13. Peak levels occur 2-4 hours
post-ingestion,
although absorption can be
m u c h s l o w e r in massive
overdose or with ingestion of
sustained-release preparations.
14. • therapeutic dose is 300-2700 mg/d
• Molecular weight of lithium carbonate?
• Li CO = 74
2 3
• Volume of distribution of 0.6-1 l/kg
• Desired levels 0.6-1.2 mEq/L
• Half-life is from 12-27 hours after a single
dose
• 36 hours in elderly persons
• Half-life grows with chronic use
17. Acute
• No tissue body burden
• Symptoms are predominately GI
• nausea, vomiting, cramping, diarrhea.
• Progression can involve neuromuscular signs
• tremulousness, dystonia, hyperreflexia, and ataxia
• Cardiac dysrhythmias have been reported
but rarely occur.
• The most common ECG finding is T-wave flattening
18. Acute-on-chronic
• Take lithium regularly and have sudden
ingestion
• May display both GI and neurologic
symptoms,
• Serum levels can be difficult to interpret
• Treated according to clinical manifestations
19. Chronic
• Large body burden of lithium
• Due to newly impaired renal excretion
possibly via hypovolemia
• Primarily neurologic.
• Mental status is often altered
• From coma to seizures
• Syndrome of Irreversible Lithium-Effectuated NeuroToxicity (SILENT)
such as cognitive impairment, sensorimotor peripheral neuropathy, and
cerebellar dysfunction.
•
21. • Does lithium cause an osmolar gap?
143 109 14.6
100 Osmolality 324 Lithium 14.5
3.6 36 1.1
22. • Does lithium cause an osmolar gap?
• Does lithium cause an anion gap?
143 109 14.6
100 Osmolality 324 Lithium 14.5
3.6 36 1.1
23. • Does lithium cause an osmolar gap?
• Does lithium cause an anion gap?
• What is lithium’s contribution to the
osmolar gap?
143 109 14.6
100 Osmolality 324 Lithium 14.5
3.6 36 1.1
24.
25.
26.
27.
28.
29. lactic acid
• does it increase the osmolar gap
• shouldn’t because it is anion
30.
31. sick patient
• 58 year old white male
• history of COPD
• automobile accident with blunt trauma to
chest
• intubated on the vent
• day 6 in the ICU, increasing oxygen demand
32. • patient is agitated and bucking the vent
• patient on pip/tazo, orazepam drip, TPN
• Lactic acid 1.3
33. • patient is agitated and bucking the vent
• patient on pip/tazo, orazepam drip, TPN
• Lactic acid 1.3
34. • patient is agitated and bucking the vent
• patient on pip/tazo, orazepam drip, TPN
• Lactic acid 1.3
138 100 24
141
3.8 18 1.2
Osm 303 Lactic Acid 1.2
35. • patient is agitated and bucking the vent
• patient on pip/tazo, orazepam drip, TPN
• Lactic acid 1.3
138 100 24 138 98 28
141 166
3.8 18 1.2 3.8 16 1.2
Osm 303 Lactic Acid 1.2 Osm 312 Lactic Acid 4
36. • patient is agitated and bucking the vent
• patient on pip/tazo, orazepam drip, TPN
• Lactic acid 1.3
138 100 24 138 98 28
141 166
3.8 18 1.2 3.8 16 1.2
Osm 303 Lactic Acid 1.2 Osm 312 Lactic Acid 4
136 94 22
154
3.8 15 1.3
Osm 325 Lactic Acid 5
37. • patient is agitated and bucking the vent
• patient on pip/tazo, orazepam drip, TPN
• Lactic acid 1.3
138 100 24 138 98 28
141 166
3.8 18 1.2 3.8 16 1.2
Osm 303 Lactic Acid 1.2 Osm 312 Lactic Acid 4
136 94 22 135 95 24
154 123
3.8 15 1.3 3.8 16 0.9
Osm 325 Lactic Acid 5 Osm 335 Lactic Acid 5
39. • icu patients
• especially with liver/
kidney dysfunction
• metabolism generates
D-lactic and or L-lactic
acid
• typically mild 2-6
• increase serum
osmolality maybe only
indication of toxicity
40.
41.
42.
43. • Contamination of spirits with 50-100%
methanol
• 154 ingestions
• 43 died without making it to the hospital
• 111 admissions with confirmed methanol
intoxication
• 25 died
• 66 survived, no sequelae
• 20 survived, + sequelae
http://www.biomedcentral.com/1472-6904/9/5
44. • found a high rate of developing eye
sequelae in the initially unaffected (8/22)
• 30% 6-year mortality found across all age
groups
49. T2-weighted MRI of the
brain: bilateral, symmetric
hyperintense putaminal
lesions, suggesting
hemorrhagic necrosis
(arrows). Direct toxicity of
formic acid (an end
product of methanol
metabolism), ischemic
injury, and acidosis are
postulated mechanisms of
putaminal injury.
50.
51.
52. • gi absorption is rapid and complete
• little use of charcoal, emesis or gastric
lavage
53. indications for ADH
inhibition
• Methanol level > 20 mg/dL
• history of ingestion and osmolal gap > 10
• strong suspicion with two of the following
• pH <7.3
• HCO < 20
3
• osmolal gap > 20
56. • ethanol has 10-20x the affinity of alcohol
dehydrogenase than other alcohols
• at 100 mg/dL it completely inhibits alcohol
dehydrogenase
• fomepazole has 500-1000x the affinity of
ADH than ethanol
66. • folic acid promotes metabolism of formate
to CO2 and water
• thiamine promotes conversion of glyoxylate
to glycine and glycolic acid to alpha-
hydroxy-beta-ketoadipate
67. ethylene glycol
• ratio of ethylene glycol to methanol
intoxications:
• 6:1
• 5,800 cases/year
71. • Glycolate causes most
of the acidosis
• oxalate + calcium
causes tissue damage
• kidney
• hearty
• brain
• lung
72. • calcium oxalate deposition can also cause
hypocalcemia
• heart failure
• hypotension
73. 3 phases of symptoms
• symptoms in three stages
• neurologic
• confusion focal neurologic defects
• cardiopulmonary dysfunction
• renal failure
74. indications for ADH
inhibition
• Ethylene glycol level > 20 mg/dL
• history of ingestion and osmolal gap > 10
• strong suspicion with two of the following
• pH <7.3
• HCO < 20
3
• osmolal gap > 10
• oxalate crystals
75.
76. • can cause a false positive assay for lactic
acidosis
• thiamine and pyridoxime may shift ethylene
glycol metabolsm to less toxic end-
products
78. • acute kidney injury is common
• hepatitis
• pancreatitis
• small changes in osmolal gap
• molecular weight 106
• dialysis is effective
79. isopropyl alcohol
• rubbing alcohol
• no acidosis
• dialysis for:
• Coma
• Hypotension
• Isopropyl level over 200
80.
81. • 131 patients
• 20 exposed to ethylene
glycol or methanol
• Using a cut-off of 10
mmol/kg
• sensitivity of 0.85
• specificity of 0.50
• cut-off of 20
• sensitivity 0.76
• specificity of 0.61
82. osmolar gap, normal anion gap
• mannitol
• causes acute renal failure from osmotic
damage of proximal tubule cells
• increased risk of acute renal failure when
the osmolar gap is over 55.
