Acid Base

Question 1

The degree of respiratory compensation expected in a metabolic acidosis can be predicted from the relationship

Answer 1

Paco 2 = (1.5 × [HCO 3 − ]) + 8 ± 2 (Winter’s equation).

Question 2

_______—defined as independently coexisting disorders, not merely compensatory responses—are often seen in patients in critical care units and can lead to dangerous extremes of pH

Answer 2

Mixed acid-base disorders

Question 3

The “normal” value for the AG reported by clinical laboratories has declined with improved methodology for measuring plasma electrolytes and ranges from _____mmol/L

Answer 3

6−12

Question 4

Which of the following can cause a decrease in the anion gap?

A. Hyperlipidemia
B. Uremia
C. Lactic acidosis
D. Salicylate intoxication

Answer 4

A

Question 5

Metabolic acidosis can occur because of an increase in _____production (such as lactate and ketoacids), loss of bicarbonate (as in diarrhea), or accumulation of endogenous acids because of inappropriately low excretion of net acid by the kidney (as in chronic kidney disease).

Answer 5

endogenous acid

Question 6

The fall in blood pH is accompanied by a characteristic increase in ventilation, especially the tidal volume (______).

Answer 6

Kussmaul respiration

Question 7

There are two major categories of clinical metabolic acidosis: ______

Answer 7

high-AG and non-AG acidosis

Question 8

The p ence of metabolic acidosis, a normal AG, and hyperchloremia denotes the presence of a ______

Answer 8

non-AG metabolic acidosis.

Question 9

Treatment of metabolic acidosis with alkali should be reserved for _____ except when the patient has no “_____ ” in plasma.

Answer 9

severe acidemia

potential HCO 3 −

Question 10

Metabolizable acid anion

Answer 10

B hydroxybutyrate, acetoacetate, lactate

Question 11

patients with a non-AG acidosis (_______)

Answer 11

hyperchloremic acidosis

Question 12

AG acidosis attributable to a nonmetabolizable anion due to advanced kidney failure (______)

Answer 12

“uremic” acidosis

Question 13

patients with a non-AG acidosis (hyperchloremic acidosis) or an AG acidosis attributable to a nonmetabolizable anion due to advanced kidney failure (“uremic” acidosis) should receive alkali therapy, either PO (NaHCO 3 tablets or Shohl’s solution) or IV (NaHCO 3 ), in an amount necessary to slowly increase the plasma [HCO 3 − ] to a target value of ______

Answer 13

22 mmol/L.

Question 14

Bicarbonate therapy in diabetic ketoacidosis (DKA) is reserved for adult patients with severe acidemia _____) and/or evidence of shock.

Answer 14

(pH <7.00

Question 15

In DKA with severe acidemia bicarbonate therapy:

Answer 15

IV, as a slow infusion of 50 meq of NaHCO3 diluted in 300 mL of a saline solution, over 30–45 min, during the initial 1–2 h of therapy.

Question 16

A reasonable initial goal in DKA is to increase the [HCO3 − ] to 1____and the pH to approximately _____, but clearly not to increase these values to normal.

Answer 16

0–12 mmol/L

7.20

Question 17

There are four principal causes of a high-AG acidosis: ______

Answer 17

(1) lactic acidosis
(2) ketoacidosis
(3) ingested toxins
(4) acute and chronic kidney failure

Question 17

Pyroglutamic acidemia may occur in critically ill patients receiving _____, which causes depletion of glutathione and accumulation of 5-oxyprolene.

Answer 17

acetaminophen

Question 18

______, which may be associated with jejunoileal bypass, short bowel syndrome, or intestinal obstruction, is due to formation of d-lactate by gut bacteria.

Answer 18

d-Lactic acid acidosis

Question 19

Alkali therapy is generally advocated for acute, severe acidemia (pH___) to improve cardiovascular function

Answer 19

<7.00

Question 20

A reasonable approach with severe acidemia is to infuse sufficient NaHCO 3 to raise arterial pH to no more than___ or the [HCO 3 – ] to no more than ____

Answer 20

7.2

12 mmol/L

Question 21

This condition is caused by increased fatty acid metabolism and the accumulation of ketoacids (acetoacetate and β-hydroxybutyrate).

Answer 21

DKA

Question 22

Ketoacidosis can occur in patients receiving____ for the same reasons as in classical DKA

Answer 22

SGLT2 antagonists

Question 23

Ketoacidosis can occur in patients receiving____ for the same reasons as in classical DKA

Answer 23

SGLT2 antagonists

Question 24

[DKA] If administered, NaHCO should be administered in only limited amounts because of the risk for___

Answer 24

cerebral edema

Question 25

Patients with DKA are typically volume depleted and require fluid resuscitation with ____

Answer 25

Isotonic Saline

Question 26

The presence of a high-AG acidosis, in the absence of hyperglycemia, in a patient with chronic alcoholism suggests the diagnosis of ___

Answer 26

AKA

Question 27

[AKA] As the circulation is restored by administration of IV fluids, the preferential accumulation of β-hydroxybutyrate is then shifted to______.

Answer 27

acetoacetate

Question 28

Patients with ____ usually present with relatively normal renal function

Answer 28

AKA

Question 29

[AKA] Extracellular fluid deficits almost always accompany AKA and should be repaired by IV administration, initially, of ________

Answer 29

saline and glucose (5% dextrose in 0.9% NaCl)

Question 30

[AKA]______ may emerge 12–24 h after admission, exacerbated by glucose infusion, and, if severe, may induce marked muscle weakness, hemolysis, rhabdomyolysis, or respiratory arrest.

Answer 30

Hypophosphatemia

Question 31

[Salicylate Induced Acidosis] Vigorous gastric lavage with _____ (not NaHCO ) should be initiated immediately

Answer 31

isotonic saline

Question 32

[SIA] All patients should receive at least one round of _____ _____ per nasogastric tube (1 g/kg up to 50 g)

Answer 32

Activated charcoal

Question 33

[SAI] Raising urine pH from 6.5 to ____ increases salicylate clearance fivefold.

Answer 33

7.5

Question 34

[SAI]_____ should be anticipated with vigorous bicarb therapy and should be treated promptly and aggressively

Answer 34

Hypokalemia

Question 35

Under most physiologic conditions, sodium, urea, and glucose generate the____ pressure of blood.

Answer 35

Osmotic

Question 36

[Alcohols] All cause an elevated osmolal gap, but only the first two cause a high-AG acidosis.

Answer 36

ethylene glycol
methanol

Question 37

The combination of both a high AG and osmolar gap is highly suspicious for____

Answer 37

EG or methanol intoxication

Question 38

This includes the prompt institution of IV isotonic fluids, thiamine and pyridoxine supplements, fomepizole, and usually, hemodialysis.

Answer 38

Ethylene Glycol Intoxication

Question 39

The agent of choice and offers the advantages of a predictable decline in EG levels without excessive obtundation, as seen during ethyl alcohol infusion

Answer 39

Fomepizole

Question 40

[EGI] Fomepizole should be continued until blood pH is _____ or the osmolar gap is <10 mOsm/kg H2O.

Answer 40

Normal

Question 41

[EGI] Hemodialysis is indicated when the arterial pH is ___, a high-AG acidosis is present, the osmolar gap exceeds 20 mOsm/kg H2 O, or there is evidence of end organ damage such as CNS manifestations and kidney failure.

Answer 41

<7.3

Question 42

The ingestion of _____ (wood alcohol) causes metabolic acidosis, and its metabolites formaldehyde and formic acid cause severe optic nerve and CNS damage

Answer 42

Methanol

Question 43

____ is the vehicle used in IV administration of diazepam, lorazepam, phenobarbital, nitroglycerine, etomidate, enoximone, and phenytoin.

Answer 43

Propylene glycol

Question 44

This form of high-gap acidosis should be considered in patients with unexplained high-gap acidosis, hyperosmolality, and clinical deterioration, especially in the setting of treatment for alcohol withdrawal

Answer 44

Propylene Glycol

Question 45

With intoxication by propylene glycol, the first response is to______

Answer 45

stop the offending infusion

Question 46

Ingested isopropanol is absorbed rapidly and may be fatal when as little as ____ of rubbing alcohol, solvent, or deicer is consumed

Answer 46

150 mL

Question 47

5-Oxoproline accumulation after acetaminophen should be suspected in the setting of an unexplained high-AG acidosis without elevation of the osmolar gap in patients receiving______.

Answer 47

acetaminophen

Question 48

The non-AG metabolic acidosis of stages 3 and 4 CKD require oral alkali replacement to increase and maintain the [HCO 3 − ] to a value mmol/L.

Answer 48

> 22

Question 49

Stool contains a higher concentration of HCO 3 − and decomposed HCO 3 − than plasma so that metabolic acidosis develops in diarrhea. T/F

Answer 49

T

Question 50

Proximal RTA (type 2 RTA) (Chap. 315) is most often due to generalized proximal tubular dysfunction manifested by glycosuria, generalized aminoaciduria, and phosphaturia (______)

Answer 50

Fanconi syndrome

Question 51

______ occurs as a result of severe pulmonary disease, respiratory muscle fatigue, or abnormalities in ventilatory control and is recognized by an increase in Paco 2 and decrease in pH

Answer 51

Respiratory acidosis

Question 52

Compensation Mechanisms:

Acute: HCO₃⁻ rises by ___ mmol/L for every 10-mmHg increase in PaCO₂.

Chronic (>24 h): HCO₃⁻ rises by ____ mmol/L for every 10-mmHg increase in PaCO₂ (maximum ~38 mmol

Answer 52

Acute 1
Chronic 4

Question 53

The most common acid-base d bance in critically ill patients and, when severe, portends a poor prognosis.

Answer 53

Chronic Respiratory Alkalosis

Question 54

_____ are the most common cause of drug-induced respiratory alkalosis because of direct stimulation of the medullary chemoreceptor

Answer 54

Salicylates

Question 55

______ is the only acid-base disorder for which compensation can return the pH to the normal value.

Answer 55

Chronic respiratory alkalosis