Meet our doctors: Michael Lew on anesthesia in cancer care
Anesthesiologists serve as key members of any patient’s surgical team. They play a vital role in and out of the operating room, helping to make decisions to protect and regulate a patient’s critical life functions (consciousness, breathing, heart rate, respiration and blood pressure) before, during and after surgical procedures.
Here Michael Lew, M.D., chair of City of Hope's Department of Anesthesiology, discusses the important and evolving role of anesthesia in cancer treatment – from surgery to critical care, as well as pain medicine, and how new technologies and research are forging new ground.
In short, what is anesthesia and what is its role in surgery?
Anesthesia is the use of medications to prevent the sensation of pain. It is used to help patients safely and comfortably undergo surgical procedures.
What are the different types of anesthesia?
There are four types of anesthesia: 1) local anesthesia, 2) regional anesthesia, 3) monitored anesthesia care and 4) general anesthesia.
Local anesthesia numbs only the part of the body where you will have surgery. Anesthetic medicines are injected or applied topically to temporarily block nerves in the surgical area. This type of anesthesia is used for minor procedures. Since local anesthesia affects just the nerves in the surgical area and not your brain, you will be awake during the procedure.
Regional anesthesia involves injecting anesthetic drugs near nerves and results in numbing larger portions of the body, so pain signals cannot reach the brain. This type of anesthesia is used for certain procedures to the abdomen, pelvis, arms or legs. The common types of regional anesthesia are spinal anesthesia, epidural anesthesia and nerve block anesthesia. You may be awake during the procedure, but you may be given medication that will make you feel relaxed or sleepy. There is always a possibility that a local or regional anesthetic may have to be converted to a general anesthetic if it wears off sooner than expected or there are any other problems during surgery.
Monitored anesthesia care is intravenous (through a vein) sedation. You may still be awake during the procedure, but you will be in a more relaxed state. This type of anesthesia may be used for less invasive (not deep into the body) surgery.
General anesthesia temporarily produces unconsciousness and is needed for major operations, so your brain does not perceive any pain signals. It involves both intravenous and inhalational agents (gases that you breathe). With this type of anesthesia, you will be completely unconscious during a surgery, with no sensations, feeling of pain, awareness, movement or memory of the surgery. Most of our procedures at City of Hope involve a general anesthesia.
Does anesthesia cause any side effects?
Patients may feel disoriented, groggy or confused when waking up from surgery. Other side effects include nausea or vomiting, which can be treated with anti-nausea medications, and a sore throat if a breathing tube was used during the surgery. The side effects of anesthesia nearly always resolve fairly quickly. However, other more specific side effects you may experience will depend on the type of anesthesia you are given. It is important to tell your doctor or nurse if you are having any of these side effects. Your doctor anticipates these situations and may be able to provide some relief.
What new procedures and technologies are impacting anesthesia? What advances have been made?
At City of Hope, the Department of Anesthesiology uses advanced technologies in the administration of anesthesia to patients. In addition, we are actively involved in research designed to provide optimal anesthetic care to our patients with cancer. The new procedures and technology focuses around the fundamental principle in anesthesia, which is safety. There have been three areas with relatively recent developments: 1) technology to improve airway management, 2) the application of ultrasound, which enhances the safety of vascular access and the placement of nerve blocks, and 3) the utilization of multimodal techniques to treat and manage pain.
Where do you see the field in the next 5 or 10 years?
Anesthesiology is rapidly evolving and will continue to improve on its already stellar safety profile by developing an increasingly individualized anesthetic plan for patients to reduce side effects and risks. Noninvasive technologies and the improvement in monitoring a patient continually are tested in the hopes of maximizing outcomes and quality of life. Lastly, anesthesiology will play a pivotal role in the multidisciplinary team approach to caring for the surgical patient during the perioperative period.
Why did you choose this profession? What inspires you to do the work you do?
Early in my medical school training, I had the opportunity to participate in an anesthesiology rotation and really enjoyed both the medical aspect, as well as the type of people who tended to gravitate toward anesthesia. Though the patient-physician relationship is relatively short, I feel strongly that an anesthesiologist’s responsibilities are paramount toward allaying the anxiety of surgery, as well as delivering a successful postoperative course. I'm inspired by knowing that I'm helping patients undergo surgeries that are oftentimes lifesaving. The inspiration for my research is the feeling that we still have a lot to learn about anesthesia and its effect upon the body. By learning more, we may be able to tailor anesthetics to provide optimized care to specific patient populations, including patients with cancer.
To learn more about the innovative anesthesia services offered at City of Hope, visit http://www.cityofhope.org/anesthesia.