Blood Gas Analysis  ·  Acid-Base  ·  Electrolytes

ABG & Electrolyte Manager – Interpret Blood Gases & Manage Ion Disorders

ABG interpretation and electrolyte management are core skills in critical care medicine. Our comprehensive ABG & Electrolyte Manager helps clinicians interpret blood gas values (pH, PaCO2, HCO3), apply Winter's formula for metabolic acidosis, diagnose respiratory and metabolic acid-base disorders, and manage electrolyte abnormalities (hyperkalemia, hyponatremia, hypocalcemia, hypomagnesemia). Evidence-based treatment protocols with precise dosing for acute and chronic disorders. Free access for ICU, ER, and critical care professionals.

Analyze ABG Now
Winter's Formula included ICU-tested protocols Acute & chronic dosing
Dual Interpretation Engine

Master ABG Analysis & Electrolyte Disorders

Two integrated tools in one: interpret blood gases with Winter's formula, then manage common electrolyte emergencies with evidence-based dosing.

🧬

ABG Interpretation

Enter pH, PaCO2, HCO3. Get primary disorder (respiratory/metabolic), alkalosis/acidosis, expected compensation, anion gap assessment.

🔢

Winter's Formula

Automatic Winter's Formula calculation for metabolic acidosis to determine if respiratory compensation is appropriate.

⚗️

Electrolyte Disorders

Manage hyperkalemia, hypokalemia, hyponatremia, hypernatremia, hypocalcemia, hypercalcemia, hypomagnesemia with acute/chronic protocols.

💊

Treatment Dosing

Precise dosing for calcium gluconate, potassium chloride, sodium bicarbonate, dextrose, and magnesium sulfate with rates and monitoring.

📊

Anion Gap Analysis

Calculate anion gap, identify MUDPILES causes, assess high or normal gap metabolic acidosis, guide differential diagnosis.

🏥

Acute/Chronic Assessment

Distinguish acute vs. chronic electrolyte disorders. Different treatment approaches for symptomatic vs. chronic asymptomatic hyponatremia.

How ABG Works

Systematic ABG Interpretation & Electrolyte Management

Step-by-Step ABG Interpretation

ABG interpretation requires systematic analysis: assess oxygenation, pH, primary acid-base disorder, appropriate respiratory compensation, anion gap, and electrolytes.

Step 1: Check Oxygenation (PaO2)

Normal: 80-100 mmHg on room air. Low <60 indicates hypoxemia (respiratory disease, cardiac R→L shunt, altitude). High >100 on room air suggests hyperventilation or supplemental O2.

Step 2: Determine Acidemia vs. Alkalemia (pH)

pH <7.35 = Acidemia | pH >7.45 = Alkalemia | 7.35-7.45 = Normal

Step 3: Identify Primary Disorder

Respiratory Acidosis: pH <7.35 + PaCO2 >45 (retention from COPD, respiratory depression, hypoventilation). Metabolic Acidosis: pH <7.35 + HCO3 <22 (lactic acidosis, DKA, RTA, diarrhea). Check anion gap.

Respiratory Alkalosis: pH >7.45 + PaCO2 <35 (hyperventilation, PE, sepsis, anxiety). Metabolic Alkalosis: pH >7.45 + HCO3 >26 (vomiting, diuretics, contraction alkalosis).

Step 4: Winter's Formula for Expected Compensation

In metabolic acidosis: Expected PaCO2 = 1.5 × [HCO3] + (8 ± 2) | Example: HCO3 = 10 → Expected PaCO2 = 1.5(10) + 8 = 23 ± 2 (range 21-25). If actual PaCO2 ≥ expected, concurrent respiratory acidosis (inadequate respiratory response). If actual < expected, concurrent respiratory alkalosis (excessive hyperventilation).

Step 5: Anion Gap Calculation

AG = [Na] − ([Cl] + [HCO3]) | Normal: 8-12 mEq/L | High AG (>12) = MUDPILES causes (Methanol, Uremia, DKA, Propylene glycol, Isoniazid, Lactic acidosis, Ethylene glycol, Salicylates). Normal AG acidosis = diarrhea, RTA, ureteral diversions.

Electrolyte Disorder Management

Disorder Normal Range Acute Treatment Monitoring
Hyperkalemia (K>5.5) 3.5-5 mEq/L Ca gluconate 10% 10 mL IV (cardiac membrane stabilizer), then insulin 10 U + D50W 25 mL IV, albuterol neb, sodium polystyrene 15-30g PO ECG, K+ q1h, EKG for peaked T waves, QRS widening
Hypokalemia (K<3.5) 3.5-5 mEq/L KCl 20-40 mEq/L IV in saline at 10 mEq/hr (max), or 20-40 mEq PO daily divided. Recheck q4-6h. Faster replacement if ECG changes. K+ q4-6h, ECG for flattened T, U waves, ST depression. Assess Mg (need correction for K repletion)
Hyponatremia (Na<135) 135-145 mEq/L Acute symptomatic: 3% NaCl IV at 4 mL/kg + furosemide. Chronic: Fluid restrict 800 mL/day, correct at 8-10 mEq/L/day max. Goal: 125-130 mEq/L if severe (seizures, altered mental status) Na+ q2h (acute), q4-6h (chronic). Watch for osmotic demyelination if correct >12 mEq/L/day
Hypernatremia (Na>145) 135-145 mEq/L Free water replacement: D5W IV or hypotonic saline (½ NS). Calculate deficit = 0.6 × weight × (Na − 140)/140. Correct over 24-48h. Concurrent hypovolemia: use NS first, then switch to free water. Na+ q4-6h. Correct at 8-10 mEq/L/day max to avoid cerebral edema
Hypocalcemia (Ca<8.5) 8.5-10.2 mg/dL (corrected) Symptomatic (tetany, seizures): Ca gluconate 10% 10-20 mL IV over 5-10 min (recheck q5-10min). Chronic: 1,000 mg elemental Ca + Vit D daily PO Ca2+ q1h, Mg (often low together), phos, ECG (prolonged QT)
Hypomagnesemia (Mg<1.7) 1.7-2.2 mg/dL MgSO4 1-2 g IV over 1 hour, or 4-8 g PO daily divided (causes diarrhea). Mild: PO replacement preferred Mg q4-6h. Note: K+ won't replicate without Mg repletion

Acute vs. Chronic Assessment

Acute disorders (<48 hours): Treat aggressively to normalize levels quickly. Symptomatic patients require urgent intervention (seizures in hyponatremia, arrhythmias in hypo/hyperkalemia). Risk of overcorrection lower.

Chronic disorders (>48 hours): Slower correction (8-10 mEq/L/day) to avoid osmotic complications. Example: chronic hyponatremia corrected too fast → osmotic demyelination syndrome (central pontine myelinolysis). Chronic hyperkalemia in dialysis patients requires slower correction.

Real-World Examples

ABG & Electrolyte Case Studies

Case 1: DKA with Metabolic Acidosis

ABG: pH 7.18 | PaCO2 22 | HCO3 8 | Na 130 | K 5.8 | Cl 95 | Glucose 450.

Analysis: Primary = Metabolic Acidosis (pH <7.35, HCO3 <22). Expected PaCO2 = 1.5(8) + 8 ± 2 = 20-24. Actual = 22 ✓ appropriate respiratory compensation. Anion Gap = 130 − (95 + 8) = 27 (HIGH, consistent with DKA/lactic acidosis).

Treatment: IV fluids (1-2 L bolus LR), insulin 0.1 U/kg/hr drip, monitor glucose/electrolytes q1-2h, replace K despite "high" serum level (total body depleted), bicarb NOT typically used unless pH <7.1.

Case 2: Respiratory Acidosis from COPD

ABG: pH 7.28 | PaCO2 68 | HCO3 32 | PaO2 45 | K 5.2

Analysis: Primary = Respiratory Acidosis (pH <7.35, PaCO2 >45). Kidneys compensating (HCO3 elevated to 32, expected ~24 without compensation). This is ACUTE-ON-CHRONIC (elevated HCO3 suggests prior chronic CO2 retention).

Treatment: Supplemental O2 (goal SaO2 >88-92%), non-invasive ventilation if pH <7.25, bronchodilators, steroids. Careful with O2 (risk of removing hypoxic drive in COPD). Avoid rapid CO2 reduction (risk of alkalosis).

Case 3: Acute Hyponatremia with Seizures

Patient: 68-year-old female, SIADH from pneumonia, Na 118, altered mental status, seizure activity. Osmolality 250, urine Na 80 (concentrated).

Acute Management: 3% NaCl IV — target rise 4-6 mEq/L/hr acutely (goal 125-130 to stop seizures). Give 4 mL/kg = 272 mL over 15 min, then reassess. Can repeat if seizures persist. Concurrent furosemide 40 mg IV to promote free water loss.

Chronic Phase: Once seizures controlled, slow correction to 8-10 mEq/L/day. Fluid restrict 500-800 mL/day. Treat underlying pneumonia. Goal Na 130-135 over next 48 hours.

Case 4: Hyperkalemia with ECG Changes

Patient: 45-year-old with acute renal failure, K 6.8, ECG shows peaked T waves and QRS widening. Symptoms: palpitations, weakness.

Emergency Treatment: (1) Ca gluconate 10% 10 mL IV over 2-3 min (stabilize heart membrane—works in seconds). (2) Insulin 10 U IV + D50W 25 mL (shifts K intracellular—works in 10-20 min, lasts 4-6 hours). (3) Albuterol 10-20 mg neb (additional shift, takes 30 min). (4) Sodium polystyrene sulfonate 15-30g PO or PR (remove K over hours).

Definitive: Emergent hemodialysis if K >7 with ECG changes or refractory to medical management. Monitor K+ q1-2h.

Common Questions

ABG & Electrolyte FAQ

How do I interpret a "double acid-base disorder"?
A patient can have two primary disorders simultaneously. Check Winter's formula: if actual PaCO2 is HIGHER than expected in metabolic acidosis, concurrent respiratory acidosis exists. If actual PaCO2 is LOWER, concurrent respiratory alkalosis. Example: DKA patient on mechanical ventilation may have metabolic acidosis + respiratory alkalosis if ventilator settings too aggressive. Use Winter's to identify these.
What does a normal anion gap metabolic acidosis indicate?
Normal anion gap (8-12) metabolic acidosis = non-anion gap acidosis. Causes: GI bicarbonate loss (diarrhea, ileostomy), renal tubular acidosis (RTA types 1, 2, 4), or medications (acetazolamide). Treat underlying cause. Type 4 RTA (hyperkalemia + acidosis) requires K depletion + alkali replacement.
Why is hypokalemia dangerous even when mild?
Hypokalemia (<3.5) increases risk of cardiac arrhythmias (especially in patients on digoxin or with underlying heart disease). Even mild K 3.0-3.5 can cause flattened T waves, U waves, ST depression on ECG. Severe hypokalemia (<2.5) causes profound weakness, paralysis, rhabdomyolysis. Always replicate K promptly and check Mg (needed for K replacement).
How do I manage electrolytes in ESRD patients?
Dialysis patients have severely restricted K intake (<2 g/day, ~50 mEq). K removal via dialysate is major factor. Avoid NSAIDs and ACE inhibitors (cause hyperkalemia). Check K before/after dialysis. If K >6 between sessions, emergency dialysis needed. Adjust dialysate K concentration based on predialysis levels.
When should I use 3% vs. isotonic saline in hyponatremia?
Use 3% NaCl for ACUTE symptomatic hyponatremia (<48h, Na <120 with seizures/altered mental status). Goal: raise Na 4-6 mEq/L to stop symptoms, then slower correction. Use isotonic (0.9%) or fluid restriction for CHRONIC asymptomatic hyponatremia to avoid osmotic demyelination syndrome.
What's the relationship between magnesium and potassium?
Up to 50% of hypokalemia is accompanied by hypomagnesemia. You CANNOT successfully replete potassium if magnesium is low—body excretes K despite supplementation. Always check Mg level; if <1.7, replicate Mg first (MgSO4 1-2g IV or magnesium oxide PO). Then K repletion works.
How does hyperkalemia affect the ECG?
Progressive ECG changes with rising K: peaked T waves (K 5.5-6), prolonged PR interval, flattened P waves, widened QRS (>120 ms), eventual sine wave pattern before cardiac arrest. These changes don't correlate perfectly with K level—some patients symptomatic at K 6, others asymptomatic at K 7. Always treat ECG changes urgently.
What causes false hyperkalemia readings?
Pseudohyperkalemia = hemolysis of RBCs during blood draw, releasing K. Occurs with prolonged tourniquet application, small-gauge needle, vigorous fist clenching before draw. If K is surprisingly high without ECG changes, check for hemolysis (pink-tinged serum, high LDH) and repeat blood draw. Use plasma (not serum) to minimize hemolysis artifact.
How do I correct sodium in cirrhosis patients with ascites?
Cirrhosis often has hyponatremia (130-135) from SIADH, portal hypertension, and splanchnic vasodilation. Avoid 3% saline (risk of osmotic demyelination in chronic hyponatremia). Use fluid restriction (500 mL/day) + tolvaptan (vaptans promote free water loss) or CVVH. Correct slowly at 8-10 mEq/L/day. Avoid vasopressors if possible (worsen splanchnic perfusion).
When should I use sodium bicarbonate in metabolic acidosis?
Sodium bicarbonate rarely used in modern practice. Only consider if pH <7.1 AND you've corrected underlying cause (fluids in hypovolemia, insulin in DKA). Bicarb can worsen hypokalemia, increase CO2 (risk in respiratory failure), and cause hypernatremia. DKA: give insulin + fluids, not bicarb. Lactic acidosis: treat hypoperfusion.
Why Use This Tool

Prevent Electrolyte Emergencies & Acid-Base Crises

Critical Life Skills: ABG interpretation and electrolyte management are tested on every medical licensing exam and essential in clinical practice.

Prevent Overcorrection: Rapid correction of hyponatremia or hyperkalemia can cause seizures, cardiac arrhythmias, and death. Get the right dosing calculated for your patient's acuity.

Rapid Decision-Making: In emergencies, you don't have time for lengthy manual calculations. Get answers in seconds with evidence-based recommendations.

  • Winter's Formula automatic calculation
  • Respiratory compensation assessment
  • Anion gap calculation and interpretation
  • Hyperkalemia emergency treatment dosing
  • Hyponatremia acute vs. chronic protocols
  • Hypocalcemia calcium replacement dosing
  • Hypomagnesemia replacement protocols
  • ICU-grade recommendations with monitoring labs
ABG & Electrolyte Interpreter – Blood Gas Analysis, Acid-Base & Ion Disorders | AimediLabs
Blood Gas Analysis  ·  Acid-Base  ·  Electrolytes

ABG & Electrolyte Manager – Interpret Blood Gases & Manage Ion Disorders

ABG interpretation and electrolyte management are core skills in critical care medicine. Our comprehensive ABG & Electrolyte Manager helps clinicians interpret blood gas values (pH, PaCO2, HCO3), apply Winter's formula for metabolic acidosis, diagnose respiratory and metabolic acid-base disorders, and manage electrolyte abnormalities (hyperkalemia, hyponatremia, hypocalcemia, hypomagnesemia). Evidence-based treatment protocols with precise dosing for acute and chronic disorders. Free access for ICU, ER, and critical care professionals.

Analyze ABG Now
Winter's Formula included ICU-tested protocols Acute & chronic dosing
Dual Interpretation Engine

Master ABG Analysis & Electrolyte Disorders

Two integrated tools in one: interpret blood gases with Winter's formula, then manage common electrolyte emergencies with evidence-based dosing.

🧬

ABG Interpretation

Enter pH, PaCO2, HCO3. Get primary disorder (respiratory/metabolic), alkalosis/acidosis, expected compensation, anion gap assessment.

🔢

Winter's Formula

Automatic Winter's Formula calculation for metabolic acidosis to determine if respiratory compensation is appropriate.

⚗️

Electrolyte Disorders

Manage hyperkalemia, hypokalemia, hyponatremia, hypernatremia, hypocalcemia, hypercalcemia, hypomagnesemia with acute/chronic protocols.

💊

Treatment Dosing

Precise dosing for calcium gluconate, potassium chloride, sodium bicarbonate, dextrose, and magnesium sulfate with rates and monitoring.

📊

Anion Gap Analysis

Calculate anion gap, identify MUDPILES causes, assess high or normal gap metabolic acidosis, guide differential diagnosis.

🏥

Acute/Chronic Assessment

Distinguish acute vs. chronic electrolyte disorders. Different treatment approaches for symptomatic vs. chronic asymptomatic hyponatremia.

How ABG Works

Systematic ABG Interpretation & Electrolyte Management

Step-by-Step ABG Interpretation

ABG interpretation requires systematic analysis: assess oxygenation, pH, primary acid-base disorder, appropriate respiratory compensation, anion gap, and electrolytes.

Step 1: Check Oxygenation (PaO2)

Normal: 80-100 mmHg on room air. Low <60 indicates hypoxemia (respiratory disease, cardiac R→L shunt, altitude). High >100 on room air suggests hyperventilation or supplemental O2.

Step 2: Determine Acidemia vs. Alkalemia (pH)

pH <7.35 = Acidemia | pH >7.45 = Alkalemia | 7.35-7.45 = Normal

Step 3: Identify Primary Disorder

Respiratory Acidosis: pH <7.35 + PaCO2 >45 (retention from COPD, respiratory depression, hypoventilation). Metabolic Acidosis: pH <7.35 + HCO3 <22 (lactic acidosis, DKA, RTA, diarrhea). Check anion gap.

Respiratory Alkalosis: pH >7.45 + PaCO2 <35 (hyperventilation, PE, sepsis, anxiety). Metabolic Alkalosis: pH >7.45 + HCO3 >26 (vomiting, diuretics, contraction alkalosis).

Step 4: Winter's Formula for Expected Compensation

In metabolic acidosis: Expected PaCO2 = 1.5 × [HCO3] + (8 ± 2) | Example: HCO3 = 10 → Expected PaCO2 = 1.5(10) + 8 = 23 ± 2 (range 21-25). If actual PaCO2 ≥ expected, concurrent respiratory acidosis (inadequate respiratory response). If actual < expected, concurrent respiratory alkalosis (excessive hyperventilation).

Step 5: Anion Gap Calculation

AG = [Na] − ([Cl] + [HCO3]) | Normal: 8-12 mEq/L | High AG (>12) = MUDPILES causes (Methanol, Uremia, DKA, Propylene glycol, Isoniazid, Lactic acidosis, Ethylene glycol, Salicylates). Normal AG acidosis = diarrhea, RTA, ureteral diversions.

Electrolyte Disorder Management

Disorder Normal Range Acute Treatment Monitoring
Hyperkalemia (K>5.5) 3.5-5 mEq/L Ca gluconate 10% 10 mL IV (cardiac membrane stabilizer), then insulin 10 U + D50W 25 mL IV, albuterol neb, sodium polystyrene 15-30g PO ECG, K+ q1h, EKG for peaked T waves, QRS widening
Hypokalemia (K<3.5) 3.5-5 mEq/L KCl 20-40 mEq/L IV in saline at 10 mEq/hr (max), or 20-40 mEq PO daily divided. Recheck q4-6h. Faster replacement if ECG changes. K+ q4-6h, ECG for flattened T, U waves, ST depression. Assess Mg (need correction for K repletion)
Hyponatremia (Na<135) 135-145 mEq/L Acute symptomatic: 3% NaCl IV at 4 mL/kg + furosemide. Chronic: Fluid restrict 800 mL/day, correct at 8-10 mEq/L/day max. Goal: 125-130 mEq/L if severe (seizures, altered mental status) Na+ q2h (acute), q4-6h (chronic). Watch for osmotic demyelination if correct >12 mEq/L/day
Hypernatremia (Na>145) 135-145 mEq/L Free water replacement: D5W IV or hypotonic saline (½ NS). Calculate deficit = 0.6 × weight × (Na − 140)/140. Correct over 24-48h. Concurrent hypovolemia: use NS first, then switch to free water. Na+ q4-6h. Correct at 8-10 mEq/L/day max to avoid cerebral edema
Hypocalcemia (Ca<8.5) 8.5-10.2 mg/dL (corrected) Symptomatic (tetany, seizures): Ca gluconate 10% 10-20 mL IV over 5-10 min (recheck q5-10min). Chronic: 1,000 mg elemental Ca + Vit D daily PO Ca2+ q1h, Mg (often low together), phos, ECG (prolonged QT)
Hypomagnesemia (Mg<1.7) 1.7-2.2 mg/dL MgSO4 1-2 g IV over 1 hour, or 4-8 g PO daily divided (causes diarrhea). Mild: PO replacement preferred Mg q4-6h. Note: K+ won't replicate without Mg repletion

Acute vs. Chronic Assessment

Acute disorders (<48 hours): Treat aggressively to normalize levels quickly. Symptomatic patients require urgent intervention (seizures in hyponatremia, arrhythmias in hypo/hyperkalemia). Risk of overcorrection lower.

Chronic disorders (>48 hours): Slower correction (8-10 mEq/L/day) to avoid osmotic complications. Example: chronic hyponatremia corrected too fast → osmotic demyelination syndrome (central pontine myelinolysis). Chronic hyperkalemia in dialysis patients requires slower correction.

Real-World Examples

ABG & Electrolyte Case Studies

Case 1: DKA with Metabolic Acidosis

ABG: pH 7.18 | PaCO2 22 | HCO3 8 | Na 130 | K 5.8 | Cl 95 | Glucose 450.

Analysis: Primary = Metabolic Acidosis (pH <7.35, HCO3 <22). Expected PaCO2 = 1.5(8) + 8 ± 2 = 20-24. Actual = 22 ✓ appropriate respiratory compensation. Anion Gap = 130 − (95 + 8) = 27 (HIGH, consistent with DKA/lactic acidosis).

Treatment: IV fluids (1-2 L bolus LR), insulin 0.1 U/kg/hr drip, monitor glucose/electrolytes q1-2h, replace K despite "high" serum level (total body depleted), bicarb NOT typically used unless pH <7.1.

Case 2: Respiratory Acidosis from COPD

ABG: pH 7.28 | PaCO2 68 | HCO3 32 | PaO2 45 | K 5.2

Analysis: Primary = Respiratory Acidosis (pH <7.35, PaCO2 >45). Kidneys compensating (HCO3 elevated to 32, expected ~24 without compensation). This is ACUTE-ON-CHRONIC (elevated HCO3 suggests prior chronic CO2 retention).

Treatment: Supplemental O2 (goal SaO2 >88-92%), non-invasive ventilation if pH <7.25, bronchodilators, steroids. Careful with O2 (risk of removing hypoxic drive in COPD). Avoid rapid CO2 reduction (risk of alkalosis).

Case 3: Acute Hyponatremia with Seizures

Patient: 68-year-old female, SIADH from pneumonia, Na 118, altered mental status, seizure activity. Osmolality 250, urine Na 80 (concentrated).

Acute Management: 3% NaCl IV — target rise 4-6 mEq/L/hr acutely (goal 125-130 to stop seizures). Give 4 mL/kg = 272 mL over 15 min, then reassess. Can repeat if seizures persist. Concurrent furosemide 40 mg IV to promote free water loss.

Chronic Phase: Once seizures controlled, slow correction to 8-10 mEq/L/day. Fluid restrict 500-800 mL/day. Treat underlying pneumonia. Goal Na 130-135 over next 48 hours.

Case 4: Hyperkalemia with ECG Changes

Patient: 45-year-old with acute renal failure, K 6.8, ECG shows peaked T waves and QRS widening. Symptoms: palpitations, weakness.

Emergency Treatment: (1) Ca gluconate 10% 10 mL IV over 2-3 min (stabilize heart membrane—works in seconds). (2) Insulin 10 U IV + D50W 25 mL (shifts K intracellular—works in 10-20 min, lasts 4-6 hours). (3) Albuterol 10-20 mg neb (additional shift, takes 30 min). (4) Sodium polystyrene sulfonate 15-30g PO or PR (remove K over hours).

Definitive: Emergent hemodialysis if K >7 with ECG changes or refractory to medical management. Monitor K+ q1-2h.

Common Questions

ABG & Electrolyte FAQ

How do I interpret a "double acid-base disorder"?
A patient can have two primary disorders simultaneously. Check Winter's formula: if actual PaCO2 is HIGHER than expected in metabolic acidosis, concurrent respiratory acidosis exists. If actual PaCO2 is LOWER, concurrent respiratory alkalosis. Example: DKA patient on mechanical ventilation may have metabolic acidosis + respiratory alkalosis if ventilator settings too aggressive. Use Winter's to identify these.
What does a normal anion gap metabolic acidosis indicate?
Normal anion gap (8-12) metabolic acidosis = non-anion gap acidosis. Causes: GI bicarbonate loss (diarrhea, ileostomy), renal tubular acidosis (RTA types 1, 2, 4), or medications (acetazolamide). Treat underlying cause. Type 4 RTA (hyperkalemia + acidosis) requires K depletion + alkali replacement.
Why is hypokalemia dangerous even when mild?
Hypokalemia (<3.5) increases risk of cardiac arrhythmias (especially in patients on digoxin or with underlying heart disease). Even mild K 3.0-3.5 can cause flattened T waves, U waves, ST depression on ECG. Severe hypokalemia (<2.5) causes profound weakness, paralysis, rhabdomyolysis. Always replicate K promptly and check Mg (needed for K replacement).
How do I manage electrolytes in ESRD patients?
Dialysis patients have severely restricted K intake (<2 g/day, ~50 mEq). K removal via dialysate is major factor. Avoid NSAIDs and ACE inhibitors (cause hyperkalemia). Check K before/after dialysis. If K >6 between sessions, emergency dialysis needed. Adjust dialysate K concentration based on predialysis levels.
When should I use 3% vs. isotonic saline in hyponatremia?
Use 3% NaCl for ACUTE symptomatic hyponatremia (<48h, Na <120 with seizures/altered mental status). Goal: raise Na 4-6 mEq/L to stop symptoms, then slower correction. Use isotonic (0.9%) or fluid restriction for CHRONIC asymptomatic hyponatremia to avoid osmotic demyelination syndrome.
What's the relationship between magnesium and potassium?
Up to 50% of hypokalemia is accompanied by hypomagnesemia. You CANNOT successfully replete potassium if magnesium is low—body excretes K despite supplementation. Always check Mg level; if <1.7, replicate Mg first (MgSO4 1-2g IV or magnesium oxide PO). Then K repletion works.
How does hyperkalemia affect the ECG?
Progressive ECG changes with rising K: peaked T waves (K 5.5-6), prolonged PR interval, flattened P waves, widened QRS (>120 ms), eventual sine wave pattern before cardiac arrest. These changes don't correlate perfectly with K level—some patients symptomatic at K 6, others asymptomatic at K 7. Always treat ECG changes urgently.
What causes false hyperkalemia readings?
Pseudohyperkalemia = hemolysis of RBCs during blood draw, releasing K. Occurs with prolonged tourniquet application, small-gauge needle, vigorous fist clenching before draw. If K is surprisingly high without ECG changes, check for hemolysis (pink-tinged serum, high LDH) and repeat blood draw. Use plasma (not serum) to minimize hemolysis artifact.
How do I correct sodium in cirrhosis patients with ascites?
Cirrhosis often has hyponatremia (130-135) from SIADH, portal hypertension, and splanchnic vasodilation. Avoid 3% saline (risk of osmotic demyelination in chronic hyponatremia). Use fluid restriction (500 mL/day) + tolvaptan (vaptans promote free water loss) or CVVH. Correct slowly at 8-10 mEq/L/day. Avoid vasopressors if possible (worsen splanchnic perfusion).
When should I use sodium bicarbonate in metabolic acidosis?
Sodium bicarbonate rarely used in modern practice. Only consider if pH <7.1 AND you've corrected underlying cause (fluids in hypovolemia, insulin in DKA). Bicarb can worsen hypokalemia, increase CO2 (risk in respiratory failure), and cause hypernatremia. DKA: give insulin + fluids, not bicarb. Lactic acidosis: treat hypoperfusion.
Why Use This Tool

Prevent Electrolyte Emergencies & Acid-Base Crises

Critical Life Skills: ABG interpretation and electrolyte management are tested on every medical licensing exam and essential in clinical practice.

Prevent Overcorrection: Rapid correction of hyponatremia or hyperkalemia can cause seizures, cardiac arrhythmias, and death. Get the right dosing calculated for your patient's acuity.

Rapid Decision-Making: In emergencies, you don't have time for lengthy manual calculations. Get answers in seconds with evidence-based recommendations.

  • Winter's Formula automatic calculation
  • Respiratory compensation assessment
  • Anion gap calculation and interpretation
  • Hyperkalemia emergency treatment dosing
  • Hyponatremia acute vs. chronic protocols
  • Hypocalcemia calcium replacement dosing
  • Hypomagnesemia replacement protocols
  • ICU-grade recommendations with monitoring labs


Essential For

All Clinicians Managing Critical Illness

ICU Physicians & Intensivists Daily tool for interpreting ABGs and managing electrolyte abnormalities in critically ill patients with organ dysfunction.
Emergency Medicine Physicians Rapid ABG interpretation and treatment of electrolyte emergencies (hyperkalemia, severe hyponatremia, hypocalcemia).
Nephrologists & Hospitalists Manage acid-base and electrolyte disorders as core part of clinical practice across all patient populations.
Critical Care Nurses Understand ABG results and electrolyte management to better anticipate physician orders and patient care needs.
Medical Students & Residents Master ABG interpretation and electrolyte management for board exams (USMLE, PLAB, INI-CET, NEET-PG).
Anesthesiologists Intraoperative ABG interpretation and electrolyte management in operating room and perioperative settings.

Interpret ABG & Manage Electrolytes Instantly

Winter's Formula, anion gap, treatment dosing — all integrated in one clinical decision tool.

Open ABG Manager
Disclaimer: This tool provides educational information and acid-base/electrolyte calculations. Clinical decisions must be made by qualified healthcare providers considering the full clinical context. Always verify calculations and follow institutional protocols.