OMSB Residency Selection (OMRSE) cheat sheet

Acute coronary syndrome: serial high-sensitivity troponin at 0 and 1-3 hours; a rise/fall pattern with at least one value above the 99th percentile upper reference limit defines acute myocardial injury.

Heart failure with reduced ejection fraction (LVEF ≤40%): start a beta-blocker, ACE inhibitor/ARB/ARNI, MRA, and SGLT2 inhibitor unless contraindicated; each class reduces mortality.

Diabetic ketoacidosis: IV isotonic saline first, then insulin infusion 0.1 units/kg/h after potassium is ≥3.3 mmol/L; add dextrose when glucose <11 mmol/L to clear ketones.

Community-acquired pneumonia severity: CURB-65 (confusion, urea >7 mmol/L, respiratory rate ≥30, BP <90/60, age ≥65) - 0-1 outpatient, 2 ward admission, ≥3 consider ICU.

Hyperkalemia with ECG changes: IV calcium gluconate first for membrane stabilization, then insulin with dextrose and salbutamol to shift potassium intracellularly; dialysis for refractory cases.

Nephrotic syndrome: proteinuria >3.5 g/day, albumin <30 g/L, edema, hyperlipidemia; in adults biopsy to exclude membranous nephropathy and minimal change disease.

Anemia: microcytic (MCV <80) suggests iron deficiency, thalassemia, or anemia of chronic disease; check ferritin, transferrin saturation, and hemoglobin electrophoresis.

Acute appendicitis: Alvarado score components are migratory pain, anorexia, nausea/vomiting, right iliac fossa tenderness, rebound, fever, and leukocytosis; score ≥7 favors operative management.

Bowel obstruction: supine and erect abdominal films show dilated loops and air-fluid levels; CT defines transition point and excludes strangulation (fever, tachycardia, rising lactate).

Trauma primary survey follows ABCDE; FAST scan detects free intraperitoneal fluid; peritonitis or hemodynamic instability mandates laparotomy.

Postoperative fever within 48 hours suggests atelectasis; days 3-5 suggest urinary or line infection; days 5-7 suggest anastomotic leak or abscess.

Thyroidectomy: recurrent laryngeal nerve injury causes hoarseness; external branch of superior laryngeal nerve injury impairs high-pitch phonation; hypocalcemia from parathyroid devascularization appears 24-72 hours post-op.

Hernia: indirect inguinal hernias pass lateral to inferior epigastric vessels and are the most common type; direct hernias pass medial and are acquired through Hesselbach's triangle.

Breast cancer staging uses TNM; sentinel lymph node biopsy is standard for clinically node-negative axilla in early invasive disease.

Neonatal resuscitation: warm, dry, stimulate, position airway; positive pressure ventilation at 21-30% oxygen if apneic or heart rate <100; chest compressions at 3:1 ratio if heart rate <60 after effective ventilation.

Pediatric maintenance fluids use the Holliday-Segar rule: 100 mL/kg/day for first 10 kg, 50 for next 10 kg, and 20 for each kg above 20.

Bronchiolitis: supportive care with oxygen and hydration; routine bronchodilators, corticosteroids, and antibiotics are not recommended.

Kawasaki disease: fever ≥5 days plus 4 of 5 features (conjunctivitis, mucosal changes, rash, extremity changes, cervical lymphadenopathy); treat with IVIG 2 g/kg and aspirin to prevent coronary aneurysms.

Pediatric dehydration: mild <5%, moderate 5-10%, severe >10% weight loss; ORS is first-line for mild-moderate; IV bolus 20 mL/kg isotonic crystalloid for shock.

Growth: weight doubles by 5 months, triples by 1 year, quadruples by 2 years; birth length increases 50% by 1 year.

Febrile seizure: simple if generalized, <15 minutes, once in 24 hours, age 6 months to 5 years; no routine EEG or anticonvulsant needed.

Preeclampsia: BP ≥140/90 after 20 weeks plus proteinuria or end-organ dysfunction; delivery is the definitive treatment; magnesium sulfate prevents and treats eclampsia.

Postpartum hemorrhage: uterine atony is the most common cause; first-line is uterine massage plus oxytocin, then carboprost, misoprostol, or tranexamic acid.

Gestational diabetes screening: 75 g OGTT at 24-28 weeks; diagnostic thresholds are fasting ≥5.1, 1-hour ≥10.0, 2-hour ≥8.5 mmol/L (any one value).

Ectopic pregnancy: transvaginal ultrasound with empty uterus and beta-hCG above the discriminatory zone (~1500-3500 mIU/mL) is suspicious; methotrexate if unruptured and hemodynamically stable.

Contraception: combined oral pills are contraindicated with migraine with aura, smoking over age 35, and history of VTE; progestin-only methods are alternatives.

Cervical cancer screening: start at age 21 with cytology every 3 years, or age 30 with co-testing every 5 years; HPV vaccination prevents types 16 and 18.

Labor stages: first stage from onset to full dilatation, second from full dilatation to delivery, third from delivery to placental expulsion (normally <30 minutes).

Hypertension: diagnose with ≥2 readings ≥140/90 on separate occasions; start lifestyle change for all and pharmacotherapy for stage 2 or high cardiovascular risk.

Type 2 diabetes: metformin first-line unless contraindicated; target HbA1c individualized, commonly <7% for most non-pregnant adults.

Asthma: stepwise therapy from inhaled corticosteroid as needed to low-dose ICS-formoterol maintenance and reliever; do not use short-acting beta-agonist alone.

Primary prevention: statins for adults with 10-year atherosclerotic cardiovascular risk ≥7.5-10% depending on guideline; check lipids and risk factors.

Antibiotic stewardship: do not prescribe antibiotics for uncomplicated viral upper respiratory infection; use symptom-based care.

Screening: colorectal cancer from age 45-50, breast cancer mammography from 40-50 depending on guideline, and cervical screening from 21.

Major depressive disorder: ≥5 symptoms for ≥2 weeks including depressed mood or anhedonia; first-line treatment is psychotherapy or SSRI.

Serotonin syndrome: clonus, hyperreflexia, agitation, hyperthermia after serotonergic agents; stop offending drugs, give benzodiazepines and cyproheptadine if severe.

Neuroleptic malignant syndrome: rigidity, fever, autonomic instability, raised creatine kinase after dopamine antagonists; stop drug, supportive care, dantrolene or bromocriptine.

Schizophrenia: positive symptoms respond to dopamine D2 blockade; metabolic monitoring (weight, glucose, lipids) is required for antipsychotics.

Bipolar I mania: elevated mood plus increased energy for ≥1 week with ≥3 symptoms; acute treatment with mood stabilizer plus antipsychotic; avoid antidepressant monotherapy.

Alcohol withdrawal: use CIWA-Ar to guide benzodiazepines; give thiamine before glucose to prevent Wernicke encephalopathy.

Cardiac arrest: high-quality CPR at 100-120 compressions/min, depth 5-6 cm, full recoil, minimize interruptions; defibrillate shockable rhythms immediately.

Anaphylaxis: intramuscular adrenaline 0.5 mg (0.5 mL of 1:1000) into the anterolateral thigh, repeat every 5 minutes; adjuncts are antihistamine and corticosteroid.

Sepsis: within 1 hour obtain cultures, measure lactate, give broad-spectrum antibiotics, and start 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L.

Acute stroke: non-contrast CT excludes hemorrhage; thrombolysis within 4.5 hours of onset; thrombectomy for large vessel occlusion up to 24 hours in selected patients.

Opioid overdose: naloxone 0.4-2 mg IV/IM/intranasal, repeat every 2-3 minutes; titrate to respiratory rate, not full consciousness.

ARDS Berlin criteria: acute onset within 1 week, bilateral opacities, PaO2/FiO2 ≤300 mmHg on PEEP ≥5 cmH2O, not fully explained by cardiac failure.

Action potential: resting membrane potential about -70 mV; depolarization from sodium influx, repolarization from potassium efflux; plateau in cardiac myocytes from calcium influx.

Cardiac output = heart rate × stroke volume; stroke volume depends on preload, afterload, and contractility.

Renal clearance C = (U × V) / P; inulin measures GFR, para-aminohippurate measures renal plasma flow.

Oxygen content = (1.34 × hemoglobin × SaO2) + (0.003 × PaO2); anemia reduces content even with normal saturation.

Pharmacokinetics: half-life = 0.693 × volume of distribution / clearance; steady state reached after about 4-5 half-lives.

Autonomic receptors: alpha-1 causes vasoconstriction, beta-1 increases heart rate and contractility, beta-2 causes bronchodilation and vasodilation, muscarinic M2 slows heart rate.

Coagulation cascade: intrinsic pathway (factors XII, XI, IX, VIII) measured by aPTT; extrinsic pathway (factor VII) measured by PT/INR; common pathway factors X, V, II, I.

Informed consent requires capacity, adequate disclosure of risks/benefits/alternatives, comprehension, and voluntariness; documented consent is not a substitute for discussion.

Four principles of biomedical ethics: autonomy, beneficence, non-maleficence, and justice; when they conflict, autonomy generally prevails for a capacitated adult.

Confidentiality may be breached when required by law, when there is serious risk to others, or with patient consent; disclose the minimum necessary information.

Adolescent confidentiality: capacity to consent to treatment is assessed by maturity and understanding; parental involvement is encouraged but not absolute in all jurisdictions.

Patient safety: root cause analysis investigates systems failures after a serious incident; incident reporting should be non-punitive and blame-free.

Medical error disclosure: inform the patient promptly, honestly, and fully; apologize and explain what will be done to prevent recurrence.

Oman's health system is organized by the Ministry of Health with tertiary referral hospitals in Muscat (Royal Hospital, Khoula Hospital) and regional hospitals and health centers providing primary care.

Universal health coverage is delivered through government-funded public facilities; the private sector provides supplementary services and insurance.

Oman's epidemiological transition: non-communicable diseases (cardiovascular disease, diabetes, cancer) now dominate morbidity, while communicable disease control remains important.

Crude birth rate and infant mortality are used to monitor maternal and child health; Oman has achieved major reductions in under-5 mortality since 1970.

Notifiable disease surveillance is mandated under Omani public health regulations; reporting triggers outbreak investigation by the Directorate General of Disease Surveillance and Control.

Health promotion priorities include tobacco control, obesity and diabetes prevention, road traffic injury reduction, and expanded immunization coverage.

Health workforce planning uses population-to-provider ratios; Omanization policies aim to increase the proportion of Omani nationals in clinical and administrative roles.