Monthly Archives: November 2014

Cheesecake files: Just how deadly is it?

Everyone said it did, but how did they know and by how much?  Statements like

“The development of AKI [Acute Kidney Injury] after CPB [Cardiopulmonary Bypass Surgery] is associated with a significant increase in infectious complications, an increase in length of hospital stay, and greater mortality.” (Kumar & Suneja, Anaesthesiology 2011 14(4):964)

are common place in the acute kidney injury literature.  When I started to look at the references for such statements I realised that they were all to individual, normally single centre, studies and that the estimates of the increased risk associated with AKI after CPB varied considerably.  Furthermore, the way AKI is defined in these studies is quite varied. This lead to two questions?

  1. Just how deadly is getting AKI after CPB?
  2. Does it matter how we define AKI in this case?

These questions are important as the answer to them helps a surgeon and patient to better assess the risk associated with choosing to have cardiopulmonary bypass surgery and what the importance is in monitoring kidney function after such a surgery.  To answer these questions required a meta-analysis the results of which I have just published (a.k.a earned a cheesecake).  A meta-analysis involves systematically searching through the literature, a sentence which takes seconds to write but months to serve, for all articles reporting an association between AKI and mortality after CPB.  Then there is learning how to put all the, sometimes disparate, data together (I had to learn a lot of R for this one) and to report on it.  As this was my first meta-analysis, I was fortunate to have the assistance of two highly competent scientists & nephrologists with meta-analysis experience, namely Dr’s Matt James of Calgary, and Suetonia Palmer of my own department in the University of Otago Christchurch.

So – what did we find?

  1. If you get AKI after CPB you about 4 time more likely to die compared to if you do not get AKI after CPB even after accounting for things like age, diabetes, and other risk factors.
  2. Somewhere between 37 and 118 lives per 10,000 CPB operations could be saved if we could find a way to eliminate AKI.
  3. How AKI was measured did not make any difference to the results.
  4. AKI after CPB was also associated with increased risk of stroke.
Figure 1 from Pickering et al, AJKD 2014

A teaser of a figure from Pickering et al, AJKD 2014

Pickering, J. W., James, M. T., & Palmer, S. C. (2014). Acute Kidney Injury and Prognosis after Cardiopulmonary Bypass: A Meta-analysis of Cohort Studies. American Journal of Kidney Diseases : the Official Journal of the National Kidney Foundation. doi:10.1053/j.ajkd.2014.09.008

ps. Sorry about the paywall folks, but as I’ve said before, if we want to put this data in front of the people it is most relevant to we haven’t the budget to always make them Open Access.


Can Doctors and Nurses help Dialysis patients recover?

In the case of dialysis dependent acute kidney injury patients this is a question which Dr Dinna Cruz  and colleagues (University of California San Diego) are asking and seeking opinions from both nephrologists and non-nephrologist doctors and nurses involved in care of dialysis patients.  It was a question which arose out of discussions at this year’s Continuous Renal Replacement Therapies conference (CRRT 2014). Personally, I think it is a brilliant starting point for research to go out and seek the opinion of those “at the coal face” actually treating patients. If that includes you, please take a moment to complete the survey. If it includes someone you know, please pass this request to participate on.  Here is Dr Cruz’s request:

Currently there is much interest regarding the recovery aspect of AKI. A specific area of interest is how to enhance recovery in patients who remain dialysis-dependent at the time of discharge. It is hypothesized that patients with potential for renal recovery may require a different care plan than the “usual” ESRD patient.

Therefore we are asking your opinion regarding the post-discharge care of such patients, using this short survey. It will take only a few minutes of your time, and represents a starting point for developing potential strategies for these patients. We think it is very important to have the input of specialists from different healthcare settings and countries to give a more balanced view.

Kindly complete the survey appropriate for your specialty, then please share both these links with other colleagues so we get more responses from around the world

For nephrologists:

For non-nephrologists, including acute and chronic dialysis nurses:

Thank you very much for your help!

Source: Anna Frodesiak-Wikimedia Commons

Source: Anna Frodesiak-Wikimedia Commons

Publication police and how to choose where to publish

“I confess, I published behind a paywall.  I’m sorry, sir, I didn’t want to, but but but I’m almost out of funds and and …..<suspect’s voice fades>”             Publication Police files, Nov.3 2024

Will peer pressure eventually lead to discrimination against those who publish behind a paywall?  Is it now a moral imperative that we publish everything open access?  If so, is that not simply morality by majority (a dangerous proposition at the best of times), or worse, morality by the most vocal?

I’m often asked “Where should I publish this?” and I must admit that “In an open access journal” is not my first response.  This is simply because there is a higher standard than mere open access (as great as that is).  Where to publish is first and foremost the answer to the question “Where will it get the attention it deserves?”  Of course, this is where ego can raise its ugly head and, worse, I have colleagues who think this means the journal with the highest impact factor, but those distractions aside, it is still the most important question.

Most of our science is simply an incremental step building on what is going before.  Most of the time it is of interest to a relatively small group of fellow researchers or those whose profession is impacted on by the research.  Furthermore, it will probably be of interest only for a short period of time before someone else builds upon it. The “attention a paper deserves” is the attention that these people for whom it has most meaning give it.  For this reason, it should be published in a manner which makes it easy for these people to read about it and access it. This will probably mean one of the professional society journals and/or one of the most read journals in the field.  In the fields of Critical Care and Nephrology where I’ve published most recently this will probably mean a European or American journal which has high readership in those jurisdictions because this is where most of the research is being done.    Of course, this does not mean my manuscript will necessarily be accepted by those journals, but if I deem it has something important to say, then that is where I should send it first.

Comparatively few of those journals are open access only, but all offer an open access option.  This tends to come with a publishing fee in the range of US$1500 to US$3000.  My budget does not stretch to paying such a fee for every publication. I am forced to be pragmatic. If my manuscript is accepted into one of those more high profile journals I have to pick and choose.  The more important I think the findings the more likely I will take the open access option.  Also, if I think the message has immediate application for clinicians (i.e. not just the narrow group of researchers in my field) I am more likely to choose open access.

There is, of course, the option to publish in more general online journals (PlosOne, PeerJ, F1000 etc) and I have done so.  However, my impression at this stage it that these do not rapidly reach the inbox of most of the very very busy researchers and clinicians in the fields I publish in.  A few (like myself), may have set up automatic search strategies or use social media to follow journals in their field, and, of course, if people are conducting PubMed or the like searches they may come across those articles.  However, their lack of specialisation and reliance on someone making more effort over and above reading the specialised professional journals they have always read, mitigates somewhat their usefulness to me to “getting the message out.”  Of course, I could choose to be a “early adopter” or “pioneer” and publish in a low cost open access journal (if my fellow authors would let me) with the hope that this will change the publishing culture of paywalls and high publishing fees elsewhere.  However, it would be at the cost of less exposure of my research to those who are most interested and active in the field.  For some of what I publish I must balance my obligation to advance the field the most by maximising the chances of exposure amongst those for whom it is likely to be of immediate interest with the more philosophical desire for open access to all and sundry from now to eternity.