Acid and Bases Flashcards
What is the winter’s equation?
Is to prove that in a primary metabolic acidosis there was a respiratory compensation
what is unique about the hyperchloremic metabolic acidosis?
there is a decrease in bicarbonate resulting in primary metabolic acidosis but no increase in the anion gap
what are the causes of non-anion gap metabolic acidosis?
- diarrhea
- renal tubular acidosis
- carbonic anhydrates inhibitors
- uretero sigmoidostomy(where more chloride will be absorbed than bicarbonate leading to a non-gap metabolic acidosis)
- Anything that contributes to excessive chloride in the body (acidifying salts like ammonium chloride/normal saline)
what is the significance of albumin when dealing with high anion gap metabolic acidosis?
if the albumin is low, then you have to take that into consideration when calculating the anion gap. for each gram of albumin that is depressed you must add 2.5 milliequivalents
what is the mnemonic for high anion gap metabolic acidosis
-GOLDMARK
GOLDMARK
- Glycols(diethylene glycol, ethelyne glycol, propylene glycol(preservative in IV lines))
- 5-oxoproline (metabolite of Tylenol)
- Lactate
- Methanol
- Aspirin
- Renal failure
- Ketoacidosis
What two conditions are associated with high lactate levels?
Ischemic bowel disease or sepsis is associated with high L-lactate levels. Short bowel due surgery, they hae overgrowth of certain bacteria which form D-lactic acid. Both L-lactate and D-lactate can cause high anion gap metabolic acidosis
what is the delta ratio
it is the formula that can be used to assess elevated anion gap metabolic acidosis and to evaluate whether a mixer acid base disorder
what does a delta ratio of 1
most of the time the increase in the anion gap and the decrease in bicarbonate is equivalent in pure high anion gap metabolic giving you a delta ratio of 1
if the delta ratio is more than 2 or less than 1
you have a co-existing non-gap acidosis (diarrhea) in addition to the high anion gap acidosis
when will the patient present with mixed acid base disturbance
- if compensation does not exist in a patient, they have a mixed disturbance
- if compensation exceeds the proposed limits, it’s a mixed acid base disturbance
primary respiratory alkalosis has what on its differential diagnose
- cardiopulmonary (which causes you to hyperventilate to improve oxygenation causes you to also expel CO2)
- Intra-cranial pathology (decompensated brain tumor, meningitis, encephalitis) (respiratory centers leading to hyperventilation)
- Drugs (salicylate, xanthines such as theophylline)
- sepsis
- liver failure
- pregnancy
- hysteria
what kind of intoxication does aspirin cause
mixed acid-base disturbance. first from the metabolic acidosis and inappropriate respiratory alkalosis compensation.
- causes mixed acid-base in adults but it is more of a respiratory alkalosis and some metabolic acidosis and respiratory component is more pronounced
- pH is normal
Xanthines cause what kind of intoxication
respiratory alkalosis. it is commonly used in the past to treat asthma
how does sepsis cause respiratory alkalosis
- sepsis can cause respiratory alkalosis due to alterations of the microcirculation
- the CNS causes you to hyperventilate during sepsis resulting in respiratory alkalosis
- a high WBC count and or fever is also seen with sepsis
What does pregnancy cause
it is associated with respiratory alkalosis. A physiological response to normal pregnancy is a respiratory alkalosis for unknown reasons. The compensation to defend the pH in any respiratory alkalosis is for the kidney to lose bicarbonate. The low bicarbonate in the pregnant woman thus represents appropriate compensation for a respiratory alkalosis which is normal in pregnancy
Hysteria can also cause what and what is the mechanism
vii. Hysteria can also cause acute respiratory alkalosis. Hysteria causes cramps and paresthesias. Calcium exists in the blood bound to albumin as well as freely. This is an equilibrium relationship. Only free calcium is pharmacologically active. Albumin-bound calcium is not pharmacologically active. The equilibrium between free calcium and bound calcium is pH dependent.
1. In respiratory alkalosis, you have hypocalcemia because the equilibrium shifts so that you have more bound calcium. Hysteria-induced respiratory alkalosis thus results in tetany. Tetany is dangerous because it can cause laryngospasm.
2. Tetany can be tested for by checking for carpopedal spasms. To elicit carpopedal spasms (i.e. Trousseau’s sign) in a person with hysteria-induced respiratory alkalosis, a blood pressure cuff is placed around the arm and inflated to a pressure greater than the systolic blood pressure and held in place for 3 minutes. This will occlude the brachial artery. In the absence of blood flow, the patient’s hypocalcemia and subsequent neuromuscular irritability will induce spasm of the muscles of the hand and forear
Respiratory acid base disturbances unlike metabolic can be
acute or chronic
what is post hypercapnic metabolic alkalosis
when a patient’s PCO2 was lowered too quickly due to intubation resulting in the seizure
what drugs can give a patient hypokalemic acidosis according to this lecture
low potassium can cause metabolic acidosis and it is due to loop diuretics like furosemide as well as diarrhea
