Friday, February 6, 2009

Friday Surgical Journal Review

I've decided that it might be fun to write up a quickie review of one of the main surgical journals as a weekly feature. And I use the word "fun" in a very broad and all-encompassing sense. I've always found that trying to stay up on my surgical literature is about as much fun as watching a Grey's Anatomy repeat on Telemundo while stranded in a motel in Guadalajara. The journal arrives in the mail all glossy and colorful, jam packed with scholarly insight and innovative new science and then maybe you set it aside for "later" but every time you open it up, you end up just skimming through a couple of the abstracts that seem vaguely interesting and as the weeks go by, the glossiness of the cover dulls and crinkles and is pocked by circular coffee cup stains and residua from spilled food. So I will break down a journal once a week (except those weeks when I don't feel like it) for the edification of myself and my sparse but loyal readers. Enjoy.

Journal of The American College of Surgeons (JACS): January 2009

1) Human Polymerized Hemoglobin for the Treatment of Hemorrhagic Shock when Blood Is Unavailable: The USA Multicenter Trial

What's the deal?: Synthetic hemoglobin (PolyHeme) as an alternative to packed red blood cells. This is a cool development. In the study, trauma patients who were hypotensive in the field were randomized to 2 resuscitation arms; saline/red blood cells vs. intital infusion with PolyHeme.

Conclusions: Similar outcomes in patients resuscitated with PolyHeme vs saline/blood products.

Usefulness: Good to know that level I trauma centers can use this stuff in a pinch. Perhaps EMS first responders can be equipped with Polyheme so that resuscitation with oxygen carrying compounds can be implemented in the field. But the cost and availability of PolyHeme is not addressed. I don't foresee places other than major Level I trauma centers even considering this any time soon.

Statistics: They used something called a "dual superiority/noniferiority primary end point". I have no idea what that means. I can only trust that the conclusions drawn are valid.

General enjoyability: Not bad. The statistics and graphs are hard to follow but the case for synthetic oxygen carrying compounds is compelling. Of interest is that previous literature suggested a higher risk of myocardial infarction in patients receiving synthetic hemoglobin. This study intially suggested more MI's as well but a subsequent review by an "independent subcommittee" of cardiologists determined that there actually NOT a higher incidence of MI in the PolyHeme group.

2) Peripheral Vascular Surgery Using Targeted Beta Blockade Reduces Perioperative Cardiac Event Rate

What's it about?: Pre-operative evaluation of patient's needing major vascular surgery.

Conclusions: For low and medium risk patients, it may been unnecessary to do anything prior to surgery other than starting them on beta blockade.

Statistics: I don't know, something about cohorts and multivariate analysis.

General enjoyability: Quite high! Surgical interns across the land can now rejoice. Instead of exhausting themselves wheeling patients all over the hospital to complete their pre-op cardiac workups, this study (along with this one) suggests that perhaps all we need to be doing in select patients is starting them on Lopressor and titrating it to a targeted heart rate of 60-65.

3) Informatics and the American College of Surgeons National Surgical Quality Improvement Program: Automated Processes Could Replace Manual Record Review

What's it about: I have no idea. I couldn't read more than the first 2 sentences.
Conclusions: Something about informatics and how wonderful they can be.
Statistics: Didn't get that far.
General Enjoyability: As close to zero as you can get.

4) Survival in Stage III Colon Cancer Is Independent of the Total Number of Lymph Nodes Retrieved

What it's about: The relationship between the number of lymph nodes harvested and survival in patients with Stage III colon cancer.

Conclusions: In stage III colon cancer (i.e cancer that has spread to the mesenteric lymph nodes), the total number of nodes harvested is not a prognostic indicator of survival. This is in contradistinction to stage II colon cancer where survival is equated with retrieval of at least 12 lymph nodes.

Usefulness: Minimal. I'll explain why. The 12 lymph node threshold for Stage II is critical because if you only get 4 nodes and they're all negative, there's a chance you've understaged your patient. This is important because in colon cancer, we give adjuvant chemotherapy anytime you have N1 disease. If you have less than 12 nodes you can never be certain that the patient is truly stage II. So most oncologists would recommend giving chemo for stage II tumors if an inadequate lymph node sampling is done. Now if you know the patient is stage III he's going to get adjuvant chemo no matter how many nodes you harvest. It doesn't matter how many nodes are positive; all it takes is one. So this study only confirms the importance of chemotherapy in lymph node positive disease. It doesn't make the same comment about the extent or adequacy of the surgery performed like in previous studies on stage II disease because, again, stage III colon cancer gets zapped with chemotherapy no matter what. It's not like you run the risk of understaging the patient. But I still think we ought to always aim for high yield lymph node harvests whenever doing surgery for colorectal cancer.

5) Stored Red Blood Cell Transfusion Induces Regulatory T Cells

What it's about: Um, the search for the mechanism of immunosuppression after an allogeneic blood transfusion and the role that induced regulatory T-cells play.

Conclusions: No comprendo.

Statistics/Design: Something along the lines of supernatants and flow cytometries and test tubes and beakers and cytokine levels.

General Enjoyability: I was stabbing myself in the knee with a steak knife as I read this and I didn't even know it.

6) Effect of Body Mass Index on Short-Term Outcomes after Colectomy for Cancer

What it's about: The consequences of being fat and having your colon whacked out.

Conclusions: Morbidly obese patients have higher rates of wound infections, dehiscence, pulmonary embolism, and renal failure after colorectal surgery.

Statistics: A retrospective review of the ACS-NSQIP database. Pretty straightforward.

General Enjoyability: Obesity is bad. We can never have enough articles in the medical literature to hammer this home.

7) Nationwide Volume and Mortality after Elective Surgery in Cirrhotic Patients

What it's about: The hazards of operating on patients with underlying severe liver dysfunction. A national database of patients with cirrhosis who underwent one of four index operations (lap chole, colectomy, AAA repair, CABG) from 1998-2005 was reviewed.

Conclusions: In-hospital mortality, length of stay, and total hospital charges were substantially higher in cirrhotic patients undergoing elective surgery.

Usefulness: Cirrhosis, strangely enough, is often not identified until a patient comes into the hospital for a "routine" procedure and all hell breaks loose. Even patients without portal hypertension (compensated cirrhosis) had a higher frequency of adverse outcomes compared to the general population. For the average general surgeon, the lesson is: do a thorough history and physical prior to elective surgery. Being able to identify those patients at risk and preparing for the worst is often half the battle....


Anonymous said...

5) Stored Red Blood Cell Transfusion Induces Regulatory T Cells

What it's about: Um, the search for the mechanism of immunosuppression after an allogeneic blood transfusion and the role that induced regulatory T-cells play.

could this have to do with looking for the reason that CABG pts do better with fresh blood? Or is that some completely different mechanism?

/sorry about the knee
//going to stay anon due to healthy medstudent running his mouth off on the internet paranoia

Kelley said...

Love the new "column!" Hilarious, and informative all at the same time!

rlbates said...

I agree with Kelley.

Anonymous said...

All work and no play makes Buckeye Surgeon a dull boy, how about a review of "Maxim" next time?

Joseph Sucher, MD FACS said...

I really enjoy your writing. Great wit and no fear of putting yourself out there for criticism. Very admirable.

Since I have a dog in a few of these articles, I can't help but comment on the intellectual aspects at the risk of being incredibly boring.

1. PolyHeme study. A number of my patients were enrolled in this study. Many of whom had hit the 6U limit. All survived. A few things to note about this study. It was a tour-de-force to make this thing happen.

First, the investigators had to deal with enrolling patients without their consent. This requires investigators to go out to the community, speak with all of the community leaders in a public forum and explain why this study is necessary and why informed consent isn't possible to obtain. This takes a huge effort and is a hurdle that can't be explained well in this post alone.

Second. The study of dual superiority/non-inferiority is just fancy statistic language. It is meant to answer the questions 1.) Is this treatment superior or 2.) if it is not superior, is it at least as good given that it has other added benefits. For Hgb Based Oxygen Carrying Solutions (HBOCs) the added benefits are a.) universally applicable b.)easy long-term storage c.)no known immunomodulating properties d.)no known risk of infectious transmission.. etc.

Third. This study was plagued with the problems that have hit other HBOC studies. Enrollment validity was challenging (up to 20% of enrollment was outside protocol for the two groups). There was difficulties with the data management. The transport time for these patients was very fast (<26 min), thus not capturing the population that is really important (> 1 hr.). These type of problems may have had perverse effects on the statistics, thus I am unsure about the final outcomes of this study.

Fourth. What is clear to me. HBOCs and future research and development of Oxygen carrying solutions are necessary as they will most certainly have a great life-saving effect for a population of people who have mortal hemorrhage and are potentially far from definitive management.

2. ACS-NSQIP. I am an informatics guy. My hospital participates in ACS-NSQIP data collection. My chairman was instrumental at the VA in the promotion of the VA-NSQIP program that is the forebearer of the ACS national program.

What this is about is extremely important. Its about coming up with informatics systems that actually capture REAL / VALID information. Currently you and I are graded on data that is filled with mis-information. Our healthcare system is built on data that is replete with so much noise that you can't see any signal. This article is essentially saying that the ACS-NSQIP program holds a lot of validity, but it is prohibitively expensive to apply across the nation and into other specialties. Therefore we need to advance the research and development of informatics in such a way as to automate the process, thus bringing the time and expense of NSQIP down to a level that will make it applicable to every institution.. Additionally instead of using only sample subsets, we could actually capture a complete dataset. Very compelling.

3. Stored RBCs.
I am getting to long winded. But I'll throw something out to your first commenter. One of the big problems with Stored RBCs is simply that they are OLD. Yup. The longer you store these babies, the worse those little cells get at their job. In fact, they have worse ability to transport and release their oxygen. They have poorer rheostatic properties making their mechanical transport through the microcirculation a problem. Not to mention that they have an immuno-suppressant effect leading to higher complication rates.

So, if your question is comparing fresh packed RBCs vs Stored RBCs then fresh wins for the above statements. If your question is about fresh "whole" blood vs Stored "packed" RBCs.. then thats a whole different animal all together.


Jeffrey Parks MD FACS said...

Thanks for the clarifications!

Anonymous said...

Hum. Hubbie had a BMT with a couple of red blood cell transfusions.

I never thought to ask how old they were. Mostly I was grateful they were there.

Hopefully there won't be a next time for me to ask the question.

Christian Sinclair said...

I am glad to see a little more practical academia coming to medical blogs. Your column is similar to why we created Pallimed Intellectual posturing in journals never helps anyone, but a good discussion of relevance to clinical care is what we need more of.

I would really encourage you to sign up at research blogging so that you can link these journal articles there so when people search for info on these articles your blog posts come up with the insightful comments.

All you need is the doi of the article and voila you instantly have the html code!

Looking forward to seeing more of this column.