Acid-Base Disorders

Question 1

Regarding Henderson Hasselbach equation, what values change and what are the effects in there pH?

Answer 1

-Elevated PCO2 and DECR HCO-3 = decr pH
-Incr HCO-3 and Low PCO2= Incr pH

Question 2

What 4 things you check in Acid-Base disorders?

Answer 2

-PCO2,pH,HCO-3 and compensation.

Question 3

What ions are taking in consideration in calculating Anion Gap.

Answer 3

-Na+, HCO-3 and Cl-

Question 4

Why checking Anion Gap is helpfull in metabolic acidosis?

Answer 4

-To determine where the problem arises. So many types.

Question 5

Normal value of Anion Gap
PCO2
HCO-3

Answer 5

3-12mEq/L
33-45 mm Hg
22-28 mEq/L

Question 6

What causes High Anion Gap Metabolic Acidosis?
>12mEq/L of Anion Gap.

Answer 6

-Methanol–>formic acid
Uremia
Diabetic ketoacidosis
Propylene Glycol–>petroleum
Isoniazid and Iron tablets
Lactic acidosis
Ethylene Glycol (Anti-Freeze)
Sialacytes

Question 7

Normal Anion Gap Metabloc acidosis

Answer 7

Hyperalimentation
Addison dis.–>
Renal Tubular Acidosis
Diarrhea–>loss HCO-3 in stools–>reabsp of Cl-
Acetozolamide
Spironolactone–>incr reabsp HCO-3
Saline infusion 0.9%-> pH=5.5–>body to secrete HCO-3–>acidosis but responds with reabsp. of Cl-

-Same mechanism for every one, when you incr acid in blood–>reabsp more HCO-3 or Cl-
-Loose HCO-3 you reabsp Cl-

Question 8

To determine respiratory compensation what formula do you use:

Answer 8

Winter Formula
-PCO2= (1.5 x HCO-3+ 8) +/- 2

Question 9

When is the Winter Formula used

Answer 9

-Metabolic acidosis/alkalosis

Question 10

Interpret

-PCO2 value within Winter range tells you
-PCO2 value greater than the range of Winter Formula
-PCO2 value less than range of Winter Formula

Answer 10

-metabolic acidosis with appropiate compensatory respiration
-metabolic acidosis + associated respiratory acidosis
-metabolic acidosis + associated respiratory alkalosis

Question 11

The compensation for respiratory acid-base disorders takes how much?

Answer 11

-At least 24hr. for kidneys to start working.

Question 12

Respiratory acidosis (>45mmHg)PCO2 ass. with..

Answer 12

Airway obstruction
Sedatives

Acute Chronic Lung dise

Chronic Lung disease
Opiods.
Weakening of resp muscles

-HYPOVENTILATION

Question 13

Respiratory Alkalosis (<35mmHg) association

Answer 13

Panic attacks
Anxiety attacks
Salicytes
Tumor brains

Pulmunary embolism
Hypoxemia (High altitudes)

HYPERVENTILATION

Question 14

Metabolic alkalosis 2 causes?

Answer 14

1.Lose of H+–>Hyperaldosteronism + Vomiting
2.HCO-3 gain: Loop diuretics (volume contraction where not much HCO-3 is lossed) + Anta-acids overdose.

Loop diuretics
Anti-acids overdose
Vomiting
Aldosteronism

Question 15

> 28mmHg HCO-3//pH>7.45
-Compensation..

Answer 15

-Metabolic alkalosis
**-Hypoventilation. **

Question 16

What happens in compensation for respiratory
-acidosis
-alkalosis

Answer 16

-Reabsp. of HCO-2
-Excretion HCO-3

Question 17

Question 18

Diagnosis

A 22-year-old woman presents to her family physician because of increasing fatigue and pale appearance. She reports that her urine appears brown each morning. There is no history of major medical illness. Laboratory studies show RBC of 3 million/mm3 and hemoglobin 10 g/dL.

Which of the following best describes the most likely mechanism of erythrocyte injury in this condition?

Answer 18

-PNH relating respiratory acidosis.
-PIGA gene mutation (hematopoetic stem cells)–>defective CD55 and DAF –>inhibits complememt acting on RBC.At night–>respiratory acidosis–>activate complement an promote hemolytic anemia–>MORNING BLOOD URINE that clears during day.
-Hemolytic anemia (low RBC and Hg), Thrombosis, blood morning urine,-Coomb test

Question 19

Spironolactone and Diarrhea diffrence in acid-base disorders?

Answer 19

-Both cause Normal Anion Gap Metabolic Acidosis +Decr HC0-3 and incr Cl- and acidic pH.
**Spironolactone has Hyperkalemia **and Diarrhea has Hypokalemia

Question 20

Hyperchloremic metabolic acidosis, what disorders present like this?

Answer 20

Renal Tubular Acidosis

Question 21

What RTA leads to this

hypophosphatemic rickets and osteomalacia.

Answer 21

-Type 2 (Faucconi syndrome)

Question 22

What causes

Contraction metabolic alkalosis?

Answer 22

Vomiting.
-Loose H+ and Volume at same time–>contraction metabolic alkalosis—>RAAS system–>promotes H+ loss in collecting tubules and Increases H+/Na+ exchanger in PCT (excretes H+ and reabsp. Na+)–> reabsp H20 due to the volume loss.

Question 23

If they give you PCO2 and HCO-3 in acid-base disorder question what should you do?

Answer 23

-Always calculate Winter Formula (compensation)

Question 24

What is the commonest MIXED acid-base disorder cause by?

Answer 24

-Aspirin cause** metabolic acidosis** (its metabolites–>lactic acid accumulates over time) and respiratory alkalosis by chainging sensitivity towards O2 and CO2–>Hyperventilation.

Question 25

Effects chronic alcohol users in your acid-base disorders

Answer 25

Question 26

Furosemide effects on:K+,Cl-,Na+,pH,HCO-3 and compensation

Answer 26

Furosemide causes **renal loss of **sodium, water, and hydrogen ions, sometimes leading to volume depletion, hypokalemia, and metabolic alkalosis with a low urine chloride.

-Incr in PCO2 as compensation.

Question 27

Benzodiazepines
-Use
A.E
Mechanism related to acid-base disorders

Answer 27

Diazepam,lorazepam
-Incr Cl- channel activity–>incr GABA neuron conduction.
-Used alcohol withdrawl, nigth terrors, sleepwalking, anxiety, panic disorders,status epilepticus.
-A.E: CNS depression severly when used along side Alcohol and Barbituates. //dependence

-Benzodiazepines (eg, lorazepam, diazepam) are administered in the emulsifying agent propylene glycol, and some patients may develop toxicity from this agent. Similar to what happens with ethylene glycol toxicity, this process causes patients to develop hyperosmolarity with an increased osmolar gap (an exogenous osmole) and anion-gap metabolic acidosis due to lactic acidosis.

Question 28

Barbituates
-Use
A.E

Answer 28

-Phenobarbital,pentobarbital,
-Facilitate GABA action by incr. duration of Cl− channel opening ,thus neuron firing decreases.
-Sedative for anxiety, seizures, insomnia, induction of anesthesia (thiopental).
-Respiratory and cardiovascular depression(can be fatal); CNS depression (can be exacerbated by alcohol use);dependence.

Question 29

Comparrision between Barbituates vs. Benzodazapines

Answer 29

-Benzo are less sedatives for respiratory depression.