ECG
Sgarbossa criteria
In LBBB, suspect STEMI with: concordant ST↑ ≥1 mm (5 pts), concordant ST↓ V1-V3 (3), discordant ST↑ ≥5 mm (2). Modified: discordant ST↑/S ratio ≥0.25.
ECG
Sgarbossa criteria
In LBBB, suspect STEMI with: concordant ST↑ ≥1 mm (5 pts), concordant ST↓ V1-V3 (3), discordant ST↑ ≥5 mm (2). Modified: discordant ST↑/S ratio ≥0.25.
ICU
MAP target in shock
Target MAP ≥65 mmHg in septic shock. Higher (75-85) only if chronic HTN and improved renal perfusion.
Pharm
Amiodarone in D5W
Amiodarone precipitates in saline at high concentrations — dilute in D5W and use non-PVC tubing for prolonged infusion.
Emergency
Don't bolus pressors
Norepinephrine, epinephrine, vasopressin must run as infusions. IV push only in arrest (epi). Bolus dosing → severe hypertension / arrhythmia.
Medicine
DKA & K⁺
Never start insulin in DKA if K⁺ <3.3 mmol/L. Replace K first, then begin insulin.
Surgery
Tension PTX is clinical
Diagnose tension pneumothorax clinically — do not wait for CXR. Decompress immediately: 2nd ICS MCL or 4th-5th ICS anterior axillary.
ECG
Wellens syndrome
Biphasic or deeply inverted T in V2-V3 + recent chest pain → critical proximal LAD lesion. Avoid stress test; refer for angiography.
ICU
ARDS lung-protective
VT 4–6 mL/kg PBW, plateau ≤30, PEEP per FiO2 table, prone if P/F <150.
Pharm
Vancomycin trough
Target AUC 400-600 (or trough 15-20 for severe MRSA). Recheck levels at steady state (4th dose) and with renal function changes.
Emergency
Posterior MI
ST depression V1-V3 with tall R waves → consider posterior STEMI. Confirm with posterior leads V7-V9 (≥0.5 mm ST↑).
Medicine
Light's criteria
Exudate if any of: pleural/serum protein >0.5, pleural/serum LDH >0.6, pleural LDH >2/3 upper limit normal serum.
Surgery
Damage control resuscitation
1:1:1 (PRBC:FFP:platelets), permissive hypotension SBP 80-90 until source control (except TBI).
ICU
RASS-targeted sedation
Light sedation (RASS 0 to -2) reduces vent days, delirium and mortality vs deep sedation.
Pharm
Steroid equivalence
Hydrocortisone 20 mg = Prednisone 5 mg = Methylprednisolone 4 mg = Dexamethasone 0.75 mg.
Emergency
CURB-65 score
Confusion, Urea>7, RR≥30, BP<90/60, age≥65. 0-1 outpatient, 2 short stay, ≥3 admit/ICU consideration.
ECG
De Winter T waves
Tall symmetric T in V1–V6 + 1–3 mm upsloping ST depression at J point + slight ST elevation in aVR → proximal LAD occlusion equivalent. Treat as STEMI.
ECG
aVR ST elevation
ST elevation in aVR ≥1 mm with diffuse ST depression elsewhere → left main / proximal LAD or triple-vessel disease. Cath lab activation.
ICU
Driving pressure in ARDS
Plateau − PEEP. Aim ≤15 cmH₂O; mortality climbs sharply above this even with low VT.
ICU
Awake prone in COVID/AHRF
Prone 12–16 h/day improved oxygenation and reduced intubation in moderate hypoxaemia. Stop if no PaO₂ improvement after 1 h.
Pharm
Adenosine + transplanted heart
Heart-transplant recipients are denervated and exquisitely sensitive — start at 1.5 mg, not 6 mg.
Pharm
Phenytoin loading rate
Max 50 mg/min IV (25 mg/min if elderly/cardiac). Faster → hypotension, asystole; use cardiac monitor.
Pharm
DOAC + P-gp / CYP3A4
Strong inducers (rifampicin, phenytoin, carbamazepine, St John's wort) reduce DOAC levels → thrombosis risk. Switch to LMWH/warfarin.
Emergency
Cricoid pressure debate
ARRC and DAS no longer mandate cricoid pressure during RSI — releases if it impedes laryngoscopy or BVM ventilation.
Emergency
Hypothermia ECG
Osborn (J) waves at QRS-ST junction. Don't terminate resuscitation until core temp ≥35 °C ("not dead until warm and dead").
Emergency
Stroke mimic clue
Hypoglycaemia, Todd's paresis, complicated migraine, conversion disorder. Always check BM and consider mimics — but don't withhold thrombolysis for likely stroke.
Medicine
SAAG in ascites
Serum albumin − ascites albumin. ≥11 g/L → portal hypertension (cirrhosis, HF, Budd-Chiari). <11 → exudative (TB, malignancy, pancreatitis).
Medicine
Wells PE shortcut
PERC-negative + low Wells (<4) → no D-dimer needed in low-prevalence setting. Wells >4 → go straight to CTPA.
Medicine
Hyponatraemia rate
Correct Na⁺ <10 mmol/L per 24 h (8 if chronic / high risk) to avoid osmotic demyelination. Re-lower with D5W ± desmopressin if overshoot.
Surgery
Boas sign
Right shoulder-tip pain → diaphragmatic irritation from acute cholecystitis (referred via phrenic C3-5).
Surgery
Compartment pressure
ΔP (DBP − compartment pressure) <30 mmHg → fasciotomy. Don't rely on absolute compartment pressure alone.
