What Is Anesthesiology? Research Areas, Funding, and Training Paths

Anesthesiology is the branch of medicine and biomedical science concerned with rendering patients safe and comfortable for surgery and other procedures, managing pain, and supporting patients whose vital functions are threatened by illness or injury. It is both a clinical specialty, whose physicians provide anesthesia, monitor and support the body through the stress of an operation, and often continue into intensive care and chronic pain care, and a research discipline spanning neuroscience, pharmacology, physiology, patient-safety science and clinical trials. (In British and Commonwealth usage the field is spelled anaesthesia or anaesthesiology; the spellings name the same discipline.) This guide explains what anesthesiology covers and how its subfields divide up, then adds the research-administration layer that generic overviews leave out: who funds anesthesia research, how the field’s main societies and journals are organized, how the research is done, and the typical training path. It is educational, not medical advice.

What Is Anesthesiology?

Anesthesiology is often summarized as “putting patients to sleep,” but the discipline is organized around a wider set of questions:

• How do anesthetic drugs work? General anesthetics produce unconsciousness, immobility and amnesia, and exactly how they do so at the molecular, cellular and brain-network level remains an active basic-science question. Anesthetic pharmacology is the discipline’s foundation.
• How is the patient kept physiologically stable? During a procedure the anesthesiologist continuously manages breathing, circulation, temperature, fluids and the body’s response to surgical stress, using monitoring of heart rhythm, blood pressure, oxygen, carbon dioxide and, increasingly, brain activity.
• How is pain prevented and treated? This includes pain during and after surgery, regional techniques that numb a part of the body (such as nerve blocks and epidurals), and the longer-term management of chronic pain conditions.
• How are patients supported when they are critically ill? Many anesthesiologists also practice critical care medicine, applying airway, ventilation and hemodynamic expertise in the intensive care unit.
• How can harm be prevented? Anesthesia safety, from airway management to medication errors to postoperative delirium, is a research field of its own.

Anesthesiology is related to, but distinct from, pharmacology (the study of how drugs act in general) and neurology (the study and treatment of nervous-system disease). It borrows heavily from both: the central question of how anesthetics alter consciousness is a neuroscience question as much as an anesthesia one.

Scope: Perioperative Care, Pain and Critical Care

The discipline is commonly described through three overlapping territories, and much anesthesia research is labeled by which of them it addresses.

Perioperative medicine

“Perioperative” describes the whole span around surgery: preparation before the operation, the anesthetic and surgery itself, and recovery afterward. Perioperative research asks which patient preparation, anesthetic technique, monitoring strategy or recovery pathway leads to better outcomes: fewer complications, faster recovery, less pain, and less long-term cognitive or functional decline. Outcomes of interest include postoperative pain, nausea, delirium, organ injury, length of stay and return to normal function.

Pain medicine

Pain research in anesthesiology covers acute postoperative pain, regional anesthesia, opioid-sparing strategies, and the transition from acute to chronic pain. Because opioids are central to perioperative pain control and carry well-known risks, how to treat pain effectively while limiting opioid exposure is a major applied question in the field.

Critical care

Critical care medicine is an independent field in its own right and is practiced by clinicians from several specialties, including anesthesiology, internal medicine, surgery and others. Anesthesia-trained intensivists contribute expertise in airway control, mechanical ventilation, sedation and circulatory support. Measurement tools that cross between anesthesia and intensive care include sedation scales such as the Richmond Agitation-Sedation Scale (RASS).

Major Subspecialties and Areas of Practice

Clinical and research activity in anesthesiology is organized into subspecialties, many of which have their own professional societies. The list below is representative rather than exhaustive:

• Cardiac, thoracic and vascular anesthesia: anesthesia for heart and lung surgery, including management of cardiopulmonary bypass.
• Obstetric anesthesia: labor analgesia, cesarean delivery and the care of pregnant patients.
• Pediatric anesthesia: caring for infants and children, with ongoing research interest in how anesthetics affect the developing brain.
• Neuroanesthesia: anesthesia for neurosurgery and management of brain physiology.
• Regional anesthesia and acute pain: nerve blocks, neuraxial techniques and ultrasound-guided approaches.
• Pain medicine: interventional and medical treatment of chronic pain.
• Critical care medicine: intensive-care practice, ventilation and sedation.
• Ambulatory (outpatient) anesthesia: anesthesia for procedures that do not require an overnight stay.
• Patient safety and quality: systems research on how to prevent anesthesia-related harm.

In the United States, the American Board of Anesthesiology (ABA) certifies anesthesiologists and also offers subspecialty certification in some of these areas, such as pain medicine and critical care medicine. Requirements change over time, so consult the ABA for current specifics.

How Anesthesiology Differs From Neighboring Disciplines

• Anesthesiologist versus nurse anesthetist. Anesthesiologists are physicians (MD or DO) who complete residency in anesthesiology. Certified registered nurse anesthetists (CRNAs) are advanced-practice nurses who also provide anesthesia, often as part of care teams. Staffing models vary by country and hospital, and the way anesthesia services are supervised and billed is a research-administration topic in its own right; see the guide to anesthesia medical direction modifiers.
• Anesthesiology versus surgery. Surgeons perform the operation; the anesthesiology team manages the patient’s physiology and pain during and around it. The two collaborate closely on perioperative decisions.
• Anesthesiology versus pain medicine. Pain medicine is a subspecialty that draws physicians from anesthesiology and from other specialties, such as neurology, physical medicine and rehabilitation, and psychiatry.
• Anesthesiology versus critical care. Overlapping practice, different training pathways. Not every intensivist is an anesthesiologist, and not every anesthesiologist works in the ICU.

A Brief History

The modern field is usually dated to the public demonstration of ether anesthesia at Massachusetts General Hospital in Boston on October 16, 1846, by William T. G. Morton. Other agents, including nitrous oxide and chloroform, followed over the next decades, and anesthesia became a safer and more systematic practice as monitoring and training improved.

The profession organized itself in the twentieth century. According to histories of the American Society of Anesthesiologists, nine physicians from Long Island, New York, formed the first professional anesthesia society, the Long Island Society of Anesthetists, whose first meeting was held on October 6, 1905. It became the New York Society of Anesthetists in 1911, the American Society of Anesthetists in 1936 and the American Society of Anesthesiologists (ASA) in 1945. Separately, the International Anesthesia Research Society (IARS) dates its founding to 1922, the year of the first issue of its journal, Current Researches in Anesthesia & Analgesia (the predecessor title of Anesthesia & Analgesia), through the efforts of Francis and Laurette McMechan.

How Anesthesia Research Is Funded

NIH and NIGMS

In the United States, the National Institute of General Medical Sciences (NIGMS) at the National Institutes of Health is the institute most associated with anesthesiology research. NIGMS states that it supports research related to anesthesiology and peri-operative pain, within its Pharmacology, Physiology, and Biological Chemistry area, and that it supports a limited number of investigator-initiated clinical trials in selected areas that include anesthesiology and peri-operative pain. Its stated interest in training covers topics such as anesthetic pharmacology, systems neurobiology, anesthesia-related critical care, and pain management especially in the perioperative period.

For clinical research training and career development, NIGMS lists several mechanisms: institutional postdoctoral training grants (T32), mentored career development awards (K08 and K23), and individual postdoctoral National Research Service Awards (F32). It also lists the Collaborative Program Grant for Multidisciplinary Teams (RM1) among mechanisms that can include anesthesiology research. NIGMS is not the only NIH source: pain research, for example, is also funded by other institutes, and the right institute for a given proposal depends on its aims, so check current funding opportunities and contact the program officer before applying. Early-career investigators will find the K-series pathway described in our guide to the K99/R00 Pathway to Independence award, and all NIH-funded work is subject to the NIH Data Management and Sharing Plan requirement.

Specialty foundations

The Foundation for Anesthesia Education and Research (FAER), a related foundation of the ASA, funds early-career anesthesia investigators. FAER reports having funded more than $63 million in research grants and programs since 1986. Its offerings include Research in Education Grants ($100,000 over two years) and the APSF-FAER Mentored Research Training Grant, a two-year, $300,000 award for anesthesia patient-safety research, a partnership with the Anesthesia Patient Safety Foundation (APSF). Award amounts and programs change each cycle, so confirm current terms with the funder.

Research administration considerations

Anesthesia research raises several recurring compliance issues. Perioperative trials enroll patients on the day of surgery, which makes the timing and process of informed consent a design question for the institutional review board. Trials of drugs and devices may require FDA regulatory oversight, and depth-of-anesthesia and other monitoring devices have their own regulatory paths. Studies in the operating room often need coordination with surgical teams, pharmacy and perioperative nursing, and department-level cost allocation matters because anesthesia services are billed separately from surgery.

Common Research Methods and Tools

• Randomized clinical trials, from small physiological studies to large pragmatic multicenter trials comparing anesthetic techniques or drug strategies. Perioperative trials often use a composite endpoint, such as a combination of major postoperative complications, to capture rare events efficiently.
• Observational and registry research, using electronic anesthesia records and multicenter perioperative data registries to study outcomes at scale. Such studies depend on careful data definitions and attention to confounding, which is where biostatistics and epidemiology come in.
• Neurophysiology and neuroimaging, including EEG-based study of anesthetic depth and consciousness, and functional imaging of how anesthetics affect brain networks.
• Pharmacokinetic and pharmacodynamic modeling, describing how anesthetic drug concentrations relate to effect.
• Human factors and simulation, studying how teams, equipment and checklists affect safety.
• Laboratory research, including molecular work on anesthetic targets and animal models of anesthetic and pain mechanisms.

Anesthesia research in animals

Basic anesthesia and pain science, and the day-to-day care of research animals generally, involves anesthetizing laboratory animals, a practice overseen at US institutions by an Institutional Animal Care and Use Committee (see IACUC) and a veterinarian responsible for animal care (see attending veterinarian). The ethical framework most often cited is the 3Rs of replacement, reduction and refinement. For more detail on compliance, see monitoring anesthetic depth in mice, USDA pain and distress categories and our overview of animal research ethics.

Societies, Journals and Organizations

Societies

• American Society of Anesthesiologists (ASA): the principal US professional society for anesthesiologists, with FAER as a related foundation.
• International Anesthesia Research Society (IARS): a research-focused society and publisher of Anesthesia & Analgesia.
• Subspecialty societies, including the Society for Pediatric Anesthesia, the Society of Cardiovascular Anesthesiologists, the Society for Obstetric Anesthesia and Perinatology, the American Society of Regional Anesthesia and Pain Medicine, and the Society of Critical Care Medicine.
• Anesthesia Patient Safety Foundation (APSF): focused on anesthesia patient safety.
• International and national bodies, such as the World Federation of Societies of Anaesthesiologists and, in the UK, the Royal College of Anaesthetists and the Association of Anaesthetists.

Journals

Major journals include Anesthesiology, Anesthesia & Analgesia, the British Journal of Anaesthesia, Anaesthesia, Regional Anesthesia & Pain Medicine, the Canadian Journal of Anesthesia and the pain-focused journal Pain. Each has its own submission and reporting expectations, so check author instructions before submitting.

Career and Training Pathways

In the United States, the ABA describes standard anesthesiology training as 12 months of fundamental clinical skills training (formerly called the clinical base year) followed by 36 months of clinical anesthesia training, four years in all. The ACGME sets the program requirements for residencies. After residency, physicians may pursue fellowships in subspecialties such as pain medicine, critical care, pediatric or cardiac anesthesia. Physicians interested in research typically add dedicated research time through a T32 training program or a K-series career development award, as noted above. Nurse anesthetists follow a separate nursing-based path, and training structures differ substantially in other countries, so check the national body for specifics.

Not everyone in the field is a clinician. Basic scientists with backgrounds in pharmacology, neuroscience, physiology and biomedical engineering work alongside anesthesiologists in academic departments, which typically host both clinical and laboratory research programs.

Frequently Asked Questions

What is anesthesiology in simple terms?

It is the medical specialty and research field concerned with anesthesia, perioperative care, pain management and, for many practitioners, critical care. Anesthesiologists keep patients safe and comfortable during procedures and manage their physiology and pain around them.

Is it anesthesiology or anaesthesiology?

Both spellings refer to the same field. “Anesthesiology” is the US spelling and “anaesthesiology” or “anaesthesia” is common in the UK and Commonwealth, as in the British Journal of Anaesthesia.

What is the difference between an anesthesiologist and an anesthetist?

In US usage, “anesthesiologist” refers to a physician specializing in anesthesiology, while “nurse anesthetist” refers to an advanced-practice nurse. In some other countries, “anaesthetist” is the ordinary term for the physician.

Who funds anesthesiology research?

In the US, NIGMS is the NIH institute most associated with anesthesiology and peri-operative pain research, supplemented by other NIH institutes for specific topics. Specialty-linked foundations such as FAER and APSF fund early-career and patient-safety work.

How long does it take to become an anesthesiologist in the US?

After medical school, the ABA describes four years of training: 12 months of fundamental clinical skills (formerly the clinical base year) plus 36 months of clinical anesthesia. Fellowship training and research years are additional.

Is anesthesiology related to critical care and pain medicine?

Yes. Both are commonly practiced by anesthesiologists, though each also draws physicians from other specialties, and both have their own certification and research communities.

Related Guides

This guide is part of a series on scientific disciplines from a research-administration perspective. See the overview of the branches of science, and the companion guides What Is Pharmacology?, What Is Neurology?, What Is Nephrology? and What Is Geriatrics?. For a compliance-oriented view of sedation practice in hospitals, see Moderate Sedation Policy Requirements.