I was invited back to The Curbsiders for a discussion about hypernatremia. I had a great time and through the magic of Hannah Abram’s production and Matt Watto’s edits it turned out pretty good. I listened Toit and I didn’t come up with any major gaffs. Take a listen. What do you think? As usual all comments should come through Twitter.
The Hypernatremia Lecture for OUWB
Las\\t Wednesday I was unable to get through the entire Sodium and Water lecture. Here is the last 17 minutes that I was not able to get to in class.
The full slide set is available here
OUWB SoM Sodium and Water Lecture
So drop box behaves strangely with Keynote files. When you get to this page by clicking the above links, press the Download button.
Here is a link to the Keynote presentation exported to powerpoint.
#KidneyCON Fluid, Electrolyte, and Acid-Base Workshop
David Goldfarb (@weddellite) and I put on a fluid, electrolyte and acid-base variety show at KidneyCON. The itinerary:
- IV fluid taste test
- Hypernatremia
- Management of calcium phosphate stones: to K-Citrate or not?
- Management of chronic hyponatremia, use of DDAVP
- Aspirin toxicity
- Hyperkalemia
Both of us had a bunch of additional cases that we didn’t get to so be sure to go deep into the presentation files.
Here are the presentation files:
- Keynote 1 (Topf)
- TMZ Emergency Medicine (Topf)
- PowerPoint (Goldfarb)
.@kidney_boy at the fluids and electrolytes workshop #KidneyCON pic.twitter.com/VpGbSc8V05
— Matthew Sparks, MD (@Nephro_Sparks) April 7, 2018
@weddellite and @kidney_boy giving a master class on electrolytes and acid base at #KIDNEYcon pic.twitter.com/xJm4Z2wPaK
— Anna Burgner MD MEHP (@anna_burgner) April 7, 2018
Making D5W and 0.9% NS with @kidney_boy in the #KidneyCON fluid workshop pic.twitter.com/zp9e6AXT8I
— Timothy Yau (@Maximal_Change) April 7, 2018
Make #KIDNEYcon great again? @kidney_boy @weddellite pic.twitter.com/Jleke2ZFKd
— Diana Mahbod, MD, CPE, FASN, FNKF (@DiMiRenalMD) April 7, 2018
@kidney_boy tries to induce hypernatremia and hyperglycemia #KIDNEYCon pic.twitter.com/7EfQsVYxEb
— David S Goldfarb, MD (@weddellite) April 6, 2018
Chef @kidney_boy mixing NS and D5W for administration to #kidneycon attendees pic.twitter.com/ChzftumYeZ
— David S Goldfarb, MD (@weddellite) April 6, 2018
Water and Osmoles for M2s
This is my Water and Osmoles lecture edited for students, specifically pre-clinical M2s.
I then broke this down into two PowerPoint presentations
Water and osmoles for residents
Water, diuretics and dysnatremia
- 89 slides
- Probably 80-90 minutes for a full delivery
- The Dysnatremia section is largely identical to the Sodium lecture above
- Fuller description of the lecture at this post
- Updated July 2011
Saltiest Sodium. Dumbest Dude.
My work-shop on sodium includes a bit on all the cases of hyponatremia due to fraternity hazing.
I also include the crazy case of Jennifer Strange.
But I had never heard of idiot induced hypernatremia until this case report:
A nineteen year old male drank a quart sized bottle of soy sauce on a bet.
Two hours later he was brought to the ER comatose and seizing. His sodium was 177. They initiated hypotonic fluids and arranged transfer to a tertiary care center. At the tertiary care center the sodium was still higher at 191. The doctors then changed the fluids to D5W at 12,000 mL per hour. They gave 6 liters of D5W in 30 minutes.
After the infusion he opened his eyes and regained spontaneous movement. He was discharged on hospital day four neurologically intact with only some minor abnormalities on the head MRI, all attributed to postictal changes.
How high is a sodium of 191? MedCalc will not even accept it as a possible sodium concentration:
A couple items of note:
- The infusion of D5W raised his serum glucose from 365 (hyperglycemia causes insulin resistance) to 1,116 mg/dL.
- The authors do not comment on what access they used to infuse D5W at a liter every five minutes.
- In addition to the hyperglycemia, the D5W infusion dropped the potassium from 5.1 to 2.5 in 30 minutes! That is kind of terrifying.
- The authors use the Katz correction for hyperglycemia, (eat it Hillier).
- The authors do not discuss how they decided on 6 liters of D5W. Full correction down to 140 would by roughly 12 liters, so perhaps they decided on 12 liters in an hour with continuous neurologic assessment and when he began to have spontaneous motor movement after 30 minutes they slowed down.
Some nerdery about the sodium exposure: He drank a quart of soy sauce. A quart is 946 mL. The article states that soy sauce is 17-18% sodium chloride. Here are some meta calculations, in case you are interested:
Update from Twitter:
@kidney_boy I would guess they used a pressure bag or infuser (e.g. Trauma 1) to get in a L every 5 min
— Seth Trueger (@MDaware) June 10, 2013
@mdaware @kidney_boyA good 14 ga 1.75 inch peripheral IV can do 333 cc/min with a 1 meter pressure head to gravity.
— philroman (@philroman) June 11, 2013
@kidney_boy I’ve seen 216 before. Started at 196, rose more with initial NS administration. Kid with ichthyosis, and bad dehydration.
— Ken Tegtmeyer (@pccm_doc) June 11, 2013
Salty dog, the highest sodium I ever saw.
A series of sodiums from 176-188 mmol/L |
Those are not glucoses. They are Sodiums. And, except for maybe an infant with congenital adrenal hyperplasia when I was a resident, those are the highest sodiums I have ever seen.
The primary management concern was the speed of correction. The first Na at 188 was drawn at 4:32 pm. Four hours later it was 177, a change of 11 mEq. Too fast. Here is the salient section from UpToDate:
Rate of correction in chronic hypernatremia — There are no definitive clinical trials, but data in children (particularly infants) suggest that the maximum safe rate at which the serum sodium concentration should be lowered in patients with chronic hypernatremia is 12 meq/L per day. To be safe, we suggest a maximum rate of correction of the serum sodium of 10 meq/L per day in patients who have had hypernatremia for at least 24 hours. The following findings provide support for this conclusion:
- A retrospective case control study included 97 children with hypernatremia and dehydration; the mean baseline serum sodium was 165 meq/L. The rate of reduction in serum sodium was significantly faster in the children who developed cerebral edema compared with children who had no complications following correction of the hypernatremia (1.0 versus 0.5 meq/L per hour).
- Similar findings were noted in another report in which the rate of reduction in serum sodium was 1.0 meq/L per hour in the nine infants who developed seizures compared with 0.6 meq/L per hour or less in 31 infants who did not develop seizures.
Burton Rose
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My patient moves 11 mEq in 4 hours after receiving 500 mL of normal saline. Now what? I was convinced that continuing normal saline would perpetuate the overly rapid correction of the sodium and put the patient at risk of cerebral edema. But since the patient was still in hypovolemic shock, I couldn’t just stop the fluids.
docx | pdf |
- Rose’s own textbook, Clinical Physiology of Acid Bas Disorders. The page to look at in my 5th edition is 777.
- Kahn et al. Controlled fall in natremia and risk of seizures in hypertonic dehydration. Intensive Care Med (1979) vol. 5 (1) pp. 27-31
- Fang et al. Fluid management of hypernatraemic dehydration to prevent cerebral oedema: a retrospective case control study of 97 children in China. Journal of Paediatrics and Child Health (2010) vol. 46 (6) pp. 301-3
- Blum et al. Safe oral rehydration of hypertonic dehydration. J Pediatr Gastroenterol Nutr (1986) vol. 5 (2) pp. 232-5
What book did this great page on maintenance fluids come from? |
Nine of the first 47 patients developed seizures that could not be explained by other etiologies (fever, hypocalcemia, hypoglycemia) and so were ascribed to rapid fluid restoration, Group I. They matched these nine to 22 age-matched children who were treated contemporaneously but did not have a seizure, Group II. The investigators then changed the protocol for treating infants with hypernatremia to 120 mL/kg/day and included data on 9 patients under 5 months who were treated this way, Group III.
Here is the primary data on the three groups:
All three groups had similar sodiums but Group I had significantly higher BUNs than Group II, with I +II vs III and I vs III being non-signifigant.
The net result was a wide spread in the rate of correction of sodium:
- The kids that seized: 1.02 mEq/L/hr
- The kids that did not seize but were on the same treatment protocol: 0.62 mEq/L/hr
- The kids on the conservative protocol, also without seizures: 0.35 mEq/L/hr
Fang looked at 97 children with hypernatremia. Mean sodium was 164.5. Mean age 13 months. He performed a case-control study with the cases being patients who developed cerebral edema. Manifestations included seizures, eyelid edema, papilledema in all the patients and bulging fontanel in 36 and pupillary abnormalities in 9 cases.
The data shows cerebral edema was more common with bolus therapy, especially when the bolus was faster, higher sodiums were associated with cerebral edema but much of that disappeared in multivariate analysis as higher sodiums were also associated with increased rate of correction and ind increased bolus rates. Using ROC the investigators found a rate of fluid administration of 6.8 ml/kg/hr was safest. And the average decrease in serum sodium in the cerebral edema group was 1 mEq/L/hr and 0.5 mEq/L/hr without cerebral edema.
The final reference is Blum’s study of oral rehydration, this is the reference my med student was upset with. As he outlined, this was a study of oral rehydration rather than a study of rates of treatment. The cohort was composed of eighteen infants, 6 months or younger admitted with hypernatremia (Na > 150) and treated with oral fluid resuscitation. They compared the hypernatremia outcomes to a second cohort of 26 infants who received IV rehydration for hypernatremia. Average sodium for both groups was 160.
In both groups the reduction of sodium was slow (0.3 mEq/L/hr) and no patient developed seizures.
In Burton Rose’s Clinical Physiology of Acid-Base and Electrolyte Disorders this observational study with no seizures is the sole reference behind the recommendation for a slow restoration of normal sodium. Weak sauce. Of note Androgue’s review of hypernatremia in the NEJM from 2000 references the same Blum and Khan articles to support its recommendation of slow treatment.
So in the end, the recommendation for slow normalization of sodium is based on a handful of studies in infants with no randomized or even prospective studies. What is unbelievable to me is no one references a study that reviews the functional/neurological outcomes of patients with the highest sodiums admitted to a large hospital based on the speed of correction. Seems like an easy study and in its absence we are left to trust in the physiology of babies.
Happy July 1st.
For the third year in a row a I had the honor to present the first morning report of the academic year. Fluids, diuretics and dysnatremia: