Advanced practice nurses, or APNs, are a specialized group of registered nurses who perform tasks once limited to physicians. The group includes nurse practitioners, certified nurse midwives, clinical nurse specialists and certified registered nurse anesthetists. Each APN performs a specific role, although their duties may overlap in some areas. For example, all APNs are authorized to prescribe medications.

About Advanced Practice Nurses

Advanced practice nurses provide direct care to individual patients; manage the care of individuals and patient populations; participate in nursing administration; and help to develop and implement health policy. APNs are expected to assume responsibility for assessment, diagnosis and treatment of medical conditions and injuries. Each state regulates the practice of APNs within the state; as a result, the role of an APN may differ from one state to another. One of the variables is whether an APN must be supervised by a physician, collaborate with a physician or is authorized to practice independently. States may also limit the conditions an APN can treat or medications she may prescribe.

Certified Nurse Midwives

Certified nurse midwives, or CNMs, are trained in both nursing and midwifery. Their role is to provide primary healthcare to women, especially those of childbearing age who require prenatal, labor and delivery care. CNMs also provide gynecological services to women of all ages, treat sexually transmitted infections, prescribe contraceptives and manage menopausal symptoms. They may also provide care to newborns. CNMs focus their obstetrical care on low- or moderate-risk mothers; high-risk pregnancies are usually referred to an obstetrician. CNMs do not perform cesarean sections.

Certified Registered Nurse Anesthetist

Certified registered nurse anesthetists, or CRNAs, administer any type of anesthetic, including general anesthesia inhaled through an endotracheal tube, spinal anesthetics and local anesthetics to numb a small area of the body. They may work in any type of surgical field, including open-heart surgery, and are expert in pain management. Although they collaborate with surgeons, dentists and other types of physicians, their work is considered the practice of nursing even when they are educated at the doctoral level.

Clinical Nurse Specialist

The clinical nurse specialist, or CNS, is an expert in a particular area of nursing practice. Her specialty might be a patient population, such as pediatrics; a setting, such as the emergency room; an illness or health area, such as cardiovascular nursing; or a type of medical problem, such as chronic pain. A CNS may provide direct care to one or more patients or act as a consultant or coach in her area of expertise. Clinical nurse specialists may perform research or interpret and evaluate clinical research performed by others. A CNS may also work in hospitals or nursing organizations as a clinical or professional leader.

Nurse Practitioners

Nurse practitioners, or NPs, provide direct primary-care services to patients of all ages. They may diagnose diseases and injuries, treat both common and acute healthcare problems, and provide preventative care. Like all advanced practice nurses, NPs are authorized to prescribe medications. They also order and interpret laboratory tests, X-rays and other diagnostic studies, and provide health teaching. NP practice emphasizes preventative care and health maintenance, although they will refer patients to specialists and other health professionals when needed.