We are racing the deadline for our ASN abstract. We have a great data set on geriatric patients in a structured CKD clinic. We need to define stable renal function. Our first try used the CKD stages. Our cohort is restricted to CKD 3b and 4. So stable was any patient who began and ended the study in the same CKD stage. This has been done in the literature, so there is some precedence but it doesn’t feel right to me.
Think about two participants in our study, both GFRs fall by 3 cc/min over three years, just about what the Baltimore Longitudinal Study on aging predicts. Patient A started with an eGFR of 31 mL and Patient B started with an eGFR of 33. These patients have the same clinical course and outcome but Patient A goes from 31 to 28 mL/min and hence from CKD Stage 3 to 4 while Patient B goes from an eGFR of 33 to 33 so his stage does not change.
I need a definition of stable renal function. You can help by filling this 5 question anonymous survey. We are looking
How would you define stable renal function:
Candidate A: Change in GFR less than 2 cc/min/yr (essentially 3x the average rate determined by the Baltimore Longitudinal Study on Aging).
Candidate B: Change of GFR of less than 20% from baseline to the end of the study
Candidate C: Change of less than 10 mL/min from the baseline visit
Note: baseline visit is the 1st contact with us with a GFR<45 mL/min(CKD stage 3b), we removed any patient who does not have a second eGFR < 45 at least 3 months before the initial measurement.
Really neat demo of an online database.
I may need to try this.
This looks pretty cool.
Here is the link to the section on kidney stones written by Murray Favus. On my brief overview it looks good.
Being in the textbook business in the era of free online textbooks, UpToDate and wiki’s has got to be a world of hurt.
The annals has an article this week on renal stents and again they fail.
They randomized 140 patients with GFR <>50% stenosis (CT angio, MRA or digital subtraction angiography) with in 1 cm of the origin of the renal artery. They also excluded patients with uncontrolled blood pressure (>140/90) this was done because if patients randomized to medical management developed uncontrollable blood pressure they could cross over and receive a stent.
The end point was a persistant 20% reduction of GFR by Cockcroft-Gault for more than a month.
Results: No significant difference between the two treatment strategies.
The Kaplan-Meier curves confirm this. The top graph is the primary outcome and the bottom graph is primary outcome plus death:
Renal angioplasty resulted a variety of complications:
Two patients in the stent group died of procedure-related causes within 30 days after stent placement. In 1 of the patients, embolization of a perforated renal artery was required; the patient subsequently developed pulmonary edema and needed mechanical ventilation, and died of a massive ischemic stroke 3 days later. The second patient had perforation of a renal artery branch; the artery was embolized, but despite re-intervention, the patient went into hypovolemic shock and experienced the acute respiratory distress syndrome, and died of multiorgan failure after 1 week.
The most common complications after stent placement were minor and mainly consisted of hematoma at the puncture site (11 patients [17%]). In 1 of these patients, secondary infection in the groin required surgical reconstruction. The patient thereafter developed end-stage renal failure, pulmonary edema, and heart failure and died 6 months after the procedure. In 2 other patients, stent placement was complicated by false aneurysm of the femoral artery. Injury to the kidney or renal artery occurred in 5 patients; however, this was never associated with loss of renal function and additional intervention was never required.
One patient in the stent group who had repeated angiography required permanent dialysis after cholesterol embolism.
So another negative trial of renal artery revascularization. We are still waiting for the publication of ASTRAL, a much larger and more definitive trial. CORAL is another trial which is ongoing and will shed further light on this subject.
This article about Simon Singh‘s battle with the British Chiropractic Association is frightening.
The consequences of letting the libel law loose on scientific debate are horrendous. Science proceeds by peer review. A researcher’s colleagues must submit his or her ideas to scrutiny without fear of the consequences. If they think they could lose their homes and savings in the libel courts, however, they will back off.
For alternative therapists are not the only ones answering their critics with lawyers. NMT, an American health giant, is suing a British doctor for questioning one of its treatments.
Incredibly the BCA has won the first legal round.
The BCA sued for libel. And on May 7th Sir David Eady, a high-court judge, ruled, in a preliminary hearing, that the “natural and ordinary meaning” of the phrase (the relevant legal test) was that the BCA was being consciously dishonest and knowingly promoting quack treatments.
The key to the court case is a claim that chiropractic treatments for problems outside of backpain are bogus that Singh made in Trick or Treatment: The Undeniable Facts about Alternative Medicine, a book he coauthored on alternative medicine.
Advancing medicine and science is impossible if writers have to self-censor themselves when discussing scientific claims.