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H/P=possibly asymptomatic; weakness, fatigue, dyspnea on exertion; PalloR, tachycardia, tachypnea, increased pulse pressure, possible systolic murmur, JaundicE; severe cases may have palpitations, syncope, mental status changes, angina, chills, abdominal pain, HepatosplenomegalY, & Brownish discoloration of urinE
Hemolytic anemia
Anemia that results when RBC lifespan is shortened and marrow production of RBCs is not capable of meeting demand for new cells (see Table 6-2)
Can be caused by defects in RBC membrane, RBC enzyme defects, hemoglobinopathies, or extracellular effects
Labs=- Hgb&Hct, + reticulocyte count, + bilirubin (indirect), + lactate dehydrogenase (LDH), normal MCV, - serum haptoglobin; Coombs' test is helpful for making diagnosis
Blood smear=schistocytes (RBC fragments), spherocytes, and/or burr cells
Hemolytic Anemias
Recent penicillin, L-dopa, quinidine, other drug use
Blood Smear=Burr cells, schistocytes
Coombs' Test=Direct +(unless due to oxidative destruction)
Drug-induced
Bind to RBC membrane and cause oxidative destruction, induce production of antidrug antibodies, form immune complexes that fix complement, or induce anti-Rh antibodies
Treatment =Stop offending agent
Hemolytic Anemias

Blood Smear=Spherocytes (warm agglutinins), RBC agglutination (cold agglutinins)
Coombs' Test=Direct +
Immune
Anti-RBC antibodies, autoimmune disease, possibly drug induced
Warm-reacting antibodies (IgG) or cold-reacting antibodies (IgM)
Treatment =Corticosteroids, avoid cold exposure (with cold-reacting antibodies), stop offending agent; splenectomy may be needed in persistent cases
Hemolytic Anemias
Prosthetic heart valve, HTN, coagulation disorder
Blood Smear=Schistocytes
Coombs' Test=Negative
Mechanical
RBCs broken by force or turbulent flow
Treatment =Treat underlying cause
Hemolytic Anemias
+Hepatosplenomegaly
Blood Smear=Spherocytes
Coombs' Test=Negative
Hereditary spherocytosis
Genetic defect of RBC membranes resulting in spherical RBCs
Treatment =Splenectomy
Hemolytic Anemias
Deficiency of G6PD (enzyme required to repair oxidative damage to RBCs); ingestion of oxidant (fava beans, ASA, sulfa drugs) causes excessive RBC hemolysis
Low G6PD (by indirect measurement); dizziness, fatigue begins within days of ingesting oxidant; mild form in blacks, more severe form in people of Mediterranean decent
Blood Smear=RBCs with “bites” taken out of them, Heinz bodies (small densities of Hgb in RBC)
Coombs' Test=Negative
G6PD deficiency
Treatment =Avoid oxidants; transfusion may be needed in severe cases
H/P=fatigue, weakness, dyspnea on exertion, PicA (i.e., craving to eat ice, dirt, etc.); pallor, tachycardia, tachypnea, increased pulse pressure, possible systolic murmur; Angular cheilitiS (i.e., irritation of lips and corners of mouth), Spooning of nailS in severe cases
Labs=- Hgb&Hct, - MCV, - or normal reticulocyte count, - FerritiN, - iron, + transferrin (i.e., total iron-binding capacity), +stool guaiac possible if secondary to GI losses
Iron-deficiency anemia
Anemia resulting from insufficient heme production secondary to insufficient iron supplies
Iron deficiency results from blood loss, poor dietary intake or absorption from the gastrointestinal (GI) tract, pregnancy, or menstruation
Complications=constipation and nausea common with iron supplementation (e.g., transfusion)
Blood smear=hypochromic microcytic RBCs (see Color Figure 6-3)
Treatment=iron supplementation (several months of treatment required to replete stores), determine cause of iron loss
H/P=fatigue, weakness, abdominal pain, arthralgias, headache, impaired short-term memory; pallor, mental developmental delays, Gingival lead lineS, Peripheral neuropathY (e.g., - motor control of extremities)
Labs= - Hgb&Hct, - MCV, + serum lead
Blood smear=microcytic RBCs, basophilic stippling of RBCs, ringed sideroblasts
Lead-poisoning anemia (acquired sideroblastic anemia)
Anemia resulting from heme synthesis inhibition by lead ingestion (more common in children, especially those in urban environments)
Similar presentation may be seen in anemia caused by alcoholism or isoniazid use
Treatment=remove source of lead; EDTA or dimercaptosuccinic acid (DMSA) for lead chelation in patients with serum lead levels >80 µg/dL
H/P=Poor nutritioN, fatigue, weakness, dyspnea on exertion, diarrhea, Sore tonguE; pallor, tachycardia, tachypnea, increased pulse pressure, possible systolic murmur; No neurologic symptomS
Labs= - Hgb&Hct, - recticulocyte count, + MCV, - serum folate
Blood smear=macrocytic RBCs, hypersegmented neutrophils
Folate-deficiency anemia
Anemia resulting from inadequate folate intake, increased folate need (e.g., poor nutrition, chemotherapy), or drug-induced folate metabolism defects (e.g., methotrexate, trimethoprim, phenytoin)
Treatment=oral folate supplementation
H/P=fatigue, weakness, dyspnea on exertion, memory loss; pallor, tachycardia, tachypnea, increased pulse pressure, possible systolic murmur, Symmetric paresthesiaS, AtaxiA, possible psychosis
Labs= - Hgb&Hct, +MCV, - vitamin B12, Schilling test useful to diagnose pernicious anemia
Blood smear=macrocytic RBCs, hypersegmented neutrophils
Vitamin B12 deficiency anemia
Pernicious anemia (i.e., autoimmune anemia owing to lack of intrinsic factor) or anemia resulting from inadequate vitamin B12 intake, ileal resection, bacterial overgrowth in GI tract, or Diphyllobothrium latum infection (a worm)
Inadequate vitamin B12 intake is usually only seen in strict vegetarians (vegans).
Treatment=monthly intramuscular vitamin B12 injections, dietary supplementation of vitamin B12
H/P=history of appropriate disease state, fatigue, weakness, dyspnea on exertion; tachycardia, pallor
Labs=mildly - Hgb&Hct, normal or - MCV, - iron, - transferrin, normal or + ferritin
Blood smear=normocytic RBCs
Anemia of chronic disease
Anemia occurring in patients with neoplasia, diabetes mellitus, autoimmune disorders, or long-standing infections
Frequently associated with trapping of iron in macrophages, decreased erythropoietin production, and increased hepcidin levels (inhibitor of iron absorption and mobilization)
Treatment=treat underlying disorder; supplemental erythropoietin
H/P=fatigue, weakness, Persistent infectionS, Poor clottinG w/ possible uncontrolled bleeding, easy bruising, persistent menstruation; pallor, petechiae, tachycardia, tachypnea, systolic murmur, increased pulse pressure
Labs= - Hgb&Hct,- WBCs,- platelets, bone marrow biopsy show hypocellularity
Aplastic anemia
Pancytopenia resulting from bone marrow failure
Due to drugs (e.g., chloramphenicol, sulfonamides, phenytoin, chemotherapeutics), toxins, viral infection, or idiopathic and congenital causes
Complications=prognosis worsens with increasing age and severity with 5-yr survival of 85% in young patients with moderate disease and 20% in elderly patients with severe disease
Treatment=stop offending agent; transfusions for acute anemia and thrombocytopenia; immunosuppressive agents and bone marrow transplant indicated to improve long-term survival
H/P=fatigue, weakness, dyspnea on exertion, angina; pallor, tachycardia, tachypnea, increased pulse pressure,hepatosplenomegaly, possible systolic murmur
Labs= - Hgb&Hct, + ferritin, + iron, - transferrin, possbile - MCV
Blood smear=multiple sizes of RBCs with normocytic, microcytic, and macrocytic cells possible; ringed sideroblasts (RBC precursors) (see Color Figure 6-6)
Sideroblastic anemia
Anemia caused by defective heme synthesis resulting in decreased Hgb levels in cells
Can be a genetic disorder or caused by alcohol, isoniazid, or lead poisoning (patient history is useful for differentiating cause)
Complications=10% patients progress to acute leukemia
Treatment=
Hereditary cases: vitamin B6 may normalize Hgb concentrations
Acquired cases: supplemental erythropoietin
Both types: significant iron overload requires therapeutic phlebotomy (mild cases) or chelation with deferoxamine (more severe cases); transfusion may be required in severe cases
Labs=- MCV, + reticulocyte count, + Bart's hemoglobin (i.e., Hgb that binds O2 but is unable to release it to tissues in α-thalassemia), + hemoglobin A2 or F in β-thalassemia; Hgb electrophoresis can detect genetic abnormalities and severity of defects
Thalassemia
Hgb defects resulting from abnormal production of heme α-globin or β-globin subunits
Disease state arises from unbalanced production ratio of α and β chains (see Table 6-4)
Normal Hgb
Composed of two α-chains and two β-chains
Four genes determine α-chain synthesis; two genes determine β-chain synthesis
α-thalassemia
More prevalent in people of Asian or African descent
Variants have between 1 and 4 defective genes
β-thalassemia
More prevalent in patients of Mediterranean descent
Variants have either one or two defective genes
Blood smear=
α-thalassemia: abnormally shaped microcytic RBCs, target cells (see Color Figure 6-7)
β-thalassemia: RBCs in variable size and shape (including microcytic cells) with basophilic stippling
Complications=chronic iron overload from repeat transfusions causes damage to heart and liver; patients with Hgb H disease and β-thalassemia major have high childhood mortality without transfusion therapy; children of asymptomatic parents with defective genes are still at risk for developing disease, depending on inherited alleles
Treatment=
α-thalassemia minor or minima and β-thalassemia minor frequently are asymptomatic and only require symptomatic treatment during periods of stress
Folate supplementation may be helpful in all symptomatic forms and in mild forms during stress
Transfusions required for more severe variants and may be needed for mild forms during periods of stress
Iron chelation may be required in patients receiving chronic transfusions
Bone marrow transplant may be helpful in children with minimal hepatomegaly, no portal fibrosis, and adequate iron chelation therapy
Thalassemia Type
No α-globin production; fetal death occurs
Hydrops fetalis
Thalassemia A w/ 4 abnormal genes
Thalassemia Type
Minimal α-globin production; chronic hemolytic anemia, pallor, splenomegaly; Bart's hemoglobin in serum; microcytic RBCs on blood smear; decreased lifespan
Hemoglobin H disease
Thalassemia A w/ 3 abnormal genes
Thalassemia Type
Reduced α-globin production; mild anemia; microcytic RBCs and target cells on blood smear
α-thalassemia minor
Thalassemia A w/ 2 abnormal genes
Thalassemia Type
Generally asymptomatic; children of carriers at increased risk for thalassemia, pending genotype of other parent
α-thalassemia minima
Thalassemia A w/ 1 abnormal genes
Thalassemia Type
No β-globin production; asymptomatic until decline of fetal hemoglobin; growth retardation, developmental delays, bony abnormalities, hepatosplenomegaly, anemia; increase in hemoglobin A2 and F; microcytic RBCs on blood smear; patients die in childhood without transfusions
β-thalassemia major
Thalassemia A w/ 2 abnormal genes
Thalassemia Type
Reduced β-globin production; mild anemia; patients can lead normal lives; transfusions may be needed during periods of stress
β-thalassemia minor
Thalassemia A w/ 1 abnormal genes
H/P=frequently asymptomatic between crises; stressful events (e.g., infection, illness, trauma, hypoxia) induce sickle cell crisis characterized by deep bone pain, chest pain, new stroke onset, painful swelling of hands and feet, dyspnea, priapism (i.e., painful, prolonged erection); growth retardation, splenomegaly, jaundice, fever, tachypnea, leg ulcers seen on examination
Labs= - Hct, + reticulocyte count, + polymorphonuclear (PMN) cells, - serum haptoglobin, + bilirubin (indirect)
Blood smear=target cells, nucleated RBCs; deoxygenation of blood produces sickle cells
Sickle cell disease
Autosomal recessive defect in β-globin chain of Hgb, leading to production of abnormal Hgb S that is poorly soluble when deoxygenated
Acidosis, hypoxia, and dehydration cause Hgb S molecules to polymerize and distort RBCs into a sickle shape that is more susceptible to hemolysis and vascular clumping than normal cells
More common in people of African heritage
Complications=
Chronic anemia, pulmonary hypertension, heart failure, aplastic crisis (usually secondary to parvovirus B19 infection), acute chest syndrome (i.e., acute pneumonia, pulmonary infarction, and embolus)
Autosplenectomy, stroke, osteonecrosis, and multiple organ ischemia (particularly kidney, heart, retina) can result secondary to vascular occlusion
Increased risk of infection by encapsulated organisms
SHARP MALICE: Stroke, Hemolytic anemia, Autosplenectomy, Renal necrosis, Priapism, MI, Acute chest syndrome, Lung infarctions, Infections, Crises (painful or aplastic), Eye disease (retinopathy).
Labs=Hemoglobin electrophoresis detects Hgb S without normal Hgb A; Hgb F may be increased
Sickledex solubility test can detect Hgb abnormalities, but cannot differentiate between carrier trait and homozygous disease state

Radiology=“fish-mouth” vertebrae; lung infiltrates in acute chest syndrome (radiologic findings in setting of chest pain and dyspnea)
Treatment=
Hydration, supplemental O2, and analgesics (frequently narcotics required) during sickle cell crises
Hydroxyurea (increases Hgb F production) and avoidance of crisis stimuli decrease frequency of crises
Pneumococcal vaccine reduces risk of infection in asplenic patients; prophylactic penicillin should be given until 5 yr of age to help prevent pneumococcal infection in asplenic children
Chronic transfusions may help keep the level of Hgb S as low as possible
Hematopoietic stem cell transplantation and gene therapy show future promise as potential cures
H/P=repeated infections with possible recent history of chemotherapy or radiation
Labs=decreased WBCs especially B and T lymphocytes
Lymphopenia without immune deficiency
Decreased lymphocyte count seen in diseases with increased cortisol levels or after chemotherapy, radiation, or lymphoma; antibody production not affected
Treatment=if possible, stop offending agents; bone marrow transplant may be needed
H/P=asymptomatic; history of predisposing condition
Addison's disease, neoplasm, asthma, allergic drug reactions, collagen vascular diseases, transplant rejection, and parasitic infections
Labs=increased eosinophil count
Eosinophilia
Abnormally high levels of eosinophils seen in Addison's disease, neoplasm, asthma, allergic drug reactions, collagen vascular diseases, transplant rejection, and parasitic infections
Treatment=treat underlying disorder, stop offending agent
H/P=weakness, chills, fatigue, recurrent infections; fever
Labs=decreased neutrophil count
Neutropenia without immune deficiency (agranulocytosis)
Decreased neutrophil count seen with some viral infections (e.g., hepatitis, human immunodeficiency virus [HIV], Epstein-Barr), drugs (e.g., clozapine, antithyroid medications, sulfasalazine, methimazole, trimethoprim-sulfamethoxazole), chemotherapy, and aplastic anemia
Treatment=treat underlying disorder, stop offending agents, granulocyte colony-stimulating factor, corticosteroids; antibiotics, whenever infection suspected
Labs=skin allergen testing or radioallergosorbent test (RAST) may be useful in determining specific allergies
Hypersensitivity reactions
Allergen-induced immunologic response by body involving cellular or humoral mechanisms
Treatment=
Contact prevention and avoidance of offending agents is important
Types of Hypersensitivity Reactions
Allergic rhinitis, asthma, anaphylaxis
Type I
IgE antibodies attached to mast cells
Allergens react with antibody to cause mast cell degranulation and histamine release
Treatment=
Type I: antihistamines, leukotriene inhibitors, bronchodilators, and corticosteroids may improve symptoms after reaction; desensitization may be considered to avoid recurrent reactions; if anaphylaxis is a concern, epinephrine injections should be kept readily available
Types of Hypersensitivity Reactions
Drug-induced or immune hemolytic anemia, hemolytic disease of the syndrome
Type II
IgM and IgG antibodies
Allergens react with antibodies to initiate Complement cascadE and cell death
Treatment=
Type II: anti-inflammatories or immunosuppressive agents
Types of Hypersensitivity Reactions
Arthus reaction, serum sickness, glomerulonephritis
Type III
IgM and IgG immune complexes
Antibodies form immune complexes with allergens, which are then deposited in tissue and initiate complement cascade
Treatment=
Type III: anti-inflammatories
Types of Hypersensitivity Reactions
Transplant rejection, allergic contact dermatitis, PPD testing
Type IV
T cells and macrophages
T cells present allergens to macrophages and secrete lymphokines that induce macrophages to destroy surrounding tissue
Treatment=
Type IV: corticosteroids or immunosuppressive agents
H/P=symptoms and signs typically occur 5 to 60 minutes after exposure; tingling in skin, itching, cough, chest tightness, difficulty swallowing and breathing (secondary to angioedema), syncope; tachycardia, wheezing, urticaria, hypotension, arrhythmias
Labs=skin testing or RAST can confirm allergic response; increased histamine and tryptase
Anaphylaxis
Severe type I hypersensitivity reaction after re-exposure to allergen (penicillins, insect stings, latex, eggs, nuts, and seafood are common causes)
Treatment=subcutaneous epinephrine, intubation (if closed airway), antihistamines, bronchodilators, recumbent positioning, intravenous (IV) hydration; vasopressors may be needed for severe hypotension; avoidance of stimuli is key to prevention; elective desensitization therapy may be appropriate following an episode, depending on allergen, to avoid future incidents
H/P=possibly asymptomatic; mucosal bleeding, petechiae, purpura, multiple ecchymoses
Labs=platelets <150,000/µL
Thrombocytopenia
Decreased number of platelets (<150,000) leading to increased risk of hemorrhage
May be idiopathic, autoimmune, or result from external causes (e.g., drugs, infection, nutrition)
Blood smear=may show low platelet numbers, small platelets, abnormal platelet granules, or neutrophilic granules, depending on etiology
H/P=easy bruising, mucosal bleeding (nose, gums), menorrhagia; multiple sites of bruising and mucosal bleeding on examination; antiplatelet drug administration can induce bleeding
Labs=+ PTT, + bleeding time, - factor VIII antigen, - vWF antigen, - ristocetin cofactor activity
von Willebrand's disease
Autosomal dominant disease with deficiencies of factor VIII and von Willebrand's factor (vWF), leading to abnormal clotting and platelet function
Treatment=desmopressin during minor bleeding, vWF concentrate and factor VIII concentrate before surgery or during major bleeding, avoidance of aspirin (ASA)
H/P=easy bruising, mucosal bleeding, melena, hematuria, delayed clot formation
Labs=+ PT, + INR
Vitamin K deficiency
Inadequate vitamin K supply because of poor intake, malabsorption, or eradication of vitamin K-producing GI flora (secondary to prolonged antibiotic use)
Vitamin K is required in synthesis of factors II, VII, IX, and X
Patients using warfarin can present with a clinical picture similar to that of vitamin K deficiency.
Treatment=vitamin K injections, fresh frozen plasma (FFP)
H/P=uncontrolled bleeding occurring spontaneously or after minimal trauma, excessive bleeding following surgical or dental procedures; hemarthroses (i.e., bleeding in joints), intramuscular bleeding, and GI or genitourinary bleeding may be evident on examination
Labs=+ PTT, normal PT, normal bleeding time, - factor VIII or IX antigen
Hemophilia
X-linked recessive disease with deficiency of either factor VIII (hemophilia A) or factor IX (hemophilia B)
Complications=death from severe, uncontrolled bleeding, HIV infection common in patients receiving frequent transfusions before mid 1980s, arthropathy from recurrent hemarthroses frequently requires eventual joint replacement
Hemophiliacs tend not to develop significant bleeds unless they have <5% clotting activity.
Treatment=factor VIII or IX replacement, desmopressin (may increase factor VIII production in hemophilia A), transfusions frequently needed in cases of large blood loss; hemarthroses and intracranial bleeds require aggressive factor replacement
H/P=appropriate history of precipitating condition; uncontrolled bleeding from wounds and surgical sites, hematemesis, dyspnea; jaundice, digital cyanosis, hypotension, tachycardia, possible neurologic or renal insufficiency signs, possible shock
Labs=- latelets, + PT, + PTT, - fibrinogen, +fibrin split products, + D-dimeR, - Hct
Blood smear=schistocytes, few platelets
Disseminated intravascular coagulation (DIC)
Widespread abnormal coagulation caused by sepsis, severe trauma, neoplasm, or obstetric complications
Initial coagulopathy with widespread clot formation occurs because of extensive activation of the clotting cascade by endothelial tissue factor released during bacteremia
Deficiency in clotting factors results from extensive clotting
Abnormal bleeding results from clotting factor deficiencies
Complications=poor prognosis without early treatment; thrombi cause numerous infarcts
Treatment=treat underlying disorder; platelets, FFP, cryoprecipitate; heparin may be needed for chronic thrombi
Thrombocytopenia
drugs, infection, aplastic anemia, folate/vitamin B12 deficiency, alcohol
Impaired production
Absent or reduced megakaryocytes caused by offending agent or abnormal megakaryocytes because of metabolic deficiency
Findings consistent with precipitating condition; bone marrow biopsy helpful for diagnosis
Treatment=Stop offending agent, treat underlying disorder, bone marrow transplantation
Thrombocytopenia
Splenomegaly, normal bone marrow biopsy, 90% platelets may be sequestered
Abnormal pooling
Splenic platelet sequestration
Treatment=May not be required; splenectomy if symptomatic
Thrombocytopenia
Diffuse thrombus formation, sudden decrease (>50%) in platelet level, positive serotonin release assay, positive heparin-induced platelet aggregation assay
Heparin-induced thrombocytopenia (HIT)
Development of antiplatelet antibodies that cause widespread platelet destruction in response to heparin therapy
Treatment=Stop all heparin use; direct thrombin inhibitors for thrombi
Thrombocytopenia
Other explanations for thrombocytopenia ruled out, platelets commonly <50,000
Idiopathic thrombocytopenia purpurea (ITP)
Autoimmune B-cell directed production of antiplatelet antibodies
Treatment=Self-limited in children; adults require corticosteroids, delayed splenectomy, intravenous (IV) immunoglobulin, plasmapheresis, or recombinant factor VIIa
Thrombocytopenia
Neurologic deficits, acute renal failure, fever, hemolytic anemia, thrombocytopenia without severe bleeding, increased reticulocyte count
Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS)
Diffuse platelet aggregation due to autoantibodies against a preventative enzyme; associated with endothelial injury and Escherichia coli O157:H7 infection
Nasty Fever Torched His Kidneys: Neurologic deficits, Fever, Thrombocytopenia, Hemolytic anemia, Kidney failure.
Treatment=Corticosteroids, plasmapheresis, FFP
Thrombocytopenia
During pregnancy, presence of antiphospholipid or lupus anticoagulant antibodies
Antiphospholipid syndrome
Development of antiphospholipid antibodies during pregnancy leading to arterial and venous thrombosis
Treatment=Anticoagulation with heparin and warfarin, hydroxychloroquine
HELLP syndrome Sequela of eclampsia associated with elevated liver enzymes and hemolytic anemia During pregnancy, HTN, increased LFTs, decreased Hgb, schistocytes on blood smear Induce delivery if fetus >34 wk gestation; anti-HTN drugs and corticosteroids to speed fetal lung maturity if preterm
ASA, aspirin; FFP, fresh frozen plasma; Hct, hematocrit; HELLP, hemolysis, elevated liver enzymes, and low platelet counts; HTN, hypertension; IV, intravenous; LDH, lactate dehydrogenase; LFTs, liver function tests; RBC, red blood cell.
Thrombocytopenia
During pregnancy, HTN, increased LFTs, decreased Hgb, schistocytes on blood smear
HELLP syndrome
Sequela of eclampsia associated with elevated liver enzymes and hemolytic anemia
Treatment=Induce delivery if fetus >34 wk gestation; anti-HTN drugs and corticosteroids to speed fetal lung maturity if preterm
H/P=malaise, chills, nausea, vomiting; fever >101.5°F/38°C, mental status changes, tachycardia, tachypnea; may progress to septic shock with hypotension, cool extremities (initially warm), and petechiae
Labs=+ (>12,000/mL) or - (<4,000/mL) WBCs; positive urine, blood, or sputum cultures needed to diagnose infection; labs may detect signs of DIC
Sepsis
Bacteremia with an associated excessive systemic inflammatory response leading to global tissue hypoxia
Common community-acquired pathogens include Streptococcus, Staphylococcus, Escherichia coli, Klebsiella, Pseudomonas, and N. meningitidis
Common nosocomial pathogens include Staphylococcus, gram-negative bacilli, anaerobes, Pseudomonas, and Candida species
Complications=septic shock, DIC
Radiology=chest x-ray may show infiltrates and pneumonia
Treatment=
Secure airway, supply adequate oxygenation (may require intubation and ventilation)
Hydration, vasopressors, inotropes, and transfusions to maintain tissue perfusion
Broad-spectrum antibiotics initially, then pathogen-specific antibiotics when agent identified by culture; remove (or change) possible routes of infection (Foley catheter, IV, etc.)
Maintain tight glycemic control
Recombinant human activated protein C may be beneficial in patients with multiorgan failure caused by septic shock
Do not start anti-biotics until after first blood culture has been collected to avoid false–negative cultures.
H/P = chills, diaphoresis, headache, myalgias, fatigue, nausea, abdominal pain, vomiting, diarrhea; periodic fever at approximately 1- to 3-day intervals, splenomegaly; P. falciparum infection can include decreased consciousness, pulmonary edema, and renal insufficiency
Malaria
Parasitic infection by Plasmodium spp. (P. vivax, P. falciparum, P. ovale, P. malariae) transmitted by Anopheles mosquito
Labs=polymerase chain reaction (PCR) for Plasmodium is highly sensitive
Blood smear = Giemsa stain shows Plasmodium spp. (Color Figure 6-9)
Treatment = antimalarials (e.g., chloroquine, etc.); atovaquone-proguanil or mefloquine used in chloroquine-resistant P. falciparum
Travelers to sub-Saharan Africa, tropical South America, or southwest Asia should take prophylactic chloroquine or mefloquine during their stay.
H/P=fatigue, sore throat, malaise; lymphadenopathy, splenomegaly, fever, tonsillar exudates
Mononucleosis
Infection by Epstein-Barr virus (EBV) affecting B cells and oropharyngeal epithelium
Transmitted by intimate contact (e.g., kissing, intercourse)
Complications=splenic rupture is rare, but patients should refrain from contact sports for 1 month after symptom onset
Labs=positive heterophile antibodies, positive EBV serology (i.e., MonoSpot test), increased WBCs
Blood smear=increased number of lymphocytes (some with abnormal appearance)
Treatment=self-limited; supportive care
Acute H/P=flulike symptoms (e.g., myalgias, nausea, vomiting, diarrhea, fatigue), sore throat, weight loss; mucosal ulcers, fever, lymphadenopathy, viral rash; symptoms typically develop 2–4 weeks after exposure and last 2 weeks
Late H/P (i.e., AIDS)=opportunistic infections and AIDS-defining illnesses begin to present, weight loss, night sweats, dementia
Human immunodeficiency virus (HIV)
RNA retrovirus (HIV-1 and HIV-2 are most common strains) that infects CD4 lymphocytes (helper T cells) and destroys them, eventually leading to acquired immune deficiency syndrome (AIDS)
Both strains transmitted in same manner; they share same risks for opportunistic infections and are treated in same manner
Compared with HIV-1, HIV-2 progresses more slowly, is less infectious in early disease, is more infectious in late disease, and is less common in the United States
Serologic tests for the two strains are slightly different and do not cross-react consistently
Virus uses reverse transcriptase to incorporate genetic material into host cell genome and produce copies of DNA
Transmitted via bodily fluids (e.g., blood, semen, vaginal secretions, breast milk)
Risk factors (U.S.)=homosexual or bisexual males, intravenous drug abuse (IVDA), blood transfusions before the mid-1980s (e.g., hemophiliacs), multiple sexual partners, heterosexual partners of other high-risk individuals, infants born to infected mothers, accidental exposure to bodily fluids (e.g., needle sticks, fluid splashes) among health care workers (low probability but possible); higher prevalence among black and Latino populations
Following acute infection, patient enters latent phase with few or no symptoms and low viral load that lasts months to years (time increases with treatment)
Labs =
Enzyme-linked immunosorbent assay (ELISA) detects HIV antibodies and is 99% sensitive; if positive, repeat ELISA performed (see Figure 6-5)
Following two positive ELISAs, Western blot (lower sensitivity but high specificity) performed to rule out false–positive findings
Rapid serologic tests are being used as initial screening test with increasing frequency, but positive results require standard serologic testing for confirmation
CD4 count is used to track extent of disease progression (AIDS is defined by CD4 count <200)
Viral load indicates the rate of disease progression (low during latent phase and high once AIDS is diagnosed) and may be useful in detection of acute infection during presentation with symptoms of seroconversion
Other nonspecific lab findings include decreased WBCs (during acute infection and again after development of AIDS), increased liver function test (LFT) findings, and mildly decreased Hgb and platelets
Treatment =
Antiretroviral therapy should be initiated for CD4 count <350, viral load >20,000, or symptomatic development of opportunistic disease
Utility of starting antiretroviral therapy in acute infection is controversial and currently not universally recommended (performed in health care workers)
Common initial highly active antiretroviral treatment (HAART) regimens
Start with two nucleoside reverse transcriptase inhibitors and either a protease inhibitor or non-nucleoside reverse transcriptase inhibitor (three antiretroviral drug minimum) (see Table 6-9)
Low dose ritonavir can be added to the initial regimen to increase protease inhibitor activity
Combination therapy (i.e., multiple drugs combined in one pill) will decrease number of pills taken at one time and help avoid dosing schedule mishaps
Compliance with therapy is vital to delaying disease progression; significant side effects associated with antiretroviral drugs is major deterrent to good compliance
Indications for changing antiretroviral regimen include failure to keep viral load <50/mL, drug toxicity, poor compliance, and suboptimal regimen
Patients with virologic failure should be tested for viral drug resistance, reviewed for drug interactions, and considered for drug substitution or addition of another drug
Drug toxicity may be amenable to changing drugs
Poor compliance can be approached by decreasing complexity of regimen (i.e., using combination pills) or enlisting family or friends to assist patient
Suboptimal regimens can be improved with drug substitution
Antibiotic prophylaxis for opportunistic infections is started when CD4 count <200; opportunistic infections treated as they occur
Trimethoprim-sulfamethoxazole (TMP-SMX) for Pneumocystis carinii pneumonia (PCP) and toxoplasmosis
Clarithromycin or azithromycin for Mycobacterium avis complex (MAC)
Isoniazid when close contacts have tuberculosis
Close following of serology is important for dictating the direction of care
Pregnant mothers with HIV should be treated to keep viral load low and should be given zidovudine during labor; newborns to HIV-positive mothers should be given zidovudine for 6 wk after birth and should be tested for presence of virus
Complications=opportunistic infections, neoplasms, cardiomyopathy, neuropathy, AIDS dementia complex, arthritis, polymyositis, anemia; although several advancements in treatment have been made, no cure or effective vaccine has been developed
AIDS (CD count?)
Shingles, oral or genital lesions
Herpes zoster/simplex
CD4 <500
Diagnosis=Tzanck smear, viral culture
Treatment=Acyclovir, foscarnet
AIDS (CD count?)
Purple subcutaneous nodules on face, chest, or extremities
Kaposi's sarcoma
CD4 <500
Diagnosis=Biopsy of lesions
Treatment=Topical alitretinoin, chemotherapy, laser therapy, radiation
AIDS (CD count?)
Prolonged diarrhea, malaise, weight loss, abdominal pain
Parasitic diarrhea (Isospora, Strongyloides, Cryptosporidium)
CD4 <500
Diagnosis=Stool culture, parasite evaluation
Treatment=Antiretroviral therapy, metronidazole, TMP-SMX, paromomycin
AIDS (CD count?)
Weight loss >10% baseline weight, chronic diarrhea, chronic weakness, fever
Wasting syndrome
CD4 <350
Diagnosis=Clinical diagnosis, EMG suggests peripheral nerve dysfunction
Treatment=Exercise, corticosteroids
AIDS (CD count?)
Cough, fever, dyspnea
Bilateral reticulonodular infiltrates on CXR
Coccidioidomycosis
CD4 <250
Diagnosis=Bilateral reticulonodular infiltrates on CXR, positive antibody screen
Treatment=Fluconazole, itraconazole, or amphotericin B
AIDS (CD count?)
Confusion, mental status changes, generalized neurologic symptoms, including tremor
History of declining mental function
AIDS dementia
CD4 <200
Diagnosis=elevated β-2 microglobulin in CSF, cerebral atrophy on CT or MRI
Treatment=May improve with antiretroviral therapy
AIDS (CD count?)
Rapid onset, productive cough, high fevers
lobar consolidation on CXR
Bacterial pneumonia (Streptococcus pneumoniae, H. influenzae, Nocardia)
CD4 <200
Diagnosis=Gram stain, lobar consolidation on CXR
Treatment=Cephalosporins, β-lactams, or macrolides
AIDS (CD count?)
Dysphagia, odynophagia
Candida esophagitis
CD4 <200
Diagnosis=Endoscopy with biopsy, Gram stain on lesion scrapings
Treatment=Topical or oral fluconazole or ketoconazole
AIDS (CD count?)
History of human papilloma virus
Cervical cancer
CD4 <200
Diagnosis=Detected by screening Papanikoleau (Pap) smear, biopsy confirms diagnosis
Treatment=Resection, topical 5-flurouracil, radiation therapy, chemotherapy
AIDS (CD count?)
Gradual onset, nonproductive cough, dyspnea on exertion, fever
Pneumocystis carinii pneumonia (PCP)
CD4 <200
Diagnosis=Bilateral infiltrates on CXR, increased LDH, sputum Gram stain
Treatment=TMP-SMX, corticosteroids
AIDS(CD count?)
Cough, night sweats, weight loss, fever
Tuberculosis
CD4 <200, high risk groups/prisons)
Diagnosis=Acid-fast bacilli, cavitary defects and hilar adenopathy on CXR, positive PPD (must be checked with anergy test)
Treatment=Isoniazid, rifampin, pyrazinamide, ethambutol
AIDS(CD count?)
Abdominal pain, GI bleeding, skin lesions, dyspnea, meningitis
Histoplasmosis
CD4 <150
Diagnosis=Bilateral infiltrates on CXR, positive antigen test
Treatment=Long-term amphotericin B or itraconazole
AIDS(CD count?)
Headache, confusion, possible focal neurologic symptoms
ring-enhancing lesions on CT or MRI
Cerebral toxoplasmosis
CD4 <100
Diagnosis=+ toxoplasma IgG antibody, ring-enhancing lesions on CT or MRI
Diagnosis=+ toxoplasma IgG antibody, ring-enhancing lesions on CT or MRI
Treatment=Pyrimethamine, sulfadiazine, clindamycin (chronic treatment may be needed)
AIDS(CD count?)
Headache, confusion, possible focal neurologic symptoms
Lymphoma (CNS or non-Hodgkin's)
CD4 <100
Diagnosis=CT or MRI shows lesion, biopsy confirms diagnosis
Treatment=Chemotherapy, radiation
AIDS(CD count?)
Ataxia, motor deficits, mental status changes
Progressive multifocal leukoencephalopathy
CD4 <100
Diagnosis=Positive PCR for JC virus DNA
Treatment=May improve with antiretroviral therapy
AIDS(CD count?)
Headache, neck stiffness, fever, mental status changes
Cryptococcal meningitis
CD4 <50
Diagnosis=Elevated pressure on lumbar puncture, yeast seen with India ink stain of CSF, positive cryptococcal antigen in CSF or serum
Treatment=Amphotericin B, fluconazole
AIDS(CD count?)
Vision loss, esophagitis, diarrhea
yellow infiltrates with hemorrhage on funduscopic exam
Cytomegalovirus (CMV)
CD4 <50
Diagnosis=Viral titer, yellow infiltrates with hemorrhage on funduscopic exam
Treatment=Ganciclovir, foscarnet, valganciclovir
AIDS(CD count?)
Fatigue, weight loss, fever, diarrhea, abdominal pain, lymphadenopathy, hepatosplenomegaly
Mycobacterium avium complex (MAC)
CD4 <50
diagnosis=Blood cultures
Treatment=Clarithromycin, azithromycin, ethambutol, rifabutin, rifampin
H/P=fatigue, headache, Burning pain in hands or feet, prurituS (especially after contact with warm water), tinnitus, blurred vision, epistaxis, abdominal pain; SplenomegalY, hepatomegaly, large retinal veins on funduscopic examination
Labs=increased Hgb, increased Hct, increased RBC mass, increased or normal WBCs and platelets, decreased erythropoietin; biopsy shows hypercellular marrow
Polycythemia vera
Myeloproliferative disorder of bone marrow stem cells leading to increased production of RBCs, WBCs, and platelets
Tends to occur after age 60 yr; many progress to leukemia
Treatment=serial phlebotomy, antihistamines (for pruritus), ASA (thrombus prophylaxis), hydroxyurea (bone marrow suppression)
Complications=thrombus formation, leukemia (acute and chronic myelogenous), stroke
H/P = Back paiN, radicular pain, weakness, fatigue, weight loss, constipation, Pathologic fractureS, frequent infections; pallor, bone tenderness
Labs=decreased Hgb, decreased Hct, decreased WBCs, increased blood urea nitrogen (BUN) and creatinine (secondary to renal insufficiency);
Multiple myeloma
Malignant proliferation of plasma cells; increased incidence with prior monoclonal gammopathy of undetermined significance (MGUS)
Abnormal monoclonal protein (M protein) produced from IgG and IgA heavy chains, and κ- and λ-light chains (these light chains are known as Bence Jones proteins)
Complications=renal failure, recurrent infections, hypercalcemia, spinal cord compression; poor prognosis with survival for 2–3 years after diagnosis
Labs=decreased Hgb, decreased Hct, decreased WBCs, increased blood urea nitrogen (BUN) and creatinine (secondary to renal insufficiency); serum protein electrophoresis (SPEP) and urine protein electrophoresis (UPEP) detect high M protein and Bence Jones proteins; bone marrow biopsy shows increased plasma cells
Radiology = “punched-out” lesions in long bones and skull
Treatment=radiation, chemotherapy, bone marrow transplant, repair of fractures, treat infections
h/p=Painless lymphadenopathy (neck), weight loss, pruritus, night sweats, fever, hepatosplenomegaly
20–40 yr or >60 yr of age
Labs=lymph node biopsy shows Reed-Sternberg cells
Hodgkin's Lymphoma
Cells of origin=B cells
Treatment=Radiation, chemotherapy
Prognosis Good, 80% cure rate unless far progressed
h/p=Painless lymphadenopathy (generalized), weight loss, fever, night sweats
EBV, HIV, congenital immunodeficiencies, rheumatic disease, <65 yr of age
lab=Lymph node or bone marrow biopsy shows lymphocyte proliferation (cleaved cells seen in follicular small cell variant)
Non-Hodgkin's Lymphoma
Cells of origin=Lymphocytes (most commonly B cells) or natural killer cells
Treatment=Palliative radiation, chemotherapy
Prognosis Poor (months for aggressive types, years for less aggressive variants), worsens with increasing age
H/P=bone pain, frequent infections, fatigue, dyspnea on exertion, easy bruising; fever, pallor, purpura, hepatosplenomegaly, lymphadenopathy
2–5 yr of age
Labs=decreased Hgb, decreased Hct, decreased platelets, decreased WBCs, increased uric acid, increased LDH; bone marrow biopsy shows abundant blasts; Philadelphia chromosome (i.e., translocation of chromosomes 9 and 22 in BCR-ABL genes) found in 15% adult cases
Blood smear=numerous blasts
Acute lymphocytic leukemia (ALL)
Most common in children (2–5 yr of age); whites > blacks
Proliferation of cells of lymphoid origin (lymphocytes)
Complications=although 5-yr survival rates are good (85%) in children, adults have worse prognosis; presence of Philadelphia chromosome carries poor prognosis
Treatment=chemotherapy (induction followed by maintenance dosing), bone marrow transplant
H/P=fatigue, easy bruising, dyspnea on exertion, frequent infections, arthralgias; fever, pallor, hepatosplenomegaly, mucosal bleeding, ocular hemorrhages
Labs=decreased Hgb, decreased Hct, decreased platelets, decreased WBCs; bone marrow biopsy shows blasts of myeloid origin and staining with MyeloperoxidasE
Blood smear=large myeloblasts with notched nuclei and Auer rods
Acute myelogenous leukemia (AML)
Proliferation of myeloid cells; both children and adults affected
Complications=relapse common, DIC; long-term survival is poor despite frequently successful remissions
Treatment=chemotherapy (regimen guided by cytogenetic analysis), bone marrow transplant
H/P=fatigue, frequent infection (secondary to no plasma cells), night sweats; fevers, lymphadenopathy, hepatosplenomegaly
>65 yr of age
Labs=increased WBCs (may be >100,000/µL); bone marrow shows lymphocyte infiltration
Blood smear=numerous small lymphocytes, smudge cells
Chronic lymphocytic leukemia (CLL)
Proliferation of mature B cells in patients >65 yr of age
Complications=malignant B cells may form autoantibodies, leading to severe hemolytic anemia; course of disease tends to be either indolent (>10-yr survival) or aggressive with high mortality within 4 yr
Treatment=supportive therapy, chemotherapy, radiation for bulky lymphoid masses, splenectomy for splenomegaly
H/P = possibly asymptomatic before progression; fatigue, weight loss, night sweats; fever, splenomegaly; blast crisis presents with worsening symptoms and bone pain
Labs = increased WBCs (>100,000/µL) with high proportion of neutrophils, decreased leukocyte alkaline phosphatase; bone marrow shows granulocyte hyperplasia; cytogenetic analysis demonstrates Philadelphia chromosome [t(9;22)] or BCR-ABL fusion gene
Chronic myelogenous leukemia (CML)
Proliferation of mature myeloid cells seen in middle-aged adults; can be associated with radiation exposure
Follows stable course for several years before progressing into blast crisis (i.e., rapid worsening of neoplasm) that is usually fatal
Complications=blast crisis signals rapid progression and is usually fatal
Treatment = chemotherapy (imatinib is promising agent), bone marrow transplant in younger patients
H/P = fatigue, frequent infections, abdominal fullness, no night sweats; no fever, Massive splenomegaly, no lymphadenopathY
Labs = decreased Hgb, Hct, platelets, and WBCs (rarely, WBCs increased); bone marrow biopsy shows lymphocyte infiltration
Blood smear = numerous lymphocytes with “hairy” projections (irregular cytoplasmic projections)
Hairy cell leukemia
Proliferation of B cells most frequently in middle-aged men
Similar in appearance to CLL (but better prognosis); may be considered an indolent type of lymphoma
Treatment = chemotherapy once patients develop symptomatic cytopenia
Risk factors=Rh- mother with any history of fetal-maternal hemorrhage (e.g., abortion, amniocentesis, third-trimester bleeding)
Hemolysis will likely cause death of fetus
Hemolytic disease of the newborn
If Rh+ fetal cells enter circulation of Rh- mother, anti-Rh antibodies may develop
Antibodies do not affect pregnancy with initial Rh interaction, but cause severe fetal RBC hemolysis in subsequent pregnancies with Rh1 fetuses (i.e., fetal hydrops)
Treatment=administration of Rho(D) immune globulin (RhoGAM) within 72 hr of delivery of initial Rh+ fetus or at any time maternal and fetal blood may have mixed will prevent development of anti-Rh antibodies and protect future pregnancies by suppressing maternal formation of anti-Rh antibodies; intrauterine fetal transfusion may be required if condition develops in utero
H/P=fatigue, dyspnea on exertion, frequent infections; frequently associated with Short staturE, Abnormal skin pigmentatioN, horseshoe kidney, and thumb abnormalities
Labs=decreased Hgb, Hct, platelets, and WBCs; increased serum α-fetoprotein; bone marrow biopsy shows hypocellularity; chromosome analysis detects multiple strand breakage
Fanconi anemia
Autosomal recessive disorder associated with bone marrow failure, pancytopenia, and increased risk of leukemia
Complications=death in childhood is common from bone marrow failure or leukemia
Treatment=antibiotics, transfusions, bone marrow or hematopoietic stem cell transplantation, hematopoietic growth factors; androgens and corticosteroids can increase bone marrow activity
H/P=fatigue, dyspnea, cyanosis, and pallor detected early in life; craniofacial abnormalities, thumb abnormalities, heart murmurs, mental retardation, hypogonadism
Labs=decreased Hgb, decreased Hct, decreased reticulocyte count, increased MCV; bone marrow biopsy shows decreased activity, but increased presence of erythropoietin
Diamond-Blackfan anemia
Congenital pure RBC anemia likely caused by a defect in erythroid progenitor cells
Treatment=transfusions, corticosteroids, bone marrow transplant
/P=abdominal distention and pain, weight loss, malaise, bone pain, diarrhea; abdominal mass, HTN, possible Horner's syndrome, proptosis, movement disorders, hepatomegaly, fever, periorbital bruising
Labs=possible increased vanillylmandelic and homovanillic acids in 24-hr urine collection
Neuroblastoma
Tumors of neural crest cell origin that may arise in adrenal glands or sympathetic ganglia
Risk factors=neurofibromatosis, tuberous sclerosis, pheochromocytoma, Beckwith-Wiedemann syndrome, Turner's syndrome, low maternal folate consumption
Complications=poor prognosis if presenting after 1 yr of age; metastasizes to bone and brain
Radiology=computed tomography (CT) may locate adrenal or ganglion tumor
Treatment=surgical resection, chemotherapy, radiation
H/P=painful soft tissue mass with swelling; large tumors frequently cause mass effect on nearby structures
Rhabdomyosarcoma
Tumor of striated muscle in children
Labs=biopsy is diagnostic
Radiology=CT or magnetic resonance imaging (MRI), shows extent of tumor
Treatment=surgical debulking, radiation, chemotherapy