Afghanistan Medical Exit Exam cheat sheet

Acute coronary syndrome: ST-elevation myocardial infarction requires urgent reperfusion; dual antiplatelet therapy plus anticoagulation is standard adjunctive care.

Diabetic ketoacidosis: anion-gap metabolic acidosis with ketonemia; treat with isotonic saline, insulin infusion, and potassium replacement once K+ is below the upper limit.

Heart failure with reduced ejection fraction: combination of ACE inhibitor/ARB or ARNI, beta-blocker, mineralocorticoid antagonist, and SGLT2 inhibitor reduces mortality.

Community-acquired pneumonia severity is stratified by CURB-65 (confusion, urea >7 mmol/L, respiratory rate >=30, blood pressure low, age >=65).

Hyponatremia: correct chronic hyponatremia slowly (typically <=8-10 mmol/L in 24 h) to avoid osmotic demyelination.

Thyroid storm is diagnosed clinically (Burch-Wartofsky score) and treated with beta-blockade, thionamide, iodine load after thionamide, and glucocorticoid.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia; biopsy guides etiology in adults.

Anemia of chronic disease shows low serum iron, low transferrin saturation, but normal-to-high ferritin; iron deficiency shows low ferritin.

Acute appendicitis: migration of periumbilical pain to right lower quadrant with McBurney point tenderness; appendectomy or antibiotics depending on severity.

Bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is nil per os, intravenous fluids, nasogastric decompression, and serial examination.

ATLS primary survey sequence: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, exposure/environment.

Shock in trauma is hemorrhagic until proven otherwise; hypotensive trauma patients receive blood products rather than large crystalloid boluses.

Hernias are at highest risk of strangulation when the neck of the sac is narrow (femoral > inguinal risk); irreducible painful hernia needs urgent surgery.

Postoperative fever timing: within 48 h consider atelectasis; days 3-5 consider urinary or wound infection; after day 5 consider abscess or deep infection.

Cholecystitis: right upper quadrant pain, Murphy sign, fever, leukocytosis; ultrasound shows wall thickening, pericholecystic fluid, or stones.

Breast cancer staging uses tumor size, nodal involvement, and distant metastasis (TNM); sentinel node biopsy is standard for clinically node-negative axilla.

Neonatal resuscitation: warm, dry, stimulate; positive pressure ventilation if apnea or heart rate <100/min; chest compressions if heart rate <60/min despite effective ventilation.

Pediatric maintenance fluids by Holliday-Segar: 100 mL/kg/day for first 10 kg, 50 mL/kg/day for next 10 kg, 20 mL/kg/day thereafter.

Acute otitis media: bulging tympanic membrane with acute onset symptoms; amoxicillin is first-line in uncomplicated cases.

Kawasaki disease: fever >=5 days plus conjunctivitis, mucositis, rash, extremity changes, cervical lymphadenopathy; treat with IVIG and aspirin to prevent coronary aneurysm.

Croup: barking cough and inspiratory stridor; dexamethasone and nebulized epinephrine for moderate-to-severe cases.

Bronchiolitis in infants is usually RSV; management is supportive (oxygen, hydration); bronchodilators and corticosteroids are not routinely effective.

Growth monitoring: weight-for-age, length/height-for-age, and weight-for-length/height plotted on WHO or CDC charts; crossing two major centiles warrants evaluation.

Intussusception: colicky pain, vomiting, currant-jelly stool; ultrasound shows target sign; air or contrast enema is diagnostic and therapeutic.

Preeclampsia: hypertension after 20 weeks plus proteinuria or end-organ dysfunction; delivery is the definitive treatment.

Eclampsia: seizures in the setting of preeclampsia; magnesium sulfate is the drug of choice for prevention and treatment of seizures.

Postpartum hemorrhage: uterine atony is the most common cause; management is uterine massage, oxytocin, then other uterotonics, tranexamic acid, and surgical measures.

Gestational diabetes screening typically occurs at 24-28 weeks with an oral glucose tolerance test.

Rhesus-negative mothers receive anti-D immunoglobulin to prevent alloimmunization; dose depends on bleeding events and fetal-maternal hemorrhage.

Normal labor stages: first stage to full cervical dilation, second stage to delivery of the baby, third stage to delivery of the placenta.

Ectopic pregnancy: amenorrhea, abdominal pain, vaginal bleeding; positive pregnancy test with empty uterus on ultrasound; treat with methotrexate or surgery.

Contraceptive effectiveness: long-acting reversible methods (implant, intrauterine device) have the lowest typical-use failure rates.

Incidence measures new cases per population at risk per time; prevalence measures all existing cases at a point or period.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value depends on disease prevalence, unlike sensitivity and specificity.

Relative risk is used in cohort studies; odds ratio approximates relative risk when the outcome is rare.

Herd immunity threshold depends on basic reproduction number: threshold = 1 - 1/R0.

Levels of prevention: primary (prevent onset), secondary (early detection), tertiary (limit disability and rehabilitation).

Cold chain: most vaccines require storage at 2-8 degrees Celsius; freezing damages adsorbed vaccines such as DTP and hepatitis B.

Maternal mortality ratio = maternal deaths per 100,000 live births during pregnancy or within 42 days of termination.

Aminoglycosides are nephrotoxic and ototoxic; monitor levels and avoid combining with other nephrotoxins.

Beta-lactam mechanism: inhibit bacterial cell wall synthesis by binding penicillin-binding proteins; bactericidal.

Warfarin inhibits vitamin K epoxide reductase; effect monitored by INR; vitamin K reverses overdose.

Heparin potentiates antithrombin; monitored by aPTT; protamine sulfate reverses unfractionated heparin.

Acetaminophen overdose: N-acetylcysteine is the antidote and is most effective when given early after ingestion.

Opioid overdose: naloxone reverses respiratory depression; titrate to restore adequate breathing.

First-order kinetics: constant fraction eliminated per unit time; zero-order kinetics: constant amount eliminated per unit time (e.g., phenytoin, ethanol at high doses).

Cytochrome P450 interactions: inhibitors (e.g., macrolides, azoles) raise levels of substrates; inducers (e.g., rifampicin, carbamazepine) lower them.

Inflammation: neutrophils dominate acute inflammation; lymphocytes, plasma cells, and macrophages dominate chronic inflammation.

Malignant tumors: poorly differentiated, infiltrative, metastasize; benign tumors are well circumscribed and do not metastasize.

Carcinoma arises from epithelium; sarcoma from mesenchymal tissue; lymphoma from lymphoid tissue.

Anion gap = Na+ - (Cl- + HCO3-); normal is roughly 8-12 mmol/L.

Osmolality can be estimated as 2 x Na+ + glucose/18 + urea/2.8 (mmol/L).

Tumor markers are not diagnostic alone; examples include AFP (hepatocellular, germ cell), CA-125 (ovarian), PSA (prostate), CEA (colorectal).

Coagulation: PT/INR reflects extrinsic and common pathway; aPTT reflects intrinsic and common pathway.

Gram stain: gram-positive organisms retain crystal violet (thick peptidoglycan); gram-negative organisms stain pink with safranin.

Cardiac output = heart rate x stroke volume; normal resting output is roughly 5 L/min.

Mean arterial pressure approximately = diastolic pressure + one-third of pulse pressure.

Lung volumes: tidal volume ~500 mL; vital capacity = inspiratory reserve + tidal + expiratory reserve; residual volume cannot be exhaled.

Glomerular filtration rate depends on net filtration pressure; autoregulation maintains flow across a range of arterial pressures.

Brachial plexus roots C5-T1; injury patterns produce characteristic motor and sensory deficits.

Femoral triangle contents (lateral to medial): femoral nerve, artery, vein, and lymphatics (empty space lateral to nerve).

Insulin lowers blood glucose by promoting cellular uptake and glycogen synthesis; glucagon raises it via glycogenolysis and gluconeogenesis.

Bohr effect: increased CO2, H+, and temperature shift the oxygen-hemoglobin dissociation curve to the right, reducing affinity.

Informed consent requires capacity, adequate disclosure, comprehension, and voluntariness; it is a process, not a signature.

Four core principles: autonomy, beneficence, non-maleficence, and justice.

Confidentiality may be breached only when legally mandated (e.g., certain communicable diseases, serious threats to identifiable others).

Decision-making capacity is assessed clinically (understanding, appreciation, reasoning, choice); competence is a legal determination.

Minors: assent from the child plus consent from parent or guardian, with exceptions for emancipated minors and specific services.

Research ethics: institutional review board approval, informed consent, and equipoise are required for human-subjects research.

Medical errors: disclose to the patient; apology and transparency are expected professional duties.

Resource allocation: triage decisions should be based on medical need and consistent criteria, not on social worth.

Cardiac arrest: high-quality chest compressions at 100-120/min with depth 5-6 cm, minimal interruptions, and early defibrillation for shockable rhythms.

Adult basic life support compression-to-ventilation ratio is 30:2 for a single rescuer; advanced airway allows continuous compressions with 1 breath every 6 seconds.

Anaphylaxis: intramuscular epinephrine into the anterolateral thigh is first-line; adjuncts include antihistamines and corticosteroids.

Sepsis: recognize infection plus organ dysfunction; give broad-spectrum antibiotics and fluids promptly; measure lactate.

Acute stroke: time is brain; non-contrast CT excludes hemorrhage before thrombolysis; thrombolysis window is typically up to 4.5 hours from onset.

Tension pneumothorax: clinical diagnosis; immediate needle decompression followed by tube thoracostomy.

Airway assessment: anticipate difficult airway using history, mouth opening, Mallampati class, and cervical mobility; plan a backup.

Poisoning: stabilize airway, breathing, circulation; activated charcoal is useful only within about one hour of ingestion and when airway is protected.

Acute coronary syndrome: ST-elevation myocardial infarction requires urgent reperfusion; dual antiplatelet therapy plus anticoagulation is standard adjunctive care.

Diabetic ketoacidosis: anion-gap metabolic acidosis with ketonemia; treat with isotonic saline, insulin infusion, and potassium replacement once K+ is below the upper limit.

Heart failure with reduced ejection fraction: combination of ACE inhibitor/ARB or ARNI, beta-blocker, mineralocorticoid antagonist, and SGLT2 inhibitor reduces mortality.

Community-acquired pneumonia severity is stratified by CURB-65 (confusion, urea >7 mmol/L, respiratory rate >=30, blood pressure low, age >=65).

Hyponatremia: correct chronic hyponatremia slowly (typically <=8-10 mmol/L in 24 h) to avoid osmotic demyelination.

Thyroid storm is diagnosed clinically (Burch-Wartofsky score) and treated with beta-blockade, thionamide, iodine load after thionamide, and glucocorticoid.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia; biopsy guides etiology in adults.

Anemia of chronic disease shows low serum iron, low transferrin saturation, but normal-to-high ferritin; iron deficiency shows low ferritin.

Acute appendicitis: migration of periumbilical pain to right lower quadrant with McBurney point tenderness; appendectomy or antibiotics depending on severity.

Bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is nil per os, intravenous fluids, nasogastric decompression, and serial examination.

ATLS primary survey sequence: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, exposure/environment.

Shock in trauma is hemorrhagic until proven otherwise; hypotensive trauma patients receive blood products rather than large crystalloid boluses.

Hernias are at highest risk of strangulation when the neck of the sac is narrow (femoral > inguinal risk); irreducible painful hernia needs urgent surgery.

Postoperative fever timing: within 48 h consider atelectasis; days 3-5 consider urinary or wound infection; after day 5 consider abscess or deep infection.

Cholecystitis: right upper quadrant pain, Murphy sign, fever, leukocytosis; ultrasound shows wall thickening, pericholecystic fluid, or stones.

Breast cancer staging uses tumor size, nodal involvement, and distant metastasis (TNM); sentinel node biopsy is standard for clinically node-negative axilla.

Neonatal resuscitation: warm, dry, stimulate; positive pressure ventilation if apnea or heart rate <100/min; chest compressions if heart rate <60/min despite effective ventilation.

Pediatric maintenance fluids by Holliday-Segar: 100 mL/kg/day for first 10 kg, 50 mL/kg/day for next 10 kg, 20 mL/kg/day thereafter.

Acute otitis media: bulging tympanic membrane with acute onset symptoms; amoxicillin is first-line in uncomplicated cases.

Kawasaki disease: fever >=5 days plus conjunctivitis, mucositis, rash, extremity changes, cervical lymphadenopathy; treat with IVIG and aspirin to prevent coronary aneurysm.

Croup: barking cough and inspiratory stridor; dexamethasone and nebulized epinephrine for moderate-to-severe cases.

Bronchiolitis in infants is usually RSV; management is supportive (oxygen, hydration); bronchodilators and corticosteroids are not routinely effective.

Growth monitoring: weight-for-age, length/height-for-age, and weight-for-length/height plotted on WHO or CDC charts; crossing two major centiles warrants evaluation.

Intussusception: colicky pain, vomiting, currant-jelly stool; ultrasound shows target sign; air or contrast enema is diagnostic and therapeutic.

Preeclampsia: hypertension after 20 weeks plus proteinuria or end-organ dysfunction; delivery is the definitive treatment.

Eclampsia: seizures in the setting of preeclampsia; magnesium sulfate is the drug of choice for prevention and treatment of seizures.

Postpartum hemorrhage: uterine atony is the most common cause; management is uterine massage, oxytocin, then other uterotonics, tranexamic acid, and surgical measures.

Gestational diabetes screening typically occurs at 24-28 weeks with an oral glucose tolerance test.

Rhesus-negative mothers receive anti-D immunoglobulin to prevent alloimmunization; dose depends on bleeding events and fetal-maternal hemorrhage.

Normal labor stages: first stage to full cervical dilation, second stage to delivery of the baby, third stage to delivery of the placenta.

Ectopic pregnancy: amenorrhea, abdominal pain, vaginal bleeding; positive pregnancy test with empty uterus on ultrasound; treat with methotrexate or surgery.

Contraceptive effectiveness: long-acting reversible methods (implant, intrauterine device) have the lowest typical-use failure rates.

Incidence measures new cases per population at risk per time; prevalence measures all existing cases at a point or period.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value depends on disease prevalence, unlike sensitivity and specificity.

Relative risk is used in cohort studies; odds ratio approximates relative risk when the outcome is rare.

Herd immunity threshold depends on basic reproduction number: threshold = 1 - 1/R0.

Levels of prevention: primary (prevent onset), secondary (early detection), tertiary (limit disability and rehabilitation).

Cold chain: most vaccines require storage at 2-8 degrees Celsius; freezing damages adsorbed vaccines such as DTP and hepatitis B.

Maternal mortality ratio = maternal deaths per 100,000 live births during pregnancy or within 42 days of termination.

Aminoglycosides are nephrotoxic and ototoxic; monitor levels and avoid combining with other nephrotoxins.

Beta-lactam mechanism: inhibit bacterial cell wall synthesis by binding penicillin-binding proteins; bactericidal.

Warfarin inhibits vitamin K epoxide reductase; effect monitored by INR; vitamin K reverses overdose.

Heparin potentiates antithrombin; monitored by aPTT; protamine sulfate reverses unfractionated heparin.

Acetaminophen overdose: N-acetylcysteine is the antidote and is most effective when given early after ingestion.

Opioid overdose: naloxone reverses respiratory depression; titrate to restore adequate breathing.

First-order kinetics: constant fraction eliminated per unit time; zero-order kinetics: constant amount eliminated per unit time (e.g., phenytoin, ethanol at high doses).

Cytochrome P450 interactions: inhibitors (e.g., macrolides, azoles) raise levels of substrates; inducers (e.g., rifampicin, carbamazepine) lower them.

Inflammation: neutrophils dominate acute inflammation; lymphocytes, plasma cells, and macrophages dominate chronic inflammation.

Malignant tumors: poorly differentiated, infiltrative, metastasize; benign tumors are well circumscribed and do not metastasize.

Carcinoma arises from epithelium; sarcoma from mesenchymal tissue; lymphoma from lymphoid tissue.

Anion gap = Na+ - (Cl- + HCO3-); normal is roughly 8-12 mmol/L.

Osmolality can be estimated as 2 x Na+ + glucose/18 + urea/2.8 (mmol/L).

Tumor markers are not diagnostic alone; examples include AFP (hepatocellular, germ cell), CA-125 (ovarian), PSA (prostate), CEA (colorectal).

Coagulation: PT/INR reflects extrinsic and common pathway; aPTT reflects intrinsic and common pathway.

Gram stain: gram-positive organisms retain crystal violet (thick peptidoglycan); gram-negative organisms stain pink with safranin.

Cardiac output = heart rate x stroke volume; normal resting output is roughly 5 L/min.

Mean arterial pressure approximately = diastolic pressure + one-third of pulse pressure.

Lung volumes: tidal volume ~500 mL; vital capacity = inspiratory reserve + tidal + expiratory reserve; residual volume cannot be exhaled.

Glomerular filtration rate depends on net filtration pressure; autoregulation maintains flow across a range of arterial pressures.

Brachial plexus roots C5-T1; injury patterns produce characteristic motor and sensory deficits.

Femoral triangle contents (lateral to medial): femoral nerve, artery, vein, and lymphatics (empty space lateral to nerve).

Insulin lowers blood glucose by promoting cellular uptake and glycogen synthesis; glucagon raises it via glycogenolysis and gluconeogenesis.

Bohr effect: increased CO2, H+, and temperature shift the oxygen-hemoglobin dissociation curve to the right, reducing affinity.

Informed consent requires capacity, adequate disclosure, comprehension, and voluntariness; it is a process, not a signature.

Four core principles: autonomy, beneficence, non-maleficence, and justice.

Confidentiality may be breached only when legally mandated (e.g., certain communicable diseases, serious threats to identifiable others).

Decision-making capacity is assessed clinically (understanding, appreciation, reasoning, choice); competence is a legal determination.

Minors: assent from the child plus consent from parent or guardian, with exceptions for emancipated minors and specific services.

Research ethics: institutional review board approval, informed consent, and equipoise are required for human-subjects research.

Medical errors: disclose to the patient; apology and transparency are expected professional duties.

Resource allocation: triage decisions should be based on medical need and consistent criteria, not on social worth.

Cardiac arrest: high-quality chest compressions at 100-120/min with depth 5-6 cm, minimal interruptions, and early defibrillation for shockable rhythms.

Adult basic life support compression-to-ventilation ratio is 30:2 for a single rescuer; advanced airway allows continuous compressions with 1 breath every 6 seconds.

Anaphylaxis: intramuscular epinephrine into the anterolateral thigh is first-line; adjuncts include antihistamines and corticosteroids.

Sepsis: recognize infection plus organ dysfunction; give broad-spectrum antibiotics and fluids promptly; measure lactate.

Acute stroke: time is brain; non-contrast CT excludes hemorrhage before thrombolysis; thrombolysis window is typically up to 4.5 hours from onset.

Tension pneumothorax: clinical diagnosis; immediate needle decompression followed by tube thoracostomy.

Airway assessment: anticipate difficult airway using history, mouth opening, Mallampati class, and cervical mobility; plan a backup.

Poisoning: stabilize airway, breathing, circulation; activated charcoal is useful only within about one hour of ingestion and when airway is protected.

Acute coronary syndrome: ST-elevation myocardial infarction requires urgent reperfusion; dual antiplatelet therapy plus anticoagulation is standard adjunctive care.

Diabetic ketoacidosis: anion-gap metabolic acidosis with ketonemia; treat with isotonic saline, insulin infusion, and potassium replacement once K+ is below the upper limit.

Heart failure with reduced ejection fraction: combination of ACE inhibitor/ARB or ARNI, beta-blocker, mineralocorticoid antagonist, and SGLT2 inhibitor reduces mortality.

Community-acquired pneumonia severity is stratified by CURB-65 (confusion, urea >7 mmol/L, respiratory rate >=30, blood pressure low, age >=65).

Hyponatremia: correct chronic hyponatremia slowly (typically <=8-10 mmol/L in 24 h) to avoid osmotic demyelination.

Thyroid storm is diagnosed clinically (Burch-Wartofsky score) and treated with beta-blockade, thionamide, iodine load after thionamide, and glucocorticoid.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia; biopsy guides etiology in adults.

Anemia of chronic disease shows low serum iron, low transferrin saturation, but normal-to-high ferritin; iron deficiency shows low ferritin.

Acute appendicitis: migration of periumbilical pain to right lower quadrant with McBurney point tenderness; appendectomy or antibiotics depending on severity.

Bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is nil per os, intravenous fluids, nasogastric decompression, and serial examination.

ATLS primary survey sequence: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, exposure/environment.

Shock in trauma is hemorrhagic until proven otherwise; hypotensive trauma patients receive blood products rather than large crystalloid boluses.

Hernias are at highest risk of strangulation when the neck of the sac is narrow (femoral > inguinal risk); irreducible painful hernia needs urgent surgery.

Postoperative fever timing: within 48 h consider atelectasis; days 3-5 consider urinary or wound infection; after day 5 consider abscess or deep infection.

Cholecystitis: right upper quadrant pain, Murphy sign, fever, leukocytosis; ultrasound shows wall thickening, pericholecystic fluid, or stones.

Breast cancer staging uses tumor size, nodal involvement, and distant metastasis (TNM); sentinel node biopsy is standard for clinically node-negative axilla.

Neonatal resuscitation: warm, dry, stimulate; positive pressure ventilation if apnea or heart rate <100/min; chest compressions if heart rate <60/min despite effective ventilation.

Pediatric maintenance fluids by Holliday-Segar: 100 mL/kg/day for first 10 kg, 50 mL/kg/day for next 10 kg, 20 mL/kg/day thereafter.

Acute otitis media: bulging tympanic membrane with acute onset symptoms; amoxicillin is first-line in uncomplicated cases.

Kawasaki disease: fever >=5 days plus conjunctivitis, mucositis, rash, extremity changes, cervical lymphadenopathy; treat with IVIG and aspirin to prevent coronary aneurysm.

Croup: barking cough and inspiratory stridor; dexamethasone and nebulized epinephrine for moderate-to-severe cases.

Bronchiolitis in infants is usually RSV; management is supportive (oxygen, hydration); bronchodilators and corticosteroids are not routinely effective.

Growth monitoring: weight-for-age, length/height-for-age, and weight-for-length/height plotted on WHO or CDC charts; crossing two major centiles warrants evaluation.

Intussusception: colicky pain, vomiting, currant-jelly stool; ultrasound shows target sign; air or contrast enema is diagnostic and therapeutic.

Preeclampsia: hypertension after 20 weeks plus proteinuria or end-organ dysfunction; delivery is the definitive treatment.

Eclampsia: seizures in the setting of preeclampsia; magnesium sulfate is the drug of choice for prevention and treatment of seizures.

Postpartum hemorrhage: uterine atony is the most common cause; management is uterine massage, oxytocin, then other uterotonics, tranexamic acid, and surgical measures.

Gestational diabetes screening typically occurs at 24-28 weeks with an oral glucose tolerance test.

Rhesus-negative mothers receive anti-D immunoglobulin to prevent alloimmunization; dose depends on bleeding events and fetal-maternal hemorrhage.

Normal labor stages: first stage to full cervical dilation, second stage to delivery of the baby, third stage to delivery of the placenta.

Ectopic pregnancy: amenorrhea, abdominal pain, vaginal bleeding; positive pregnancy test with empty uterus on ultrasound; treat with methotrexate or surgery.

Contraceptive effectiveness: long-acting reversible methods (implant, intrauterine device) have the lowest typical-use failure rates.

Incidence measures new cases per population at risk per time; prevalence measures all existing cases at a point or period.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value depends on disease prevalence, unlike sensitivity and specificity.

Relative risk is used in cohort studies; odds ratio approximates relative risk when the outcome is rare.

Herd immunity threshold depends on basic reproduction number: threshold = 1 - 1/R0.

Levels of prevention: primary (prevent onset), secondary (early detection), tertiary (limit disability and rehabilitation).

Cold chain: most vaccines require storage at 2-8 degrees Celsius; freezing damages adsorbed vaccines such as DTP and hepatitis B.

Maternal mortality ratio = maternal deaths per 100,000 live births during pregnancy or within 42 days of termination.

Aminoglycosides are nephrotoxic and ototoxic; monitor levels and avoid combining with other nephrotoxins.

Beta-lactam mechanism: inhibit bacterial cell wall synthesis by binding penicillin-binding proteins; bactericidal.

Warfarin inhibits vitamin K epoxide reductase; effect monitored by INR; vitamin K reverses overdose.

Heparin potentiates antithrombin; monitored by aPTT; protamine sulfate reverses unfractionated heparin.

Acetaminophen overdose: N-acetylcysteine is the antidote and is most effective when given early after ingestion.

Opioid overdose: naloxone reverses respiratory depression; titrate to restore adequate breathing.

First-order kinetics: constant fraction eliminated per unit time; zero-order kinetics: constant amount eliminated per unit time (e.g., phenytoin, ethanol at high doses).

Cytochrome P450 interactions: inhibitors (e.g., macrolides, azoles) raise levels of substrates; inducers (e.g., rifampicin, carbamazepine) lower them.

Inflammation: neutrophils dominate acute inflammation; lymphocytes, plasma cells, and macrophages dominate chronic inflammation.

Malignant tumors: poorly differentiated, infiltrative, metastasize; benign tumors are well circumscribed and do not metastasize.

Carcinoma arises from epithelium; sarcoma from mesenchymal tissue; lymphoma from lymphoid tissue.

Anion gap = Na+ - (Cl- + HCO3-); normal is roughly 8-12 mmol/L.

Osmolality can be estimated as 2 x Na+ + glucose/18 + urea/2.8 (mmol/L).

Tumor markers are not diagnostic alone; examples include AFP (hepatocellular, germ cell), CA-125 (ovarian), PSA (prostate), CEA (colorectal).

Coagulation: PT/INR reflects extrinsic and common pathway; aPTT reflects intrinsic and common pathway.

Gram stain: gram-positive organisms retain crystal violet (thick peptidoglycan); gram-negative organisms stain pink with safranin.

Cardiac output = heart rate x stroke volume; normal resting output is roughly 5 L/min.

Mean arterial pressure approximately = diastolic pressure + one-third of pulse pressure.

Lung volumes: tidal volume ~500 mL; vital capacity = inspiratory reserve + tidal + expiratory reserve; residual volume cannot be exhaled.

Glomerular filtration rate depends on net filtration pressure; autoregulation maintains flow across a range of arterial pressures.

Brachial plexus roots C5-T1; injury patterns produce characteristic motor and sensory deficits.

Femoral triangle contents (lateral to medial): femoral nerve, artery, vein, and lymphatics (empty space lateral to nerve).

Insulin lowers blood glucose by promoting cellular uptake and glycogen synthesis; glucagon raises it via glycogenolysis and gluconeogenesis.

Bohr effect: increased CO2, H+, and temperature shift the oxygen-hemoglobin dissociation curve to the right, reducing affinity.

Informed consent requires capacity, adequate disclosure, comprehension, and voluntariness; it is a process, not a signature.

Four core principles: autonomy, beneficence, non-maleficence, and justice.

Confidentiality may be breached only when legally mandated (e.g., certain communicable diseases, serious threats to identifiable others).

Decision-making capacity is assessed clinically (understanding, appreciation, reasoning, choice); competence is a legal determination.

Minors: assent from the child plus consent from parent or guardian, with exceptions for emancipated minors and specific services.

Research ethics: institutional review board approval, informed consent, and equipoise are required for human-subjects research.

Medical errors: disclose to the patient; apology and transparency are expected professional duties.

Resource allocation: triage decisions should be based on medical need and consistent criteria, not on social worth.

Cardiac arrest: high-quality chest compressions at 100-120/min with depth 5-6 cm, minimal interruptions, and early defibrillation for shockable rhythms.

Adult basic life support compression-to-ventilation ratio is 30:2 for a single rescuer; advanced airway allows continuous compressions with 1 breath every 6 seconds.

Anaphylaxis: intramuscular epinephrine into the anterolateral thigh is first-line; adjuncts include antihistamines and corticosteroids.

Sepsis: recognize infection plus organ dysfunction; give broad-spectrum antibiotics and fluids promptly; measure lactate.

Acute stroke: time is brain; non-contrast CT excludes hemorrhage before thrombolysis; thrombolysis window is typically up to 4.5 hours from onset.

Tension pneumothorax: clinical diagnosis; immediate needle decompression followed by tube thoracostomy.

Airway assessment: anticipate difficult airway using history, mouth opening, Mallampati class, and cervical mobility; plan a backup.

Poisoning: stabilize airway, breathing, circulation; activated charcoal is useful only within about one hour of ingestion and when airway is protected.

Acute coronary syndrome: ST-elevation myocardial infarction requires urgent reperfusion; dual antiplatelet therapy plus anticoagulation is standard adjunctive care.

Diabetic ketoacidosis: anion-gap metabolic acidosis with ketonemia; treat with isotonic saline, insulin infusion, and potassium replacement once K+ is below the upper limit.

Heart failure with reduced ejection fraction: combination of ACE inhibitor/ARB or ARNI, beta-blocker, mineralocorticoid antagonist, and SGLT2 inhibitor reduces mortality.

Community-acquired pneumonia severity is stratified by CURB-65 (confusion, urea >7 mmol/L, respiratory rate >=30, blood pressure low, age >=65).

Hyponatremia: correct chronic hyponatremia slowly (typically <=8-10 mmol/L in 24 h) to avoid osmotic demyelination.

Thyroid storm is diagnosed clinically (Burch-Wartofsky score) and treated with beta-blockade, thionamide, iodine load after thionamide, and glucocorticoid.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia; biopsy guides etiology in adults.

Anemia of chronic disease shows low serum iron, low transferrin saturation, but normal-to-high ferritin; iron deficiency shows low ferritin.

Acute appendicitis: migration of periumbilical pain to right lower quadrant with McBurney point tenderness; appendectomy or antibiotics depending on severity.

Bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is nil per os, intravenous fluids, nasogastric decompression, and serial examination.

ATLS primary survey sequence: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, exposure/environment.

Shock in trauma is hemorrhagic until proven otherwise; hypotensive trauma patients receive blood products rather than large crystalloid boluses.

Hernias are at highest risk of strangulation when the neck of the sac is narrow (femoral > inguinal risk); irreducible painful hernia needs urgent surgery.

Postoperative fever timing: within 48 h consider atelectasis; days 3-5 consider urinary or wound infection; after day 5 consider abscess or deep infection.

Cholecystitis: right upper quadrant pain, Murphy sign, fever, leukocytosis; ultrasound shows wall thickening, pericholecystic fluid, or stones.

Breast cancer staging uses tumor size, nodal involvement, and distant metastasis (TNM); sentinel node biopsy is standard for clinically node-negative axilla.

Neonatal resuscitation: warm, dry, stimulate; positive pressure ventilation if apnea or heart rate <100/min; chest compressions if heart rate <60/min despite effective ventilation.

Pediatric maintenance fluids by Holliday-Segar: 100 mL/kg/day for first 10 kg, 50 mL/kg/day for next 10 kg, 20 mL/kg/day thereafter.

Acute otitis media: bulging tympanic membrane with acute onset symptoms; amoxicillin is first-line in uncomplicated cases.

Kawasaki disease: fever >=5 days plus conjunctivitis, mucositis, rash, extremity changes, cervical lymphadenopathy; treat with IVIG and aspirin to prevent coronary aneurysm.

Croup: barking cough and inspiratory stridor; dexamethasone and nebulized epinephrine for moderate-to-severe cases.

Bronchiolitis in infants is usually RSV; management is supportive (oxygen, hydration); bronchodilators and corticosteroids are not routinely effective.

Growth monitoring: weight-for-age, length/height-for-age, and weight-for-length/height plotted on WHO or CDC charts; crossing two major centiles warrants evaluation.

Intussusception: colicky pain, vomiting, currant-jelly stool; ultrasound shows target sign; air or contrast enema is diagnostic and therapeutic.

Preeclampsia: hypertension after 20 weeks plus proteinuria or end-organ dysfunction; delivery is the definitive treatment.

Eclampsia: seizures in the setting of preeclampsia; magnesium sulfate is the drug of choice for prevention and treatment of seizures.

Postpartum hemorrhage: uterine atony is the most common cause; management is uterine massage, oxytocin, then other uterotonics, tranexamic acid, and surgical measures.

Gestational diabetes screening typically occurs at 24-28 weeks with an oral glucose tolerance test.

Rhesus-negative mothers receive anti-D immunoglobulin to prevent alloimmunization; dose depends on bleeding events and fetal-maternal hemorrhage.

Normal labor stages: first stage to full cervical dilation, second stage to delivery of the baby, third stage to delivery of the placenta.

Ectopic pregnancy: amenorrhea, abdominal pain, vaginal bleeding; positive pregnancy test with empty uterus on ultrasound; treat with methotrexate or surgery.

Contraceptive effectiveness: long-acting reversible methods (implant, intrauterine device) have the lowest typical-use failure rates.

Incidence measures new cases per population at risk per time; prevalence measures all existing cases at a point or period.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value depends on disease prevalence, unlike sensitivity and specificity.

Relative risk is used in cohort studies; odds ratio approximates relative risk when the outcome is rare.

Herd immunity threshold depends on basic reproduction number: threshold = 1 - 1/R0.

Levels of prevention: primary (prevent onset), secondary (early detection), tertiary (limit disability and rehabilitation).

Cold chain: most vaccines require storage at 2-8 degrees Celsius; freezing damages adsorbed vaccines such as DTP and hepatitis B.

Maternal mortality ratio = maternal deaths per 100,000 live births during pregnancy or within 42 days of termination.

Aminoglycosides are nephrotoxic and ototoxic; monitor levels and avoid combining with other nephrotoxins.

Beta-lactam mechanism: inhibit bacterial cell wall synthesis by binding penicillin-binding proteins; bactericidal.

Warfarin inhibits vitamin K epoxide reductase; effect monitored by INR; vitamin K reverses overdose.

Heparin potentiates antithrombin; monitored by aPTT; protamine sulfate reverses unfractionated heparin.

Acetaminophen overdose: N-acetylcysteine is the antidote and is most effective when given early after ingestion.

Opioid overdose: naloxone reverses respiratory depression; titrate to restore adequate breathing.

First-order kinetics: constant fraction eliminated per unit time; zero-order kinetics: constant amount eliminated per unit time (e.g., phenytoin, ethanol at high doses).

Cytochrome P450 interactions: inhibitors (e.g., macrolides, azoles) raise levels of substrates; inducers (e.g., rifampicin, carbamazepine) lower them.

Inflammation: neutrophils dominate acute inflammation; lymphocytes, plasma cells, and macrophages dominate chronic inflammation.

Malignant tumors: poorly differentiated, infiltrative, metastasize; benign tumors are well circumscribed and do not metastasize.

Carcinoma arises from epithelium; sarcoma from mesenchymal tissue; lymphoma from lymphoid tissue.

Anion gap = Na+ - (Cl- + HCO3-); normal is roughly 8-12 mmol/L.

Osmolality can be estimated as 2 x Na+ + glucose/18 + urea/2.8 (mmol/L).

Tumor markers are not diagnostic alone; examples include AFP (hepatocellular, germ cell), CA-125 (ovarian), PSA (prostate), CEA (colorectal).

Coagulation: PT/INR reflects extrinsic and common pathway; aPTT reflects intrinsic and common pathway.

Gram stain: gram-positive organisms retain crystal violet (thick peptidoglycan); gram-negative organisms stain pink with safranin.

Cardiac output = heart rate x stroke volume; normal resting output is roughly 5 L/min.

Mean arterial pressure approximately = diastolic pressure + one-third of pulse pressure.

Lung volumes: tidal volume ~500 mL; vital capacity = inspiratory reserve + tidal + expiratory reserve; residual volume cannot be exhaled.

Glomerular filtration rate depends on net filtration pressure; autoregulation maintains flow across a range of arterial pressures.

Brachial plexus roots C5-T1; injury patterns produce characteristic motor and sensory deficits.

Femoral triangle contents (lateral to medial): femoral nerve, artery, vein, and lymphatics (empty space lateral to nerve).

Insulin lowers blood glucose by promoting cellular uptake and glycogen synthesis; glucagon raises it via glycogenolysis and gluconeogenesis.

Bohr effect: increased CO2, H+, and temperature shift the oxygen-hemoglobin dissociation curve to the right, reducing affinity.

Informed consent requires capacity, adequate disclosure, comprehension, and voluntariness; it is a process, not a signature.

Four core principles: autonomy, beneficence, non-maleficence, and justice.

Confidentiality may be breached only when legally mandated (e.g., certain communicable diseases, serious threats to identifiable others).

Decision-making capacity is assessed clinically (understanding, appreciation, reasoning, choice); competence is a legal determination.

Minors: assent from the child plus consent from parent or guardian, with exceptions for emancipated minors and specific services.

Research ethics: institutional review board approval, informed consent, and equipoise are required for human-subjects research.

Medical errors: disclose to the patient; apology and transparency are expected professional duties.

Resource allocation: triage decisions should be based on medical need and consistent criteria, not on social worth.

Cardiac arrest: high-quality chest compressions at 100-120/min with depth 5-6 cm, minimal interruptions, and early defibrillation for shockable rhythms.

Adult basic life support compression-to-ventilation ratio is 30:2 for a single rescuer; advanced airway allows continuous compressions with 1 breath every 6 seconds.

Anaphylaxis: intramuscular epinephrine into the anterolateral thigh is first-line; adjuncts include antihistamines and corticosteroids.

Sepsis: recognize infection plus organ dysfunction; give broad-spectrum antibiotics and fluids promptly; measure lactate.

Acute stroke: time is brain; non-contrast CT excludes hemorrhage before thrombolysis; thrombolysis window is typically up to 4.5 hours from onset.

Tension pneumothorax: clinical diagnosis; immediate needle decompression followed by tube thoracostomy.

Airway assessment: anticipate difficult airway using history, mouth opening, Mallampati class, and cervical mobility; plan a backup.

Poisoning: stabilize airway, breathing, circulation; activated charcoal is useful only within about one hour of ingestion and when airway is protected.

Acute coronary syndrome: ST-elevation myocardial infarction requires urgent reperfusion; dual antiplatelet therapy plus anticoagulation is standard adjunctive care.

Diabetic ketoacidosis: anion-gap metabolic acidosis with ketonemia; treat with isotonic saline, insulin infusion, and potassium replacement once K+ is below the upper limit.

Heart failure with reduced ejection fraction: combination of ACE inhibitor/ARB or ARNI, beta-blocker, mineralocorticoid antagonist, and SGLT2 inhibitor reduces mortality.

Community-acquired pneumonia severity is stratified by CURB-65 (confusion, urea >7 mmol/L, respiratory rate >=30, blood pressure low, age >=65).

Hyponatremia: correct chronic hyponatremia slowly (typically <=8-10 mmol/L in 24 h) to avoid osmotic demyelination.

Thyroid storm is diagnosed clinically (Burch-Wartofsky score) and treated with beta-blockade, thionamide, iodine load after thionamide, and glucocorticoid.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia; biopsy guides etiology in adults.

Anemia of chronic disease shows low serum iron, low transferrin saturation, but normal-to-high ferritin; iron deficiency shows low ferritin.

Acute appendicitis: migration of periumbilical pain to right lower quadrant with McBurney point tenderness; appendectomy or antibiotics depending on severity.

Bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is nil per os, intravenous fluids, nasogastric decompression, and serial examination.

ATLS primary survey sequence: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, exposure/environment.

Shock in trauma is hemorrhagic until proven otherwise; hypotensive trauma patients receive blood products rather than large crystalloid boluses.

Hernias are at highest risk of strangulation when the neck of the sac is narrow (femoral > inguinal risk); irreducible painful hernia needs urgent surgery.

Postoperative fever timing: within 48 h consider atelectasis; days 3-5 consider urinary or wound infection; after day 5 consider abscess or deep infection.

Cholecystitis: right upper quadrant pain, Murphy sign, fever, leukocytosis; ultrasound shows wall thickening, pericholecystic fluid, or stones.

Breast cancer staging uses tumor size, nodal involvement, and distant metastasis (TNM); sentinel node biopsy is standard for clinically node-negative axilla.

Neonatal resuscitation: warm, dry, stimulate; positive pressure ventilation if apnea or heart rate <100/min; chest compressions if heart rate <60/min despite effective ventilation.

Pediatric maintenance fluids by Holliday-Segar: 100 mL/kg/day for first 10 kg, 50 mL/kg/day for next 10 kg, 20 mL/kg/day thereafter.

Acute otitis media: bulging tympanic membrane with acute onset symptoms; amoxicillin is first-line in uncomplicated cases.

Kawasaki disease: fever >=5 days plus conjunctivitis, mucositis, rash, extremity changes, cervical lymphadenopathy; treat with IVIG and aspirin to prevent coronary aneurysm.

Croup: barking cough and inspiratory stridor; dexamethasone and nebulized epinephrine for moderate-to-severe cases.

Bronchiolitis in infants is usually RSV; management is supportive (oxygen, hydration); bronchodilators and corticosteroids are not routinely effective.

Growth monitoring: weight-for-age, length/height-for-age, and weight-for-length/height plotted on WHO or CDC charts; crossing two major centiles warrants evaluation.

Intussusception: colicky pain, vomiting, currant-jelly stool; ultrasound shows target sign; air or contrast enema is diagnostic and therapeutic.

Preeclampsia: hypertension after 20 weeks plus proteinuria or end-organ dysfunction; delivery is the definitive treatment.

Eclampsia: seizures in the setting of preeclampsia; magnesium sulfate is the drug of choice for prevention and treatment of seizures.

Postpartum hemorrhage: uterine atony is the most common cause; management is uterine massage, oxytocin, then other uterotonics, tranexamic acid, and surgical measures.

Gestational diabetes screening typically occurs at 24-28 weeks with an oral glucose tolerance test.

Rhesus-negative mothers receive anti-D immunoglobulin to prevent alloimmunization; dose depends on bleeding events and fetal-maternal hemorrhage.

Normal labor stages: first stage to full cervical dilation, second stage to delivery of the baby, third stage to delivery of the placenta.

Ectopic pregnancy: amenorrhea, abdominal pain, vaginal bleeding; positive pregnancy test with empty uterus on ultrasound; treat with methotrexate or surgery.

Contraceptive effectiveness: long-acting reversible methods (implant, intrauterine device) have the lowest typical-use failure rates.

Incidence measures new cases per population at risk per time; prevalence measures all existing cases at a point or period.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value depends on disease prevalence, unlike sensitivity and specificity.

Relative risk is used in cohort studies; odds ratio approximates relative risk when the outcome is rare.

Herd immunity threshold depends on basic reproduction number: threshold = 1 - 1/R0.

Levels of prevention: primary (prevent onset), secondary (early detection), tertiary (limit disability and rehabilitation).

Cold chain: most vaccines require storage at 2-8 degrees Celsius; freezing damages adsorbed vaccines such as DTP and hepatitis B.

Maternal mortality ratio = maternal deaths per 100,000 live births during pregnancy or within 42 days of termination.

Aminoglycosides are nephrotoxic and ototoxic; monitor levels and avoid combining with other nephrotoxins.

Beta-lactam mechanism: inhibit bacterial cell wall synthesis by binding penicillin-binding proteins; bactericidal.

Warfarin inhibits vitamin K epoxide reductase; effect monitored by INR; vitamin K reverses overdose.

Heparin potentiates antithrombin; monitored by aPTT; protamine sulfate reverses unfractionated heparin.

Acetaminophen overdose: N-acetylcysteine is the antidote and is most effective when given early after ingestion.

Opioid overdose: naloxone reverses respiratory depression; titrate to restore adequate breathing.

First-order kinetics: constant fraction eliminated per unit time; zero-order kinetics: constant amount eliminated per unit time (e.g., phenytoin, ethanol at high doses).

Cytochrome P450 interactions: inhibitors (e.g., macrolides, azoles) raise levels of substrates; inducers (e.g., rifampicin, carbamazepine) lower them.

Inflammation: neutrophils dominate acute inflammation; lymphocytes, plasma cells, and macrophages dominate chronic inflammation.

Malignant tumors: poorly differentiated, infiltrative, metastasize; benign tumors are well circumscribed and do not metastasize.

Carcinoma arises from epithelium; sarcoma from mesenchymal tissue; lymphoma from lymphoid tissue.

Anion gap = Na+ - (Cl- + HCO3-); normal is roughly 8-12 mmol/L.

Osmolality can be estimated as 2 x Na+ + glucose/18 + urea/2.8 (mmol/L).

Tumor markers are not diagnostic alone; examples include AFP (hepatocellular, germ cell), CA-125 (ovarian), PSA (prostate), CEA (colorectal).

Coagulation: PT/INR reflects extrinsic and common pathway; aPTT reflects intrinsic and common pathway.

Gram stain: gram-positive organisms retain crystal violet (thick peptidoglycan); gram-negative organisms stain pink with safranin.

Cardiac output = heart rate x stroke volume; normal resting output is roughly 5 L/min.

Mean arterial pressure approximately = diastolic pressure + one-third of pulse pressure.

Lung volumes: tidal volume ~500 mL; vital capacity = inspiratory reserve + tidal + expiratory reserve; residual volume cannot be exhaled.

Glomerular filtration rate depends on net filtration pressure; autoregulation maintains flow across a range of arterial pressures.

Brachial plexus roots C5-T1; injury patterns produce characteristic motor and sensory deficits.

Femoral triangle contents (lateral to medial): femoral nerve, artery, vein, and lymphatics (empty space lateral to nerve).

Insulin lowers blood glucose by promoting cellular uptake and glycogen synthesis; glucagon raises it via glycogenolysis and gluconeogenesis.

Bohr effect: increased CO2, H+, and temperature shift the oxygen-hemoglobin dissociation curve to the right, reducing affinity.

Informed consent requires capacity, adequate disclosure, comprehension, and voluntariness; it is a process, not a signature.

Four core principles: autonomy, beneficence, non-maleficence, and justice.

Confidentiality may be breached only when legally mandated (e.g., certain communicable diseases, serious threats to identifiable others).

Decision-making capacity is assessed clinically (understanding, appreciation, reasoning, choice); competence is a legal determination.

Minors: assent from the child plus consent from parent or guardian, with exceptions for emancipated minors and specific services.

Research ethics: institutional review board approval, informed consent, and equipoise are required for human-subjects research.

Medical errors: disclose to the patient; apology and transparency are expected professional duties.

Resource allocation: triage decisions should be based on medical need and consistent criteria, not on social worth.

Cardiac arrest: high-quality chest compressions at 100-120/min with depth 5-6 cm, minimal interruptions, and early defibrillation for shockable rhythms.

Adult basic life support compression-to-ventilation ratio is 30:2 for a single rescuer; advanced airway allows continuous compressions with 1 breath every 6 seconds.

Anaphylaxis: intramuscular epinephrine into the anterolateral thigh is first-line; adjuncts include antihistamines and corticosteroids.

Sepsis: recognize infection plus organ dysfunction; give broad-spectrum antibiotics and fluids promptly; measure lactate.

Acute stroke: time is brain; non-contrast CT excludes hemorrhage before thrombolysis; thrombolysis window is typically up to 4.5 hours from onset.

Tension pneumothorax: clinical diagnosis; immediate needle decompression followed by tube thoracostomy.

Airway assessment: anticipate difficult airway using history, mouth opening, Mallampati class, and cervical mobility; plan a backup.

Poisoning: stabilize airway, breathing, circulation; activated charcoal is useful only within about one hour of ingestion and when airway is protected.

Acute coronary syndrome: ST-elevation myocardial infarction requires urgent reperfusion; dual antiplatelet therapy plus anticoagulation is standard adjunctive care.

Diabetic ketoacidosis: anion-gap metabolic acidosis with ketonemia; treat with isotonic saline, insulin infusion, and potassium replacement once K+ is below the upper limit.

Heart failure with reduced ejection fraction: combination of ACE inhibitor/ARB or ARNI, beta-blocker, mineralocorticoid antagonist, and SGLT2 inhibitor reduces mortality.

Community-acquired pneumonia severity is stratified by CURB-65 (confusion, urea >7 mmol/L, respiratory rate >=30, blood pressure low, age >=65).

Hyponatremia: correct chronic hyponatremia slowly (typically <=8-10 mmol/L in 24 h) to avoid osmotic demyelination.

Thyroid storm is diagnosed clinically (Burch-Wartofsky score) and treated with beta-blockade, thionamide, iodine load after thionamide, and glucocorticoid.

Nephrotic syndrome: proteinuria >3.5 g/day, hypoalbuminemia, edema, hyperlipidemia; biopsy guides etiology in adults.

Anemia of chronic disease shows low serum iron, low transferrin saturation, but normal-to-high ferritin; iron deficiency shows low ferritin.

Acute appendicitis: migration of periumbilical pain to right lower quadrant with McBurney point tenderness; appendectomy or antibiotics depending on severity.

Bowel obstruction: air-fluid levels and dilated loops on plain film; initial management is nil per os, intravenous fluids, nasogastric decompression, and serial examination.

ATLS primary survey sequence: airway with cervical spine protection, breathing, circulation with hemorrhage control, disability, exposure/environment.

Shock in trauma is hemorrhagic until proven otherwise; hypotensive trauma patients receive blood products rather than large crystalloid boluses.

Hernias are at highest risk of strangulation when the neck of the sac is narrow (femoral > inguinal risk); irreducible painful hernia needs urgent surgery.

Postoperative fever timing: within 48 h consider atelectasis; days 3-5 consider urinary or wound infection; after day 5 consider abscess or deep infection.

Cholecystitis: right upper quadrant pain, Murphy sign, fever, leukocytosis; ultrasound shows wall thickening, pericholecystic fluid, or stones.

Breast cancer staging uses tumor size, nodal involvement, and distant metastasis (TNM); sentinel node biopsy is standard for clinically node-negative axilla.

Neonatal resuscitation: warm, dry, stimulate; positive pressure ventilation if apnea or heart rate <100/min; chest compressions if heart rate <60/min despite effective ventilation.

Pediatric maintenance fluids by Holliday-Segar: 100 mL/kg/day for first 10 kg, 50 mL/kg/day for next 10 kg, 20 mL/kg/day thereafter.

Acute otitis media: bulging tympanic membrane with acute onset symptoms; amoxicillin is first-line in uncomplicated cases.

Kawasaki disease: fever >=5 days plus conjunctivitis, mucositis, rash, extremity changes, cervical lymphadenopathy; treat with IVIG and aspirin to prevent coronary aneurysm.

Croup: barking cough and inspiratory stridor; dexamethasone and nebulized epinephrine for moderate-to-severe cases.

Bronchiolitis in infants is usually RSV; management is supportive (oxygen, hydration); bronchodilators and corticosteroids are not routinely effective.

Growth monitoring: weight-for-age, length/height-for-age, and weight-for-length/height plotted on WHO or CDC charts; crossing two major centiles warrants evaluation.

Intussusception: colicky pain, vomiting, currant-jelly stool; ultrasound shows target sign; air or contrast enema is diagnostic and therapeutic.

Preeclampsia: hypertension after 20 weeks plus proteinuria or end-organ dysfunction; delivery is the definitive treatment.

Eclampsia: seizures in the setting of preeclampsia; magnesium sulfate is the drug of choice for prevention and treatment of seizures.

Postpartum hemorrhage: uterine atony is the most common cause; management is uterine massage, oxytocin, then other uterotonics, tranexamic acid, and surgical measures.

Gestational diabetes screening typically occurs at 24-28 weeks with an oral glucose tolerance test.

Rhesus-negative mothers receive anti-D immunoglobulin to prevent alloimmunization; dose depends on bleeding events and fetal-maternal hemorrhage.

Normal labor stages: first stage to full cervical dilation, second stage to delivery of the baby, third stage to delivery of the placenta.

Ectopic pregnancy: amenorrhea, abdominal pain, vaginal bleeding; positive pregnancy test with empty uterus on ultrasound; treat with methotrexate or surgery.

Contraceptive effectiveness: long-acting reversible methods (implant, intrauterine device) have the lowest typical-use failure rates.

Incidence measures new cases per population at risk per time; prevalence measures all existing cases at a point or period.

Sensitivity = true positives / (true positives + false negatives); specificity = true negatives / (true negatives + false positives).

Positive predictive value depends on disease prevalence, unlike sensitivity and specificity.

Relative risk is used in cohort studies; odds ratio approximates relative risk when the outcome is rare.

Herd immunity threshold depends on basic reproduction number: threshold = 1 - 1/R0.

Levels of prevention: primary (prevent onset), secondary (early detection), tertiary (limit disability and rehabilitation).

Cold chain: most vaccines require storage at 2-8 degrees Celsius; freezing damages adsorbed vaccines such as DTP and hepatitis B.

Maternal mortality ratio = maternal deaths per 100,000 live births during pregnancy or within 42 days of termination.

Aminoglycosides are nephrotoxic and ototoxic; monitor levels and avoid combining with other nephrotoxins.

Beta-lactam mechanism: inhibit bacterial cell wall synthesis by binding penicillin-binding proteins; bactericidal.

Warfarin inhibits vitamin K epoxide reductase; effect monitored by INR; vitamin K reverses overdose.

Heparin potentiates antithrombin; monitored by aPTT; protamine sulfate reverses unfractionated heparin.

Acetaminophen overdose: N-acetylcysteine is the antidote and is most effective when given early after ingestion.

Opioid overdose: naloxone reverses respiratory depression; titrate to restore adequate breathing.

First-order kinetics: constant fraction eliminated per unit time; zero-order kinetics: constant amount eliminated per unit time (e.g., phenytoin, ethanol at high doses).

Cytochrome P450 interactions: inhibitors (e.g., macrolides, azoles) raise levels of substrates; inducers (e.g., rifampicin, carbamazepine) lower them.

Inflammation: neutrophils dominate acute inflammation; lymphocytes, plasma cells, and macrophages dominate chronic inflammation.

Malignant tumors: poorly differentiated, infiltrative, metastasize; benign tumors are well circumscribed and do not metastasize.

Carcinoma arises from epithelium; sarcoma from mesenchymal tissue; lymphoma from lymphoid tissue.

Anion gap = Na+ - (Cl- + HCO3-); normal is roughly 8-12 mmol/L.

Osmolality can be estimated as 2 x Na+ + glucose/18 + urea/2.8 (mmol/L).

Tumor markers are not diagnostic alone; examples include AFP (hepatocellular, germ cell), CA-125 (ovarian), PSA (prostate), CEA (colorectal).

Coagulation: PT/INR reflects extrinsic and common pathway; aPTT reflects intrinsic and common pathway.

Gram stain: gram-positive organisms retain crystal violet (thick peptidoglycan); gram-negative organisms stain pink with safranin.

Cardiac output = heart rate x stroke volume; normal resting output is roughly 5 L/min.

Mean arterial pressure approximately = diastolic pressure + one-third of pulse pressure.

Lung volumes: tidal volume ~500 mL; vital capacity = inspiratory reserve + tidal + expiratory reserve; residual volume cannot be exhaled.

Glomerular filtration rate depends on net filtration pressure; autoregulation maintains flow across a range of arterial pressures.

Brachial plexus roots C5-T1; injury patterns produce characteristic motor and sensory deficits.

Femoral triangle contents (lateral to medial): femoral nerve, artery, vein, and lymphatics (empty space lateral to nerve).

Insulin lowers blood glucose by promoting cellular uptake and glycogen synthesis; glucagon raises it via glycogenolysis and gluconeogenesis.

Bohr effect: increased CO2, H+, and temperature shift the oxygen-hemoglobin dissociation curve to the right, reducing affinity.

Informed consent requires capacity, adequate disclosure, comprehension, and voluntariness; it is a process, not a signature.

Four core principles: autonomy, beneficence, non-maleficence, and justice.

Confidentiality may be breached only when legally mandated (e.g., certain communicable diseases, serious threats to identifiable others).

Decision-making capacity is assessed clinically (understanding, appreciation, reasoning, choice); competence is a legal determination.

Minors: assent from the child plus consent from parent or guardian, with exceptions for emancipated minors and specific services.

Research ethics: institutional review board approval, informed consent, and equipoise are required for human-subjects research.

Medical errors: disclose to the patient; apology and transparency are expected professional duties.

Resource allocation: triage decisions should be based on medical need and consistent criteria, not on social worth.

Cardiac arrest: high-quality chest compressions at 100-120/min with depth 5-6 cm, minimal interruptions, and early defibrillation for shockable rhythms.

Adult basic life support compression-to-ventilation ratio is 30:2 for a single rescuer; advanced airway allows continuous compressions with 1 breath every 6 seconds.

Anaphylaxis: intramuscular epinephrine into the anterolateral thigh is first-line; adjuncts include antihistamines and corticosteroids.

Sepsis: recognize infection plus organ dysfunction; give broad-spectrum antibiotics and fluids promptly; measure lactate.

Acute stroke: time is brain; non-contrast CT excludes hemorrhage before thrombolysis; thrombolysis window is typically up to 4.5 hours from onset.

Tension pneumothorax: clinical diagnosis; immediate needle decompression followed by tube thoracostomy.

Airway assessment: anticipate difficult airway using history, mouth opening, Mallampati class, and cervical mobility; plan a backup.

Poisoning: stabilize airway, breathing, circulation; activated charcoal is useful only within about one hour of ingestion and when airway is protected.