Nurse anesthetists, or certified registered nurse anesthetists (CRNAs), are advanced practice registered nurses with specialized graduate level education, training, and certification in anesthesiology.
CRNAs provide services similar to those provided by anesthesiologists. CRNAs have administered anesthesia for over 100 years in the United States, and they administer the majority of anesthetics in the United States.
The majority of CRNAs work in conjunction with anesthesiologists (MDs). Their responsibilities, whether in collaboration or functioning independently, are largely related to operative procedures. As the scope of practice for anesthesiologists broadens, so does that of CRNAs. Pain management teams established in most hospitals now have CRNA members. The newest Joint Commission on Accreditation of Health Organizations (JCAHO) accreditation regulations mandate that acute care institutions have a pain management (assessment and intervention, with outcomes evaluation) system in place. The CRNA is part of that team. Laws regarding the level of collaboration required between physicians and CRNAs vary from state to state.
The first step in a CRNA's role in the operative setting is evaluation of the patient prior to anesthesia. This includes reviewing the patient's history, ordering diagnostic tests and consultations, interviewing the patient, discussing the anesthesia with the patient, obtaining informed consent for anesthesia or assuring that informed consent has been obtained, and ordering preoperative medications and fluids.
The CRNA is responsible for the formulation and implementation of an anesthesia care plan, which should detail the needs, treatment, and expected out-comes for the patient. The CRNA must choose the appropriate mode of anesthesia for the needs of the patient. Local anesthesia is numbing of a small, specific area so that a patient can have a procedure free of pain. Sedation alters the patient's level of consciousness so that the patient is more relaxed and less aware of uncomfortable sensations. Regional anesthesia (i.e., spinal blockade, axillary blockade, etc.) causes a loss of sensation to a specific region of the body. General anesthesia results in a loss of consciousness and lack of sensation throughout the body and as such carries the greatest risk of all anesthesias for the patient. The CRNA must assess the risks and benefits of each type of anesthesia in the context of the individual patient.
During the course of the operative procedure, the CRNA administers anesthetics and any adjunctive medications or fluids needed to induce and maintain anesthesia and patient homeostasis. Managing the patient's pulmonary status and oxygen saturation is one of the chief responsibilities of the CRNA, as respiratory failure or compromise is a key risk associated with anesthesia or sedation. The CRNA must confirm that the airway remains patent and that ventilation and oxygen equipment is working correctly. Techniques such as endotrachael intubation and extubation, mechanical ventilation, pharmacologic treatment, and respiratory therapy help to maintain a patent and functioning pulmonary system. The CRNA is also responsible for carefully checking equipment such as the anesthesia machine, mechanical ventilator, and oxygen equipment for safety and functionality prior to any procedures.
The patient's physiologic status, especially hemodynamics, must be monitored at all times during anesthesia. Vital signs, pulse oximetry, heart monitors, and monitors on oxygen and ventilation systems are examples of methods for monitoring the patient's response and status of equipment. Neuromuscular function and status must also be monitored when neuromuscular-blocking drugs are administered. The patient's position may need to be shifted during lengthy procedures in order to prevent injuries related to anesthesia-induced immobility, but prevention of anticipated pressure points is the first step. The CRNA is responsible for prevention or correction of any abnormal response to anesthesia. For example, an episode of respiratory compromise may lead to an acid-base imbalance. Symptoms of respiratory compromise or acid-base imbalance can be detected through physiologic changes such as cyanosis or hyperventilation and tests such as arterial blood gases and oxygen saturation. The CRNA is trained to quickly detect and correct this problem. There are two key abnormal responses that could prove fatal to the patient without early recognition and appropriate intervention by the CRNA: malignant hyperthermia and anaphylaxis (systemic allergic response). Both have cardinal signs and prescribed intervention procedures.
Even after the procedure is complete, the CRNA remains involved in extubation, assessing emergence, and initial recovery from anesthesia. The CRNA will follow up postoperatively to evaluate and treat any anesthesia side effects, determine when the patient is safely recovered from anesthesia, and discharge the patient from the postanesthesia care unit (PACU) or recovery room when appropriate.
In addition to the more traditional roles related to surgery, CRNAs are prepared to administer emergency care in any setting, including airway management, fluid and medication administration, and other interventions requiring advanced cardiac life support(ACLS) skills.
CRNAs also practice in the area of acute and chronic pain management through specialized techniques using drugs, regional anesthetics, or devices (such as a patient controlled anesthesia pump). They may also be asked to consult in the areas of respiratory care and are required to respond to cardiac arrest codes, especially when they occur with patients in the emergency department.
CRNAs may also choose to specialize in specific patient populations such as pediatrics, geriatrics, cardiovascular, neurology, or obstetrics.
It is important that the CRNA document in the chart descriptions of any of the above roles, providing details about the procedure, techniques, equipment, clinical situation, and patient outcomes.
Practice settings for CRNAs include independent or group practice in hospitals (i.e., surgical suites or obstetrical delivery rooms), outpatient surgery facilities, and dental, ophthalmology, podiatry, or plastic surgery offices. Military treatment facilities often use CRNAs as the chief anesthesia providers in facilities such as mobile care units or veterans hospitals. CRNAs may also work in the areas of research, quality assurance, critical care management or oversight, and administrative roles. Currently there are some states where CRNAs are granted the right to independent practice without physician supervision.
Education and training
There are over 80 university-affiliated educational programs for nurse anesthetists in the United States. In order to qualify for CRNA education, the nurse must have a bachelor of science in nursing degree or another science or health care-related baccalaureate-level degree, a current registered nurse license, and a minimum of one year acute care experience. Some CRNA programs require two years experience in either the operating room or critical care. Accredited CRNA programs require a 24- to 36-month program that includes a graduate degree and clinical training. After this training is complete, the nurse anesthetist must pass a national certification exam in order to become a CRNA. CRNAs must be recertified every two years and that requires continuing education credits specific to the specialty as well as proof of a designated number of hours spent giving anesthesia to patients.
It has been projected that more CRNAs will be required and utilized in the future. According to the American Association of Nurse Anesthetists (AANA), 50% of hospitals and 65% of rural hospitals currently use nurse anesthetists as their sole anesthesia providers. Furthermore, the AANA has summarized reports by organizations including the National Academy of Sciences, the Centers for Disease Control, and the U.S. House of Representatives and concluded that CRNAs are a cost-effective and equally safe alternative to anesthesiologists. There is an ongoing controversy between the American Society of Anesthesiologists and the AANA, in the face of requests of managed care companies to cut costs, that contests the independent practice option for CRNAs. The contention by the physician's group is that CRNA independent practice is not as safe for patients as MD supervision would be, but, to date, that has not been proved to the satisfaction of regulatory agencies. The needs for available, safe, and effective care ensure the ongoing need for CRNAs in the health care environment especially in areas where there is a scarcity of anesthesiologists, such as remote centers and rural populations.
Arterial blood gases— Measurement of oxygen, carbon dioxide, pH, bicarbonate, and their chemical relationships in the arterial blood in order to determine oxygenation and acid-base balance.
Cyanosis— Blue coloring of the skin around the eyes, lips, or fingers that signals low blood oxygen levels.
Extubation— Removal of an endotrachael tube.
Homeostasis— A state of physiologic balance.
Intubation— Insertion of an endotrachael tube to protect or restore the airway.
Mechanical ventilation— The use of a respirator or manual method to assure that the patient receives adequate oxygenation.
Patent— Open or unobstructed.
Pulse oximetry— Measurement of oxygen levels and heart rate through a device worn on the finger or ear lobe.
McIntosh, L. Essentials of Nurse Anesthesia. New York: McGraw Hill, 1995.
Nagelhout, J., and K. Zaglaniczny. Nurse Anesthesia, 2nd ed. Pasadena, CA: Kaiser Permanente, 2001.
American Association of Nurse Anesthetists. 222 South Prospect Avenue, Park Ridge, IL 60068-4001. (847) 692-7050. 〈http://www.aana.com/〉.
Joint Commission on Accreditation of Healthcare Organizations. 1 Renaissance Blvd, Oakbrook Terrace, IL 60181. (800) 994-6610. 〈http://www.jcaho.org/〉.