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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EmergentEM

Hypothermia & Drowning

Core temp < 35°C. Mild (32–35°C): shivering. Moderate (28–32°C): loss of shivering, confusion, Osborn waves. Severe (< 28°C): VF risk, appears dead. Warm before declaring death. Active rewarming for moderate-severe.

🔍 Overview

Classification

Severity	Temp Range	Key Features	Treatment
Mild	32–35°C	Shivering, tachycardia, vasoconstriction, altered judgment	Passive external rewarming (blankets, warm room). Remove wet clothing.
Moderate	28–32°C	Shivering stops, confusion→stupor, bradycardia, Osborn (J) waves on ECG, atrial fibrillation	Active external rewarming (Bair Hugger, warm packs to axillae/groin). Warm IV fluids 40–42°C.
Severe	< 28°C	Coma, areflexia, VF risk, fixed dilated pupils, appears dead	Active core rewarming (warm humidified O₂, peritoneal/pleural lavage, ECMO). Withhold meds until ≥ 30°C.
Profound	< 24°C	Asystole, no vital signs. May still be salvageable with rewarming.	ECMO/cardiopulmonary bypass (gold standard). Prolonged CPR. Do NOT declare death.

"No one is dead until they are warm and dead." Do NOT declare death until core temp ≥ 32°C and rewarming efforts have failed. Hypothermia is neuroprotective -full recovery has occurred after prolonged cold-water submersion.

🚨 Management

Rewarming Strategies

Method	Indication	Rate of Rewarming
Passive external (blankets, warm room, remove wet clothes)	Mild hypothermia (32–35°C). Patient can generate heat via shivering.	0.5–2°C/hr
Active external (Bair Hugger, warm packs to axillae/groin)	Moderate hypothermia (28–32°C). Shivering lost, patient cannot self-rewarm.	1–2°C/hr
Warm IV fluids (NS/LR at 40–42°C)	Moderate–severe. Adjunct to other rewarming methods.	Modest contribution (~0.5°C/hr alone)
Warm humidified O₂ (42–46°C via ETT or NRB)	Moderate–severe. Active core rewarming adjunct.	1–1.5°C/hr
Peritoneal/pleural lavage (42°C warm saline)	Severe (< 28°C) when ECMO unavailable. More effective than bladder lavage.	2–4°C/hr
ECMO / cardiopulmonary bypass	Severe hypothermic cardiac arrest. Gold standard.	5–10°C/hr

Cardiac Arrest in Hypothermia

ECMO/CPB -gold standard rewarming for VF arrest in hypothermia. Rewarms at 5–10°C/hr.
Continue CPR -may need prolonged resuscitation
Defibrillation: May attempt up to 3 shocks if temp < 30°C. If unsuccessful, defer further shocks until core temp ≥ 30°C.
Medications: Withhold vasopressors and antiarrhythmics until core temp ≥ 30°C (drugs don't work and accumulate in cold circulation)

Drowning Management

Rescue breathing is the priority -drowning is a hypoxic event. Begin ventilation as soon as possible, even in the water if safe.
Cervical spine precautions -maintain inline stabilization if diving injury, trauma, or mechanism suggests c-spine injury. However, routine c-spine immobilization in all drowning victims is NOT supported.
Warm IV fluids -most drowning victims are hypothermic. Start warm NS/LR (40–42°C). Treat concomitant hypothermia aggressively per rewarming protocols above.
Pulmonary edema -watch for delayed pulmonary edema 24–48 hours post-submersion. Aspirated water disrupts surfactant and damages alveolar epithelium. CXR may be initially normal but deteriorate.
Freshwater vs saltwater -freshwater is hypotonic (washes out surfactant, absorbed into circulation). Saltwater is hypertonic (pulls fluid into alveoli). Clinical management is the same for both.
Prognostication:
- Submersion time -strongest predictor. > 25 min submersion in warm water = very poor prognosis.
- Water temperature -cold water (< 6°C) is neuroprotective. Full neurologic recovery reported after > 60 min submersion in ice water (especially children).
- Age -children have better outcomes than adults due to higher surface-area-to-body-mass ratio → faster cooling → more neuroprotection.
- CPR duration and initial rhythm -faster ROSC = better outcome. VF is better than asystole.

Cold-water drowning in children: Aggressive rewarming and prolonged resuscitation are warranted. The combination of rapid cooling + diving reflex can provide profound neuroprotection. Do not stop early.

🧪 Workup

Core temperature -rectal or esophageal probe (NOT oral/tympanic -inaccurate in hypothermia)
ECG -Osborn (J) waves, prolonged intervals, atrial fibrillation, VF
ABG -pH interpretation complex (use temperature-corrected values)
BMP -hyperkalemia (cell lysis), hypoglycemia
CBC, coags (hypothermia causes coagulopathy)
Lactate
TSH, cortisol -rule out myxedema/adrenal crisis as cause

💊 Medications

Intervention	Details	Notes
Warm IV NS/LR (40–42°C)	250–500 mL boluses	Use fluid warmer. Contributes modestly to rewarming.
Warm humidified O₂	42–46°C via ETT or NRB	Active core rewarming adjunct
Warm bladder lavage	42°C NS via 3-way Foley	Moderate core rewarming
Warm peritoneal lavage	42°C NS via peritoneal catheter	More effective than bladder lavage
ECMO	Venoarterial (VA-ECMO)	Gold standard for severe hypothermic cardiac arrest. Rewarms 5–10°C/hr.

Withhold IV medications until core temp ≥ 30°C. Drugs are ineffective in cold circulation, don't metabolize, and accumulate → risk of toxicity when patient rewarms.

📋 On Rounds

Pimp Questions

What are Osborn (J) waves?

Positive deflection at the J point (junction of QRS and ST segment) on ECG, pathognomonic for hypothermia. Appear at core temp < 32°C, increase in amplitude as temperature drops. Also called "J waves" or "hypothermic hump." Resolve with rewarming. Not an indication for anti-arrhythmic therapy.

Why is K⁺ > 12 mEq/L considered non-survivable in hypothermia?

Severe hyperkalemia (> 12) in hypothermia indicates massive cell lysis and tissue death -the cells have been irreversibly damaged by ice crystal formation. This level of intracellular potassium release means the patient likely has extensive organ damage incompatible with survival, even with successful rewarming. It is one of the few criteria used to guide termination of resuscitation in hypothermic arrest.

📋 Case 1, Moderate Hypothermia (Found Down)

Patient: 78M found on his kitchen floor by a neighbor. Last seen well 18 hours ago. Confused, minimally responsive. Temp: 30.1°C (rectal). HR 38 (bradycardia). BP 88/54. RR 8.

ECG: Sinus bradycardia with Osborn (J) waves at the J-point. QTc prolonged. No VF.

Labs: K⁺ 5.8, glucose 48 (hypoglycemic), lactate 3.2, TSH pending, cortisol pending.

Management:

Remove all wet/cold clothing. Dry skin. Wrap in warm blankets.
Active external rewarming: Bair Hugger forced-air warming blanket. Warm packs to axillae and groin (high-flow areas). Target: rewarm the trunk first.
Warm IV fluids: NS at 40–42°C via fluid warmer, 250–500 mL bolus. Correct hypoglycemia with D50W.
Do NOT treat bradycardia or AF with medications, the arrhythmia is from hypothermia and will resolve with rewarming.
Check TSH and cortisol, hypothyroidism and adrenal insufficiency are precipitating causes of hypothermia in the elderly.
K⁺ 5.8: Monitor closely. Expected to improve with rewarming. K⁺ >12 = non-survivable (massive cell lysis); K⁺ 5.8 is compatible with survival.
Serial core temps q1h (esophageal or rectal probe) and continuous telemetry during rewarming.

Teaching point: In elderly patients found down, always measure core temperature. Oral/tympanic temps are unreliable, use rectal or esophageal probe. Check TSH and cortisol; hypothyroidism is a classic precipitant of hypothermia in the elderly.

📋 Case 2, Severe Hypothermia with VF Arrest

Patient: 32M found unresponsive in a snowbank by ski patrol. No pulse, no respirations. Estimated outdoor exposure 2+ hours. Initial core temp: 24°C.

In the field: CPR initiated immediately. AED delivered 1 shock, rhythm remained VF. Patient transported to ED with ongoing CPR.

In the ED:

Confirm core temperature with esophageal probe: 24°C, profound hypothermia
Continue CPR, do not stop. Hypothermia is neuroprotective; viable patients have been resuscitated after >6 hours of CPR.
Attempt defibrillation × 3 total (have already done 1 in field). If unsuccessful at <30°C, defer further shocks until core temp ≥30°C.
Withhold epinephrine and amiodarone until core temp ≥30°C, drugs accumulate and are ineffective in cold circulation.
ACTIVATE ECMO TEAM STAT, VA-ECMO is the gold standard for hypothermic cardiac arrest. Can rewarm at 5–10°C/hr.
K⁺: 7.2, compatible with survival. Proceed with rewarming.
ECMO initiated. Core temp rises over 90 minutes to 32°C → spontaneous ROSC, VF terminates. Patient extubated day 3. Full neurologic recovery.

Teaching point: K⁺ >12 mEq/L = non-survivable (massive cell lysis). This patient's K⁺ 7.2 meant the cells were still viable, aggressive ECMO rewarming was warranted. "No one is dead until warm and dead."

📋 Case 3, Cold-Water Drowning in a Child

Patient: 7F falls through ice on a frozen pond. Submerged approximately 45 minutes before rescue. Core temp on EMS arrival: 22°C. No pulse. Pupils fixed and dilated. Cyanotic.

EMS: CPR initiated. Bystanders attempted rescue within 5 minutes of submersion.

ED Management:

Core temp 22°C, do NOT declare death. "No one is dead until warm and dead."
Fixed dilated pupils, absent reflexes: all expected findings at this temperature. Do not use these as markers of irreversibility in hypothermia.
ECMO activation, VA-ECMO for hypothermic cardiac arrest. Children have better outcomes than adults (faster cooling via diving reflex + higher surface-area-to-mass ratio).
Warm via ECMO, core temp rises to 36°C over 2 hours. ROSC at core temp 30°C (sinus bradycardia → normal sinus rhythm with rewarming).
Post-resuscitation care: Targeted temperature management at 33–36°C × 24h. ICU monitoring. Neurologic exam serially.
Day 5: Extubated. Neurologically intact. Discharged day 10.

Teaching point: The mammalian diving reflex + rapid hypothermic cooling in ice water provides profound neuroprotection in children. The protective combination: apnea + bradycardia + peripheral vasoconstriction + near-freezing temperatures drops oxygen consumption to near zero. Full neurologic survival after prolonged submersion is well-documented in pediatric cold-water drowning, never stop early.

⚡ Summary

Classification

Mild 32-35°C (shivering). Moderate 28-32°C (no shivering, J waves). Severe <28°C (VF, coma).

Golden Rule

"No one is dead until warm and dead." Do not declare death until core temp ≥ 32°C.

Rewarming

Mild: passive. Moderate: Bair Hugger, warm IV. Severe: ECMO (gold standard for arrest).

Cardiac Arrest

Continue CPR. Max 3 shocks if <30°C, defer more until ≥30°C. Withhold meds until ≥30°C.

K⁺ Prognostic

K⁺ > 12 mEq/L = non-survivable (massive cell lysis). Serial K⁺ guides resuscitation.

Afterdrop

Core temp drops further after rescue -cold peripheral blood returns to core. Rewarm core first.