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Surgery Rotation (Sx, Heme, Musculoskeletal)

Terms in this set (205)

Hemostasis
Explanation
Foremost in the evaluation of a wound, in any setting, is hemostasis. Large amounts of blood pooling or notable pulsations warrant urgent exploration for arterial damage, which could need emergent clamping and ligation.

To provide healthy tissue for approximation during closure, debridement of devitalized tissue may be necessary if there is obvious necrosis.

Wound cleansing and debridement are most important in the prevention of secondary infections. Cleansing is best performed with normal saline under mild pressure using a 14-gauge angiocatheter on a 30-60 cc syringe. This may require use of local anesthesia, such as tetracaine-adrenaline-cocaine or lidocaine-adrenaline-tetracaine gel or nerve block with 1% or 2% lidocaine. Very young or anxious patients may also require possible sedation with benzodiazepines, fentanyl, or ketamine.

While hemostasis is being achieved, a thorough history of the mechanism of injury should be assessed to determine wound contamination, presence of retained foreign bodies, and probable depth of injury. A tetanus immunization history should also be determined.

Closure of the wound may or may not be needed. Superficial scrapes and abrasions do not require closure. Deep lacerations that penetrate into or beyond the dermis may require direct closure with sutures or adhesives to provide an epithelial covering for healing by primary intention after thorough cleansing and debridement. Clean wounds can be closed within 8 hours of injury. Contaminated wounds typically should be left open if more than 6 - 8 hours old and allowed to heal spontaneously or by secondary intention, though late closure (tertiary intention) may be considered if no infection is evident. This usually includes puncture wounds or bite wounds.
B thalassemia
Explanation
The correct answer is β-thalessemia. β-thalassemia is caused by mutations in the b-globin gene causing a reduced amount of b-globin to be produced. Individuals affected with b-thalassemia are normal at birth due to the presence of HbF. Anemia develops over the first few months, and symptoms become progressively more severe. It is characterized by failure to thrive, feeding difficulties, easy fatigue, bouts of fever and diarrhea, intestinal problems, and hepatosplenomegaly. Peripheral blood smear shows the presence of nucleated red blood cells. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) are decreased; so is hemoglobin (<7 g/dl). Mutation analysis of the b-globin gene is available on a clinical basis.

α-thalassemia is caused by mutations in the alpha-globin genes, leading to decreased production of these polypeptide chains. 2 pairs of genes are involved, and inheritance is complicated. Symptoms range from no clinical abnormalities (a mutation in only 1 of the 4 genes) to lethal to the embryo (a mutation in each of the 4 genes).

Sickle cell anemia occurs almost exclusively in the African-American population; 1 in 400 African-Americans in the US are affected. It is characterized by anemia, growth retardation, developmental delay, and increased risk of infection. The altered red blood cells cause bloodflow to become sluggish and can cause occlusion of vessels. Jaundice may be present. Bone changes, which can be seen on X-ray, occur due to chronic marrow hyperactivity. Typical appearance includes a short trunk with long extremities and a tower-shaped skull. Aplastic crisis can occur when infection is present, and severe bone pain is common. Diagnosis is made by hemoglobin electrophoretic testing.

Hemophilia A and von Willebrand disease are bleeding disorders caused by deficiencies of different clotting factors: hemophilia A occurs when factor VIII is deficient; von Willebrand disease occurs when the von Willebrand factor is deficient or abnormal. They are clinically similar. They are characterized by prolonged or renewed bleeding after injuries, tooth extractions, or surgery. Coagulation factor assays are used for diagnosis. Hemophilia A is inherited in an X-linked recessive manner; only males are affected. Von Willebrand disease is inherited in an autosomal dominant manner.
CLL
Explanation
The patient in the above scenario most likely has chronic lymphocytic leukemia (CLL). This is most likely due to the presenting symptoms, which include the patient's age (typically after 50 years of age, with a median age being 70), fatigue, and lymphadenopathy. Initial labs completed show an abnormally elevated white blood cell count with significant lymphocytosis; usually 75 - 98% of the cells are smaller (but mature-appearing) lymphocytes. Bone marrow biopsy is markedly infiltrated, with small (but mature) lymphocytes.

Hairy cell leukemia (HCL) is incorrect; lymphadenopathy is rarely found in this pathology with organomegaly found in almost all cases. Pancytopenia is present, and the evidence of 'hairy cells' are found on the peripheral blood smear, which are described as having cytoplasmic projections.

Acute myeloid leukemia (AML) is incorrect because symptoms of AML are usually only present for days or even weeks prior to the patient presenting for clinical evaluation. Symptoms include unusual bleeding from the skin and mucosal surfaces, bone/joint pain, evidence of petechiae and purpura. The hallmark AML laboratory finding is pancytopenia with circulating blasts; more than 20% marrow blasts are conclusive for the diagnosis of AML.

Acute lymphocytic leukemia (ALL) most often is characterized by a combination of pancytopenia with circulating blasts. The bone marrow biopsy will also be hyper-cellular and largely consisting of blasts. An amount of 20% or more blasts in the marrow is required to diagnose ALL; this is not consistent with the findings in the above scenario.

Chronic myeloid leukemia (CML) is the incorrect choice due to several factors: CML is typically a leukemia found in middle age patients with the median age at presentation being 55 years old. Patients will have fatigue, night sweats, a low-grade fever, and splenomegaly present. On very rare occasions, patients may also have blurred vision, respiratory distress, or even priapism. The hallmark finding of CML is the laboratory finding of the bcr/abl gene in the peripheral blood; this also known as the Philadelphia chromosome. The patient above is negative for this finding.
Thrombotic thrombocytopenic purpura
Explanation
TTP is a related condition that is characterized by microangiopathic hemolysis and platelet aggregationhyaline thrombi, whose formation is unrelated to coagulation system activity. It is also distinguished by the formation of hyaline thrombi in many organs, causing partial obstruction in the blood vessels. Von Willebrand factor is synthesized by the endothelial cells and built up into large multimers. The larger ones are called unusually large von Willebrand factor or ULWF. These are quickly broken down to the normal sized von Willebrand factor by a cleaving protease called ADAMTS-13, the deficiency of which, in TTP, leads to widespread accumulation of ULWF, platelet activation and aggregation, and formation of multiple thrombi.

TTP typically presents with the pentad of fever; microangiopathic hemolytic anemia; thrombocytopenia; neurological symptoms like tinnitus, blurred vision, headache, confusion, lethargy and seizures; and renal disease. Renal involvement is less severe than HUS and may be limited to hematuria or proteinuria, whereas neurological symptoms predominate unlike in HUS. The disease is fatal without treatment, which includes plasma exchange daily till neurological symptoms resolve and platelet count and LDH normalize. Other therapeutic measures include steroids, aspirin, immunoglobin, immunosuppressive agents, and splenectomy.

Hemolytic-uremic syndrome (HUS) is a primarily pediatric condition characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. In children it occurs after infection with toxin producing E. coli strain O157:H7 or shigella dysenteriae. In adults, sporadic cases occur after chemotherapy with mitomycin, cisplatin, bleomycin, or gemcitabine or with adenocarcinomas of breast GI tract, pancreas, or prostate. Renal function tests and peripheral smear (schistocytes are seen) are done. Therapeutic options include plasma exchange, dialysis, control of hypertension, low dose aspirin, and steroids. Prognosis remains poor, even with optimal treatment, since plasmapheresis appears to be ineffective in drug induced HUS. Discontinuing the offending drug is a must.

ITP, usually a diagnosis of exclusion, is an immune mediated thrombocytopenia caused by antibodies to platelets that presents with mucosal bleeding and petechiae. The acute form is seen in children after a viral illness, whereas the chronic form is commonest in young women, aged between 20-50 years. Adults present with purpura, menorrhagia, epistaxis, gingival bleeding, and bruising tendency. Low platelet count is found, sometimes severe, with increased megakaryocytes. All other lines of cells are usually normal. Therapy includes high dose steroids, immunosuppressive treatment with azathioprine, IVIG, or splenectomy. Platelet concentrate may be considered for transfusion.

APS is characterized by antibodies against phospholipids or plasma proteins bound to phospholipids and may be idiopathic or associated with SLE, rheumatoid diseases, infections, drugs, and neoplasms. It is associated with thrombotic events, fetal loss, thrombocytopenia, and neurological events. Renal disease of multiple etiology can occur. PT and PTT are prolonged. Treatment includes anticoagulation, antiplatelet therapy, and immunosuppressants.

DIC involves a complex series of events initiated by a systemic illness like sepsis, trauma, malignancy, abruptio placentae, etc, which manifests as a frequently catastrophic hematologic syndrome. Thrombosis and bleeding diathesis co-exist. Activation of the coagulation pathway causes thrombosis. Platelets and fibrinogen are consumed, causing bleeding. PT and PTT are prolonged. There is thrombocytopenia and increased fibrin degradation products. Therapy includes treating the underlying disease and administration of platelets and plasma to bleeding patients, whereas anticoagulation is reserved for thrombotic complications.

TTP is a related condition that is characterized by microangiopathic hemolysis and platelet aggregationhyaline thrombi, whose formation is unrelated to coagulation system activity. It is also distinguished by the formation of hyaline thrombi in many organs, causing partial obstruction in the blood vessels. Von Willebrand factor is synthesized by the endothelial cells and built up into large multimers. The larger ones are called unusually large von Willebrand factor or ULWF. These are quickly broken down to the normal sized von Willebrand factor by a cleaving protease called ADAMTS-13, the deficiency of which, in TTP, leads to widespread accumulation of ULWF, platelet activation and aggregation, and formation of multiple thrombi.

TTP typically presents with the pentad of fever; microangiopathic hemolytic anemia; thrombocytopenia; neurological symptoms like tinnitus, blurred vision, headache, confusion, lethargy and seizures; and renal disease. Renal involvement is less severe than HUS and may be limited to hematuria or proteinuria, whereas neurological symptoms predominate unlike in HUS. The disease is fatal without treatment, which includes plasma exchange daily till neurological symptoms resolve and platelet count and LDH normalize. Other therapeutic measures include steroids, aspirin, immunoglobin, immunosuppressive agents, and splenectomy.
G6PD deficiency
G6PD deficiency is a very common X-linked hemolytic disorder affecting millions across the world. The highest incidence is among people of African, Asian, or Mediterranean descent.

Glucose-6-phophate dehydrogenase is an enzyme in red cells that is vital to the integrity of the cell. Deficient individuals are susceptible to hemolysis under oxidant stress caused by drugs like sulfa and antimalarials, infections, or noxious agents like fava beans. Oxidant stress causes denatured hemoglobin, resulting in Heinz bodies. During an acute event, as in this patient, rapid hemolysis causes acute anemia, hemoglobinuria (thus the dark urine), abdominal and back pain, jaundice, and even renal failure. G6PD levels are normal to low during an acute attack, since the replacement reticulocytes are young and have adequate enzyme levels. G6PD level should be measured after an acute attack is over. Removing the precipitating agent and getting oxygen and rest is usually sufficient during an acute attack.

Hereditary spherocytosis is another type of hemolytic anemia due to congenital red cell membrane defect, causing red cell swelling and resulting in the typical small round spherocytes without any central pallor, as in a normal RBC. This results in increased osmotic fragility, and red cells are easily destroyed in the spleen. Symptoms vary from incidental diagnosis to severe anemia, to neonatal hyperbilirubinemia, to hydrops fetalis in utero. Patients may present with biliary symptoms in adulthood.

Sickle cell anemia is a hemoglobin disorder mostly occurring in African Americans in which there is a mutation in the amino acid sequence in the globin chains, resulting in severe structural and functional changes in the red cells. The hemoglobin molecule gets polymerized, resulting in rigidity of the molecule and causing red cells to have an altered shape resembling a sickle. This predisposes the red cells to undergo hemolysis with stressors like infections. Patient may have crises of different types, including aplastic, painful, hemolytic, etc. Gallstone disease may occur. Frequent visits to the ER are common with chest pain (acute chest syndrome), abdominal pain from splenic infarctions, and infections due to encapsulated organisms. Acute chest syndrome is defined as a new infiltrate on chest X-ray along with new symptoms such as cough, tachypnea, dyspnea, and fever. It is probably due to pulmonary infarction, due to sickle cells along with infection. Chest X-ray, sputum cultures, and blood cultures are requested. Treatment is mainly supportive with oxygen, appropriate antibiotics, fluid management, chest physiotherapy, and incentive spirometry.

Labs show chronic anemia with Hb of 5-10g/d. WBC count, arterial blood gases, and liver function tests are done. Electrophoresis can confirm diagnosis. Parvovirus infection induces aplastic crisis. Oxygen, analgesia, and blood transfusions are necessary to treat the patient.

Porphyria is an autosomal dominant disease due to genetic or acquired deficiencies in the activity of enzymes in the heme biosynthetic pathway. Symptoms include abdominal pain, dark urine, and neurological and psychiatric manifestations. UA shows high porphyrin content.

Autoimmune hemolytic anemia occurs due to development of antibodies directed at red cells, resulting in their destruction. It occurs in patients with systemic autoimmune disorders like SLE and ulcerative colitis, lymphoproliferative disorders like lymphomas, and in AIDS. Steroids and splenectomy may be needed to treat this condition. Patients present with anemia, jaundice fever, abdominal pain, and dark urine. Labs show anemia with normal RBC indices, increased reticulocyte count, nucleated red cells and spherocytes in the peripheral smear, and erythroid hyperplasia in the bone marrow. Coomb's test may be positive. Transfusion may be life saving.
Ceftriaxone and Vancomycin
Explanation
The correct response is ceftriaxone and vancomycin. This patient most likely has hematogenous osteomyelitis. Osteomyelitis refers to inflammatory destruction of bone due to infection. There are 2 main categories of osteomyelitis:
Hematogenous osteomyelitis, which is most commonly found in children and occurs secondary to sepsis
Osteomyelitis directly resulting from the spread of bacteria from an adjacent infection (infected diabetic foot ulcer), trauma (open fractures), or vascular insufficiency (peripheral vascular disease). Osteomyelitis resulting from bacteremia is a disease most frequently associated with sickle cell disease, injection drug users, diabetes mellitus, and the elderly. Patients with this form of osteomyelitis often present with sudden onset of high fever, chills, pain, and tenderness of the involved bone.
Among patients with hemoglobinopathies such as sickle cell disease, osteomyelitis is caused most often by Salmonella paratyphi. In sickle cell disease, as well as with the other hemoglobinopathies, Salmonella osteomyelitis is 10 times more common than osteomyelitis caused by other organisms. Staphylococcus aureus is the 2nd most common cause of osteomyelitis in SCD patients. Any empiric antibiotic regimen will need to provide adequate cover for both of these organisms.
A 3rd-generation cephalosporin, such as ceftriaxone or cefotaxime, plus an antistaphylococcal agent (vancomycin or clindamycin and nafcillin) is a reasonable choice; the treatment will provide coverage for both Salmonella and Staphylococcus. If this child had acquired the infection while in the hospital, vancomycin or clindamycin would be the most appropriate empiric antistaphylococcal coverage, not nafcillin, because of the increased prevalence of hospital-acquired infection with methicillin-resistant S. aureus (MRSA).
Nafcillin and Vancomycin is incorrect. This combination covers for MRSA, but not Salmonella.
Fluoroquinolone should not be used in this case. Current evidence in the medical literature has demonstrated an increase in the emergence of fluoroquinolone-resistant Salmonella paratyphi species.
Gentamicin and Vancomycin is incorrect. Gentamicin is an aminoglycoside most effective against Gram-negative bacteria.
Chloramphenicol has historically been most effectively against Salmonella osteomyelitis in SCD. It is not widely used systemically today due to toxicity; however, it does still have a place in severe salmonella infections, and it could be a viable empiric choice along with vancomycin in this case.
Idiopathic thrombocytopenic purpura
Explanation Hemolytic-uremic syndrome (HUS) is a primarily pediatric condition characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. In children it occurs after infection with toxin producing E. coli strain O157:H7 or shigella dysenteriae. In adults, sporadic cases occur after chemotherapy with mitomycin, cisplatin, bleomycin, or gemcitabine, or with adenocarcinomas of breast GI tract, pancreas, or prostate. Renal function tests and peripheral smear (schistocytes are seen) are done. Therapeutic options include plasma exchange, dialysis, control of hypertension, low dose aspirin, and steroids. Prognosis remains poor even with optimal treatment, since plasmapheresis appears to be ineffective in drug induced HUS. Discontinuing the offending drug is a must.
TTP is a related condition that is characterized by microangiopathic hemolysis and platelet aggregationhyaline thrombi, whose formation is unrelated to coagulation system activity. It is also distinguished by the formation of hyaline thrombi in many organs, causing partial obstruction in the blood vessels. Von Willebrand factor is synthesized by the endothelial cells and built up into large multimers. The larger ones are called unusually large von Willebrand factor or ULWF. These are quickly broken down to the normal sized von Willebrand factor by a cleaving protease called ADAMTS-13, the deficiency of which, in TTP, leads to widespread accumulation of ULWF, platelet activation and aggregation, and formation of multiple thrombi.

TTP typically presents with the pentad of fever, microangiopathic hemolytic anemia, thrombocytopenia, neurological symptoms like tinnitus, blurred vision, headache, confusion, lethargy and seizures, and renal disease. Renal involvement is less severe than HUS and may be limited to hematuria or proteinuria, whereas neurological symptoms predominate unlike in HUS. The disease is fatal without treatment, which includes plasma exchange daily till neurological symptoms resolve and platelet count and LDH normalize. Other therapeutic measures include steroids, aspirin, immunoglobin, immunosuppressive agents, and splenectomy.

ITP, usually a diagnosis of exclusion, is an immune mediated thrombocytopenia caused by antibodies to platelets that presents with mucosal bleeding and petechiae. The acute form is seen in children after a viral illness, whereas the chronic form is commonest in young women, aged between 20-50 years. Adults present with purpura, menorrhagia, epistaxis, gingival bleeding, and bruising tendency. Low platelet count, sometimes severe, is found with increased megakaryocytes. All other lines of cells are usually normal. Therapy includes high dose steroids, immunosuppressive treatment with azathioprine, IVIG, or splenectomy. Platelet concentrate may be considered for transfusion.

APS is characterized by antibodies against phospholipids or plasma proteins bound to phospholipids and may be idiopathic or associated with SLE, rheumatoid diseases, infections, drugs, and neoplasms. It is associated with thrombotic events, fetal loss, thrombocytopenia, and neurological events. Renal disease of multiple etiology can occur. PT and PTT are prolonged. Treatment includes anticoagulation, antiplatelet therapy, and immunosuppressants.

DIC involves a complex series of events initiated by a systemic illness like sepsis, trauma, malignancy, abruptio placentae, etc., which manifests as a frequently catastrophic hematologic syndrome. Thrombosis and bleeding diathesis co-exist. Activation of the coagulation pathway causes thrombosis. Platelets and fibrinogen are consumed, causing bleeding. PT and PTT are prolonged. There is thrombocytopenia and increased fibrin degradation products. Therapy includes treating the underlying disease and administration of platelets and plasma to bleeding patients, whereas anticoagulation is reserved for thrombotic complications.
ACL
A Non-impact rotational or hyperextension forces are the most common mechanisms for sustaining a tear of the ACL. One third of patients report hearing an audible popping sound as their ACL tear occurred. Because the ACL is a vascular structure, when it tears a rapid bloody effusion (hemarthrosis) usually develops which effects mobility of the joint. Lateral collateral ligaments are the least likely to be injured as the type of force necessary to cause injury would be a varus stress which is unlikely to occur in typical circumstances. Medial collateral ligament injuries are fairly common and produced by a valgus force that stresses the ligament. This can occur in many sporting events including those in which another competitor might fall on or dive into the lateral aspect of the knee. Trauma to a knee can result in tears of both the ACL and MCL in certain situations. A tear of the quadriceps tendon usually occurs when a person falls on a knee that is partially flexed. As the quadriceps muscle contract to prevent excessive flexion, the force and momentum of the fall may overwhelm the knee extension mechanism and cause the rupture. No such mechanism occurred in our scenario. Posterior cruciate injuries occur when the tibia is driven posterior in relation to the femur as may happen when a car dashboard is driven into the tibias during a major front impact collision. A powerful hyperextension force can result in both ACL and PCL tears (usually in that order). PCL tears are much more uncommon than ACL tears and don't generally occur with basic rotational forces as described in our patient scenario.
The most likely diagnosis in this patient is polyarticular juvenile rheumatoid arthritis (JRA).
This form of JRA is seen in approximately 35% of patients with JRA. It is characterized by symmetrical involvement of five or more joints. Two subsets of the disease exist that are distinguished by the presence or absence of rheumatoid factor. A positive rheumatoid factor is most commonly seen in girls with later disease onset (at least 8 years old). An antinuclear antibody (ANA) test may be positive but is more likely to be positive with the pauciarticular form. In the early stage of the disease, the x-ray may be normal or show soft tissue swelling and periarticular osteopenia. In addition to the positive ANA of pauciarticular JRA patients, the arthritis must be present in four or fewer joints. Early onset disease is commonly seen in girls aged 1 to 5 years and has a positive ANA; up to 30% of patients will also have eye involvement. Late onset disease is more common in male patients, with involvement of the large joints. Systemic JRA, also known as "Still disease," is seen in about 10% to 15% of children with JRA. It is characterized by daily intermittent fever spikes and a transient, nonpruritic, pale pink, blanching macular, or maculopapular rash found on the trunk. A positive rheumatoid factor is rare in this form of JRA. Reactive arthritis is usually associated with a recent viral or bacterial infection. Infectious arthritis more commonly presents as monarticular and is usually acute in onset.
Influenza, pneumococcal, and meningococcal vaccine
Explanation
Children with sickle cell disease require influenza, pneumococcal, and meningococcal vaccine immunization, in addition to the regular childhood vaccination.

Heptavalent pneumococcal conjugate vaccine (PCV) should be administered to all children at 2, 4, and 6 months and a booster at 12 - 15 months of age. In addition to this, children with sickle cell disease require another type of pneumococcal vaccine called the 23-valent pneumococcal vaccine (PPV) that needs to be administered between 2 - 5 years of age, as well as a booster at 5 years. The PPV vaccine is recommended in addition to PCV in certain high risk groups who have a higher risk of developing pneumococcal disease. These include sickle cell disease, functional or anatomic asplenia, immunocompromised individuals, and chronic cardiac or pulmonary disease.

Influenza vaccine is recommended for children between 6 - 23 months of age as routine immunization, whereas certain high risk groups such as sickle cell disease, diabetes, HIV, cardiac disease, and conditions that compromise the respiratory function require annual influenza vaccination.

Meningococcal conjugate vaccine is administered to all children aged 11 - 12 years, as well as unvaccinated adolescents at 15 years of age and to college freshmen living in dormitories. Vaccination is also recommended to children above 2 years with high risk, such as complement deficiency, sickle cell disease, and persons with functional or anatomic asplenia.

DTaP, Hepatitis B vaccine, IPV, varicella vaccine, Tdap, and MMR vaccine are not the additional vaccines required in sickle cell disease.
Compression ultrasonography
Explanation
The correct response is compression ultrasonography.

Venous thromboembolism is a dangerous condition, and orthopedic surgery poses a major risk factor for its occurrence. Factors associated with the development of thromboemboli are summarized in "Virchow's triad" of altered blood flow (e.g., stasis, turbulence), hypercoagulable state, and endothelial disruption - all of which are present in the postoperative period. The disruption of the endothelium that occurs with a surgical incision exposes a "sticky" surface within blood vessels upon which platelets are more likely to aggregate. In addition, the inflammatory response brought about by surgical trauma promotes the production of procoagulant substances, which further increase the risk of thrombus formation. Finally, physical immobility in the postoperative period promotes venous stasis.

When lower extremity venous thromboembolism is suspected, the diagnostic test of choice is venous ultrasonography. The test is safe and inexpensive, making it an ideal screening study. Normal veins compress when external pressure is applied by an ultrasound probe. If blood clot is present in a vein, compressibility is lost, thereby signaling the presence of an obstruction to blood flow. In addition to compression, Doppler may be used with ultrasound to further evaluate flow dynamics.

Contrast-enhanced MRI uses differences in the absorption of radiofrequency waves to develop detailed images of bone, soft tissue, and blood vessels. Although MRI can be used to identify venous thromboembolism, the test is expensive and contraindications exist. For this reason, it is not the recommended diagnostic test when lower extremity venous thromboembolism is suspected.

Contrast venography involves injection of contrast dye into the venous system in order to outline the pathway of vessels and identify blockages. Though considered the "gold standard" for the diagnosis of venous thromboembolism, it is not the preferred first test, as it carries associated risks including contrast-induced renal dysfunction and allergic reactions.

Conventional X-ray does not identify venous thrombi and is therefore not a useful study when this diagnosis is suspected.

B-type natriuretic peptide (BNP) is a polypeptide secreted by cardiac ventricles in response to excessive stretching of the heart muscles. Plasma levels of this peptide are elevated in the presence of congestive heart failure and roughly correlate with the severity of left ventricular dysfunction and resultant pulmonary edema. As a result of this finding, measurement of plasma BNP is useful in the diagnostic evaluation of patients presenting with dyspnea. However, it is not a helpful study in the setting of suspected lower extremity venous thromboembolism.

Of note, D-dimer is a substance that has been noted to rise in the setting of venous thromboembolism. However, the test is non-specific; elevated d-dimer levels also occur from other causes, such as cancer, pneumonia, and postoperatively. For this reason, while a normal d-dimer level can be used to rule out the diagnosis of venous thromboembolism, an elevated value does not verify the diagnosis.
Anemia secondary to iron deficiency
Explanation
The clinical and laboratory findings are suggestive of anemia due to iron deficiency. Low serum iron, increased total iron-binding capacity (TIBC), and low ferritin along with the patient's typical peripheral smear of microcytic hypochromic red blood cells are all findings supportive of a diagnosis of anemia secondary to iron deficiency. The most common causes of iron deficiency are deficit in the diet and blood loss from conditions such as menorrhagia. The diagnostic tests are a blood smear showing microcytic hypochromic red blood cells. The serum iron concentration is low. Transferrin or total iron-binding capacity (TIBC), which is the protein that transports iron, is elevated, but the saturation of this protein is decreased. Ferritin, which is the protein that stores iron in the body, is low due to excessive depletion of the iron stores. In addition to the administration of iron and a high iron-bioavailability diet, treatment depends on the cause of the bleeding.

Low serum iron, low TIBC, and increased ferritin are the lab findings seen in anemia due to chronic disease or inflammation. It can be seen as a result of infections, inflammatory diseases, or neoplasias. Blood smear can be normal or can show similar characteristics to the one seen in iron deficiency. The serum iron is low and the TIBC is low with low percentage saturation; however, the serum ferritin levels are high. The patient has good storage of iron, but it cannot be used in the production of red cells. The treatment of this type or anemia consists of treating the underlying disease.

Normal-to-increased serum iron levels, normal TIBC, and increased ferritin are characteristic of sideroblastic anemia. This group of anemia is characterized by erythroblasts in bone marrow showing iron deposits in their mitochondria on Prussian blue staining. The etiology can be idiopathic, hereditary, or toxic, such as in cases of lead intoxication. Blood smear can be normal or show microcytic hypochromic red cells. The treatment of this type of anemia consists of treating the underlying cause, pyridoxine, iron chelation with desferrioxamine, and blood cells transfusions.

Megaloblastic anemia is a condition in which the red blood cells are bigger than normal (MCV >115 fl). There are many different causes, such as drugs (anticonvulsants, methotrexate, etc.), but deficiencies of vitamin B12 and folic acid in the diet are the most common cause. Megaloblastic anemia due to nutritional deficiency of vitamin B12 takes years to manifest, because the reserve is used very slowly. Patients experience features of anemia and neurological symptoms, such as confusion and peripheral neuropathy. Folic acid deficiency in the diet may also produce megaloblastic anemia, but it does not produce neurological symptoms.

Thalassemias are a group of inherited disorders; they are characterized by a decrease in the production of the alpha or beta chains of hemoglobin. The diagnosis is done by genetic studies, and there is no definitive treatment available yet.
Painful swelling of hands and feet
Explanation
The correct response is painful swelling of hands and feet.

Patients with sickle cell anemia (SCA) are often asymptomatic during the 1st few months of life. When patients are over 6 months of age, the 1st symptoms usually make up what is known as hand-foot syndrome (dactylitis). The etiology is vasoocclusion and can be triggered by dehydration, cold temperatures, stress, or infection. Pain management is the hallmark of treatment for children with these symptoms.

Patients with SCA can experience retinopathy that is often silent until very serious complications occur (e.g., retinal detachment, hyphema). While retinal deterioration is something that does occur with SCA, it would not be a presenting symptom.

The yellowing of skin and eyes are signs of jaundice; this can occur in patients with SCA due to the rapidly occurring breakdown of red blood cells. These symptoms are usually not present at the onset of the symptoms.

Both delayed growth and delayed puberty are symptoms of SCA, but are long-term sequelae and would not be the precipitating factor for an initial office visit for a diagnosis of SCA.

Tachycardia and fever are not specific, and they could be related to various illnesses; however, when related to SCA, tachycardia and fever may be associated with an infection or acute chest syndrome. Bilateral infiltrates caused by a decrease in hemoglobin and pulmonary infarction can also be seen in acute chest syndrome. Acute chest syndrome is the most common cause of death in patients with SCA. Infection was more common in the past, but has become more controlled and less of an issue; it is still prevalent in patients with SCA.
Anemia of chronic disease
Explanation
The lab findings of low serum iron, low total iron-binding capacity (TIBC), and increased ferritin are suggestive of chronic disease or inflammation as the cause of the patient's anemia. It can be seen as a result of infections, chronic inflammatory diseases, or neoplasias. Blood smear can be normal or can show similar characteristics to those seen in iron deficiency anemia. The serum iron is low and TIBC is low, with low percentage saturation; however, the serum ferritin level is high. The patient has good storage of iron, but it cannot be used in the production of red cells. The treatment of this type of anemia consists of treating the underlying disease.

Low serum iron, increased TIBC, and low ferritin are seen in patients with microcytic anemia secondary to iron deficiency. The most common causes of iron deficiency are blood loss and deficit in the diet. In developed countries, a dietary deficiency of iron is rare. Diagnostic test includes a blood smear showing microcytic hypochromic RBCs. The transferrin or total iron-binding capacity (TIBC), which is the protein that transports the iron, is elevated, but the saturation of this protein is decreased. Ferritin, which is the protein that stores iron in the body, is low due to excessive depletion of the iron stores. In addition to the administration of iron and a high iron-bioavailability diet, treatment depends on the cause of the bleeding.

Normal-to-increased serum iron levels, normal TIBC, and increased ferritin are characteristic of sideroblastic anemia. This is characterized by erythroblasts in bone marrow showing iron deposits in their mitochondria on Prussian blue staining. The etiology can be idiopathic, hereditary, or toxic, such as in cases of lead intoxication. Blood smear can be normal or show microcytic hypochromic red cells. The serum iron is increased, the TIBC is normal, and the ferritin is increased. The treatment of this type of anemia consists of treating the underlying cause through administration of pyridoxine, iron chelation with desferrioxamine, and blood cells transfusions.

Megaloblastic anemia is a condition in which the red blood cells are bigger than normal (MCV >115 fl). There are many different causes, such as drugs (anticonvulsants, methotrexate, etc.), but deficiencies of vitamin B12 and folic acid in the diet are the most common cause. Vitamin B12 deficiency takes years to manifest because the reserve is used very slowly. Patients experience anemia and neurological symptoms, such as confusion and peripheral neuropathy. Folic acid deficiency produces megaloblastic anemia, but it does not produce neurological symptoms.

Thalassemias are a group of inherited disorders; they are characterized by a decrease in the production of the alpha or beta chains of hemoglobin. The diagnosis is done by genetic studies, and there is no definitive treatment available yet.
thalassemia
Explanation
Thalassemia is an anemia that is hypochromic and microcytic. Basophilic stippling is often observed. It is an inherited disorder of hemoglobin synthesis characterized by a diminished synthesis of the beta chains, and compensatory synthesis of alpha chains. The ineffective erythropoiesis and hemolysis causes an increased proliferation of the erythroid cells and skeletal changes due to extramedullary hematopoiesis. The peripheral smear shows presence of codocytes and dacrocytes along with the basophilic stippling of the RBCs. Beta-thalassemia is confirmed by hemoglobin electrophoresis. The genotype will determine the severity of the disease. In severe cases, the patients require frequent transfusions, which may eventually lead to iron overload as a complication. Splenectomy is usually performed after the age of 6-7 in order to reduce transfusion requirements.

Sickle cell anemia is characterized by the presence of sickled RBCs in the peripheral blood. The sickling results from the substitution of valine for glutamic acid in the hemoglobin molecule. This is a hemolytic anemia seen mainly in patients of African descent. Stressful conditions, such as hypoxia, may cause sickling and thus sludging of erythrocytes. This sludging leads to infarction of the lungs, spleen, or kidneys in homozygous individuals. The peripheral smear contains sickled RBCs, poikilocytosis, Howell-Jolly bodies, and target cells. The reticulocyte count is usually increased.

Aplastic anemia is characterized by a slight macrocytosis and usually decreased reticulocyte count. There is a reduction in all blood formed elements leading to pancytopenia. Hematopoietic tissue function is affectively reduced. The reduced hematopoietic tissue function is, many times, due to a reaction to chemicals or drugs. However, neoplasia, pregnancy, infectious processes, radiation, and immunological reactions can also produce aplastic anemia.

Megaloblastic anemia is caused by an impairment of DNA synthesis by any of several causes (vitamin B12 deficiency; folate deficiency; and a host of other inborn errors of metabolism). The symptoms include weakness, palpitation, easy fatigability, light-headedness, and shortness of breath. There is severe pallor present; slight jaundice and congestive heart failure can also develop. Glossitis, weight loss, and neurological abnormalities can also be present. B12 or folate supplementation will reverse the anemia, except for the unresponsive form in which the etiological mechanism must be investigated (such as inborn errors of metabolism etc.).

Paroxysmal nocturnal hemoglobinuria (PNH) is a condition characterized by RBC breakdown and release of hemoglobin into the urine, manifested as dark-colored urine in the morning. This is a clinical syndrome characterized by a triad of hemolytic anemia, pancytopenia, and thrombosis. The disorder mainly afflicts young adults, and the chief symptom is irregular episodes of hemoglobinuria that often occur in the morning. There are 2 main causes thought to produce this disorder: an abnormality of the red blood cell membrane and the hemolytic action of complement on the red blood cells. The sucrose hemolysis test and Ham's test can be used to help in the differential diagnosis.
Anemia of chronic disease
Explanation Iron deficiency anemia is the most common form of anemia in USA, where almost 20% women are said to be iron deficient. It is most commonly caused in young to middle aged women due to excessive blood loss during menstruation or as a result of successive pregnancies with poor antenatal care as in the developing countries. Blood loss could also be from a peptic ulcer or GI tumor, e.g. colon cancer. Symptoms occur insidiously with fatigue and mild dyspnea, irritability, and weakness. Nails may become brittle and spoon shaped, also known as koilonychia. Epithelial changes from iron deficiency may cause angular stomatitis, glossitis, and koilonychia; these findings are clinically apparent. The rare clinical triad of cervical dysphagia, iron-deficiency anemia, and the presence of esophageal webs is referred to as the Plummer-Vinson or Patterson-Kelly syndrome. Associated findings include cheilitis, glossitis, and koilonychia. The pathogenesis of Plummer-Vinson syndrome remains enigmatic. Iron therapy can improve esophageal motility in affected patients. Chronically affected patients may require mechanical esophageal dilatation. All of these epithelial alterations are rare in children.
The most devastating consequence of iron deficiency is neurocognitive deficits, which affect children of all ages. Infants and toddlers, in whom such deficits may be irreversible, are vulnerable. Transferrin receptors that are expressed on endothelial cells of the cerebral microvasculature are the gateways for iron entry into the brain. Iron is critical for oligodendrocyte and dopaminergic metabolism. Therefore, iron deficiency can result in hypomyelination, which may be the basis of neurocognitive deficits. Labs typically show microcytosis and hypochromia, as in this patient. Iron studies show low iron and high binding capacity. Low ferritin is the most specific blood test for iron deficiency. High ferritin levels can occur in several different conditions and is non specific. Apart from enriching the diet with iron-rich foods, ferrous sulfate tablets can be given. It is given for 2-3 months (325 mg thrice a day) until significant improvement in Hb is seen.

Anemia of chronic disease is characterized by HB of 10-11g/dl in mild cases; however, 20% patients may have a Hb of <8g/dL. It is associated with any chronic disease like collagen vascular diseases, renal failure, diabetes mellitus with nephropathy, heart diseases, other inflammatory conditions, and malignancies. The anemia is not due to iron deficiency but due to diminished iron utilization by the bone marrow or impaired marrow response to erythropoietin. Labs show normocytosis and normochromia. Serum iron level may be normal or slightly low; TIBC is low; and ferritin is normal or high. Correction of the underlying disease is the treatment.

Pernicious anemia is a megaloblastic anemia due to vitamin B12 (cobalamin) deficiency. There is a lack of intrinsic factor necessary for B12 absorption in the terminal ileum. Folic acid deficiency due to inadequate intake or decreased absorption can also cause megaloblastic anemia as in alcoholics. However, vitamin B12 has a neurological function, and its deficiency is associated with neurological signs and symptoms like peripheral nerve damage, causing paresthesias, posterior column deficits like ataxia, and in severe cases, cerebral deficiencies like dementia and other neuropsychiatric symptoms. The Schilling test is used to diagnose pernicious anemia. After a loading dose of intramuscular vitamin B12, an oral dose of radiolabeled vitamin B12 is given, and excretion in urine is measured. Due to saturated plasma transport proteins from the intramuscular vitamin B12, normally more than 7% is excreted. If there is decreased absorption, then less than 3% is excreted in the urine. In the second step, oral radiolabeled vitamin B12 is given with intrinsic factor, and excretion in urine is measured. If there is a deficiency of intrinsic factor, as in pernicious anemia, then more vitamin B12 will be absorbed and a higher percentage excreted in the urine. A combination of macrocytic anemia, neural deficits, and atrophic glossitis is indicative of pernicious anemia. Labs show large red cells (macrocytes) in the peripheral smear with hypersegmented neutrophils and occasional megaloblasts. Serum iron studies are normal. Antibodies to the intrinsic factor may be found in the blood. Treatment is with parenteral vitamin B12.

Thalassemias are genetic disorders characterized by decreased synthesis of one of the globin chains due to abnormalities in the genes responsible for the synthesis of the globin portion of the hemoglobin molecule. They are named according to the deficient chain. Alpha thalassemias are due to deficient alpha chain synthesis. 4 syndromes can occur, varying from mild asymptomatic anemia to hydrops fetalis. Beta thalassemias are characterized by deficiency of beta chains. Beta thalassemia major is a severe transfusion dependent childhood disease and beta thalassemia minor is a mild anemia agreeable with a full normal life. Labs show microcytosis and hypochromia with bizarre red cell morphology, poikilocytosis, target cells, etc. High red cell turnover may cause high serum iron levels and ferritin. Blood transfusions may result in iron overload.

Aplastic anemia is a disorder of stem cell failure occurring in patients of all ages, with hypocellularity of bone marrow without chromosomal abnormalities. It can be caused by drugs, radiation, and viral infections. CBC shows pancytopenia with reticulocytopenia due to marrow failure. Peripheral blood smear shows normal morphology of cells. Treatment includes removal of offending agents, supportive care, hematopoietic cell transplant, androgens, and chemotherapeutic agents. Iron studies are not helpful because the indices are normal.
Hemophilia C
Explanation
Hemophilia C is an inherited autosomal disorder characterized by deficiency of factor XI and is common in Ashkenazi or Iraqi Jews. Patients are usually asymptomatic and spontaneous bleeds into joints, soft tissues, and muscles are rarely seen in Factor XI deficiency. Bleeding usually occurs after tooth extractions, trauma, or surgery, such as tonsillectomy. Hemophilia C should be suspected in patients with prolonged aPTT and a positive family history of life-long bleeding disorder affecting both the male and female family members. This condition is primarily treated with FFP and other adjunctive measures such as fibrin glue and antifibrinolytics. Replacement with Factor XI concentrates can be done when available.

In addition to general supportive therapy, a cryoprecipitate or factor VIII concentrates are recommended for the treatment of hemophilia A, an X-linked disorder that results in deficiency of Factor VIII. The diagnostic characteristic is a decrease in Factor VIII. Patients who bleed frequently even without discernible trauma usually show <1 percent Factor VIII activity. Many patients with mild hemophilia A and most with von Willebrand's disease can be treated with desmopressin (DDAVP).

A deficiency of von Willebrand's factor is characteristic of von Willebrand's disease. In addition to supportive measures and cryoprecipitate, desmopressin (DDAVP) is preferred in most cases. It is often seen in females who started their period and postpartum hemorrhage. Factor VIII and platelet function is affected. It is the most common bleeding disorder.

Christmas disease, hemophilia B, is a Factor IX deficiency that produces a clinical picture similar to hemophilia A. It is diagnosed by the deficiency of Factor IX. The recommended treatment is administration of Factor IX concentrates.

Thrombocytopenia may be congenital or acquired and is characterized by decreased circulating platelets in the blood. The patient presentation, lab tests, and treatment are not suggestive of Hemophilia A, B, thrombocytopenia, or von Willebrand's disease.
Hairy cell-leukemia
Explanation
Hairy-cell leukemia (HCL) is a rare B cell neoplasm that most often occurs in older men. Patients usually present with symptoms related to impairment of the bone marrow, such as infections and bleeding, although they may be asymptomatic. The physical examination is usually only significant for splenomegaly; laboratory studies typically reveal pancytopenia. The bone marrow aspirate is often dry secondary to fibrosis; biopsy may be needed to make the diagnosis.

Treatment of HCL is indicated only if there is worsening splenomegaly or lymphadenopathy or if there are more than 20,000 hairy cells/μl. The current treatment of choice is either cladribine or pentostatin; both of these agents have been shown to induce remission in 80% of patients. Although splenectomy may improve symptoms, it does not affect the disease itself.

'Chronic lymphocytic leukemia (CLL)' is an incorrect response. Patients with CLL have a higher-than-normal white blood cell count

'Chronic Myelogenous Leukemia (CML)' is an incorrect response. Patients with CML present with splenomegaly, but they have a higher-than-normal white blood cell count.

Multiple myeloma is very unlikely, given the dry marrow aspirate. Patients with multiple myeloma would be expected to a have high plasma cell count on bone marrow biopsy or aspirate.

Myelofibrosis is unlikely. Most patients with Myelofibrosis present with moderate-to-severe anemia, but in contrast, the peripheral smear appears abnormal and is characterized by teardrop shaped red blood cells.
Explanation The correct answer is Gaisböck's syndrome. This syndrome is prevalent in hypertensive, obese males who smoke and present with erythrocytosis on CBC. This is a relative polycythemia in which there is a normal RBC mass in the presence of decreased plasma volume resulting in a hemoconcentration. Since this is a relative or spurious polycythemia, erythropoietin levels are normal. Other causes of hemoconcentration include burns, stress, diuretics, and decreased oral intake.
Erythropoietin levels are low-to-normal in Polycythemia Vera (PV), but to make the clinical diagnosis of PV, there must be 3 major criteria: increased RBC mass, normal O2 saturation, and splenomegaly. Since splenomegaly was not present, the diagnosis could be made with the first 2 major criteria plus the addition of 2 minor criteria: leukocytosis in the absence of infection and elevated platelets with abnormal function resulting in bleeding or thrombosis. In this patient, the leukocyte and platelet counts are normal, so the criteria for diagnosing PV are not met. Likewise, he lacks the characteristic rubor of extremely high levels of erythrocytosis.

Kidney diseases, such as hydronephrosis or renal cysts, and erythropoietin-secreting renal tumors can produce an inappropriate rise in erythropoietin levels and a subsequent, secondary erythrocytosis.

Carboxyhemoglobinemia could be present as a result of smoking, but would cause tissue hypoxia, as would sleep apnea. Tissue hypoxia increases production of erythropoietin resulting in a secondary, compensatory erythrocytosis. This patient had a normal pulse oximetry saturation and no evidence of cyanosis.