IM Fluids & Electrolytes - Maryam AlTayeb.pdf

Fluids ★

Basics of Fluids

Fluids

Fluid Management in Pediatrics ★

Electrolytes & Associated Disturbances ★

Sodium

Potassium

Calcium

Phosphate

Magnesium

Chloride

Acid-Base Disorders ★

<aside> 🏕️ SMORE: change in PCO2 in the Same direction as pH → Metabolic disorder; change in PCO2 in the Opposite direction to pH → REspiratory disorder

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Approach to Acid-Base Disorders - Maryam Altayeb.pdf

<aside> ⚗️ How to approach to acid-base disorders

1. Patient’s history and presenting symptoms — use clinical clues to guide your initial idea of what it could be!
   1. Vomiting points towards a metabolic alkalosis due to loss of acid
   2. Diarrhea points towards a metabolic acidosis due to loss of base
   3. Respiratory disorders (hyper vs hypoventilation, CO2 retention [COPD])
   4. Medication/drug use (ex: asprin overdose = initial respiratory alkalosis followed by metabolic acidosis, opioid overdose leading to decreased repiratory drive & respiratory acidosis)
2. Evaluate the pH (normal: 7.4): A value <7.35 signifies acidosis whereas a value >7.45 indicates alkalosis.
3. Identify the primary process: Differentiate respiratory from metabolic processes by determining the PaCO2 (normal: 40) and HCO3− (normal: 24).
   1. pH < 7.35 (acidemia): Primary disorder is an acidosis.
      • ↓ pH and ↓ HCO3: metabolic acidosis
      • ↓ pH and ↑ PCO2: respiratory acidosis
   2. pH > 7.45 (alkalemia): Primary disorder is an alkalosis.
      • ↑ pH and ↑ HCO3: metabolic alkalosis
      • ↑ pH and ↓ PCO2: respiratory alkalosis
4. Identify compensation:
   1. Respiratory compensation: acute or chronic
      • Metabolic Acidosis: Winter’s formula; expected PaCO2 = (1.5 x HCO3) + 8 ± 2
      • Metabolic Alkalosis: ~ 7mmHg ↑ in PaCO2 per 10mEq/L ↑ in HCO3 (0.7mmHg per 1 mEq/L)
   2. Metabolic compensation (renal): chronic only; 72 hrs
      • Respiratory Acidosis: ~4mEq/L ↑ in HCO3 per 10mmHg ↑ in PaCO2
      • Respiratory Alkalosis: ~4mEq/L ↓ in HCO3 per 10mmHg ↓ in PaCO2
      • Because increased PaCO2 leads to an increased hydrogen ion concentration in the body, the kidneys begin to compensate by increasing resorption of HCO3− to help buffer the excess acid & vice versa. </aside>

• Note: In respiratory acidosis, the renal compensation begins after several hours and takes several days to complete. After approximately 72 hours, the expected compensatory increase in HCO3− is approximately 4 mEq/L for every 10 mm Hg elevation in PaCO2.

Metabolic Acidosis

Respiratory Acidosis

Respiratory Alkalosis

Metabolic Alkalosis