Amazing, Amusing & Awesome Acidosis Anecdotes... And Gnarly Mnemonics Kent R. Olson, MD Medical Director California Poison Control System Clinical Professor of Medicine UC San Francisco

 Case 1: An Acidic Alcoholic n A 44 yo man was found unconscious, with a suicide note and a half-empty bottle of Jim Beam. n BP 110/80HR 110RR 24 n pH 7.47 pCO 2 22pO 2 88 n Na 140 K 3.8 Cl 106 HCO 3 18 n ETOH 0.18 gm/dL

 Causes of Metabolic Acidosis: “MUDPILES” n Methanol n Uremia n DKA n Phenformin, Paraldehyde n INH, Iron n Lactic acid n Ethylene glycol n Salicylate

 Salicylate Intoxication: n Typical mixed acid-base abnormality: – Respiratory alkalosis – Metabolic acidosis n May be acute or chronic n Large OD may cause delayed peak n Treatment: – Alkalinize urine, restore serum pH – Hemodialysis

 Case 2: A Gapped Gipper n 30 yo M found comatose n Temp 86F, pH 6.9 n Na 147, K 4.9, Cl 105, Bicarb 5 –Anion gap 37 n Glu 166, BUN 16, Cr 1.5 n Measured Osm 331 –Osm gap 23 n Ethanol “zero”

 The Osmolar Gap: Osm = 2 (Na) + BUN/2.8 + Glucose/18 Gap = Measured - Calculated Osm = n Causes of Osm Gap: – Ethanol – Isopropyl alcohol & Acetone – Methanol & Ethylene glycol – Other alcohols & glycols n Erroneous results: – Wrong tube; Different specimen times – Falsely normal gap with vaporization method

 Methanol poisoning METHANOL FORMALDEHYDE FORMIC ACID ANION GAP ACIDOSIS ANION GAP ACIDOSIS ELEVATED OSMOLAR GAP ELEVATED OSMOLAR GAP

 Ethylene Glycol & Methanol: n Osmolar gap n Anion gap –Lactate low, does not account for gap –Early in the intoxication, anion gap may be absent n Additional clues: (may be unreliable) –EG: urine crystals, fluorescence –Methanol: visual disturbance

 Ethylene Glycol & Methanol: n Main DDx: Alcoholic Ketoacidosis –Anion and Osmolar gaps –Low lactate –AKA clues: GETS BETTER over a few hrs with fluids and dextrose Ketone levels +/- (beta-hydroxybutyrate)

 Case 3: Not on the List n A 15 year old young woman was found comatose (GCS 7) n BP 92/34 mm Hg HR 120/min n RR 24/min pulse ox 94% (room air) n pH 7.16 pCO2 27 pO2 127 n Anion gap 20 –Salicylate negative –Methanol, EG negative

 Case 3, cont. n She became more obtunded and was intubated n Treated with IV fluids n Received bicarbonate 50 mEq x 1 n Recovered, extubated in 12 hours n Admitted to ingesting 500 ibuprofen tablets (200 mg size) Seifert SA et al: J Tox Clin Tox 2000; 38:55-7

 Ibuprofen n Common NSAID n Propionic acid derivative –Contributes to acidosis –(Naproxen is also a PA derivative) n Moderate OD: GI upset n Severe OD: –Coma, seizures –Hypotension, renal failure –ARDS

 Case 4: A Surprising Finding n 28 yo F found comatose in a hotel room, 2 empty bottles of Extra Strength Tylenol (total about 150 gm) n BP 120/50, HR 130, pupils midrange n pH 7.03, HCO3 4, anion gap 25 n ASA negative, APAP 850 mg/L n AST 70 n Lactate >11 mmol/L

 Acetaminophen n Case (continued): –ETOH, Methanol, Ethylene Glycol tests all negative –Patient later developed liver, renal failure

 Acetaminophen n Massive ingestion: –Rare cause of early onset metabolic acidosis –Mechanism unknown, probably acute metabolic dysfunction in liver cells –Can also cause coma, hypotension n Different mechanism than hepatic injury

 Cases 5-6: Metabolic Madness n Ataxic 2 yo child –Na 152 –HCO3 12, pH 7.24 –Ammonia 80 n Obtunded 25 yo F –BP 60s systolic –pH 7.16, pCO2 37, pO2 66 –Hypoglycemia (glucose = 50s) –Calcium 6.6

 Valproic acid (Depakote) n Common anticonvulsant n Increasing use in psychiatry n Metabolic dysfunction –Hypoglycemia –Hypocalcemia –Elevated ammonia –Encephalopathy n Coma and rarely cerebral edema n Consider hemodialysis if VPA>1000

 Cases 7-8: Caustic Cocktails n A sulfuric anion gap: n 33 yo M ingested "Hot Shot Drain Cleaner" containing 9% sulfuric acid n BP /palp, drooling, in pain n ET intubated shortly after arrival n Initial Na 143, K 8.1, Cl 97, HCO3 <5, –Anion gap >40 n Lactate 2.1

 Caustic Cocktails, continued... n Not an anion gap: n 43 yo F ingested Lysol Toilet Bowl Cleaner (HCl %, pH <1) n Pain! Serum CPK 26,812 n pH 7.19, CO2 24 n Na 144 Cl 121 HCO –Anion gap = 4.4

 A Final Stumper: n A 5 year old Laotian immigrant girl was brought to the ED at 3 AM very lethargic n History of nausea and vomiting starting at 1 AM n BP 89/42 HR 103 R 16 T 97 n Pupils 4 mm, skin normal n Mouth dry, active peristalsis

 Case 9 Continued... n According to the father, at 6 pm the previous evening the family had eaten a meal of steamed wild root n They collected it near the Berkeley Marina and considered it a tasty substitute for bamboo shoots n At 1 AM all 5 family members experienced nausea and vomiting; the 5 yo also had diarrhea

 Case 9, Continued... n Shortly after admission, the child's pupils were noted to be dilated and poorly reactive n Respirations were shallow, and the HR was 65/min n pH 6.8 pCO 2 21 pO n Shortly after, the child had a tonic- clonic seizure

 Case 9, Continued... n Further Hx: n The family said a brother was taking some type of “chest medicine” n A family member was sent home to retrieve the bottle….

 Common causes of seizures n Cocaine/amphetamines n Tricyclic antidepressants n Bupropion n Diphenhydramine n Tramadaol n Isoniazid (INH) n Phenothiazines & antipsychotics

 Case, continued n The bottle contained erythromycin n A blood cyanide level was 6 mg/L n The wild root was identified as pampas grass; although usually non- toxic, at certain times of the year it elaborates cyanogenic (cyanide- producing) glycosides.

 “MUDPILES” revised? n Methanol or metformin n Acetaminophen or AKA (“maudespil?”) n Uremia n DKA or Depakote n Phenformin or paracetamol n INH, Iron or ibuprofen n Lactic acid n Ethylene glycol n Salicylate or syanide?

 A Shorter Mnemonic: n SALAD:Lab Test: –SalicylateASA –AlcoholsOsm –Lactic acidLactate –AnuriaBUN/Cr –DKAGlucose

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