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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EmergentPulmonology

Pneumothorax

Air in the pleural space. Primary spontaneous (tall thin young male, no lung disease), secondary (COPD, CF), traumatic, or iatrogenic. Tension pneumothorax = clinical diagnosis → needle decompress, don't wait for CXR.

🔍 Overview

Types

Type	Cause	Key Features
Primary spontaneous (PSP)	Rupture of apical bleb/bulla in otherwise healthy lung	Tall, thin, young male, smoker. Usually small. Low recurrence after first episode (~30%), high after second (~50%).
Secondary spontaneous (SSP)	Underlying lung disease (COPD, CF, Pneumocystis, ILD, LAM)	More dangerous -limited pulmonary reserve. Even small PTX can cause significant compromise. Lower threshold for intervention.
Traumatic	Blunt/penetrating chest trauma, rib fractures	Chest tube. Evaluate for hemothorax (check pleural Hct).
Iatrogenic	Central line (subclavian > IJ), thoracentesis, lung biopsy, positive pressure ventilation	Post-procedure CXR. Small iatrogenic PTX in stable patient → may observe.
Tension	One-way valve effect → progressive air trapping → mediastinal shift → ↓ venous return → hemodynamic collapse	CLINICAL DIAGNOSIS: hypotension + JVD + absent breath sounds + tracheal deviation away. Needle decompression BEFORE imaging. 14–16G needle, 2nd ICS, midclavicular line (or 5th ICS, anterior axillary line).

Detailed Causes

The Types table above gives the high-level categories. The high-yield differential below is what to look for on history, imaging, and bedside evaluation.

Primary Spontaneous (no underlying lung disease)

Apical subpleural bleb rupture -most common. Tall, thin, young male; smoker (~20× risk).

Secondary Spontaneous: Obstructive Lung Disease

COPD / emphysema (bullae rupture) -most common cause of SSP. Older smoker. Even a small PTX is dangerous (no pulmonary reserve).
Severe asthma -during acute exacerbation. Concomitant pneumomediastinum possible.
Cystic fibrosis -young patient with recurrent infections and bronchiectasis. PTX is a poor prognostic sign.
Alpha-1 antitrypsin deficiency -young non-smoker (or modest smoker) with basal-predominant emphysema. Co-existing liver disease.

Secondary Spontaneous: Infectious

Pneumocystis jirovecii pneumonia (PCP) -HIV/AIDS or other immunocompromise. Can cause bilateral PTX. High recurrence.
Tuberculosis (cavitary) -endemic exposure, weight loss, night sweats, cavitary lesion on imaging.

Secondary Spontaneous: Cystic / Bullous

Lymphangioleiomyomatosis (LAM) -young woman of reproductive age with recurrent PTX. Tuberous sclerosis association, renal angiomyolipomas. Treat with sirolimus.

Secondary Spontaneous: Interstitial Lung Disease

Idiopathic pulmonary fibrosis (IPF) -late-stage disease with honeycombing. PTX heralds poor prognosis.

Secondary Spontaneous: Connective Tissue Disorders

Marfan syndrome (FBN1) -tall, arachnodactyly, lens dislocation, aortic root dilation. Apical blebs.
Ehlers-Danlos (vascular type, COL3A1) -hyperextensible skin, joint laxity. Vessel and organ rupture risk.

Secondary Spontaneous: Special

Catamenial pneumothorax (thoracic endometriosis) -right-sided, recurrent, within 24-72h of menses in reproductive-age women. Treat with hormonal suppression plus VATS.
Lung malignancy (primary or metastatic) -cavitary lesion erodes into pleura. Smoker, weight loss.

Traumatic

Blunt chest trauma -rib fracture lacerating pleura. MVC, fall, sports injury. Often associated with hemothorax.
Penetrating trauma -stab wound, gunshot. Open ("sucking") chest wound: cover with three-sided dressing.
Barotrauma -diving (rapid ascent without exhalation), blast injury. Concomitant air embolism risk.

Iatrogenic

Central line placement (subclavian > IJ) -~1-3% rate even with ultrasound guidance. Always get post-line CXR.
Thoracentesis / pleural drainage -~3% with US guidance, > 10% without.
CT-guided transthoracic needle biopsy -highest iatrogenic rate (~15-20%). Most resolve with observation alone.
Mechanical ventilation barotrauma -high PEEP, high tidal volumes, ARDS. Watch for progression to tension PTX, especially in patients with bullous disease.
CPR -rib fractures, occasionally direct pleural injury. Always check post-resuscitation CXR after prolonged or vigorous CPR.

High-yield clue patterns:

Tall thin young male, sudden pleuritic pain at rest: primary spontaneous (apical bleb).
Recurrent right-sided PTX in reproductive-age woman, around menses: catamenial / thoracic endometriosis.
Young woman with renal angiomyolipomas, recurrent PTX: LAM (check for tuberous sclerosis).
PTX + skin fibrofolliculomas + renal tumors: Birt-Hogg-Dubé.
HIV with bilateral PTX: PCP until proven otherwise.
Post-procedure PTX in a previously stable patient: recently placed line, biopsy, or thoracentesis.

🚨 Management

Management by Size and Type

Scenario	Management
Small PSP (< 2 cm at apex), stable	Observation + high-flow O₂ (accelerates reabsorption 4×). Repeat CXR in 4–6h. Discharge if stable and improving.
Large PSP (≥ 2 cm) or symptomatic	Needle aspiration (14–16G, 2nd ICS) → recheck CXR. If re-expands → observe. If fails → chest tube. BTS Guidelines, 2023: aspiration first-line for PSP.
SSP -any size	Chest tube (14–28 Fr) connected to water seal or low suction (−20 cmH₂O). These patients have no reserve. Do NOT just observe SSP.
Tension PTX	Immediate needle decompression → chest tube. Do not wait for CXR.
Recurrent PSP (≥ 2 episodes ipsilateral)	VATS with pleurodesis (mechanical or chemical). Recurrence after first: ~30%. After VATS: < 5%.

High-flow O₂ (15 L/min via non-rebreather) accelerates pneumothorax reabsorption by creating a nitrogen gradient -the pleural air (mostly N₂) is absorbed faster when alveolar N₂ is reduced. Speeds reabsorption from ~1.25%/day to ~5%/day.

📋 On Rounds

Why does high-flow O₂ speed pneumothorax reabsorption?

Pleural air is ~78% nitrogen. High-flow O₂ washes nitrogen out of the blood (by displacing it in the alveoli), creating a partial pressure gradient for N₂ between the pleural space and the capillary blood. This draws N₂ from the pleural collection into the bloodstream, where it's exhaled. The rate of reabsorption increases from ~1.25%/day to ~5%/day -approximately 4× faster.

When does a pneumothorax require a chest tube vs observation?

Tension PTX → immediate needle decompression (14–16G needle, 2nd intercostal space midclavicular line) followed by chest tube. Large PTX (> 2–3 cm at apex) or symptomatic → chest tube (14–16 Fr pigtail for PSP, 24–28 Fr for traumatic/secondary). Small PTX (< 2 cm), asymptomatic, primary spontaneous → observe 3–6 hours with repeat CXR. If stable → discharge with 24–48h follow-up CXR. Secondary PTX (in COPD, ILD, CF)

What is tension pneumothorax and how do you treat it before imaging?

Tension PTX is a CLINICAL DIAGNOSIS -do NOT wait for imaging. Mechanism: one-way valve effect → air enters pleural space with each breath but can't exit → progressive pressure buildup → mediastinal shift → IVC compression → obstructive shock. Signs: severe dyspnea, tachycardia, hypotension, absent breath sounds on affected side, tracheal deviation AWAY from affected side (late sign), distended neck veins, subcutaneous emphysema.

What is the Fleischner Society recommendation for incidentally detected pneumothorax?

Trick question -Fleischner is for pulmonary nodules, not pneumothorax. This is a common confusion. For pneumothorax management: BTS guidelines are the standard. Small primary spontaneous PTX (< 2 cm at hilum) + minimal symptoms → observation + supplemental O₂ + repeat CXR in 2-4h. If stable → discharge with 24-48h follow-up. Large (> 2 cm) or symptomatic → aspiration (with small-bore catheter) or chest tube. Secondary PTX (COPD, ILD, CF)

Clinical Examples

📋 Case 1, Primary Spontaneous Pneumothorax

Patient: 24M, tall and thin (6'3", 155 lb), sudden right-sided pleuritic chest pain while at rest. SpO₂ 96%. CXR: 25% right pneumothorax. Hemodynamically stable. No underlying lung disease.

Key findings: Primary spontaneous PTX, rupture of apical subpleural blebs in a classic demographic (tall, thin, young male, smoker). No underlying lung disease. Moderate size (> 2 cm at hilum).

Management:

Needle aspiration with small-bore catheter (14-16G, 2nd ICS MCL), first-line for large primary spontaneous PTX per BTS guidelines
If aspiration successful (lung re-expands on repeat CXR): observe 4-6h → discharge with 24-48h follow-up CXR
If aspiration fails: small-bore chest tube (12-14 Fr) with Heimlich valve or underwater seal
Supplemental O₂ (increases nitrogen gradient → accelerates pneumothorax reabsorption 4×)
Smoking cessation counseling (recurrence risk 30% if continues smoking vs 15% if stops)

Teaching point: Needle aspiration is first-line for primary spontaneous PTX, it's as effective as chest tube with less pain, shorter hospital stay, and fewer complications. Large-bore chest tubes are overused for simple pneumothoraces.

📋 Case 2, Secondary Pneumothorax in COPD

Patient: 68M with severe COPD (FEV1 28%). Acute worsening dyspnea. SpO₂ 82% on 2L NC (baseline 90%). CXR: left pneumothorax ~20%. HR 112, BP 108/68.

Key findings: Secondary spontaneous PTX in COPD, even a small PTX is dangerous because of minimal pulmonary reserve. BTS guidelines: ALL secondary PTX > 1 cm or symptomatic need intervention (lower threshold than primary).

Management:

Small-bore chest tube (12-14 Fr), not aspiration (higher failure rate in secondary PTX)
Connect to underwater seal with -20 cmH₂O suction
Admit to monitored bed (not discharge like primary PTX)
If persistent air leak > 5 days: thoracic surgery consult for VATS pleurodesis
Careful O₂ titration, target SpO₂ 88-92% (COPD CO₂ retainer risk)

Teaching point: Secondary PTX is always more dangerous than primary, the diseased lung cannot compensate. Threshold for intervention is lower (any symptomatic PTX), and these patients require admission, not outpatient management.

📋 Case 3, Recurrent Pneumothorax Requiring Pleurodesis

Patient: 28M with third right-sided spontaneous PTX in 2 years. Current episode: 35% PTX, managed with chest tube (resolved in 48h). Previous 2 episodes also required chest tubes.

Key findings: Recurrent ipsilateral PTX, after first episode, recurrence risk is ~30%. After second episode, ~50%. After third, > 80%. Definitive prevention is indicated.

Management:

VATS (video-assisted thoracoscopic surgery) with blebectomy + mechanical pleurodesis, gold standard for recurrent PTX
VATS: resect apical blebs + abrade parietal pleura → adhesion formation prevents recurrence (< 5% recurrence after VATS)
Alternative: chemical pleurodesis via chest tube (talc slurry) if not a surgical candidate
CT chest to assess bleb distribution before surgery
Absolute indication for pleurodesis: second ipsilateral PTX, first contralateral PTX (bilateral), occupational risk (pilots, divers)

Teaching point: Pleurodesis after second ipsilateral PTX is standard of care. VATS blebectomy + pleurodesis reduces recurrence from > 50% to < 5%. Pilots and scuba divers should have pleurodesis after FIRST episode due to occupational hazard.

📣 Sample Presentation

One-Liner

"Mr. Scott is a 22-year-old tall, thin male presenting with sudden right-sided pleuritic chest pain and dyspnea. CXR shows 30% right pneumothorax. Hemodynamically stable. SpO₂ 97%."

Key Points to Cover on Rounds

Primary spontaneous pneumothorax -classic demographics (tall, thin, young male). Large (30% at apex), symptomatic. Treatment: 14 Fr pigtail chest tube placed under US guidance, connected to water seal. Post-procedure CXR: lung re-expanded, no residual PTX. Air leak: resolved by 12h. O₂ applied (accelerates pleural nitrogen reabsorption). Plan: chest tube to water seal ×12h → if no recurrence on CXR → remove and observe ×6h → discharge if stable. Recurrence counseling: 30% chance of recurrence. If 2nd episode → VATS with pleurodesis. Avoid flying ×2 weeks, avoid scuba diving permanently.

🧪 Workup

Workup

See the Overview and Management tabs for the pneumothorax workup algorithm (CXR upright expiratory, CT chest for occult/loculated, CTA if PE suspected, ABG for oxygenation).

💊 Medications

Medications

Medication details (high-flow O₂ to accelerate air reabsorption, analgesia for chest tube, pleurodesis agents like talc/doxycycline for recurrent pneumothorax) are in the Management tab with evidence-based dosing.

⚡ Summary

Summary

Tension PTX

Clinical diagnosis -don't wait for imaging. Absent breath sounds, tracheal deviation, hypotension, JVD. Needle decompress immediately (2nd ICS MCL or 4th/5th ICS AAL).

Primary Spontaneous

Tall thin young male. Small (< 2cm) + minimal symptoms → observe + O₂ + repeat CXR. Large or symptomatic → aspiration or chest tube.

Secondary

COPD, ILD, CF, PCP. Lower threshold for intervention (these patients can't tolerate lung loss). All ≥ 1cm or symptomatic → chest tube + admit.

Chest Tube

14-28 Fr pigtail or surgical chest tube. Connect to water seal or suction. Post-procedure CXR. Remove when: no air leak + lung expanded on CXR × 12-24h.

Recurrence

30% after 1st episode, 60% after 2nd. After 2nd → VATS with pleurodesis (chemical or mechanical). Prevents recurrence.

Counseling

No flying × 2 weeks post-resolution. No scuba diving ever (unless pleurodesis performed). Return if sudden chest pain or dyspnea.

📄 One Pager

Pulmonology / Emergency · One Pager

Pneumothorax

Tension = clinical diagnosis → needle decompress immediately. Primary spontaneous: small → observe, large → aspiration/tube. Secondary: lower threshold for tube. Recurrence → VATS + pleurodesis.

🧪 Types

Primary spontaneous: tall thin young male, no lung disease. Secondary: COPD, ILD, CF, PCP (lower threshold for intervention -can't tolerate lung loss). Tension: one-way valve → obstructive shock.

🚨 Tension PTX -Don't Wait for Imaging

Absent breath sounds + tracheal deviation + hypotension + JVD. Needle decompress: 14-16G, 2nd ICS MCL or 4th/5th ICS AAL. Then chest tube. Clinical diagnosis -decompress first, image after.

💊 Management

Small primary (<2cm) + minimal symptoms → observe + O₂ + repeat CXR. Large/symptomatic → aspiration or chest tube (14-28 Fr pigtail). Remove tube when: no air leak + expanded on CXR × 12-24h.

💊 Key Drugs

Needle decompression14-16G, 2nd ICS MCL (tension)

Pigtail chest tube14 Fr (small catheter)

Supplemental O₂Accelerates reabsorption

Pain controlOpioids/NSAIDs as needed

⚠️ Pitfalls

Waiting for CXR in tension PTX (clinical diagnosis → decompress)
Discharging without recurrence counseling (30% after 1st episode)
Not admitting secondary PTX (these patients decompensate quickly)
Flying within 2 weeks (risk of re-expansion)