You are called by ED for an encephalopathic pt who is acidotic and subsequently seized in front of the ED physician and was intubated. initial pH 7.02 with a pco2 of 49, O2 of 124, Bicarb of 8. Lactate was 5.3. Serum Osmolality was elevated at 344. Creatinine 3.7. His wife says he is a drinker but this AMS seems different then when hes normally intoxicated. Hes never seized before. last drink was only a few hours ago. She says hes seemed altered for the last 24 hours and hasn't urinated much at all.What are your next steps in work up (labs, imaging, consults, etc)?What are your differential diagnosis?
Tuesday, June 19, 2018
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With this rather significant presentation, that patient most likely had a toxic alcohol or ethylene glycol ingestion, I would obtain a broad lab work with methanol and ethylene glycol in the urine, a CMP, methanol level, and calculate an osmolar gap as I suspect that patient has a profound osmolar gap based on the limited history and the ABG does support this.
ReplyDeleteHaving a seizure unfortunately does increase this possible rather significantly, otherwise the profound metabolic acidosis with the pH as well as the severely depressed bicarbonate all point to a toxic ingestion. Along with above a CT head w/o contrast is well warranted, and an emergent nephrology for dialysis would also be appropriate.
I suspect that patient likely has a high anion gap metabolic acidosis and the differentials as lengthy including lactic acidosis, ketoacidosis 2/2 to ETOH ingestion, uremia, toxic alcohol vs. ethylene glycol ingestion.
A very intensive medical history and medication use should also be investigated and also get a salicylate level to ensure this is not the cause of the metabolic acidosis.
While waiting for nephro and potential dialysis, patient should be started on ethanol or fomepizole (this is superior), and high dose B6 and thiamine to prevent to formation of oxalic acid, and because this patient's pH is less than 7.3, he would be a appropriate candidate sodium bicarbonate IV bolus 1-2 meq/kg.
Finally get a neurology consult for further evaluation of patient's mental status if it does not improve.
Otherwise patient's metabolic acidosis could be due to a secondary cause such as sepsis and should have a full evaluation of sepsis including cultures, and antibiotic regiment as well as IVF resuscitation as appropriate and follow the patient as appropriate.
In addition to the above labs, CBC w/ diff, procalcitonin, blood, urine, and sputum cultures, magnesium, phosphorus should be ordered at the very least to augment your workup, as well as serial ABGs.
Ethylene glycol poisoning (Uptodate)
Physiological Approach to Assessment of Acid–Base Disturbances NJEM
So you have a gentleman who is an alcoholic with new onset seizures, Acute renal failure with minimal urine output in the last 24 hours and who has a severe metabolic acidosis along with elevated lactate who has been intubated secondary to new onset seizure.
ReplyDeleteCMP to identify his anion gap along with liver function. He could be uremic, his ammonia could be severely elevated. We need to calculate his osmolar gap as he currently has a serum osmolality severely elevated at 344 with normal 275-295. Will need a urinalysis to check for any oxylate crystals for possible ethylene glycol ingestion. I want a renal US to see if he is obstructed.
Will consult nephrology in case emergent dialysis is needed. Will consult Neurology and order an EEG for this new onset seizure. Again his seizure could all be metabolic related from renal failure, uremia, hyperammonemia, alcohol withdrawal less likely since he just stopped drinking a few hours ago. It's possible poison control will need to be contacted. Will need a UDS, toxicology screen, and ETOH level. Can place on SAS protocol. He will need to be in the ICU and monitored closely.
After patient is stable we can contact his PCP to gain access to records to see what his baseline labs are.
Differential Diagnosis:
1. New onset seizures 2/2 to possible Uremia, hyperammonemia, alcohol withdrawal less likely vs toxic metabolic encephalopathy requiring mechanical ventilation
2. Toxic metabolic encephalopathy 2/2 possible ethylene glycol ingestion vs other
3. AGMA likely secondary to lactic acidosis vs other no history of diabetes.
References:
UpToDate: anion gap metabolic acidosis, osmolar gap, new onset seizures
For an encephalopathic patient with history of alcoholism there is concern for overdose/toxic ingestion.
ReplyDeleteDifferential diagnosis: Alcohol overdose, methanol, ethyl alcohol, lactic acidosis, cerebrovascular accident, diabetic ketoacidosis, alcoholic ketoacidosis, uremia, sepsis
This patient will need a BMP to determine if this is an anion gap versus non anion gap metabolic acidosis. High anion gap metabolic acidosis is more consistent with history of ingestions and with this patient's severe acidosis this is most likely. With the BMP you can also calculate the serum osmolality, which the blood alcohol level should be factored into. The difference between the measured and calculated is serum osmolality is the osmolal gap. If this is a greater than 10 there is likely an elevation of unmeasured osmoles with concern for methanol and ethylene glycol. Ingestion of these substances can lead to blindness and kidney failure and requires emergent diagnosis and treatment, which may include dialysis.
Acidosis/toxic ingestion can cause encephalopathy. A CT head should be done to rule out acute cerebrovascular accident. You may also consider CT abdomen pelvis versus retroperitoneal ultrasound to evaluate kidneys and rule out obstruction.
Consult poison Control. Patient may need to be started on Ethyl alcohol or fomepizole. Nephrology should also been consulted for possible emergent dialysis. As the patient is severely acidotic he may also require a bicarb drip. Patient will need fluid resuscitation with trending of BMP and lactic acid q.4 hours. Other workup included magnesium, phosphorus, urine drug screen, blood alcohol level, serum ketones, urinalysis with microscopy, urine lytes, urine osmolality, serum osmolality, salicylate level, serum ammonia. Monitor urine output. Patient should also be kept on seizure, aspiration, fall precautions. Patient may need a neurology consult and EEG if initial workup is negative. The patient does not necessarily need seizure prophylaxis at this time. He can be started on a p.r.n. benzodiazepine or drip for sedation while on the ventilator. It is unlikely that the patient is withdrawing from alcohol as his last drink was only few hours ago. Monitor the serum sodium and do not correct more than 8-10 mEq over the 1st 24 hours as this can also be a cause for seizures. This patient is encephalopathic a detailed history should be taken from his wife and family. Past medical records with baseline kidney function would be helpful. Other baseline workup should include a CBC, chest x-ray, electrocardiogram to rule out other sources of acidosis. With his severe metabolic derangements, encephalopathy secondary to seizures requiring mechanical ventilation the patient will need to be admitted and closely monitored in the intensive care unit.
https://resident360.nejm.org/pages/home?resource_collection_id=critical-care&subtopic=acid-base-status-electrolytes&subgroup=fast-facts
With patient’s history of alcohol abuse with presentation of metabolic acidosis with new onset seizure and AKI, it is likely that patient had toxic encephalopathy secondary toxic alcohol ingestion of methanol or ethylene glycol that would cause metabolic acidosis. With AKI, ethylene glycol metabolites would be slower to eliminate. As far as labs, I would get a CMP to calculate anion gap (suspected to have high anion gap metabolic acidosis), ethylene glycol level, methanol level, and isopropyl alcohol level, UDS including salicylate and acetaminophen levels, and calculate osmotic gap. I would also get finger stick to rule out hypoglycemia. EKG to rule out conduction system causes, also ethylene glycol causes prolonged QTc. Repeat ABG. I would get an EEG and consult neurology for new onset seizure, however, it is likely secondary to the increased acidemia. I would consult nephrology for possibility of emergent dialysis for toxic alcohol levels. Renal US for decreased urine output. Patient should be started on fomepizole or ethanol to inhibit the enzyme alcohol dehydrogenase, and placed on SAS protocol with folic acid, thiamine, and multivitamin. Patient should also be started on IVF for resuscitation, blood cultures, and follow sepsis protocol. I would admit to the ICU in cause patient develops hyperpnea, Kussmaul respirations, or hypotension that would require immediate intervention. IF patient’s acidemia is severe, give patient sodium bicarbonate bolus.
ReplyDeleteDifferential Diagnosis: (GOLDMARK) Glycols, Oxoproline, Lactate, Methanol, Aspirin, Renal function (Uremia), and Ketoacidosis
https://www.uptodate.com/contents/approach-to-the-adult-with-metabolic-acidosis?search=metabolic%20acidosis%20anion%20gap&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
https://www.uptodate.com/contents/methanol-and-ethylene-glycol-poisoning?search=methanol%20toxicity&source=search_result&selectedTitle=1~35&usage_type=default&display_rank=1
In this pt, it seems likely that pt could be experiencing a toxic encephalopathy 2/2 toxic ingestion w/ methanol or ethylene glycol, especially w/ his history of alcohol use. Pt's metabolic acidosis evident via pH and bicarb levels would also be consistent w/ this. CT imaging of the head would need to be done in any mentally altered pt to assess for intracranial pathology. Fingerstick glucose check and EKG would also be warranted to check for endocrine causes and EKG could assess for conduction abnormalities. BMP/CMP would need to be ordered to calculate an anion gap. Serum calcium, serum ethanol, methanol, ethylene glycol, and isopropyl alcohol concentrations should also be ordered. Salicylate and acetaminophen levels should also be checked. UDS should also be checked to evaluate for other possible substances that are contributing to pt's current state. Because the pt is seizing, he really should be evaluated by Neurology. Pt should also be evaluated by Nephrology 2/2 AKI and poor urine output. Dialysis may be needed. Pt's airway should be secured due to pt's altered mental status and bicarb can be given to alleviate acidosis. Ethanol or Fomepazole may be given to inhibit alcohol dehydrogenase. Folate, Thiamine, and MVI should also be given 2/2 concern for toxic ingestion and history of alcohol use. Pt should also be rehydrated w/ IV fluids and electrolytes monitored. Pt should be closely monitored as hemodynamic status could be very labile.
ReplyDeleteDifferential Diagnosis: Alcohol ketoacidosis, sepsis, CVA, toxic encephalopathy 2/2 methanol/ethylene glycol ingestion, AGMA 2/2 lactic acidosis
https://www.uptodate.com/contents/methanol-and-ethylene-glycol-poisoning?search=ethylene%20glycol&source=search_result&selectedTitle=1~41&usage_type=default&display_rank=1#H18
Good responses from everyone. The most important things to recognize here is the possibility of a toxic alcohol ingestion. Alcoholic ketoacidosis itself could produce many of the described lab findings and symptoms however is much less dangerous overall and that it generally does not produce acute renal failure. The fact that his last alcoholic drink was only a few hours ago tells you his seizure was probably not an alcohol withdrawal seizure although heavy drinkers can still sees despite being legally intoxicated based on their alcohol consumption. The elevated serum osmolality tells you more than likely there is a significantly positive osmolar gap. Acute renal failure and more importantly, 24 hr of anuria coupled with encephalopathy greatly increases suspicion for ethylene glycol or methanol ingestion. Absence of visual disturbances would make ethylene glycol the more likely. Proceeding with a full laboratory workup as many of indicated is definitely the 1st step. There are multiple other differential diagnosis that need to be worked up. Most important is early recognition that if this is toxic alcohol, he is highly likely to have recurrent seizures and overt renal failure with uncontrollable metabolic acidosis without emergent hemodialysis and the 1st call should be to Nephrology to assess for urgent pre-emptive hemodialysis. Adjunct therapy such as fomepizole or ethanol drips are also indicated but dialysis takes precedence. This is also a diagnosis were you generally make the call based on the lab findings in front of you and clinical picture as you will not get the laboratory results of the toxic alcohols and the metabolites back in a timely fashion to wait on administration of fomepizole/ethanol and initiation of dialysis.
ReplyDeletePS. Do not forget to also treat the underlying alcohol intoxication itself and be prepared for alcohol withdrawal. The patient most definitely needs thiamine and folate administration and benzodiazepine therapy while working up and treating the toxic alcohol ingestion.
Take away points
Early recognition of possible toxic alcohol ingestion in the setting of anuric renal failure and immediate evaluation for hemodialysis