I. Introduction                                    Return to the Beginning

Nurses in most settings care for patients before and after surgery, and as such, have opportunities for patient teaching related to anesthesia. Recently, the subject of awareness ("waking up") during surgery has been highlighted by the media, but according to the American Society of Anesthesiologists (ASA), these media reports are often erroneous and spread unnecessary fear. Yet, there are risks related to anesthesia. Since nurses are patient advocates, and often spend more time with patients before and after surgery than other health care providers, it's imperative that nurses know the facts about anesthesia risks so they can educate and reassure patients, and assist them to make truly informed decisions.

Case Study

You're working on the medical-surgical floor at Big City Memorial Hospital. Mrs. Rosemary Parks, 76, has just been admitted with a fractured hip after a fall at home early this morning. The emergency room physician told her she would probably need surgery, but the consulting orthopedic surgeon hasn't seen her yet. Her husband and adult daughter are at her bedside. All three are quite anxious about the possibility of surgery, since Mrs. Parks "woke up" during her gallbladder surgery 20 years ago. She says she remembers being awake for a few minutes and hearing the surgeon asking for different instruments, but she couldn't open her eyes or move. She doesn't remember feeling any pain; just the panic at not being able to tell anyone what was happening. She hasn't had surgery since then, and is afraid this could happen again. Fortunately, you're attending an inservice about Risks of Anesthesia given by a nurse anesthetist later this morning. You tell Mrs. Parks and her family that you'll keep her comfortable until the orthopedic surgeon sees her, and if he decides surgery is necessary, you'll discuss it with them this afternoon.

The word “anesthesia” comes from two Greek words meaning “without feeling.” The goals of anesthesia are relief of physical pain, relief of mental or emotional stress, and management of medical problems. Typically, anesthesia is associated with operative procedures, but the scope of anesthesiology actually extends to respiratory therapy, management of acute and chronic pain, and care of critically ill patients. Physicians in this specialty are anesthesiologists. Nurses can also specialize in anesthesia, and are called Certified Registered Nurse Anesthetists (CRNA). The educational differences and scope of practice will be discussed later.

Brief History of Anesthesia

Surgical anesthesia with inhaled ether was first performed in 1842 by Dr. Crawford W. Long in rural Georgia. In 1846, Dr. William T. Morton, a dentist, successfully administered ether for a mandibular tumor removal in front of an audience at Massachusetts General Hospital. A newspaper reporter was present in the audience, and thus, the discovery of surgical anesthesia soon spread worldwide. Beginning in 1847, ether was used in England for labor pain, and chloroform gained public acceptance when it was successfully administered to Queen Victoria in 1853 during the birth of Prince Leopold.

 Another American dentist, Dr. Horace Wells, recognized the anesthetic potential of nitrous oxide after a painless tooth extraction on himself. However, an attempt to use nitrous oxide during a demonstration procedure at Massachusetts General Hospital failed, and it wasn’t until a Chicago surgeon, Dr. Edmond W. Andrews, used nitrous oxide with oxygen in 1868 that the possibility of using this gas as an anesthetic began to be accepted.

Ether, chloroform, and nitrous oxide were the primary anesthetics until the 1920s, when drugs with greater flexibility and fewer side effects began to be preferred. Other inhaled anesthetics were developed over the next 30 years, but these had the unfortunate drawbacks of either being explosive when in contact with oxygen, or toxic. Ironically, the science used to develop the atomic bomb led to the discovery of fluorinated inhaled anesthetics in the 1950s. The first, fluroxene, had a low blood solubility and minimal cardiovascular depression; however, it often caused nausea and vomiting, was possibly hepatotoxic and carcinogenic, and was flammable at high concentrations; thus, it was withdrawn from the market in 1975. Research then focused on methyl ethyl ether derivatives because these don’t cause cardiac dysrhythmias. Currently, nitrous oxide, isoflurane, desflurane, and sevoflurane are the most commonly used inhaled anesthetics.

 Cocaine was the first injectable anesthetic used, beginning in the 1880s. In 1905, procaine replaced cocaine for regional anesthesia. Currently, lidocaine, bupivacaine, ropivacaine, and tetracaine are the most frequently used local anesthetics.

 In 1934, thiopental was introduced for rapid intravenous induction of anesthesia. In 1989, propofol was developed, providing a similar onset time to thiopental, but with a quicker and more complete reversal of drug effects.

Types of Anesthesia

 There are different categories of anesthesia.

• Infiltration: Local anesthetic is injected directly into the tissue at the site of operation.
• Regional: Local anesthetic is injected around a major nerve bundle, causing temporary numbness in a limited area of the body. Regional anesthesia includes peripheral nerve blocks, which involve a small area such as a hand or foot, and spinals and epidurals, which can numb only half of the body.
• General: General anesthesia is accomplished with inhaled and/or intravenous anesthetic, making the patient completely unaware. General anesthesia acts directly on the brain and spinal cord, whereas infiltration and regional anesthesia act on the nerves. Muscle relaxing drugs (for example, succinylcholine) may also be used for paralysis to eliminate body movement during surgery. Because all muscles are affected, including the diaphragm, endotracheal intubation and ventilatory assistance are required. Also, muscle relaxing drugs don't have any analgesic or anesthetic effects, so they should only be used with other drugs that do provide those effects. Paralysis without adequate anesthesia is a cause of intraoperative awareness, which is discussed below.
• Sedation: During short or outpatient procedures, sedation with opioids, propofol, or midazolam (Versed) may be used to decrease patient anxiety and limit patient recall of the procedure.

General Statistics

Patients are often afraid of anesthetic complications, sometimes more so than operative complications. Since nurses are involved in preparing patients for surgery, it's helpful for them to be aware of the actual statistics of anesthetic complications. It's estimated that 28 million people undergo anesthesia and surgery every year in the United States, and approximately one in every 250,000 anesthetizations will result in death. (The death rate for motor vehicle accidents is 41:250,000 and from household injuries, 22:250,000.) (Stoelting & Miller, 2000). Anesthesiologists have been at the forefront in developing new technology that has improved patient safety during surgery 25-fold in the last 20 years.

Injuries can also result from anesthesia or associated procedures, including peripheral nerve damage, eye damage, dental or oral trauma from intubation, fetal/newborn injury, pulmonary aspiration, allergic reaction/anaphylaxis, and intraoperative awareness. (Each of these will be discussed later.) Anesthesiologists identify difficult airway management as the greatest patient safety issue (Stoelting & Miller, 2000). When adverse events do occur, it can be difficult to differentiate between an event due to anesthesiologist error (breach in the standard of care) and an unavoidable event that occurred in spite of optimal care.

In 1985, the American Society of Anesthesiologists started the Anesthesia Patient Safety Foundation to "assure that no patient shall be harmed by anesthesia." This group provides research grants to promote a better understanding of preventable injuries related to anesthesia, and endorses national and international communication about the causes and solutions for preventable harm. Anesthesiology is the only medical specialty with a foundation specifically dedicated to patient safety (Stoelting & Miller, 2000).