Page 1731 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

1200 PART 11: Special Problems in Critical Care

TABLE 124-9 Examples of Drugs/Toxins Causing an Agitated Physiologic State TABLE 124-11 Selected Drugs Affecting Pupil Size
Sympathomimetics Miosis (Constricted) Mydriasis (Dilated)
Adrenergic agonists Barbiturates Amphetamines
Amphetamines Carbamates Anticholinergics
Caffeine Clonidine Antihistamines
Cocaine Ethanol Cocaine
Ergot alkaloids Isopropyl alcohol Cyclic antidepressants
Monoamine oxidase inhibitors Organophosphates Dopamine
Theophylline Opioids (meperidine may cause mydriasis) Drug withdrawal
Anticholinergics Glutethimide
Antihistamines Phencyclidine (PCP) Lysergic acid diethylamide (LSD)
Antiparkinsonian drugs Phenothiazines Monamine oxidase inhibitors
Antipsychotics Physostigmine
Antispasmodics Pilocarpine
Cyclic antidepressants
Cyclobenzaprine
TABLE 124-12 Selected Drugs and Toxins Affecting Muscle Tone
Drug withdrawal
Dystonic Reactions Dyskinesias Rigidity
β-Blockers
Haloperidol Anticholinergics Black widow spider bite
Clonidine
Ethanol Metoclopramide Cocaine Malignant hyperthermia
Phenothiazines Phencyclidine Neuroleptic malignant syndrome
Opioids
Data from Olson KR, Pentel PR, Kelley MT. Physical assessment and differential diagnosis of the poisoned
Sedative-hypnotics
patient. Med Toxicol. January-February 1987;2(1):52-81.
Hallucinogens
Lysergic acid diethylamide (LSD) anion gap resulting from decreased unmeasured cations is rare but may
Marijuana occur in severe potassium, calcium, or magnesium depletion. The most
Mescaline common cause of an elevated anion gap is an increase in unmeasured
anions. This includes accumulation of organic acids, as in lactic acidosis
Phencyclidine or ketoacidosis, or accumulation of the anions of organic acids such as
Other sulfate and phosphate in uremia. Common causes of an elevated anion
Thyroid hormones gap are listed in Table 124-13.
Toxic ingestions may increase unmeasured anions and elevate the
anion gap (eg, ethylene glycol elevates the anions glycolate and lac-
The presence of an anion gap indicates that there are more unmea- tate). An elevated anion gap mandates consideration of toxic ingestion,
sured anions than cations, since total serum cations equals total even in the presence of ketones or lactate, which can occur with toxic
serum anions. Unmeasured cations include potassium, magnesium, and ingestion. 33,34 Drugs associated with an elevated anion gap are included
calcium, totaling about 11 mEq/L under normal conditions. The con- in Table 124-14.
centration of unmeasured anions, including mainly albumin, sulfates,
phosphates, and organic acids, is about 23 mEq/L (hence the difference
of approximately 12 mEq/L). It follows that the presence of hypoalbu- TABLE 124-13 Common Causes of an Elevated Anion Gap
31
minemia requires a downward adjustment of the expected normal anion Lactic acidosis
gap: The anion gap falls 2.5 mEq/L for every 1 g/L decrease in plasma Uremia
albumin concentration. 32 Sepsis
The anion gap increases through three possible mechanisms: a
decrease in unmeasured cations, an increase in unmeasured anions, or a Rhabdomyolysis
laboratory error in measurement of Na , Cl , or HCO . An increase in Ketoacidosis
−
−
+
3
Diabetic
TABLE 124-10 Common Drugs/Toxins Causing Delirium and Confusion Alcoholic
Alcohol/drug withdrawal Starvation
Anticholinergics Toxic ingestions
Antihistamines Ethylene glycol
Carbon monoxide Methanol
Cimetidine Acetaminophen (5-oxoproline)
Heavy metals Paraldehyde
Lithium Salicylate
Salicylates Metabolic alkalosis with volume depletion

section11.indd 1200 1/19/2015 10:51:57 AM