When to intubate in GCS?

GCS ≤ 8 requires intubation for airway protection. The patient cannot protect their own airway at this level of consciousness. Motor score is the most prognostically important component.

What is the best initial fluid for sepsis resuscitation?

Lactated Ringer's (LR) is the preferred resuscitation fluid. The SMART trial (2018) showed balanced crystalloids reduced death, new renal failure, and persistent renal dysfunction compared to normal saline.

When to start vasopressors in septic shock?

Start norepinephrine (first-line vasopressor) if MAP remains < 65 mmHg after initial 30 mL/kg crystalloid resuscitation, or earlier if patient is profoundly hypotensive. Do not delay pressors to complete full fluid resuscitation.

Why can serum uric acid be normal during acute gout?

During acute inflammation, IL-6 increases renal urate excretion and redistributes urate from plasma to tissues. Up to 40% of acute gout flares have normal serum uric acid. Joint aspiration with polarized microscopy is needed for definitive diagnosis.

How do you distinguish lupus flare from infection in SLE?

Key clues: CRP is low/normal in flare but elevated in infection. Complement (C3/C4) drops in flare but is normal/elevated in infection. Procalcitonin is elevated in bacterial infection but normal in flare. Anti-dsDNA rises in flare, stable in infection.

What is the difference between DKA and HHS?

DKA features acidosis (pH 600), hyperosmolality (> 320), and minimal ketosis -typically in Type 2 DM. DKA requires insulin drip; HHS requires aggressive fluid resuscitation first.

When to give tPA in acute ischemic stroke?

IV alteplase (tPA) can be given within 4.5 hours of last known well time in eligible patients. CT head must rule out hemorrhage first. For large vessel occlusion, mechanical thrombectomy can be performed up to 24 hours with favorable imaging.

What antibiotics for community-acquired pneumonia?

Inpatient non-ICU: ceftriaxone + azithromycin. ICU: ceftriaxone + azithromycin (add vancomycin if MRSA risk). Outpatient healthy: amoxicillin. Outpatient with comorbidities: augmentin + azithromycin or respiratory fluoroquinolone. Duration: 5 days if clinically stable for 48 hours.

How to interpret iron studies?

Iron deficiency: low ferritin (< 30), high TIBC, low iron, low transferrin saturation (< 20%). Anemia of chronic disease: normal/high ferritin (acute phase reactant), low TIBC, low iron. A ferritin of 50-100 in an inflamed patient may still represent iron deficiency.

What is the correction rate for hyponatremia?

Correct sodium no more than 8 mEq/L in 24 hours to avoid osmotic demyelination syndrome (ODS). For symptomatic severe hyponatremia with seizures, give 3% hypertonic saline 100-150 mL bolus over 10-20 minutes. If overcorrected, use D5W + DDAVP rescue protocol.

When to start antibiotics in meningitis?

Within 30-60 minutes. Do NOT delay antibiotics for LP or CT. Draw blood cultures, start empiric antibiotics (vancomycin + ceftriaxone ± ampicillin if > 50 or immunocompromised), then perform LP when possible. Dexamethasone should be given before or with the first antibiotic dose.

DOACs vs warfarin in antiphospholipid syndrome?

DOACs are contraindicated in APS. The TRAPS trial (2018) showed rivaroxaban was inferior to warfarin with more thrombotic events in triple-positive APS patients. Warfarin with INR target 2-3 is the standard for APS, indefinitely.

How to manage scleroderma renal crisis?

ACE inhibitors (captopril) are life-saving -start immediately and titrate aggressively. Do NOT hold for rising creatinine. Steroids > 15 mg prednisone per day precipitate scleroderma renal crisis. ARBs are NOT a substitute -evidence is only for ACEi.

What are the 4 pillars of heart failure treatment?

Guideline-directed medical therapy (GDMT) for HFrEF: (1) ARNI or ACEi/ARB, (2) beta-blocker (carvedilol, metoprolol succinate, or bisoprolol), (3) MRA (spironolactone or eplerenone), (4) SGLT2 inhibitor (dapagliflozin or empagliflozin). All four should be initiated and titrated to target doses.

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ECG Interpretation

A systematic approach to every ECG. Rate → rhythm → axis → intervals → ST-T changes. Learn the patterns that can kill -STEMI, hyperkalemia, PE, WPW, and long QT.

📐 Systematic ECG Reading

Step 1 -Rate

Regular rhythm: 300 ÷ (number of large boxes between R-R). Or: 300, 150, 100, 75, 60, 50 for 1, 2, 3, 4, 5, 6 large boxes.
Irregular rhythm: count QRS complexes in a 6-second strip (30 large boxes) × 10
Normal: 60–100 bpm. Bradycardia < 60. Tachycardia > 100.

Step 2 -Rhythm

Regular vs irregular? (march out R-R intervals with calipers or paper)
P waves present? Upright in II = sinus origin. Absent = Afib/junctional. Flutter waves (sawtooth) = Aflutter.
P:QRS relationship? 1:1 = sinus. More P's than QRS = AV block. No relationship = complete heart block.

Step 3 -Axis

Lead I	Lead aVF	Axis
↑	↑	Normal (−30° to +90°)
↑	↓	Left axis deviation (think: LAFB, LVH, inferior MI)
↓	↑	Right axis deviation (think: RVH, PE, LPFB, lateral MI)
↓	↓	Extreme/indeterminate (think: ventricular rhythm, lead misplacement)

Step 4 -Intervals

Interval	Normal	If Abnormal
PR	120–200 ms (3–5 small boxes)	Long (> 200): 1st degree AV block. Short (< 120): WPW (look for delta wave), junctional rhythm.
QRS	< 120 ms (3 small boxes)	120–150: incomplete BBB, IVCD. > 150: LBBB, RBBB. > 200: hyperkalemia, TCA OD, severe conduction disease.
QTc	M < 450 ms, F < 470 ms	> 500 ms: high risk for torsades de pointes. Causes: drugs (haloperidol, ondansetron, amiodarone, FQ), electrolytes (↓K, ↓Mg, ↓Ca), congenital LQTS.

Step 5 -ST Segment & T Waves

ST elevation: STEMI, pericarditis (diffuse + PR depression), Brugada, early repolarization, LV aneurysm
ST depression: ischemia (demand or NSTEMI), digoxin ("scooped"), LVH strain pattern, reciprocal changes
T wave inversion: ischemia, Wellens pattern (LAD critical stenosis), PE (right precordial), LVH strain, intracranial event (deep cerebral T waves)
Peaked T waves: hyperkalemia (#1), early STEMI (hyperacute T waves), benign early repolarization

⚡ Must-Know Patterns

Pattern	ECG Findings	Clinical Significance
Hyperkalemia progression	Peaked T waves → prolonged PR → loss of P waves → wide QRS → sine wave → VFib/asystole	Give calcium immediately if QRS widening. The most lethal ECG pattern you'll see. See Hyperkalemia.
STEMI	ST elevation ≥ 1 mm in ≥ 2 contiguous limb leads, or ≥ 2 mm in precordial leads. Reciprocal ST depression. See STEMI Criteria tab.	Cath lab activation.
De Winter T waves	Upsloping ST depression + peaked T waves in V1–V6. No ST elevation.	LAD STEMI-equivalent. Activate cath lab even without classic STE.
Wellens syndrome	Type A: biphasic T waves in V2–V3. Type B: deep symmetric T wave inversions in V2–V3.	Critical LAD stenosis. Patient may be pain-free when ECG obtained. Do NOT stress test → send to cath lab.
PE	Sinus tachycardia (#1), S1Q3T3 (not sensitive), right axis deviation, RBBB, right precordial T inversions (V1–V4), P pulmonale	ECG is often normal in PE. Most reliable sign: sinus tachycardia.
WPW	Short PR (< 120 ms) + delta wave (slurred QRS upstroke) + wide QRS	Avoid AV nodal blockers (adenosine, CCB, digoxin, BB) in Afib + WPW → can cause VFib. Use procainamide or cardioversion.
Brugada	Type 1: coved ST elevation > 2 mm + T wave inversion in V1–V3 (pseudo-RBBB).	Risk of sudden cardiac death. Unmasked by fever, Na-channel blockers. Treatment: ICD.
TCA overdose	QRS > 100 ms + R wave in aVR > 3 mm + right axis + sinus tachycardia	Sodium bicarbonate. QRS > 160 = VT risk. See Toxicology.
Complete heart block	Regular P waves marching through at one rate, QRS at a slower rate. No PR relationship. AV dissociation.	Transcutaneous pacing → transvenous pacing. Atropine may help if junctional escape (narrow QRS). Atropine does NOT work if infranodal block (wide QRS).
Pericarditis	Diffuse ST elevation (concave-up, "smiley face") + PR depression (best in II) + Spodick's sign (downsloping TP segment)	Distinguish from STEMI: diffuse (not territorial), PR depression, no reciprocal changes, concave-up morphology.

❤️ STEMI Localization

Territory	STE Leads	Reciprocal Δ	Coronary Artery	Complications
Anterior	V1–V4	II, III, aVF	LAD	LV dysfunction, CHF, VT/VF, anterior wall aneurysm
Lateral	I, aVL, V5, V6	III, aVF	LCx or diagonal	Mitral regurgitation (papillary muscle)
Inferior	II, III, aVF	I, aVL	RCA (85%) or LCx (15%)	Bradycardia, heart block (RCA supplies AV node). Check right-sided leads (V4R) for RV infarct.
RV infarct	V4R ≥ 1 mm STE	-	Proximal RCA	Preload-dependent → fluids, NO nitrates/diuretics/morphine.
Posterior	ST depression V1–V3 (mirror image) + tall R wave V1	-	PDA or LCx	Often missed. Get posterior leads (V7–V9): STE ≥ 0.5 mm confirms.

New LBBB is no longer an automatic STEMI-equivalent. Use Sgarbossa criteria: (1) concordant STE ≥ 1 mm = 5 pts, (2) ST depression ≥ 1 mm in V1–V3 = 3 pts, (3) discordant STE ≥ 5 mm = 2 pts (modified: use proportional ratio > 0.25 of preceding S wave). Score ≥ 3 → STEMI despite LBBB.