As part of my role as a board member of the eAJKD I was able to interview Iain Macdougall regarding his survey of emerging and novel anemia therapies in AJKD. It was a fun interview and I’m proud of how the post turned out. Check it out.
St Clair Specialty Cleaned up in Hour Detroit’s Survey of Top Docs
I work at St Clair Specialty Physicians a nephrology group in Southeast Michigan. In the most recent Top Docs roundup by Hour Detroit, we cleaned up in nephrology with 6 of the 16 selections and also had the top vote getter in hypertension. Great work Drs. Bellovich, Butcher, Khairullah, Provenzano and Steigerwalt.
Crazy Medical Presentation, or Craziest Medical Presentation?
Giles Brindley, the man who gave whole new meaning to PowerPoint.
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In 1983 Professor Brindley presented his findings on papaverine injection and erectile dysfunction. His presentation was a bit unconventional as recounted by (PDF) Laurentz Klotz, a senior resident who attended the presentation.
…four or five of the women in the front rows threw their arms up in the air, seemingly in unison, and screamed loudly. The scientific merits of the presentation had been overwhelmed, for them, by the novel and unusual mode of demonstrating the results.
via Andy Ihnotko. Additional and comprehensive coverage at AlignMap
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.
My Apple Predictions. 2012 edition
Last year I published a list Apple predictions and I will post a complete score card. However, some of my predictions can not be judged until Apple announces its first quarter results on January 24th. I will however provide my 2012 predictions now.
iPad
The iPad 3 will be announced February 28th and released March 16th. The iPad 3 will include a Retina Display with a resolution of 2048×1536. The case will largely look like the current iPad but Apple will introduce colors (again) like the iPod Nano and possibly patterns like the old Flower Power and Blue Dalmatian iMacs.
The cellular equipped iPad 3 will come with LTE radios in addition to the 3g and 2g radios they currently have. The large battery capacity of the iPad will make this luxury a possibility even though the iPhone 5 will lag behind with 3g.
The iPad 3 will also have the new quad-core A6 processor and get the same battery life as the current iPad except when using the LTE radio.
The memory options will remain16, 32, and 64 gb. This will be the last iOS device to include the 30 pin dock connector. The iPad 3 will get Siri. Prices will remain the same.
The current iPad 2 will continue as a discount model to fight the Kindle Fire and what-ever 7 inch piece of crap Eric Schmidt is talking about. The iPad 2 will only be available in 16 gb, but will still be available with WiFi or WiFi +cellular. The iPad 2 will be priced at $349 for the WiFi version and $479 for the WiFi +cellular
In addition to Verizon and AT&T, Sprint will get both iPads. Sprint will introduce a discounted price that bundles the wireless internet for your phone and iPad in order to solidify its position as the bargain wireless plan.
Last year I estimated cumulative sales of 65 million iPads (total of 2010 and 2011 iPad sales). Barring a total sales frenzy over this past Christmas I’m was a wee bit optimistic, with cumulative sales coming in closer to 54 million (that assumes iPad sales of 14 million in the Christmas quarter, 90% more than last Christmas, and 30% more than previous quarter). I am going to predict sales of 60 million iPads in 2012.
iPhone
The iPhone 5 will be introduced in September and go on sale two weeks later. The message of the design is durability. Apple will use the same nano-coating that Motorola used on the RAZR to make it more water repellant. Apple will brand this with a unique name and claim it to be a major breakthrough.
Continuing with the theme of durability, Apple will abandon the 30-pin dock connector and seal the entire body of the phone. All data connections will need to be done wirelessly. A new MagSafe-like connector will be introduced for charging. Additionally the iPhone will lose the glass back, and it will be replaced with an aluminum one like on the iPad.
NFC will be added to go along with an electronic wallet system called iCash. This will be linked to your iTunes account.
The phone will be slightly thinner than the iPhone 4, but will largely have the same form factor. There will not be a tear-drop shaped design. The screen size remains 3.5 inches. Like the iPad 3, it will be released in multiple colors. The rear camera gets better, the device gets thinner, the phone receives the quad core A6.
With the introduction of the iPhone 5, the iPhone 4S is only offered with 16 gb and moves down to $99. The 8 gb iPhone 4 becomes the free offering in developed countries and the 3GS soldiers on as the price leader in emerging economies.
Data from Asymco. |
- 8 gb WiFi $229
- 32 gb WiFi $329 WiFi + Cellular $399
- 64 gb WiFi $429 WiFi + Cellular $499
Throughout 2012 there is not a peep about the next version of OS X.
Apple introduces a revamped Apple TV at WWDC and it goes on sale in September. It remains the little iOS box that is currently sold with a bigger processor and a new version of the OS and Siri. An iOS device running iOS 6 will be required to act as the microphone for Siri. It will also gain the ability to add apps from the iTunes App Store. The Apple TV Set will also be introduced in June for a September or October role out. The Apple TV set (iPanel?) will not offer any significant feature beyond the Apple TV. However, it will come bundled with a 7 inch iPad to act as a remote control, game controller and auxiliary screen. Additionally, any iPhone, iPad and iPod running iOS will be able to duplicate the functions of this uber-remote.
Tim Cook will remain the CEO and there will be a steady trickle of VPs leaving the company for other CEO positions. Names that will stay include Cook, Cue, Ive and Schiller. Forstall, Mansfield are among the Veeps who may move on.
A lot of companies might try to entice the architect of the iPhone to be their top guy and with a young Tim Cook (born 1960) secure as CEO, an ambitious Forstall might make the jump. Can you imagine Scott Forstall being tapped to replace Ballmer at Microsoft?
John Gruber, a closet reader of PBFluids?
Take a look at my post on Andy Warhol, Coke and the iPhone
And now, Gruber’s post on the same subject.
One time. Just one time, I want to get linked by Gruber.
Coffee + MacBook Air = No posts for awhile
I spilled an entire cup of coffee on my laptop.
Dead laptop.
Last back-up, 7 weeks old.
Lost blogging momentum.
I have a pile of half written posts and should be out of the funk soon.
I have also purchased a dropbox account and will not be caught with two-month old back-ups again. That’s a pretty good new years resolution, though better would be to not spill cups of coffee into my laptop.