Thursday, February 25, 2016

More on activity restrictions after surgery

In early January, I blogged about the dearth of evidence about activity restrictions after surgery.

A number of people commented and most agreed that there is little basis for most of the activity restrictions surgeons currently use.

An anonymous reader told me about a 2008 study from Creighton University that generated some interesting data about intra-abdominal pressures associated with some common activities. Here’s a summary of the paper.

The authors managed to find 10 healthy volunteers all of whom could bench press at least 100 pounds and were willing to have nasogastric manometry catheters placed and Foley catheters inserted into their urinary bladders.

Intra-abdominal pressures were recorded as each subject coughed 10 times as hard as possible, bench pressed varying amounts of weight from 26 to 114 pounds, and vomited after receiving ipecac syrup and drinking about 500 mL of water.

Pressures in the stomach and bladder correlated fairly well. To keep things simple, let’s look at gastric pressures only.

The highest mean and maximum pressures were found during vomiting. Coughing produced similar pressures. Most interestingly, intragastric pressures during weightlifting were significantly lower with a mean of 2 mmHg and a maximum of 52 mmHg, p <0 .001.="" br="">The authors mentioned that another group had found similar intra-abdominal pressures with subjects bench pressing 25 pounds.

Another unexpected finding was that although the differences were not significant, the mean intragastric pressures were inversely proportional to the amount of weight lifted.

Maybe we should tell postoperative patients not lift less than 26 lbs.

The authors were focused on measuring pressures that would disrupt a gastric anastomosis. They calculated that an intragastric pressure of 290 mmHg generated by vomiting was about 1/50 of the 20N [Newton] force that would disrupt a gastric suture line in a porcine model as demonstrated by other investigators.

The effect of repetitive stress such as found in patients with a chronic cough were unknown, but they said “the intra-abdominal pressures generated in our study alone do not appear to be responsible for hernia formation.”

The Creighton study authors concluded, "The common postoperative lifting restriction, although logical, has little evidence to support it." They called for more research in this area.

Unfortunately, their call has not been answered.


DrP said...

I have a post-operative incisional/ventral hernia and have found no studies to suggest what my weight-lifting or other isometric exercise limitations should be.
Are you aware of any evidence-based recommendations in this area

Skeptical Scalpel said...

I am not aware of any evidence-based guidelines. That's why I've written two posts about it. I'm hoping someone will chime in and enlighten us. We'll see.

Anonymous said...

The only thing I can think of that caused my former surgeon to nix activity was fear of a lawsuit & being a wuss. I was in pretty good shape before and after my last 2 surgeries (ok, anesthesia issues on the last but that was it).

Skeptical Scalpel said...

I think fear of lawsuits is a very real reason why such restrictions exist. Add to that a lack of real evidence and you now see why surgeons say don't lift more than 10 lbs for X weeks.

William Reichert said...

My wife went to a dentist to have gum surgery on the area under one tooth. The dentist told her she could not do "any" exercise
including long walks for three weeks after the surgery.I told her we needed a second opinion. SO she went to my dentist who thought the
proposed restrictions were hilarious. He did the surgery and she returned to normal activity right after and has done well.
After encounters with some surgeons I was told to take a long course of antibiotics to "prevent" infections.I searched the
literature and decided that the evidence for that was non existent and did not take them.I had no problems. A lot of medicine is of dubious value or worse. Buyer beware.

The Doctor Isn't In said...

I think most of our post op orders contain stuff based on simply passing them down from generation to generation. I questioned WAY back when, some of the details we had in our post op orders when in my residency. All I got was the typical "so DOCTOR you think your limited experience is sufficient to make changes?"
I realized that my requests were in deed at most at risk of altering "the standard of care" as well as potentially being in the dog house so why bother. To this day I use standardized boilerplate PO orders and haven't looked back to question them. I teach those same orders to all my generation of residents and fellows as well how pathetic!
A friend of mine a Dentist was sued a few decades back for not prescribing an antibiotic after extracting a "loose tooth." The jury determined he violated the SOC and to this day I can only find nothing on why it was a violation. It seems that just because they always do it seems to be enough to keep it going and violating it based on science is sufficient to get you in the hoosegow
Dr D

Skeptical Scalpel said...

William and Dr D, thanks for the comments. I agree with the notion that prophylactic antibiotics should not be taken for more than 24 hours.

We are all guilty of passing down dogma. I certainly did. I have more time to think about these things now. "Standard of care" is whatever a lawyer and his expert witnesses can convince a jury to find.

I had forgotten about a post on this subject I wrote last year. Here's the link -

Khim Kwah said...

Hi Dr Skeptical Scalpel, I like and agree with your post. I wrote a similarly themed post at my old blog about sternal precautions post-CABG:

More often than not, I find activity restrictions imposed by some surgeons to be impossible to live up to. That is why I don't adhere to them strictly...

Skeptical Scalpel said...

Khim, thanks for the comment and the link to your post. I have written about restrictions that are impossible to follow too. See the link in my comment of 2/26/16 just above yours.

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