- Diseases, Disorders & Conditions
Obesity: Risk for Surgery and Anesthesia
Types of Anesthesia
Many people facing surgery find that anesthesia scares them more than the operation, itself. The idea of giving up control of your body to a stranger is anxiety-provoking, for sure, even if you know it's a highly trained professional. Anesthesia is remarkably safe, compared to days gone by, but there are still some risks. Most people, though, have some side effects for a day or two but no real complications.
There are illnesses and medical conditions that increase your risk of complications and problems during and after your anesthetic. And, the common condition of obesity is among them. Your anesthesiologist may or may not mention this to you as it is a condition that cannot be changed when they meet you on your day of surgery. And while there are effects of obesity on anesthesia, anesthesiologists are trained to deal with them so most issues, if they exist, are minor.
General Anesthesia: The phrase "general anesthesia" indicates that medications will be used to achieve a state of unconsciousness. You will not be able to hear, see or feel anything during the surgery. Usually, a breathing tube, inserted into your windpipe, or a breathing mask, situated in the back of your throat (both after you are asleep) help to deliver oxygen and gas anesthesia.
Spinal Anesthesia: Numbing medication is injected with a small, skinny needle into the spinal fluid below where the spinal cord ends in the back. The medication bathes the nerves to make the lower half of the body numb. This is used for some low-abdominal, pelvic, hip and knee surgeries.
Epidural Anesthesia: Anesthesiologists place skinny tubing (called a catheter) into the back to bathe the nerves exiting the spinal cord and make the lower part of the body numb. This catheter is placed specifically outside the covering of the spinal column (the dura). The space outside the dura is called the epidural space.
Regional and Local Anesthesia: Regional anesthesia includes techniques like nerve blocks to numb a region of the body supplied by a nerve or group of nerves. Local anesthesia involves numbing just the area of the body directly where the surgery will be done. The terminology can be confusing as spinals and epidurals are sometimes included in the "regional" category.
Risks of Obesity for Anesthesia
The risks of obesity during an anesthetic depend on several factors including what type of anesthesia is to be used, the level of obesity of the patient, other coexisting medical conditions and the surgery to be done.
General Anesthesia Risk: The anesthesiologist examines the "airway" prior to giving anesthesia. This includes looking at the head and neck. Extra tissue around the face can make giving oxygen with a mask more difficult after the patient is asleep. Also, increased neck thickness may present challenges with placing a breathing tube. Oxygen levels decrease much more rapidly in obese patients, as well, giving the anesthesiologist less time to respond to the difficulty.
A heavy chest and abdomen also make it more difficult for a patient to take deep breaths after surgery and anesthesia in a "groggy", weakened state. Pneumonia is more likely to develop in areas of the lung that don't fully expand after surgery and obesity makes it harder to inflate the lungs.
A study published in the British Journal of Anaesthesia in March of 2011 revealed that obesity can double the risk of serious airway issues such as emergency tracheostomy (cutting a hole in the front of the neck into the windpipe to deliver oxygen), admission to the ICU and brain damage.
Spinal, Epidural and Regional Anesthesia Risk: The biggest risk with these types of anesthesia is increased difficulty with performing the procedures. All of these rely on landmarks that the anesthesia provider feels to find the right location. If extra adipose tissue overlies the landmarks, they are harder to feel and the procedure becomes more difficult and risky and more likely to fail.
Reducing Risk: If your surgery is being planned for more than a few months in the future, start living a healthier lifestyle now .
**Lose weight if you can, but do it sensibly. A little weight loss goes a long way to reducing risk, not just for your surgery, but for your life in general. Use the scheduled surgery as the motivation to get started. Eat a balanced, healthy diet with all the stuff you know you should eat - fruits, veggies, healthy fats and a variety of foods in general.
**Exercise. Even if you don't lose substantial weight, the strength and stamina you gain will benefit you in your recovery. We often liken surgery and anesthesia to jogging a long distance. Anything you can do to get stronger will be helpful.
**Stay as healthy as possible: Don't smoke or drink excessively.
If your surgery is soon, you probably won't lose a lot of weight, but you can still follow the other recommendations to minimize your risk.
**In addition, continue to treat any problems you have that may be related to obesity.
--If you are having a major surgery, visit your primary care doctor and ask for recommendations on what you should do to stay as healthy as possible before your operation. Find out if you need any special tests before your surgery.
--Maintain good control of your blood sugar if you are diabetic. If you take medications by mouth (such as metformin) to control your blood sugar, ask when you should take your last dose before surgery.
--Take your blood pressure medicines as prescribed and check your blood pressure at home, if possible, to make sure it's under good control. Ask at your pre-op appointment if there are any medications you should stop the day before surgery.
--Use your CPAP machine if you have one for sleep apnea. Using this machine improves oxygen levels and decreases the work on the heart and lungs. If you are staying overnight in the hospital, ask if you should bring your machine with you.
And know that even with some increased risk, many, many people go through surgery and anesthesia every day and complications are quite rare.
After your surgery: Follow your doctor's or nurse's recommendations.
--If you are told to get out of bed and walk, do it, even if you don't feel like it or if you are sore. Obesity predisposes to problems like blood clots in the legs or lungs and partial lung collapse. Walking and moving around helps minimize these complications.
--Use the "incentive spirometer" if you are given one. This device measures the force with which you are able to take deep breaths. You will be given instructions on use. This also helps the lungs reexpand fully after surgery.
From the American Society of Anesthesiologists.
- Obesity and Anesthesia
Obesity and Anesthesia