BCPS MCPS Part-1 cheat sheet

ATP yield: 1 glucose → ~30-32 ATP via malate-aspartate shuttle (heart/liver) or ~28-30 via glycerol-3-phosphate shuttle (muscle); glycolysis nets 2 ATP + 2 NADH.

Michaelis-Menten: v = Vmax[S]/(Km+[S]); Km is the substrate concentration at half Vmax and inversely reflects enzyme affinity; Lineweaver-Burk plot y-intercept = 1/Vmax, x-intercept = -1/Km.

DNA replication is semiconservative; leading strand synthesized continuously by DNA polymerase III, lagging strand as Okazaki fragments joined by DNA ligase; 5'→3' synthesis direction.

Hardy-Weinberg equilibrium: p² + 2pq + q² = 1 and p + q = 1; deviations indicate selection, drift, nonrandom mating, mutation, or migration.

Osmolarity = Σ (concentration × number of particles); normal plasma osmolality ≈ 275-295 mOsm/kg; effective osmoles (tonicity) exclude urea.

Henderson-Hasselbalch: pH = 6.1 + log([HCO3-]/(0.03 × PaCO2)); respiratory acidosis → ↑PaCO2, metabolic acidosis → ↓HCO3- with compensatory hyperventilation.

Resting membrane potential ≈ -70 mV in neurons, set mainly by K+ permeability (Nernst equation); depolarization opens voltage-gated Na+ channels, repolarization via K+ efflux.

Cell cycle checkpoints: G1/S (p53, Rb), G2/M (cyclin B/CDK1), spindle assembly checkpoint; loss of p53 permits replication of damaged DNA.

Inflammation mediators: histamine (early vasodilation), prostaglandins (pain/fever), leukotrienes (bronchoconstriction), TNF-α and IL-1 (endothelial activation).

Acute coronary syndrome: STEMI → immediate reperfusion (PCI within 90 min of first medical contact); NSTEMI/unstable angina → risk-stratify with GRACE, dual antiplatelet + anticoagulant, early invasive if high risk.

Heart failure with reduced EF (≤40%): guideline-directed quadruple therapy - ARNI/ACEi, beta-blocker, MRA, SGLT2 inhibitor - each reduces mortality.

Diabetes diagnostic thresholds: fasting glucose ≥126 mg/dL, 2-h OGTT ≥200 mg/dL, HbA1c ≥6.5%, or random ≥200 mg/dL with symptoms; repeat to confirm unless unequivocal.

DKA management: isotonic saline first, IV insulin after K+ ≥3.3 mEq/L, add dextrose when glucose <200-250 mg/dL, replace potassium aggressively; total body K+ is depleted despite normal serum K+.

Community-acquired pneumonia: CURB-65 (confusion, urea >7 mmol/L, RR ≥30, BP low, age ≥65) guides site of care; start empiric antibiotics within 4-6 h if admitted.

Hypertension first-line: thiazide diuretic, ACEi/ARB, or calcium channel blocker; ACEi/ARB preferred in diabetes with proteinuria; avoid ACEi in bilateral renal artery stenosis and pregnancy.

COPD: post-bronchodilator FEV1/FVC <0.70 confirms airflow obstruction; GOLD ABE groups guide inhaled therapy; long-term oxygen improves survival if PaO2 ≤55 mmHg or saturation ≤88%.

Stroke: noncontrast CT excludes hemorrhage; IV alteplase within 4.5 h of onset if no contraindication; thrombectomy up to 24 h in selected large-vessel occlusion.

Cirrhosis complications: ascites → sodium restriction + spironolactone/furosemide; varices → nonselective beta-blocker or band ligation; SBP → albumin plus third-generation cephalosporin.

ATLS primary survey: Airway with cervical spine protection, Breathing, Circulation with hemorrhage control, Disability (GCS), Exposure; treat life threats before definitive diagnosis.

Shock classification: class I <15% blood loss, II 15-30% (tachycardia, narrowed pulse pressure), III 30-40% (hypotension, confusion), IV >40% (lethargy, negligible urine output).

Acute appendicitis: migration of periumbilical pain to right lower quadrant with rebound tenderness; Alvarado score ≥7 supports operative management; pregnancy shifts appendix upward.

Bowel obstruction: air-fluid levels and dilated loops on upright film; initial management = NPO, nasogastric decompression, IV fluids, electrolytes; surgery for strangulation signs (fever, tachycardia, peritoneal signs).

Hernia: indirect inguinal passes lateral to inferior epigastric vessels through deep ring; direct passes medial; femoral hernia is below inguinal ligament and high strangulation risk.

Dental caries: Streptococcus mutans ferments sucrose to lactic acid demineralizing enamel; fluoride promotes remineralization as fluorapatite; early white-spot lesions are reversible.

Pulpitis: irreversible pulpitis → spontaneous throbbing pain, heat sensitivity, nonresponsive to cold; treatment is root canal therapy or extraction; reversible pulpitis responds to cold and resolves with restoration.

Odontogenic infection: Ludwig's angina is bilateral submandibular/sublingual cellulitis with floor-of-mouth elevation and airway risk; secure airway and IV antibiotics, then drainage.

Surgical site infection prevention: prophylactic antibiotic within 60 min before incision, redose for long operations or major blood loss, maintain normothermia and normoglycemia.

Estimated date of delivery: Naegele's rule = first day of last menstrual period + 7 days − 3 months (280 days); first-trimester ultrasound is most accurate for dating.

Antepartum hemorrhage: placenta previa → painless bright-red bleeding, avoid digital/vaginal exam until location known; placental abruption → painful bleeding, uterine tenderness, fetal distress.

Preeclampsia: BP ≥140/90 after 20 weeks plus proteinuria or end-organ dysfunction; severe features include BP ≥160/110, platelets <100,000, transaminases >2× normal, pulmonary edema, visual symptoms; delivery is definitive.

Ectopic pregnancy: triad of amenorrhea, abdominal pain, vaginal bleeding; discriminatory hCG ~3,500 mIU/mL; hemodynamically unstable → immediate surgery; stable → methotrexate if criteria met.

Postpartum hemorrhage: uterine atony most common cause; uterotonics (oxytocin, carboprost, misoprostol), bimanual massage, balloon tamponade, then surgical ligation/hysterectomy.

Contraception: combined oral contraceptives contraindicated in migraine with aura, smoking age ≥35, hypertension, VTE history; progestin-only and copper IUD are alternatives.

Cervical cancer screening: cytology every 3 years at age 21-29; co-testing or HPV primary screening every 5 years from age 30-65; stop after adequate negative screening to age 65.

Ovarian torsion: sudden severe unilateral pelvic pain with nausea; Doppler may be normal; surgical detorsion and ovarian preservation is preferred over oophorectomy.

Normal labor stages: first stage to full dilatation, second stage to delivery, third stage to placental expulsion; active third-stage management with oxytocin reduces hemorrhage.

APGAR scores at 1 and 5 minutes: Appearance, Pulse (<100 = 1, ≥100 = 2), Grimace, Activity, Respiration; score ≥7 is generally reassuring; resuscitation begins before scoring.

Neonatal jaundice: physiologic peaks day 3-5 in term infants; pathologic if onset <24 h, bilirubin rising >5 mg/dL/day, or direct hyperbilirubinemia; treat with phototherapy per hour-specific nomogram.

Growth: birth weight doubles by 5 months and triples by 12 months; length increases ~25 cm in first year; head circumference grows ~12 cm in first year.

Developmental milestones: social smile 6 weeks, sits unsupported 6-8 months, walks 12-15 months, two-word phrases 18-24 months; loss of milestones warrants evaluation.

Paediatric dehydration: mild <5%, moderate 5-10%, severe >10% body weight loss; ORS is first-line for mild-moderate; IV isotonic fluid boluses for severe or impaired consciousness.

Kawasaki disease: fever ≥5 days plus conjunctivitis, mucosal changes, rash, extremity changes, cervical lymphadenopathy; IVIG plus aspirin prevents coronary aneurysms.

Bronchiolitis: most common cause is respiratory syncytial virus; wheeze, tachypnea, retractions; treatment is supportive (oxygen, hydration); bronchodilators and steroids not routinely recommended.

Vaccination schedule: hepatitis B at birth; DTaP, IPV, Hib, PCV at 2, 4, 6 months; MMR and varicella at 12-15 months with boosters at 4-6 years.

Febrile seizures: simple if generalized, <15 minutes, once in 24 h, age 6 months-5 years; no routine EEG or anticonvulsant prophylaxis; workup focuses on source of fever.

Major depressive disorder: ≥5 symptoms for ≥2 weeks including depressed mood or anhedonia; first-line treatment is psychotherapy, SSRI, or combination; assess suicide risk at every visit.

Bipolar I disorder: at least one manic episode (≥1 week elevated/irritable mood plus increased energy); acute mania treated with mood stabilizer (lithium, valproate) plus atypical antipsychotic; antidepressants alone can trigger mania.

Schizophrenia: ≥2 of delusions, hallucinations, disorganized speech, grossly disorganized/catatonic behavior, negative symptoms for ≥6 months with ≥1 month active symptoms; first-line antipsychotic; monitor metabolic effects.

Serotonin syndrome: clonus, hyperreflexia, agitation, hyperthermia after serotonergic agents; stop offending drug, supportive care, benzodiazepines, cyproheptadine for severe cases.

Neuroleptic malignant syndrome: rigidity, fever, autonomic instability, elevated CK after dopamine antagonists; stop agent, aggressive cooling, dantrolene or bromocriptine.

Alcohol withdrawal: tremor, anxiety, seizures 6-48 h, delirium tremens 48-96 h; treat with benzodiazepines, thiamine before glucose to prevent Wernicke encephalopathy.

Lithium: narrow therapeutic index 0.6-1.2 mEq/L; toxicity signs include tremor, ataxia, vomiting, confusion; monitor renal and thyroid function; avoid NSAIDs and thiazides.

Opioid use disorder: first-line medication is buprenorphine or methadone; naltrexone is an alternative; naloxone reverses acute overdose.

Delirium versus dementia: delirium has acute onset, fluctuating course, inattention; dementia is chronic progressive cognitive decline with preserved consciousness; delirium is a medical emergency.