Acid/Base Meds Flashcards
Respiratory Alkalosis Mnemonic
PAST PH
- Panic attacks
- Anxiety attacks
- Salicylates
- Tumors
- Pulmonary embolism
- Hypoxemia
Metabolic Alkalosis Mnemonic
LAVAlUP
- Loop Diuretics ( Furosemide, Bumetanide, Torsemide)
- Antacid use
- Vomiting
- Aldosterone increase (UP)
Respiratory Acidosis Mnemonic
AS A COW
- Airway obstruction/Aminoglycosides/Anesthetics
- Sedative Use
- Acute lung disease
- Chronic lung disease
- opioids
- Weakening of the respiratory muscles
UMetabolic Acidosis with Large anion Gap Mnemonic
MUD PILES
- Methanol, metformin
- Uremia
- Diabetic ketoacidosis (or alcoholic ketoacidosis)
- Paraldehyde, phenformin
- Isoniazid, iron
- Lactic acidosis
- Ethylene glycol (antifreeze), ethanol
- Salicylates
Metabolic Acidosis with Normal Anion Gap Mnemonic
USED CAR
- Ureteral diversion
- Saline infusion
- Exogenous acid
- Diarrhea
- Carbonic anhydrase inhibitor (acetazolamide)
- Adrenal insufficiency
- Renal tubular acidosis
Treatment of Metabolic Acidosis
identify and tx underlying causes
- NaHCO3- indicated when:
- renal dysfunction→ not enough HCO3- is regenerated
- Severe acidemia: pG <7.10
- goal: increase HCO3- by 10mEq/L; and ph> 7.2
- ½ of the amount is given over 3-4 hours; then remainder given over 8-24 hours
- ****1mEq/kg/dose and monitor***
NaHCO3 IV
used to treat metabolic acidosis
- can be used with loop diuretics to avoid too much fluid (fluid overload)
- indicated when:
- renal dysfunction → not enough HCO3- regenerated
- severe acidemia: pH<7.10
- ½ of the amount is given over 3-4 hours; then remainder given over 8-24 hours
-
one amp is 50mL (or 50mEq)
- can give up to 3 amps + 1L D5W
Oral NaHCO3
used to tx metabolic acidosis
- generally preferred with chronic metabolic acidosis
- can be given as tab or powder
- indicated when:
- renal dysfunction → not enough HCO3- regenerated
- severe acidemia: pH<7.10
- ½ of the amount is given over 3-4 hours; then remainder given over 8-24 hours
K-citrate
used to tx metabolic acidosis
- helpful when the acidosis is coupled with hypoK+
- be cautious with renal impairment → needs to be avoided if pt has hyperK+ (can cause increased HyperK+)
Tx of Metabolic Alkalosis
- pts rarely have symptoms due to alkalemia
- sxs often related to volume depletion
- muscle cramps
- dizziness depending on position
- HypoK+ → muscle weakness, polyuria, polydipsia
- sxs often related to volume depletion
-
Tx: tx the underlying cause
- i.e. meds, citrate containing products (K-citrate used to tx metabolic acidosis), or acetate in parenteral nutrition → causes HCO3- levels to rise
- alkalosis caused by vomiting, NG suction, or diarrhea +/- urinary Cl- (<25mEq/L) → saline infusion
- acetazolamide (carbonic anhydrase inhibitor) → reduces HCO3- concentration
- ******Hemodialysis or HCl infusion for life-threatening metabolic alkalosis******
Tx of Respiratory Acidosis
represents ventilation failure or impaired control of ventilation
- hypoxemia + hypercapnia
- severe, acute respiratory acidosis =
- HA, blurred vision, restlessness and anxiety, tremors, somnolence, and/or delirium
- Tx = identify cause and tx that:
- opiate/opioids → naloxone
- acute bronchospasm/asthma → bronchodilators
- assisted ventilation and mod-severe acidosis → BiPAP
- NOTE: NaHCO3 may actually worsen acidemia due to increased CO2 generation so do NOT use this
- Goals:
- careful monitoring of pH
- maintain oxygenation
- improve alveolar ventilation
Tx of Respiratory Alkalosis
represents hyperventilation
- sxs: irritability of central and peripheral nervous system
- light headedness, altered consciousness, cramps, syncope
- severe cases: HypoPhos shifts from ECF to ICF
- tx: identify cause and tx accordingly
- for mild-moderate severity in spontaneously breathing pts → no specific tx
-
severe alkalosis:
- rebreathing
- rebreathing mask, or paper bag
- mechanical ventilation
- high level sedation or paralysis is a good option
- rebreathing
Change in Bicarbonate equations for acute respiratory acidosis vs alkalosis
- Acute Respiratory Acidosis: (approx normal)
- [change]HCO3- = 0.1 x [change]PaCO2
- 10% of [change]PaCO2
- [change]HCO3- = 0.1 x [change]PaCO2
- Acute Respiratory Alkalosis: (approx normal)
- [change]HCO3- = 0.2 x [change]PaCO2
- 20% of [change]PaCO2
- [change]HCO3- = 0.2 x [change]PaCO2
Change in Bicarbonate equations for chronic respiratory acidosis vs alkalosis
- Chronic Respiratory Acidosis: (increased bicarb)
- [change]HCO3- = 0.35x [change]PaCO2
- 35% of [change]PaCO2
- [change]HCO3- = 0.4 x [change]PaCO2
- 40% of [change] PaCO2
- [change]HCO3- = 0.35x [change]PaCO2
Total Body Water
- TBW = 60% of body weight
- ⅓ is ECF
- ¼ = plasma fluid
- ¾ = interstitial fluid
- ⅔ = ICF
Major Extracellular Ions
Na+, Cl-, HCO3-
Major Intracellular Ions
K+, Mg2+, PO42-, SO42-
Osmolality vs Osmolarity
- osmolality = osmoles of solute per mass (kg) of solvent
- Osmolarity = osmoles of solute per volume (L) of solvent → volume changes with temperature
Normal Plasma/Serum Osmolarity
275-290mOsmoles/L
- 2 [Na] + [glucose]/18 + [BUN]/2.8 =osm/L
What do changes in plasma tonicity cause ADH to do?
- Osmolarity >295 mOsm/L = max ADH release
- osmolarity <280 mOsm/L = inhibits release of ADH
S/sxs of Volume Deficits
- acute weight loss
- decreased skin turgor
- oliguria (production of small amounts of urine)
- >100mL/day but <400mL/day
- concentrated urine
- tachycardia
- prolonged cap refill
- decreased BP
- sensation of thirst, weakness, dizziness, muscle cramps
- orthostatic hypotension