.

When you consider hypoxia as the cause, the evidence can be obtained by pulse oximetry which shows Sao2 usually less than 90 – now, you need to consider the etiology of hypoxia – is it a hypoventilation as in COPD or is it a deadspace such as in pulmonary embolism or is it shunting as in collapse, pneumonia or ARDS? Such information can be obtained by ordering initial tests such as arterial blood gases and chest x-ray. Calculate the A-a gradient from the blood gases. ABGs give important clues – presence of hypercapnia usually indicates COPD/ opiod overdose etc as the causes of hypoxia. Presence of hypocapnia with low po2 and increased A-a gradient goes more in favor of pulmonary embolism.

If chest x-ray is normal but A-a gradient is increased on the ABGs, you should question yourself on what could be possibly causing the gradient with out any evidence of obvious disease on the CXR. This most likely indicates underlying pulmonary embolism in which case you need to pursue further tests to diagnose it such as V/Q scan or Spiral CT scan. Such an analytical approach will allow you to choose the correct diagnosis.

b) Shock – shock is mainly of four types such as Hypovolemic, cardiogenic. distributive and obstructive. Understanding this simple basic pathophysiology behind shock can help you diagnose the etiology of shock and there by, institute life saving therapy.
Pulmonary embolism can cause obstructive shock i.e; hemodynamically unstable PE. This is also referred to as Acute corpulmonale ( Acute right ventricular failure). Diagnosing PE as the cause of shock is very important because immediate thrombolysis can lyse the thrombus that is obstructing the right ventricular outlet there by, restoring left ventricular filling and the blood pressure. Hence, it is a life saving decision to give thrombolytics in a hemodynamically unstable PE.

c) In any patient with persistent tachycardia with out obvious causes, one should consider if this patient is at risk for PE. If the patient has risk factors for PE, then a v/q scan or spiral CT must be obtained to rule out PE.

d) As mentioned above, hypoxemic respiratory failure in the presence of normal chest x-ray and increased A-a gradient on the ABGs strongly suggests PE as a possiblity.

e) Acute right ventricular strain can be presented to you in the form of an EKG with a typical S1Q3T3 pattern on the EKG or ST elevation in I or t-inversions in lead III. Always, it is important to rule our right ventricular MI or ischemia in these cases because such an MI can also cause similar changes. Obtaining cardiac enzymes is helpful to consider acute MI when there is elevated troponin but it should be remembered that a massive PE can also cause some elevation in troponin. So, best test in such a scenario where there is acute right ventricular strain pattern on the EKG would be a 2D-Echocardiogram. 2D-Echo will help you see wall motion abnormalities – if only some or single segment of the right ventricle wall are hypokinetic, it favors right ventricular MI. If the entire right ventricle is hypokinetic, it goes more in favor of Pulmonary embolism ( imagine a massive clot obstructing the right ventricle outlet, obviously, the entire right ventricle will not move – seen as global hypokinesis of RV on the 2D ECHO)

The above mentioned are some unique confusing scenarios in pulmonary embolism presentation. In the next chapter, we will discuss the diagnosis and management of stable vs. unstable PE

Self Assessment Questions:

1) A 75 year-old man with history of hypertension presents to the emergency room with complaints of shortness of breath and palpitations. His vital reveal a heart rate 142/min, blood pressure 130/86, temperature 98.6 and oxygen saturation of 89% on room air. On auscultation, there are no rhonchii or crepitations, the heart rate was irregular and rapid with out any murmurs. The patient is placed on oxygen by nasal cannula. An urgent EKG is obtained which reveals rapid atrial fibrillation with no evidence of significant ST-T changes. The patient is started on diltiazem. Chest x-ray is normal and a brain natriuretic peptide is 80ng/L. Electrolytes, TSH and complete blood count are with in normal limits. Cardiac enzymes are drawn. Arterial blood gases reveal a pH of 7.48, po2 of 58, pco2 of 20 on room air ( Fio2 of 21%). The next step in establishing the etiology of his atrial fibrillation :

A) Cardiac catheterization
B) Spiral CT scan of the chest
C) Venos doppler of lower extremities
D) 2D Echocardiogram
E) D-Dimer

2) What is the most likely etiology of atrial fibrillation in Case 1?

A) Acute ST elevation MI
B) Acute pulmonary embolism
C) Pneumothorax
D) COPD exacerbation
E) Congestive heart failure

3) A 65 year-old man with history of recently diagnosed metastatic colon cancer being treated with chemotherapy is admitted to the hospital with constipation and vomiting. His colon cancer was diagnosed by colonoscopy 2 months ago when he presented with massive GI bleeding. At this admission, patient is diagnosed with bowel obstruction secondary to descending colon cancer and underwent a palliative left hemicolectomy to provide symptomatic relief. He has no occult or gross GI bleeding at this time. On the sixth post-operative day, you are called by the nurse because the patient’s blood pressure is 80/40. His heart rate is 82, respiratory rate 24 and temperature of 100.6. The patient is given Normal saline bolus. A CXR is normal. EKG reveals a prominent S wave in lead I, a Q wave and inverted T wave in lead III. Of note, a pre-operative EKG was completely normal. First set of cardiac enzymes are negative. A bedside 2D echo reveals global hypokinesis of the right ventricle. A repeat blood pressure obtained after normal saline bolus is still low at 70/40. The most likely etiology of the shock in this patient is :

A) Hypovolemia
B) Septic shock
C) Acute myocardial infarction leading to cardiogenic shock
D) Acute pulmonary embolism
E) Tension Pneumothorax

4) Most important next step in treating this patient’s shock?

A) Continued fluid boluses
B) Antibiotics and pressor support with dopamine
C) Intra-aortic balloon counter-pulsation followed by urgent cardiac catheterization.
D) Anticoagulation with heparin
E) Tissue plasminogen activator ( tpA)
F) Embolectomy
G) Chest tube placement.
H) Inferior vena cava filter

5) The patient was appropriately treated. The discharge recommendations should include :
A) Inferior venacava filter
B) Life-long low-molecular weight heparin
C) Life-long coumadin
D) Hypercoagulability testing
E) Compression stockings

Q1) Ans. D
– 2D echocardiogram in this case will help to evaluate for different etiologies of atrial fibrillation such as acute MI, acute PE and valvular heart disease. From the question, we understand that hypoxia could have possibly initiated the atrial fibrillation. A normal CXR rules out gross lung pathologies such as emphysema, pneumothorax, ARDS, pulmonary edema and pneumonia which could be various etiologies of hypoxia. However, pulmonary embolism and acute MI can not be readily eliminated from a normal Chest X-ray. Hence, a quick bed side echo should be considered. If the Echo reveals segmental hypokinesis of right ventricle, this favors the diagnosis of Acute MI where as if it revealed a global hypokinesis of the right ventricle, it would more favor a diagnosis of acute pulmonary embolism.

– Spiral CT scan is a close distractor here since one may choose this considering the strong diagnosis of pulmonary embolism in the above case. However, spiral CT scan will help you to confirm or rule out PE but it does not help you to evaluate for other possible etiologies of atrial fibrillation at the same time. Hence, 2D echo is a superior initial test in the above case.

– Urgent cardiac catheterization should be performed in the presence of ST elevation MI. There is no evidence of ST elevation in the above case.

– Venos doppler of lower extremities should be considered once we are more certain that PE is the most likely etiology and hence, is not an initial test.

– D-Dimer can be used as a screening test for PE when the pre-test probability is low. A low D-dimer combined with a low pre-test probability of PE can be used to rule out PE. While a low D-dimer < 500 may exclude PE, a higher d-dimer is non-specific and does not differentiate between other causes of thromosis such as DIC, presence of arterial thrombi, PE and DVT.

Q2) B.
The presence of Hypoxia, hypocapnia and increased A-a gradient (about 70) with a normal CXR findings in the above question indicates that an Acute Pulmonary Embolus is the most likely diagnosis.
Choice A – is not the answer because the EKG did not reveal any ST elevations.
Choice C – is not the answer since the physical exam revealed normal breath sounds and CXR was normal.
Choice D – is not the answer since the ABGs in the above patient reveal Hypocapnia and increased A-a gradient. Hypercapnia secondary to acute CO2 retention is often a feature of COPD exacerbation. The A-a gradient is usually normal in COPD except in emphysema.
Choice E – a normal CXR, absence of significant CHF physical findings and a BNP ( brain natriuretic peptide) less than 100 virtually rules out Congestive Heart Failure.

Q3) D.
Pulmonary embolism is a common complication that can occur in post-surgical patients, usually after post-operative day 5.
The patient has a very high risk profile for pulmonary embolism. The clinical probability of the PE from his history is extremely high – age > 60 years, cancer, immobilization and surgery with in last few days are well known risk factors for pumonary embolism which this patient clearly possess. Also, sudden appearance of right ventricular strain pattern (S1Q3T3) and a classic acute corpulmonale findings on 2D Echo suggests that PE is the most underlying etiology for this patient’s shock. ( Obstructive type shock)

Although. all the other choices are potential causes for shock in the above patient, their probability can be reduced by considering and analyzing important clues in the question.

– Choice A not correct – Failure to respond to normal saline indicates that this is not hypovolemia. Also, hypovolemic shock should not produce acute right ventricular strain on the EKG or hypokinesis on the 2D Echo.

– Choice B not correct – Fever may suggest sepsis but it needs to be remembered that fever can also be seen with PE. Also, septic shock should not produce acute right ventricular strain on the EKG or acute right ventricular hypokinesis alone on the 2D Echo.

– Choice C not correct – Acute MI is a possiblity but it usually produces segmental hypokinesis rather than global hypokinesis on 2D Echo. The cardiac enzymes are also negative.

– Choice E not correct since CXR was normal.

Q4) F.
Pulmonary embolectomy is the correct choice. In scenarios where thrombolysis is contraindicated, embolectomy is used for patients with PE who are hypotensive despite supportive measures (persistent systolic BP ≤ 90 mm Hg after fluid therapy and O2) i.e; hemodynamically unstable PE.
The patient has obstructive shock and obstruction should be removed urgently to restore the blood pressure. Clot can be lysed by thrombolysis or mechanically with embolectomy. The patient had GI bleeding in last 6 months which is an absolute contraindication to thrombolysis and also, surgery 6 days ago which is a relative contraindication for tpa. Hence, embolectomy is the choice.

Choice A – not correct – this is the treatment of hypovolemic shock. Hypovolemic shock is unlikely because of the above mentioned reasons in this patient.

Choice B – not correct – this is the treatment of septic shock. Septic shock is unlikely because of the above mentioned reasons in this patient.

Choice C – not correct – this is the treatment of cardiogenic shock. Cardiogenic shock is unlikely because of the above mentioned reasons in this patient.

Choice D – not correct – this is the treatment of stable pulmonary embolism. In unstable pulmonary embolism, clot obstruction must be relieved rapidly with thrombolysis or embolectomy. If tpa is planned, Heparin should only be started 24 hours after thrombolytics. Heparin will help in preventing further clot extension or further embolism but will not help in immediately treating the obstructive shock.

Choice E – not correct – The patient has contraindications for tpa ( thrombolytics). Absolute contraindications to thrombolytics include prior hemorrhagic stroke, ischemic stroke within 1 yr, active external or internal bleeding from any source, intracranial injury or surgery within 2 mo, intracranial tumor, GI bleeding within 6 mo, and CPR.

Relative contraindications include recent surgery (≤ 10 days), hemorrhagic diathesis (as in hepatic insufficiency), pregnancy, current use of anticoagulants and an INR > 2, punctures of large noncompressible veins (eg, subclavian or internal jugular veins), recent femoral artery catheterization (eg, ≤ 10 days), peptic ulcer disease or other conditions that increase the risk of bleeding, and severe hypertension (systolic BP > 180 or diastolic BP > 110 mm Hg).

Choice G – not correct – This is the treatment for tension pneumothorax. Tension pneumothorax is an important cause of obstructive shock but a normak CXR rules it out.

Choice H – not correct – this is the treatment for pulmonary embolism or DVT in the presence of contraindications to anticoagulation with heparin or warfarin or in cases of warfarin failure.
Indications for IVC filters:
– Contraindications to anticoagulation
– Recurrent DVT (or pulmonary emboli) despite adequate anticoagulation ( i.e; warfarin failure)
– In patients with low cardio-pulmonary function and extensive DVT ( extending in to inferior venacava) – where any additional small pulmonary emboli may compromise their cardio-pulmonary status further.

Q5) B.
LMWH is superior to warfarin in preventic venos thromboembolism in cancer patients. Cancer is a hypercoagulable condition and this patient hence, requires life-long anticoagulation.
Choice A is incorrect. IVC filter is indicated for thromboembolism prophylaxis in the presence of absolute contraindication to anticoagulation. The patient has no active bleeding. Also, IVC filter can only protect against PE but not against DVT .
Choice C is incorrect because LMWH is superior to warfarin in cancer patients.
Choice D is incorrect – the patient already has a known hypercoagulable state which is a cancer and requires life long anticoagulation with LMWH. This is not a idiopathic PE where full hypercoagulability work-up would be warranted.
Choice E is incorrect – compression stockings are more effective for preventing calf than proximal DVT and thus, provides inadequate prevention. Also, they are contraindicated in patients with active DVT or those with possible occult DVT as compression can dislodge the clots and lead to PE in those with active DVT.

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