Question

Michael, a 54-year-old male, was admitted to the emergency department (ED). He was conscious but his level of consciousness (LOC) was diminished. He was neither very alert nor coherent in responding to verbal questioning. Michael was responsive to pain stimulus. He did not have “alcohol breath” or a “fruity odor” upon exhalation. Michael admitted that his vision was slightly blurred and that he was seeing double (diplopia). Slight nystagmus was evident. Michael experienced multiple episodes of emesis. Additional symptoms included cephalalgia, slurred speech, and unsteady gait. Lips and fingernails were bluish in color.

Vital signs were as follows:

Pulse=110 beats per minute	normal: ~80
Blood	normal: 120/80
pressure = 100/74 mmHg
Respirations = 28 per minute	normal: 12–16

Results of the initial laboratory tests were as follows:

Serum Chemistries	Results	Reference Interval
Note: N/A="notapplicable."
Sodium (mEq/L)	135	136–145
Potassium (mEq/L)	4.5	3.5–5.1
Chloride (mEq/L)	108	98–107
Carbon dioxide (mEq/L)	7	23–29
Anion gap (mEq/L)	20	6–10
Glucose (mg/dL)	162	74–100
Creatinine (mg/dL)	1.5	0.9–1.3
Urea nitrogen (mg/dL)	17	6–20
Calculated osmol (mOsm/kg)	285	282–300
Ethanol (mg/dL)	<10	N/A
Acetaminophen (μg/mL)	<2.5	N/A
Salicylate (mg/dL)	<2.8	N/A
Hematology Results
WBC (×10^9/L)	11.0	4.0–11.0
RBC (×10^12/L)	4.3	4.7–6.1
Hemoglobin (g/dL)	11	13.0–18.0
Hematocrit (%)	34.9	39–50
Platelets (×10^9/L)	110	140–440
Urinalysis
Color:	amber	yellow
Appearance:	hazy	clear
pH	6	5–6
Specific gravity	1.028	1.002–1.030
All other dipstick results	Negative
Microscopic analysis	Birefringent octahedral, envelope-shape calcium oxalate crystals

Issues and Questions to Consider

1. What course of action should the clinician pursue?

2. What is the possible origin of the calcium oxalate crystals in the urine?

3. What additional laboratory tests should be considered?

The ED physician exposed a urine specimen provided by Michael to a Wood’s lamp and the specimen emitted a yellow-green color (i.e., it glowed). The physician suspected the presence of a chemical substance in the urine that may be ethylene glycol. Additional laboratory tests were requested and included the following:

Serum Chemistries	Results	RI or Cutoff Values
Drug Abuse Urine (DAU) screen: negative for seven classes of abused drugs
Serum osmolality (mOsm/kg) (Using freezing-point depression osmometry)	372	275–295
Osmol gap (mOsm/kg)	87	5–10
Volatiles:
Ethylene glycol (mg/dL)	190	Toxic ≥20
Methanol (mg/dL)	<1.5	Toxic ≥3.0
Isopropanol (mg/dL)	<1.0	Toxic ≥1

Issues and Questions to Consider

1. Explain the cause of the increased osmol gap.

2. Why did the urine emit a yellow-green color when irradiated with ultraviolet light using a Wood’s lamp?

3. Is the ethylene glycol concentration representative of a toxic dose?

4. Why is ethylene glycol toxic to the human body?

5. What is the treatment for ethylene glycol ingestion?

Answer 1

1. Course of action should be

• aggressive gastric lavage to prevent absorption of drug
• ethanol infusion or 4 methylpyrazole
• sodiym bicArbonate , thiamine and vit B6 to correct metabolic acidosis
• correction of hypocalcemia with calcium chloride
• hemodialysis to remove methanol or other metabolites

2. ethylene glycol is metabolised to glycolic acid by alcohol dehydrogenase that fuurthur in series combine with calcium from the blood forms calcium oxalate. Deposition of calcium oxalate in kidneys causes renal toxicity and appearance of calcium oxalate crystals in urine.

3. Osmol gap, serum osmolality, Serum analysis of ethylene glycol should be done.An elevated serum level of ethylene glycol confirms ethylene glycol poisoning. Significant toxicity is often associated with levels greater than 25 milligrams per deciliter (mg/dL)

4. Increased osmol gap is due to presence of elevated level of uncharged molecules like ethylene glycol. Ethanol in blood.

5. urine emitted colour because ethylene alcohol when used as antifreeze contains fluoroscein which gives colour to urine on irradiation