Patho Acid Base

35問 • 2年前

問題一覧

Acid Sources

Carbonic acid (H2CO3), Lactic Acid, Sulfuric Acid, Phosphoric Acid, Ketone Bodies

Buffer Systems

Plasma (bicarb-carbonic acid, Hbg), Intracellular (protein, phosphate), Kidneys (bicarb, ammonia, phosphate), Lungs (CO2)

Buffer systems help absorb

H+ or OH- (hydrogen ions or hydroxide ions)

Left side of equation

Lungs: Gain H+—> shift to left—> lungs increase ventilation to expel CO2

Right side of equation

Kidneys: Lose H+—> shift to right—> lungs retain more CO2

First line of defense against alternations in acid base

Bicarbonate

Negative charge, buffers H+, binds to Ca, changes amount of free Ca based in acid base

Albumin

Add H2O—>H2CO3–>Carries carbonic acid (H2CO3)—>dissociated—> Hbg buffers H+. In lungs, process reverses and CO2 expired

Hbg

Buffer that increases amount of Ca in the blood

Albumin

Inorganic Phosphates

HPO4-2/H2PO4 - Buffer

Organic Phosphates

ATP, ADP, AMP, glucose-1-phosphate, and 2,3-DPG (diphosphoglycerate)

If Chemical Buffers cannot keep up this kicks in

Lungs

If Lungs cannot keep up this kicks in

Kidneys

How the lungs compensate

Change minute ventilation

Kidneys regulate extracellular fluid H+ in 3 ways:

1. Secrete H+ for removal in urine 2. Reabsorption of filtered bicarbonate ions 3. Production of new bicarbonate ions

Reabsorption of bicarbonate ions

Combine excess H+ in tubules with phosphates and ammonia to excrete bicarbonate that is then reabsorbed

Bicarbonate production and reabsorption must slow down, thus H+ secretion decreases and phosphorus and ammonia not excreted

Alkalosis

Increased CO2 increase H+ production—> H+ is secreted in tubule fluid and combines with CO2 and H2O and/or NH3 or NaHPO4–> bicarbonate that is reabsorbed as buffer

Acidosis

Acid Base Labs

Serum CO2, ABG (most accurate), Base excess/deficit, O2 Saturation

Reduction in serum bicarbonate. Increase acid production: lactic acidosis, ketoacidosis, ingestion; Loss of bicarbonate: GI losses, kidney losses, elevated aldosterone; Diminished renal acid secretion

Metabolic Acidosis

Manifestations: Decreased myocardial contractility, decreased CO, Catecholamine resistant hypotension, Hyperkalemia and ventricular arrhythmias

Metabolic Acidosis

Anion Gap Normal

6-12

Gap Acidosis

>12

Non-Gap Acidosis

</= 12

Gap Acidosis Manifestations

MUDPILES: Methanol, Uremia, DKA, Paraldehyde/phenformin/propofol, Iron/INH, Lactic acidosis, Ethylene glycol, Salicylates

Non-Gap Acidosis Manifestations

Kidney losses, GI losses, Volume overload, Hypernatremia (fluid restriction), Kidney failure

Excess bicarbonate or deficiency of H+. Excess bicarbonate and inability to excrete excess bicarbonate from kidneys. Causes: Emesis (Hydrochloric Acid loss) and Diuretic use.

Metabolic Alkalosis

Manifestations: Hypokalemia (ATach, PVCs), muscle cramps and weakness); Hypocalcemia (Paresthesia); Hypoventilation

Metabolic Alkalosis

Excess PaCO2. Causes: Airway obstruction, PNA, Pulmonary Edema, ARDS, COPD, Brain stem injury, Oversedation, Spinal muscle atrophy, Guillain Barre

Respiratory Acidosis

Manifestations: H/A, Blurred vision, Muscle cramps, Disorientation, Restlessness, Seizures, Respiratory rate initially increased then decreased

Respiratory Acidosis

Deficiency of PaCO2 - Blow off too much CO2. Causes: Hypoxemia, Hypermetabolism (fever, anemia, hyperthyroidism), Neuro (panic disorders, head injury)

Respiratory Alkalosis

Manifestations: Tachypnea, Dizziness, Confusion, Seizures, Decreased Ca (Paresthesia)

Respiratory Alkalosis

Acid-Base Reaction Enzyme

Carbonic Anhydrase

In alkalosis, albumin

Binds more Ca+

Serum CO2 will:

Increase in Alkalosis and Decrease in Acidosis

Patho Renal

Two Clean Queens · 100問 · 2年前

Patho Renal