Salicylate Toxicity

Question 1

Earliest signs and symptoms of salicylate toxicity can develop when?

Answer 1

1-2 hours after ingestion

Question 2

Acute salicylate toxicity signs and symptoms

Answer 2

N/V, GI irritation, tinnitus, tachypnea/hyperpnea, respiratory alkalosis or respiratory acidosis, metabolic acidosis (anion gap or non-anion gap), altered mental status (AMS)/hallucinations, coma, seizures, hyperglycemia or hypoglycemia (neuroglycopenia), pulmonary edema, hepatic injury, coagulopathy, cerebral edema, ARDS, hyperthermia

Question 3

The 4 worst symptoms of salicylate toxicity

Answer 3

Coagulopathy, cerebral edema, ARDS, hyperthermia

Question 4

Patient characteristics of an acute salicylate toxicity

Answer 4

Younger
Ingest it intentionally/suicidal ideation
Easy to diagnose due to severely elevated serum concentrations
Death is uncommon

Question 5

Chronic salicylate toxicity symptoms

Answer 5

Nonspecific symptoms, usually misdiagnosed

Question 6

Chronic salicylate toxicity is usually associated with what?

Answer 6

Serum concentrations >60mg/dl, AMS, acid-base disturbances

Question 7

What may be present in chronic salicylate toxicity?

Answer 7

Cerebral edema and acute lung injury

Question 8

Patient characteristics of chronic salicylate toxicity

Answer 8

Older

Don’t ingest intentionally/iatrogenic

Under-recognized as a diagnosis because they have an intermediate elevation in serum concentrations

Death is more common due to delayed diagnosis

Question 9

Acid-base stages of salicylate toxicity: early

Answer 9

Primary respiratory alkalosis, alkalemia, alkaluria

Question 10

Early acid-base stage: levels of serum and urine pH

Answer 10

Both pH levels are low

Question 11

Acid-base stages of salicylate toxicity: intermediate

Answer 11

mixed respiratory alkalosis and anion gap metabolic acidosis, alkalemia, and aciduria

Question 12

Intermediate acid-base stage: levels of serum and urine pH

Answer 12

Serum pH is high, urine pH is low

Question 13

Acid-base stages of salicylate toxicity: late

Answer 13

metabolic acidosis with either a respiratory alkalosis or respiratory acidosis, acidemia, and aciduria

Question 14

Late acid-base stage: levels of serum and urine pH

Answer 14

Both pH levels are high

Question 15

Evaluation and diagnostic testing of salicylate toxicity: what should you get?

Answer 15

Serum salicylate level, blood gas and anion gap to classify the acid/base disorder

Question 16

Salicylate toxicity is associated with what serum concentrations?

Answer 16

> 30mg/dl

Question 17

Therapeutic range for inflammatory conditions

Answer 17

15-30mg/dl

Question 18

Therapeutic range for analgesia

Answer 18

5-10mg/dl

Question 19

Mild symptom serum levels for acute toxicity

Answer 19

> 150-200mg/kg (6.5g of ASA)

Question 20

Severe symptom serum levels for acute toxicity

Answer 20

> 300-500mg/kg

Question 21

Serum level for chronic toxicity

Answer 21

> 100mg/kg/day for several days

Question 22

Salicylate toxicity treatment: GI decontamination

Answer 22

MDAC

Question 23

What does MDAC do in salicylate toxicity?

Answer 23

Prevent absorption of unabsorbed salicylates

Question 24

When to consider MDAC in salicylate toxicity

Answer 24

If there’s a pharmacobezoar or an ER preparation is used

Question 25

Salicylate toxicity treatment: IV fluid administration

Answer 25

Hypovolemia should be corrected with administration of crystalloids (NS, LR, PlasmaLyte A)

Question 26

Salicylate toxicity treatment: glucose administration dose

Answer 26

0.5-1g/kg of dextrose followed by PRN additional bolus doses or a continuous infusion for severe salicylate toxicity

Question 27

Why is glucose administered in salicylate toxicity?

Answer 27

To ensure appropriate concentration of glucose in the CSF despite normal serum concentrations

Question 28

Cornerstone of salicylate toxicity treatment

Answer 28

Serum and urine alkalization

Question 29

Purpose of serum and urine alkalization in salicylate toxicity

Answer 29

Shifts salicylate out of the brain and tissues and into the serum to promote renal elimination

Question 30

How to ion trap salicylate in the serum and urine

Answer 30

IV sodium bicarb

Question 31

When to use IV sodium bicarb in salicylate toxicity

Answer 31

ALL SYMPTOMATIC PATIENTS SHOULD GET IT

Question 32

IV sodium bicarb bolus dose

Answer 32

1-2mEq/kg

Question 33

What does the IV sodium bicarb bolus dose do?

Answer 33

Increase serum pH → shifts of potassium from serum into intracellular space via the H+/K+ pump

Question 34

IV sodium bicarb continuous infusion

Answer 34

150 mEq sodium bicarb in 1000ml of D5W at a rate of 1.5-2x the maintenance rate

Question 35

Goal urine pH in salicylate toxicity treatment

Answer 35

7.5-8

Question 36

What levels should you maintain in the serum during sodium bicarb treatment in salicylate toxicity?

Answer 36

Potassium

Question 37

What happens (chemically speaking) after serum and urine alkalization?

Answer 37

Increase less mobile, non-permeable, ionized form of salicylate in urine; it occurs because salicylic acid is a weak acid → leads to trapping of salicylic acid in the urine where it’s excreted → enhances elimination of salicylate from the body

Question 38

When can hemodialysis be considered in salicylate toxicity?

Answer 38

Serum salicylate level >100mg/dl

Serum salicylate level >90mg/dl with impaired renal function OR failure of supportive therapies

Serum salicylate level >80mg/dl with impared renal function AND failure of supportive therapies

Supplemental O2 required due to AMS from hypoxemia

Question 39

When to D/C hemodialysis in salicylate toxicity treatment

Answer 39

When the serum salicylate level is <19mg/dl and patient is clinically improving

Question 40

Monitoring for salicylate toxicity: how often should you monitor the salicylate level?

Answer 40

q2-4h until patient is clinically improving with a low serum salicylate concentration and a normal or high serum pH

Question 41

Monitoring for salicylate toxicity: what else should you monitor?

Answer 41

Serum pH

Question 42

When to monitor patients more frequently in salicylate toxicity

Answer 42

Critically ill patients