Now another study--one that looked at the factors causing post-operative infections has come up with the same finding.
The study is:
Postoperative Hyperglycemia and Surgical Site Infection in General Surgery Patients Ashar Ata et al. Arch Surg. 2010;145(9):858-864. doi:10.1001/archsurg.2010.179
You can read a good summary of this study, with more information than is found in the abstract here: Science Daily: Postoperative High Blood Sugar Appears to Be Associated With Surgical Site Infection
The researchers examined the records of 2090 patients. For 1561 of these patients, blood sugar measurments were recorded and 803 of these blood sugar measurements were taken within 12 hours of surgery.
The researchers found that in the group as a whole the following factors were predictive of surgical site infection (SSI):
increasing age, emergency status, American Society of Anesthesiologists physical status classes P3 to P5, operative time, more than 2 U of red blood cells transfused, preoperative glucose level higher than 180 mg/dL... diabetes mellitus, and postoperative hyperglycemia.But here's where things get interesting. Because the researches found that,
After adjustment for postoperative glucose level, all these variables ceased to be significant predictors of SSI; only incremental postoperative glucose level remained significant.And what was the postoperative glucose level at which bad things started to happen?
Readers of this blog, don't all answer at once, but you're right!
It was 140 mg/dl the very same blood sugar level we have long been telling people with diabetes should be the very highest they ever let their blood sugar reach if they can possibly avoid it.
In the type of surgery studied in which post operative infection was by far the most common--colorectal surgery, where 14.11% of patients suffered infections, the researchers found that those with blood sugars higher than 140 mg/dl were over three times more likely to suffer infection as those without.
Science Daily also quotes the full text article as saying,
In conclusion, we found postoperative hyperglycemia to be the most important risk factor for surgical site infection in general and colorectal cancer surgery patients, and serum glucose levels higher than 110 milligrams per deciliter were associated with increasingly higher rates of post-surgical infection.WHEN YOU MUST HAVE SURGERY
What makes this study so important is this: If you go in for a major procedure it is almost 100% certain that, despite your protests, the anesthetist will hook you up to a glucose drip before surgery. This guarantees that no matter how perfectly you have been eating, your blood sugar will be at least 140 during your surgery--a number that surgeons, trained to believe that 200 mg/dl (11.1 mmol/L) is "Diabetic" will tell you was a "nice normal blood sugar" as mine did.
The only way to avoid this is to negotiate it with the surgeon before you commit to the surgery and get it in writing in a form that you can give to the hospital staff before the surgery.
No matter what you have been told orally, the staff in the hospital will listen only to the surgeon and pay attention to you only if they see written instructions that look like they could lead to a law suit.
Unfortunately, if my experience is anything to go by, getting such written instructions may be impossible, even with an otherwise excellent surgeon. Therefore, it would be a good idea to print out this study and keep it in your file of important medical papers so that you can take it with you when you have your preliminary meeting with the surgeon.
Once your surgery is done, you are not out of the woods. The food you will be given in the hospital will be the "diabetic menu." This may be called a "Carb-controlled diet" (It was at the hospital I stayed in) but this is misleading. It is, in fact, the same old dangerously high carb/ low fat diet that nutritionists still defend to the death--the death of the patients with diabetes who eat it.
For breakfast you'll be offered toast with jelly but no butter, cereal with skim milk, and sugary fruit, so that you face the choice of starving or raising your blood sugar well over that 140 mg/dl level. The rest of your meals will be thin slices of fat free mystery meat and starchy veg, with fruit--canned in corn syrup--for dessert.
Again your only defense here is signed orders from your doctor, which may be very hard to attain. That is because most doctors do NOT understand that the carbs you eat are what raise your blood sugar. They really don't.
And they remain convinced that blood sugars up to 200 mg/dl are not dangerous and that it is a mysterious disease called "diabetes" that harms people, not exposure to high blood sugars.
Doctors also believe, without question, that high fat diets cause heart attacks and that it is much healthier for you to eat that toast and jelly than a fresh egg.
So before you go into a hospital for elective surgery, if possible, get a letter, signed by your surgeon or another doctor who practices at the hospital where you are having your surgery ordering the nutrition staff to allow you to order at will from the regular menu and forbidding them to make you eat foods from the "diabetic" menu.
If it isn't possible, arrange for friends or family members to bring you the foods you need to eat to keep your blood sugars normal. Arrange to go home where you have control over your food supply as soon as it is possible.
If you are forced to go to a nursing home after surgery, make sure that your doctor orders the nursing home staff to allow you or a chosen family member who understands your dietary needs to control what you eat and, again, forbid the use of the "diabetic" diet. Otherwise, you will be forced to eat the high carb/low fat diet that will raise your blood sugar and make surgical infection more likely.