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Acid-Base Physiology (Pediatrics) - Coggle Diagram

- - - - Physiologic Buffers
        
        Bicarbonate/Carbonic acid system
        
        Located primarily in RBCs
        
        Phosphate buffers
        
        Located within bone
- - - - If the compensation is appropriate
        
        simple acid–base disorder is presen
      - compensation is not appropriate
        
        mixed disorder is present.
- - - - Kidney increase acid secretion
        
        Impaired ability to excrete acid by the kidney eg RTA, Renal failure
        
        Addition of acid to the body (exogenous or endogenous) eg DKA, Salicylate intoxication
  - - - impaired cardiac contractility & an increased risk of arrhythmias
    - - hypotension
        
        shock
    - - persistent pulmonary hypertension
    - - lethargy and coma.
  - - - normal anion gap
        
        Diarrhea
        
        Renal tubular acidosis (RTA)
        
        Urinary tract diversions
        
        Posthypocapnia
        
        Ammonium chloride intake
      - increased anion gap.
        
        Lactic Acidosis
        
        Ketoacidosis
        
        Kidney Failure
        
        Poisoning
      - Aniongap=[Na+]−[Cl−]−[HCO −]
  - - - Sodium bicarbonate
        
        1 mEq/kg in emergency
- - - - maintained by volume depletion
    - - chloride- resistant metabolic alkalosis.
  - - - Diuretics (loop or thiazide)
      - Chloride
        
        losing diarrhea
        
        deficient formula
      - Cystic fibrosis
      - Gastric losses
        
        Emesis, Nasogastric suction
      - Post-hypercapnia
    - - High blood pressure
        
        Adrenal adenoma or hyperplasia
      - Normal blood pressure
        
        Gitelman syndrome
  - - - most common causes
  - - - nasogastric suction
      - Diuretics eliminated
      - potassium supplementation and potassium-sparing diuretics
      - acetazolamide decreases resorption of bicarbonate in the proximal tubule
- - - - anxiety, dizziness, headache, confusion, asterixis, myoclonic,jerks, hallucinations, psychosis, coma, and seizures.
    - - arrythmias
      - arterial pH <7.2 impairs cardiac contractility and the normal response to catecholamines
  - - - Encephalitis, tumor, medications
    - - GBS, Poliomyelitis, medications eg. Oganophosphates
    - - Pneumonia, pneumothorax, asthma
    - - Aspiration, Laryngospasm
    - - Flail chest, cardiac arrest
  - - - upper airway disease
  - - - hypoxic
        
        oxygen
    - - Pco2 >75 mm Hg
- - - - asymptomatic
    - - chest tightness, palpitations, lightheadedness, circumoral numbness, and paresthesias of the extremities
  - - - low serum bicarbonate
  - - - rebreathing into a paper bag increases the patient’s Pco2.
- - - - Calculate the Maintenance fluid required of a 5yo child with BW of 15 kg
      - Overweight child - base the calculations on the lean body weight - estimated by using the 50th percentile of body weight for the child’s height.
  - - - Very-low- birthweight infants can have insensible losses of 100-200 mL/kg/24 hr
        
        Fever - 10-15% increase in maintenance water needs for each 1°C (1.8°F) increase in temperature above 38°C (100.4°F)
    - - Half-normal saline (0.45% NaCl)
        
        Na 77
        Cl 77
      - 0.2 normal saline (0.2% NaCl)
        
        Na 34
        Cl 34
      - Normal saline (0.9% NaCl)
        
        Na 154
        Cl 154
      - Ringer lactate
        
        Na 130
        Cl 109
        K 4
        Ca 3
        Lactate 28
      - Normal saline (NS) and Ringer lactate (LR) are isotonic solutions
        approximately the same tonicity as plasma
  - - - Average Composition of Diarrhea
        
        Sodium: 55 mEq/L
        
        Potassium: 25 mEq/L
        
        Bicarbonate: 15 mEq/L
      - Approach to Replacement of Ongoing Losses
        
        Solution: D5 1/2 NS + 30 mEq/L sodium bicarbonate + 20 mEq/L KCl Replace stool mL/mL every 1-6 hr
        D5, 5% dextrose; NS, normal saline.
    - - Average Composition of Gastric Fluid
        
        Sodium: 60 mEq/L
        
        Potassium: 10 mEq/L
        
        Chloride: 90 mEq/L
      - Approach to Replacement of Ongoing Losses
        
        Solution: normal saline + 10 mEq/L KCl
        Replace output mL/mL every 1-6 hr
    - - Oliguria/Anuria
        
        Replacement of insensible fluid losses (25–40% of maintenance) with D5 1/2 NS
        
        Replace urine output mL/mL with D5 1/2 NS ± KCl
      - Polyuria
        
        Replacement of insensible fluid losses (25–40% of maintenance) with D5 1/2 NS ± KCl
        
        Measure urine electrolytes
        Replace urine output mL/mL with solution based on measured urine electrolytes
        D5, 5% dextrose; NS, normal saline.
  - - - Moderate dehydration
        
        (5–10% in an infant; 3–6% in an older child or adult)
        
        sign
        
        Tachycardia; little or no urine output; irritable/lethargic; sunken eyes and fontanel; decreased tears; dry mucous membranes; mild delay in elasticity (skin turgor); delayed capillary refill (>1.5 sec); cool and pale
      - Severe dehydration
        
        (>10% in an infant; >6% in an older child or adult)
        
        sign
        
        Peripheral pulses either rapid and weak or absent; decreased blood pressure; no urine output; very sunken eyes and fontanel; no tears;parched mucous membranes; delayed elasticity (poor skin turgor); very delayed capillary refill (>3 sec); cold and mottled; limp, depressed
        consciousness
      - Mild dehydration
        
        (<5% in an infant; <3% in an older child or adult)
        
        sign
        
        Normal or increased pulse; decreased urine output; thirsty
      - Fluid Management of Dehydration
        
        Restore intravascular volume:
        Isotonic fluid (NS or LR): 20 mL/kg over 20 min Repeat as needed
        Calculate 24 hr fluid needs: maintenance + deficit volume
        Subtract isotonic fluid already administered from 24 hr fluid needs Administer remaining volume over 24 hr using 5% dextrose NS + 20 mEq/L KCl
        Replace ongoing losses as they occur
        LR, Ringer lactate; NS, normal saline.