Clinical Skills and OSCE Guide - Cases and Examples

Identify the p wave as atrial depolarization and contraction, followed by the qrs complex for ventricular contraction and the t wave for repolarization, with st segment changes signaling myocardial infarction.

Describe atrial fibrillation as rapid atrial contractions that shake the atria, impair atrial to ventricular blood flow, raise clot risk, show absent p waves on ECG, and treat with cardioversion.

Atrial flutter causes rapid atrial contractions at 250–350 beats per minute with sawtooth P waves on ECG and clot risk leading to pulmonary embolism; treat with ablation and anticoagulation.

Ventricular tachycardia causes rapid ventricular contractions over 100 bpm with limited filling, risking fainting or cardiac death. Recognize on electrocardiogram by absent p waves and wide qrs; treat with defibrillation.

First degree heart block stems from mild AV pathway obstruction, delaying ventricular contraction after atrial activity. Treat underlying causes; most patients are asymptomatic.

Second-degree AV block Mobitz type I shows progressive P-R interval prolongation with a dropped QRS, caused by damage to the electrical pathway, and is treated with atropine after excluding causes.

Identify second-degree AV block Mobitz type II on ECG by random QRS drops with normal P waves. Recognize symptoms may include weakness, dizziness, or syncope, and manage with pacemaker therapy.

Explore third-degree heart block, detailing complete atrioventricular dissociation with independent P waves and QRS complexes, its causes, symptoms, and pacing-based treatments from temporary to permanent pacemakers.

Identify myocardial infarction as ischemia from obstruction of coronary vessels due to atherosclerosis. Recognize ECG signs and typical chest pain radiating to the left.

Identify torsades de pointes as QT prolongation–driven arrhythmia caused by anti-arrhythmic overdose or electrolyte changes, with twisting points on ECG and need to accelerate the heart rate to prevent arrest.

Assess the sensory, motor, and reflex components of the S1 nerve root, focusing on sensation over the lateral foot and fifth toe, and the Achilles reflex.

Perform the piriformis test (side-lying or seated) to screen for piriformis syndrome. A positive test occurs when moving the affected limb triggers leg pain, noting other possible causes.

Assess tuberculosis using chest x-ray with sputum analysis and acid-fast staining, confirm with biopsy; use PPD skin test induration thresholds or IGRA blood test to detect infection.

Summarize the rotator cuff muscles—supraspinatus, infraspinatus, teres minor, and subscapularis—their actions and innervation, plus common tests like the empty can, lateral rotation, Hornblower, and lift-off/bear hug.

Explore tendon reflex pathways from plantar and Babinski signs to ankle, patellar, biceps, and triceps reflexes, and differentiate hyperreflexia, areflexia, and related conditions like hypothyroidism and multiple sclerosis.

Master the newborn primitive reflexes: rooting, suckling, grasping, placing, parachute, and Moro, and understand the asymmetrical tonic neck reflex to prepare for exams and clinical practice.

Detect hearing loss and its cause using Weber and Rinne tests with tuning fork. Interpret Rinne as air longer than bone; if equal, sensorineural loss; if bone longer, conductive loss.

Assess thyroid nodules with TSH and T4, ultrasound, and fine-needle aspiration for nodules >1 cm; cold nodules have malignant potential, hot nodules unlikely cancer, and use radioiodine uptake.

Master the abc sequence for emergency care—airway, breathing, circulation, disability, exposure, and fever assessment—with practical steps for choking, anaphylaxis, tension pneumothorax, ventilation, intravenous fluids, intraosseous access, and secondary survey.

The complete blood count, or CBC, presents key values such as WBC, RBC, hemoglobin, hematocrit, MCV, MCHC, and platelets to detect inflammation, infection, anemia, dehydration, polycythemia, and coagulation.

Alt rises with hepatocyte injury such as hepatitis or cirrhosis; ast rises with muscle or heart conditions and alcoholism; alp and bilirubin indicate biliary obstruction, while albumin reflects liver health.

Explore how cardiac enzymes—troponin, CNB, and myoglobin—aid chest pain evaluation, with reference levels, timing of rises, and how kidney excretion affects urine color.

Explore coagulation profiles for surgery, including pt/inr for warfarin monitoring, aptt for heparin, fibrinogen, d-dimer, and platelets; identify bleeding and thrombotic risks.

Assess the basal metabolic panel to monitor glucose first, then calcium, sodium, potassium, chloride, and renal markers (BUN and creatinine) to gauge hydration and kidney safety for IV contrast.

Obtain blood cultures before starting intravenous antibiotics in septic shock to identify organisms, then tailor therapy after results and monitor response with cultures from blood, urine, sputum, and wounds.

CT scans provide fast, high-resolution imaging for trauma, brain hemorrhage, and abdominal or chest assessment with IV, oral, or perirectal contrast. They aid diagnosing appendicitis, aortic dissection, embolism, and hemorrhage.

Visualize soft tissues such as the brain and spinal cord with MRI, which is not ionizing and often uses IV contrast to reveal early strokes and other neurological findings.

Deliver rapid, portable imaging to detect bone fractures and urgent chest or abdominal conditions, while minimizing ionizing radiation and noting limited soft-tissue detail.

Ultrasound offers real-time, noninvasive, non-ionizing imaging that fits to the ED for trauma fast exams, cholecystitis, appendicitis, heart and pericardium, pregnancy, central lines, chest pathologies, joints, AAA, and DVT detection.

Identify common newborn rashes by pattern and color, including nevus simplex and hemangioma, and distinguish port-wine stain, congenital melanocytic nevus, congenital melanocytosis, and cafe au lait spots.

Streptococcus forms long chains and uses toxins, M protein-mediated immune mimicry, and pus production to drive diseases such as scarlet fever, necrotizing fasciitis, toxic shock-like syndrome, and post-streptococcal glomerulonephritis.

Staphylococcus aureus is gram-positive, beta-hemolytic, catalase- and coagulase-positive, with hemolysin and protein A, causing skin infections, pneumonia, endocarditis, MRSA, toxic shock syndrome, and food poisoning.

Differentiate gonococci and meningococci infections by transmission, virulence factors (IgA protease, capsule, pili), and outcomes, noting glucose vs maltose fermentation and treatment with ceftriaxone or azithro.

Explore respiratory syncytial virus, an enveloped, single stranded RNA paramyxovirus common in children, causing apnea in newborns, with upper to lower respiratory symptoms and Palivizumab for high risk infants.

Explore the hepatitis A–E viruses, their transmission, incubation, progression to acute or chronic liver disease, and associated histopathology, including cancer risk and pregnancy outcomes.

Classify neonatal conjunctivitis by onset to guide treatment: chemical irritation at birth; nasiriyah infection within seven days; chlamydia after seven days; viral infection after twenty days; eye drops at birth.

Identify rheumatic fever as autoimmune reaction to group A streptococci causing arthritis, carditis, nodules, erythema marginatum, and chorea. Apply Jones criteria diagnose and treat with penicillin five to ten years.

Identify scarlet fever caused by group a streptococci with a positive pcr test, featuring sandpaper rash and strawberry tongue, confirmed by rapid strep test and treated with penicillin.

Identify clostridium tetani’s tetanospasmin toxin blocking GABA and glycine, causing sardonicus, trismus, and opisthotonus; administer antitoxins, provide supportive care, and vaccinate at two months (one month for high-risk newborns).

Bordetella pertussis, a gram-negative bacterium, produces pertussis toxin and causes three stages—catarrhal, paroxysmal, convalescent—with whooping cough; macrolides are recommended during the catarrhal stage.

the lecture uses a modified pseudomonas mnemonic to memorize pneumonia in CF, sepsis, ecthyma gangrenosum, UTIs, and infections, plus exotoxin A, endotoxin, pyocyanin, and antipseudomonal beta-lactams, aminoglycosides, and carbapenems.

Mycoplasma pneumonia is an unsustainable bacterium with a sterol cell wall cultured on agar, causing walking pneumonia with an x-ray mismatch. Treat with macrolides, doxycycline, or fluoroquinolones; penicillin is ineffective.

Explore how Clostridium botulinum's exotoxin inhibits acetylcholine receptors, causing descending flaccid paralysis; adults acquire it from undercooked foods, while infants ingest honey-associated spores that germinate in the gut.

Identify how Clostridium difficile toxins A and B cause diarrhea and pseudomembranous colitis, diagnose by PCR, and manage with metronidazole, vancomycin, fidaxomicin, or fecal transplant, noting toxic megacolon risk.

Group B strep infection can be very serious for the newborn; treat with intravenous penicillin when the rectal vaginal culture is positive or delivery occurs before 37 weeks.

Explore four E. coli types. Hemorrhagic E. coli O157 causes hemolytic uremic syndrome and dysentery; enteropathogenic, enterotoxigenic, and enteroinvasive strains differ in mucosal interaction and treatment with penicillins and cephalosporins.

Diagnose Legionella by silver stain, charcoal agar culture, or urine antigen; transmit via water and air, Legionnaires disease causes hyponatremia and is treated with macrolides or fluoroquinolones.

Listeria grows in raw meat and unpasteurized dairy, can cross the placenta, and spreads via listeriolysin O and actin-based motility, risking pregnancy and disease in immunocompromised patients; treatment is ampicillin.

Identify Nocardia as a gram-positive aerobic bacterium with filamentous, fungus-like structure found in soil, TB-like presentation with negative PPD, and treat with folate inhibitors such as sulfonamides or trimethoprim.

Examine rabies transmission from bats and other animals, including potential airborne exposure, its nerve-to-brain spread, key clinical signs like hydrophobia, and post-exposure treatment with wound cleaning, vaccine, and immunoglobulins.

Explain three-stage Lyme disease from erythema migrans to cardiac and neurological complications caused by Borrelia from deer tick exposure in northeast US, and review doxycycline treatment and pregnancy options.

Understand left- and right-sided heart failure, their pulmonary congestion and edema, and manage acute cases with oxygen, diuretics, and nitrates.

Describe how circle of Willis occlusions produce contralateral motor and sensory loss, aphasia or neglect, and visual field deficits, plus aneurysm effects on optic chiasm and third nerve.

Identify Stevens-Johnson syndrome as a life-threatening mucocutaneous reaction, often due to anti-epileptic drugs, with dermal-epidermal separation, Nikolsky sign, mucosal involvement, and SJS involves less than 30% body surface area.

Gout presents as red, hot, swollen joints with pain, managed by pain relief and ice, while prevention focuses on weight, hydration, low red meat, avoiding alcohol, and lowering uric acid.

Unveil systemic lupus erythematosus as an autoimmune disease causing malar butterfly rash, hair loss, anemia, and risk of clots; review kidney, pericarditis, pleural, and brain involvement.

Describe renal colic as the common presentation of kidney stones, with severe flank pain radiating to the groin and possible hematuria; calcium oxalate stones are most common.

Understand the pilosebaceous unit and how plugging, sebum buildup, and Propionibacterium acnes with androgens drive acne inflammation and progression from comedones to pustules.

Analyze the genetics of alpha thalassemia, from minima and minor to hemoglobin H and hemoglobin Bart. Understand how gene defects alter alpha globin and cause hemolytic anemia and hydrops fetalis.

Explain how preload, cardiac output, and afterload determine shock mechanics across cardiac shock, hypovolemic shock, and fistula-related high-output heart failure.

Recognize tension pneumothorax by vital signs instability and signs like tracheal deviation, mediastinal shift, hyperresonance, and unilateral decreased breath sounds, enabling rapid diagnosis and treatment.

Diverticulitis occurs when small pockets in the sigmoid colon inflame, causing lower abdominal pain with diarrhea or constipation, fever; diagnosed by CT scan, colonoscopy, or sigmoidoscopy, and treated with antibiotics.

Understand cellulitis as a progressive skin infection that can spread beneath the skin due to Staphylococcus aureus or Streptococcus pyogenes; drain collections first, then antibiotics, risk factors include lymphedema.

Vitiligo is an autoimmune attack on melanocytes causing depigmented patches, especially on the face and hands, with decreased melanocytes on biopsy, treated with cortisol, tacrolimus, or psoralen and light therapy.

Erythema multiforme forms dark reddish to purple shapes, including target lesions and vesicles. Triggers include herpes simplex, Mycoplasma pneumoniae, and drugs; identify and stop the cause, recheck.

Explore polymyositis and dermatomyositis as autoimmune muscle diseases with proximal weakness, distinct antibodies, and biopsy patterns, alongside skin signs and tumor associations, treated with steroids and methotrexate.

Urticaria presents as itchy, well-demarcated hives from mast cell degranulation, with triggers such as heat, coffee, or alcohol, possibly with angioedema; acute lasts under six weeks, chronic beyond six.

Understand psoriasis, its characteristic plaques and distribution, and the associated histology and clinical features, including nail and eye involvement. Review treatment options from topical therapies to phototherapy and systemic agents.

Learn to recognize compartment syndrome from trauma, electrical burns, or excessive fluid resuscitation, and perform escharotomy within six hours or fasciotomy for severe cases or delayed diagnosis.

Explain vancomycin-related red man syndrome, a non-allergic histamine release with 5–13% incidence, presenting with rash, swelling, and breathing difficulty; outline management: stop infusion and use antihistamines or prophylaxis.

Identify early pregnancy signs including breast soreness, darker areola, cramps, spotting, rising temperature, nausea, frequent urination, and mood changes, plus bloating, food cravings and aversion, acne, heartburn, and weight gain.

Pulmonary hypertension, results from COPD or fibrosis causing hypoxia and heart strain; diagnosed by imaging and catheterization, treated with prostacyclin analogues, endothelin antagonists, cyclic GMP stimulants, or lung transplant.

Deep vein thrombosis can cause pulmonary embolism by clots reaching the lungs. The lecture covers risk factors, diagnostic tests, and treatments including noac, lmwh, warfarin, and ivc filters.

Preeclampsia is hypertension with proteinuria or endocrine dysfunction after 20 weeks gestation. Delivery is the definitive treatment, and intravenous magnesium helps prevent eclampsia in high risk patients.

Liver failure presents with jaundice and pruritus, portal hypertension with varices and ascites, hepatorenal syndrome, and hepatic encephalopathy, while pregnancy, alcohol use, diabetes or obesity shape prognosis.

Lead poisoning inhibits ferrochelatase and Ala dehydratase, causing basophilic stippling and microcytic anemia, with bone metaphysis deposition and risk of wrist or foot drop and encephalopathy.

Triggers an autoimmune attack on Schwann cells, causing segmental demyelination and ascending motor paralysis from toes to cranial nerves. Monitor respiratory status and employ plasmapheresis or immunoglobulins as needed.

Explain how hypertension arises from vascular tension due to hypervolemia or cardiac contraction, and how diuretics, calcium channel blockers, ACE inhibitors, ARBs, beta blockers, and alpha blockers lower blood pressure.

Discover how alpha and beta adrenergic receptors regulate smooth muscle, heart, and glands via catecholamines, and how agonists and antagonists treat hypertension, asthma, benign prostatic hyperplasia, and depression.

Amphotericin B and nystatin disrupt the fungal wall, with amphotericin B for systemic infections (Candida) and intrathecal use for meningitis; nystatin treats infections and oral thrush, nephrotoxicity remains a concern.

Compare first-generation and second-generation H1 antihistamines and explain how H2 receptors in the stomach reduce acid secretion; cover allergy, motion sickness, peptic ulcers, and gastritis, plus key side effects.

Digoxin inhibits the sodium potassium ATPase, increasing intracellular calcium to strengthen myocyte contraction and activate the vagus to lower heart rate in heart failure.

Block calcium channels in vessels or heart to manage blood pressure and contraction, categorize into dihydropyridines and non-dihydropyridines, with nimodipine used for subarachnoid hemorrhage.

Amlodipine is a calcium channel blocker for hypertension and angina, dosed 2.5-10 mg. Common side effects include edema; liver metabolism causes interactions, and it is safe in pregnancy and lactation.

Explain how opioid receptor agonism hyperpolarizes cells to reduce release of pain mediators. Summarize key opioids and actions, from pentazocine and butorphanol to morphine and methadone, plus common side effects.

Inhibits central nervous system cyclooxygenase, providing antipyretic and mild analgesic effects with no peripheral anti-inflammatory action. Replenish glutathione with NAC or cysteine to counter acetaminophen overdose-induced napqi toxicity.

Aspirin irreversibly inhibits cyclooxygenase, blocking COX-1 at low doses to reduce thromboxane A2 and thin the blood, and COX-2 at high doses for anti-inflammatory effects.

Antagonizes muscarinic receptors, an anticholinergic action that increases sympathetic drive. Use includes treating bradycardia and reducing secretions; it causes dry mouth, urinary retention, mydriasis, glaucoma risk, and hyperthermia.

Block peptidoglycan synthesis by binding the d-alanine d-alanine glycoprotein to treat serious gram-positive infections like MRSA, VRE, and C. difficile.

Explore fluoroquinolones, drugs ending with floxacin, that inhibit DNA topoisomerase II and IV to treat gram-positive and gram-negative infections, including pseudomonas. Note tendon injury risk and other side effects.

Angiotensin II receptor blockers, or sartans, block the receptor to lower blood pressure without bradykinin-related cough, and protect against diabetic nephropathy in patients who cannot tolerate ACE inhibitors.