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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EMERGENTCardiology

Aortic Dissection

Tear in the aortic intima with blood tracking into the media. Stanford A (ascending) = surgical emergency with ~1% mortality per hour untreated. Stanford B (descending) = medical management unless complicated. HR and BP control are immediate priorities.

🔍 Overview

Stanford Classification

Type	Involvement	% of Cases	Mortality (Untreated)	Treatment
Stanford A	Ascending aorta (± descending)	~60%	~1–2% per hour for first 48h	Emergent surgery. Call CT surgery immediately. IRAD Registry, Hagan 2000
Stanford B	Descending aorta only (distal to L subclavian)	~40%	~10% at 30 days	Medical management (BP + HR control). Surgery/TEVAR only if complicated.

Any dissection involving the ascending aorta = Type A = surgery. It doesn't matter if it also extends into the descending aorta -ascending involvement dictates management.

Presentation

"Tearing" or "ripping" chest/back pain -acute onset, maximal at onset (unlike MI which crescendos), may migrate as dissection propagates
BP differential > 20 mmHg between arms -dissection flap compromising subclavian
Pulse deficit -absent or diminished pulses in one limb
Aortic regurgitation murmur (Type A -flap disrupts aortic valve)
Stroke symptoms (carotid involvement), ACS/STEMI (coronary involvement), paraplegia (spinal artery), mesenteric ischemia, AKI (renal artery)

Classic pitfall: Type A dissection involving the RCA → inferior STEMI on ECG. If you give tPA or anticoagulate for "MI," the patient bleeds into the pericardium → tamponade → death. Always consider dissection before treating STEMI, especially with tearing pain, pulse deficits, or widened mediastinum.

Diagnosis

Test	Role
CTA chest/abdomen/pelvis TEST OF CHOICE	Sensitivity > 95%. Shows intimal flap, true vs false lumen, extent, branch vessel involvement. Get with arterial phase + delayed phase.
TEE (transesophageal echo)	If too unstable for CT. Can be done at bedside / in OR. Excellent for Type A. Limited for distal descending.
CXR	Widened mediastinum (~60% sensitivity -absence does NOT rule out dissection). May see left pleural effusion.
D-dimer	Elevated in > 95% of dissections. Negative D-dimer has high NPV -can help rule out in low-pretest probability. Not reliable alone.

🚨 Management

Immediate -All Dissections

HR first, then BP. Dropping BP without slowing HR increases aortic wall shear stress (dP/dt) and propagates the dissection.

Step 1 -HR Control

IV beta-blocker first. Target HR < 60 bpm. Esmolol 500 mcg/kg bolus → 50–200 mcg/kg/min (preferred -ultra-short acting, titratable). Or labetalol 20 mg IV q10 min. Must control HR BEFORE adding vasodilators.

Step 2 -BP Control

Target SBP 100–120 mmHg. If BB alone insufficient → add nicardipine 5–15 mg/hr or nitroprusside 0.3–5 mcg/kg/min (only AFTER HR controlled). Clevidipine is another option (ultra-short acting CCB).

Pain Control

IV morphine or fentanyl. Pain drives sympathetic response → HR/BP elevation → propagation. Aggressive pain control is part of the treatment.

Type A -Surgical Emergency

Emergent CT surgery consult -do not delay for any reason
Ascending aorta replacement ± aortic valve repair/replacement ± coronary reimplantation
Mortality without surgery: 50% at 48h. With surgery: 15–25%.
Tamponade → emergent pericardiocentesis as bridge to OR (limited drainage -just enough to restore perfusion)

Type B -Medical Management

Uncomplicated Type B: BP/HR control + pain management + ICU monitoring. Long-term oral BB + amlodipine. Repeat imaging at 48–72h, 1 month, 6 months, then annually. INSTEAD-XL, Nienaber 2013 ADSORB, Brunkwall 2014
Complicated Type B (malperfusion, rupture, refractory pain, rapid expansion) → TEVAR (thoracic endovascular aortic repair) or open surgery.

Medications

Drug (Brand)	Dose	Role
Esmolol (Brevibloc) 1ST LINE	500 mcg/kg bolus → 50–200 mcg/kg/min	Preferred BB -ultra-short t½ (9 min), highly titratable. Stops fast if complications.
Labetalol (Trandate) 1ST LINE	20 mg IV q10 min (max 300 mg) or 1–2 mg/min drip	α + β blocker. Good alternative if esmolol drip unavailable. Longer acting.
Nicardipine (Cardene) ADD-ON	5–15 mg/hr IV	Add if BP not at target despite BB. Do NOT use alone without BB.
Nitroprusside (Nipride) ADD-ON	0.3–5 mcg/kg/min	Potent vasodilator. Only use AFTER HR controlled -reflex tachycardia worsens shear stress. Cyanide toxicity > 48h.

📋 On Rounds

Why must you control HR before BP in aortic dissection?

dP/dt (the rate of rise of aortic pressure) is the primary driver of dissection propagation -not the absolute BP alone. Vasodilators (like nitroprusside) that drop BP without slowing HR cause reflex tachycardia, which paradoxically increases dP/dt and wall shear stress, potentially extending the dissection. Beta-blockers reduce both HR and contractility, lowering dP/dt. Always achieve HR < 60 first, then add vasodilators if needed for BP.

A patient presents with inferior STEMI and tearing chest pain radiating to the back. What should you think?

Type A aortic dissection involving the right coronary artery. The dissection flap can occlude the RCA ostium → inferior STEMI. If you give tPA, heparin, or dual antiplatelets for a "primary MI," the patient bleeds into the false lumen or pericardium → tamponade → death. Always consider dissection when STEMI presents with atypical features: tearing/migratory pain, pulse deficits, wide mediastinum, or new aortic regurgitation murmur.

Why is the target HR < 60 in aortic dissection, and why do you start a beta-blocker before a vasodilator?

HR and dP/dt (the rate of rise of aortic pressure) are the main determinants of aortic wall shear stress. The faster the heart beats and the harder it contracts, the more force is applied to the dissection flap → propagation. Beta-blockers reduce both HR and contractility (dP/dt) -esmolol IV is first-line (short-acting, titratable). You must start the BB BEFORE any vasodilator (e.g., nicardipine)

How do you differentiate Stanford Type A from Type B, and why does it change everything?

Type A: involves the ascending aorta (regardless of where the tear starts) → SURGICAL EMERGENCY. Mortality increases 1-2% per hour without surgery. Complications: aortic regurgitation, tamponade, coronary malperfusion (MI), stroke. Type B: involves only the descending aorta (distal to left subclavian) → medical management (HR/BP control). Surgery only if complicated (malperfusion, rupture, refractory pain, rapid expansion).

Clinical Examples

📋 Case 1, Type A Dissection with Tamponade

Patient: 58M, HTN and Marfan syndrome, presents with acute tearing chest pain radiating to back. Appears pale and diaphoretic.

Key findings: BP 180/110 right arm, 145/90 left arm (pulse deficit). HR 110. JVD, distant heart sounds, new diastolic murmur (AR). CTA: Stanford Type A dissection from aortic root to descending aorta. Pericardial effusion. Troponin elevated (RCA involvement).

Management:

Esmolol 500 mcg/kg bolus then drip, target HR < 60 FIRST
Then add nicardipine drip for SBP target < 120
EMERGENT cardiac surgery consult, Type A = surgical emergency (mortality 1-2%/hour without surgery)
Type and crossmatch 6 units pRBC, FFP, platelets available
Do NOT give tPA or anticoagulation despite troponin elevation (would be fatal)

Teaching point: Type A dissection with pericardial effusion = blood tracking into the pericardium. This patient has a triad of dissection + tamponade + aortic regurgitation. The inferior STEMI pattern is from RCA ostial involvement by the dissection flap. If sent to cath lab for "STEMI," the anticoagulation will be catastrophic.

📋 Case 2, Uncomplicated Type B Dissection

Patient: 64M, longstanding uncontrolled HTN (non-adherent), cocaine use. Presents with severe interscapular pain of sudden onset.

Key findings: BP 228/124, HR 96. No pulse deficits. Cr 1.3 (baseline). Lactate normal. CTA: Stanford Type B dissection from left subclavian to celiac trunk. No malperfusion.

Management:

Esmolol drip, HR to < 60 first, then nicardipine for SBP 100-120
IV morphine for pain control (pain drives sympathetic surge → worsens shear stress)
Uncomplicated Type B = medical management (HR/BP control)
Serial imaging (CTA in 48-72h, then 1, 3, 6, 12 months)
Transition to oral labetalol + amlodipine when stable x 24h on drip

Teaching point: Uncomplicated Type B dissection is managed medically. Surgery only if complicated: malperfusion, rupture, refractory pain, or rapid expansion. INSTEAD-XL, 2013 showed benefit of TEVAR for uncomplicated Type B only at 5 years, not acutely.

📋 Case 3, Type B with Mesenteric Malperfusion

Patient: 71F, HTN and DM2, initially managed medically for Type B dissection. 18 hours after admission, develops severe abdominal pain, bloody diarrhea, and rising lactate.

Key findings: Lactate 6.2 (was 1.1 on admission). Cr rising from 1.3 to 2.8. CT angiography: true lumen compression with SMA involvement. Absent bowel peristalsis.

Management:

This is NOW a complicated Type B, emergent intervention required
Vascular surgery / interventional radiology for TEVAR ± SMA stenting
Continue aggressive HR/BP control
NPO, NG tube, broad-spectrum antibiotics for possible bowel ischemia
Monitor for bowel necrosis (may require exploratory laparotomy if peritonitis develops)

Teaching point: Malperfusion syndrome converts uncomplicated to complicated Type B and mandates urgent intervention. Rising lactate + end-organ dysfunction in a patient with known dissection should trigger immediate reimaging and surgical/IR consultation. Mesenteric ischemia from dissection carries mortality > 50% without intervention.

📣 Sample Presentation

One-Liner

"Mr. Franklin is a 62-year-old with longstanding uncontrolled HTN presenting with acute tearing chest pain radiating to the back. BP 210/120 in right arm, 168/95 in left. CTA shows Stanford type B aortic dissection extending from left subclavian to celiac trunk."

Key Points to Cover on Rounds

Stanford type B (descending) -medical management. HR 58 on esmolol drip (target <60). SBP 118 on nicardipine drip (target 100-120). No malperfusion signs: renal function stable, bowels functioning, distal pulses symmetric. CT surgery aware -no surgical indication currently. Pain controlled with IV morphine. Plan: transition to oral BB + amlodipine when stable ×24h, serial imaging.

Monitoring -Aortic Dissection

Arterial line -continuous BP monitoring mandatory. SBP target 100-120 mmHg.
HR q5-15 min during drip titration. Target HR <60 bpm.
Urine output hourly -renal malperfusion if declining.
Neuro checks q1-2h -carotid extension (stroke, altered mental status).
Distal pulses q2-4h -bilateral radial, femoral, DP. New deficit = malperfusion.
Serial CTA -if conservative management. 48-72h, then 1-2 weeks, 1/3/6/12 months.

🧪 Workup

Diagnostic Evaluation -Aortic Dissection

Time-critical diagnosis. Type A dissection mortality increases 1-2% per hour without surgery. Do NOT delay imaging for labs.

Test	Findings	Clinical Significance
CTA chest/abdomen/pelvis GOLD STANDARD	Intimal flap, true/false lumen, extent of dissection, branch vessel involvement	Sensitivity >95%. Defines Stanford type (A vs B), extent, malperfusion. Get full aorta (chest through pelvis).
CXR	Widened mediastinum (>8 cm), abnormal aortic contour, left pleural effusion	Insensitive (~60%) but may be first clue. Normal CXR does NOT rule out dissection.
Type & Screen	-	Prepare for potential emergent surgery. Crossmatch if Type A.
CBC	H/H for baseline	Serial Hgb to monitor for hemorrhage. Leukocytosis common (stress response).
BMP	Cr (baseline), electrolytes	Renal function -renal artery malperfusion? Baseline before contrast.
Coags (PT/INR, aPTT)	Baseline coagulation	Pre-surgical assessment. DIC can develop with extensive dissection.
Troponin	May be elevated	Coronary malperfusion (Type A extending into coronary ostia → STEMI mimic). Also consider concurrent ACS.
Lactate	Elevated if malperfusion	Mesenteric ischemia, limb ischemia, shock. Rising lactate = urgent surgical indication.

💊 Medications

Key Medications -Aortic Dissection

HR first, THEN BP. Always achieve heart rate control before adding vasodilators. Pure vasodilators without beta-blockade cause reflex tachycardia, increasing aortic shear stress and propagating the dissection.

Drug	Dose	Route	Notes
Esmolol (Brevibloc) 1ST LINE -HR	500 mcg/kg bolus, then 50-200 mcg/kg/min drip	IV	Target HR <60 bpm FIRST. Ultra-short half-life (9 min) -easily titratable. Preferred initial agent.
Nicardipine (Cardene) ADD FOR BP	5-15 mg/hr IV drip	IV	Add AFTER beta-blocker for SBP target <120 mmHg. Smooth arterial vasodilator. No reflex tachycardia when BB already on board.
Labetalol (Trandate) ALTERNATIVE	20 mg IV bolus, then 1-2 mg/min drip	IV	Combined alpha + beta blockade. Alternative to esmolol + nicardipine. Less titratable than esmolol.
Nitroprusside ADJUNCT ONLY	0.25-10 mcg/kg/min	IV	NEVER without prior beta-blockade. Potent vasodilator -reflex tachycardia worsens dissection. Cyanide toxicity risk with prolonged use.
IV Morphine	2-4 mg IV q5-15min PRN	IV	Pain control is critical -pain drives sympathetic surge → elevated HR/BP. Reduces shear stress.

Avoid: pure vasodilators (hydralazine, nitroprusside) without beta-blockade. Avoid anticoagulation until dissection is excluded or surgical plan is defined.

⚡ Summary

Summary

Type A

Ascending aorta involved → SURGICAL EMERGENCY. Mortality 1-2%/hr without surgery. Call CT surgery immediately.

Type B

Descending only → Medical management. HR < 60 + SBP 100-120. Surgery only if complicated (malperfusion, rupture).

First Drug

Esmolol IV (BB before vasodilator). Reduce HR first, then BP. Vasodilators alone → reflex tachycardia → worsens dissection.

Imaging

CTA chest/abdomen/pelvis. If CTA unavailable → TEE. CXR may show widened mediastinum but is insensitive.

Suspect When

Tearing chest/back pain + BP differential between arms + unequal pulses + history of HTN or Marfan.

Malperfusion

Stroke (carotid), MI (coronary), bowel ischemia (mesenteric), renal failure (renal), limb ischemia (iliac).

📄 One Pager

Cardiology / Vascular · One Pager

Aortic Dissection

Tearing pain + BP differential + unequal pulses. Type A = surgery NOW. Type B = HR < 60 + SBP 100-120. BB before vasodilators.

🧪 Classification

Stanford Type A: ascending aorta involved → SURGICAL EMERGENCY
Stanford Type B: descending only (distal to L subclavian) → medical management
DeBakey I: ascending + descending. II: ascending only. III: descending only
Mortality: Type A = 1-2%/hour without surgery

🚨 Immediate Management

Esmolol IV first (BB before vasodilator)
Target HR < 60, then SBP 100-120
Add nicardipine AFTER HR controlled
Type A → CT surgery emergently
Type B → ICU, medical management, serial imaging

⚠️ Malperfusion Syndromes

Stroke (carotid dissection)
MI (coronary ostia involvement)
Mesenteric ischemia (celiac/SMA)
Renal failure (renal artery)
Limb ischemia (iliac)
Spinal cord ischemia (artery of Adamkiewicz)

💊 Key Drugs

Esmolol500 mcg/kg bolus → 50-200 drip

Nicardipine5-15 mg/hr drip

Labetalol20 mg IV → drip alternative

PainIV morphine/fentanyl

⚠️ Pitfalls

Vasodilator before BB (reflex tachy worsens dissection)
Delaying CTA for other workup
Missing Type A -always scan the ascending aorta
Thrombolytics for "STEMI" that is actually dissection