Top ten stories of 2010 includes brain monitoring

Minimizing the Risks of General Anesthesia in Surgery

Jerry H. Trachtman, Attorney
(866) 735-1102 Ext 405

Posted by Jerry H. Trachtman
August 12, 2010 3:20 PM

This information is not intended to constitute advice or a recommendation relating to a particular medical condition or treatment. It is not a substitute for a consultation with your own medical professional.

According to a study reported in Anesthesiology (April, 2009), the journal of the American Society of Anesthesiologists, between 1999 and 2005 there were 2,211 anesthesia-related deaths in the United States. Of those deaths, almost half (47%) were the result of general anesthesia overdose.

On May 18, 2010, CNN published the story of a woman who woke up in the middle of major surgery. The first thing she heard was “Cut deeper, pull harder.” Although the general anesthesia she had received was insufficient to keep her unconscious, it kept her from screaming or even moving a finger. According to a study reported by the Mayo Clinic, about 1 or 2 people in every 1000 may wake up while under general anesthesia, which is known as “anesthesia awareness”. Although in most cases the person does not feel pain, some people do experience excruciating pain and develop long-term psychological problems.

Clearly, anyone who is about to undergo a surgical procedure under general anesthesia has good reason to question the anesthesiologist in advance of surgery, and to ask how the appropriate drug and its dosage will be determined in order to assure good quality anesthesia without the risk of an overdose. Too much anesthetic can result in death, temporary mental impairment, or permanent brain damage, and too little can result in anesthesia awareness. Unfortunately for us, the administering of general anesthesia appears to be as much an imprecise art as it is a science.

The word “anesthesia” can be defined as “loss of sensation or awareness”. Every day, thousands of people undergo surgery with the safe, effective use of anesthesia. Local anesthesia numbs a small part of the body, usually by injections or ointments. Regional anesthesia is the use of a local anesthetic to numb a larger part of the body by injecting the local anesthetic drugs near the nerve bundle affecting the desired area, with the effect of interrupting the signals between that area and the brain. Sometimes referred to as “blocks,” the most common regional anesthetics are epidural and spinal. General anesthesia is the inducing of a state of controlled unconsciousness accompanied by the absence of pain, the paralysis of the entire body, and loss of memory. During general anesthesia, drugs are injected into a vein or gases may be breathed into the lungs. Interestingly, the precise mechanism of general anesthesia is not yet fully understood, and research to understand it is ongoing.

General anesthesia is more than simply putting the patient to sleep. The loss of consciousness experienced in sleep, compared to the loss of consciousness induced by general anesthesia, is significantly different. When we fall asleep, our consciousness fades and we enter sleep cycles. These cycles are classified as either REM (rapid eye movement) sleep, when remembered dreams occur, or non-REM sleep, during which the sleeper may be drowsy and lose consciousness, or may even be in deep sleep, but dreams are more like short flashes and are usually not remembered. The sleeper passes through several stages during a typical sleep and several transitions between REM and non-REM sleep occur. When we sleep, our brain is in its most active state, organizing knowledge and memories.

On the operating table, the brain uses less oxygen and is less active. The general anesthesia applied before surgery needs to guarantee not only the loss of consciousness, but also sedation, immobility, the loss of memory, and the absence of pain. Since general anesthesia inhibits the parts of the brain which are required for REM sleep, anesthetized subjects do not have REM sleep and usually do not remember dreams. While sleep can be reversed by shaking or loud noises, general anesthesia is reversed only by eliminating the anesthetic drugs.

Traditionally, anesthesiologists are trained to monitor vital signs — the patient’s oxygenation (concentration of oxygen in the blood and inspired gas), ventilation (breathing), circulation (EKG, blood pressure, and heart rate) and temperature – in order to assess the depth and effectiveness of general anesthesia. By continuously monitoring the patient’s vital signs, together with the anesthesiologist’s clinical experience and judgment, the anesthesiologist determines if a correct amount of anesthetic is being administered to safely keep the patient unconscious. According to Barry L. Friedberg, MD, a Board Certified anesthesiologist who has been quoted in medical journals and anesthesia textbooks, and who has lectured on the subject to surgeons and anesthesiologists in the United States, Canada, Mexico, the Dominican Republic, Israel and Venezuela, anesthesiologists would be able to determine a more exact general anesthesia dosage if they would use a device known as a brain function monitor to more accurately monitor consciousness.

“The brain is the target for anesthesia. It’s critical for the brain to be measured with a brain activity monitor; however, most anesthesiologists are not doing this”, says Dr. Friedberg. “Brain monitoring doesn’t replace vital signs monitoring, but vital signs monitoring can’t give you the information that the brain monitor does,” he says. “Anesthesiologists were trained like I was years ago to believe that heart rate and blood pressure changes are a clue to what goes on inside the brain, but to make sure you give enough you always have to overmedicate by 20 to 30 percent. Using a brain monitor, of course, this type of practice becomes superfluous because it turns out that heart rate and blood pressure changes have almost nothing to do whatsoever with what’s going on in your brain.” “It’s a [$25.00 disposable] sensor that sits on the forehead and plugs into a computer and the computer generates a number from 0 to 100 that allows you to measure the individual response of each patient, so instead of a one size fits most you get a this size is your size for your operation today.” “Without a brain monitor, anesthesiology is not an exact science. With a brain monitor, each patient becomes an open book test instead of a mystery to be solved.” Dr. Friedberg emphasizes he does not make money by spreading this message, he does not have a financial interest in the monitor manufacturers, and he does not have an axe to grind with the drug companies. “We should focus on caring for patients, and understanding the long term risks of overmedicating patients while in surgery. We should be using every tool available to keep them healthy and reduce unnecessary risks through the entire treatment process.” “Nobody should have general anesthesia without a brain monitor. Most people don’t realize that if they don’t ask specifically, the anesthesiologist is not going to use it.”

Currently there are brain monitors available in almost half the operating rooms in the United States. Brain function monitoring technology is widely studied and widely accepted, and is supported by more than 3,300 published studies. The technology has been used on more than 34 million patients around the world, and is utilized in more than 80% of the top ranked US hospitals (according to US News and World Report ranking). However, there is controversy about the effectiveness of the use of brain function monitors.

Some studies claim there is no benefit in using brain function monitoring to prevent anesthesia awareness. Other studies suggest that the decision to use a brain function monitor should be made on a case-by-case basis by the anesthesiologist for selected patients, such as patients undergoing trauma surgery or cesarean section who cannot tolerate a deep anesthetic. Providing a lighter than normal anesthetic to at-risk patients may be a necessary step taken by the anesthesiologist. Advocates like Dr. Friedberg say brain monitoring is essential to ensure the patient achieves the appropriate level of anesthesia. Nevertheless, the American Society of Anesthesiologists foresees brain activity monitoring as a standard of care in the administration of general anesthesia.

Tags: surgery, anesthesia overdose, anesthesia awareness, brain monitor, brain function monitor