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Operating Room

Operating room


An operating room (OR), also called surgery center, is the unit of a hospital where surgical procedures are performed.


An operating room may be designed and equipped to provide care to patients with a range of conditions, or it may be designed and equipped to provide specialized care to patients with specific conditions.


OR environment

Operating rooms are sterile environments; all personnel wear protective clothing called scrubs. They also wear shoe covers, masks, caps, eye shields, and other coverings to prevent the spread of germs. The operating room is brightly lit and the temperature is very cool; operating rooms are air-conditioned to help prevent infection.

The patient is brought to the operating room on a wheelchair or bed with wheels (called a gurney). The patient is transferred from the gurney to the operating table, which is narrow and has safety straps to keep him or her positioned correctly.

The monitoring equipment and anesthesia used during surgery are usually kept at the head of the bed. The anesthesiologist sits here to monitor the patient's condition during surgery.

Depending on the nature of the surgery, various forms of anesthesia or sedation are administered. The surgical site is cleansed and surrounded by a sterile drape.

The instruments used during a surgical procedure are different for external and internal treatment; the same tools are not used on the outside and inside of the body. Once internal surgery is started, the surgeon uses smaller, more delicate devices.

Operating room equipment

An operating room has special equipment such as respiratory and cardiac support, emergency resuscitative devices, patient monitors, and diagnostic tools.

Life support and emergency resuscitative equipment

Equipment for life support and emergency resuscitation includes the following:

  • Heart-lung bypass machine, also called a cardiopulmonary bypass pumptakes over for the heart and lungs during some surgeries, especially heart or lung procedures. The heart-lung machine removes carbon dioxide from the blood and replaces it with oxygen. A tube is inserted into the aorta to carry the oxygenated blood from the bypass machine to the aorta for circulation to the body. The heart-lung machine allows the heart's beating to be stopped during surgery.
  • Ventilator (also called a respirator)assists with or controls pulmonary ventilation. Ventilators consist of a flexible breathing circuit, gas supply, heating/humidification mechanism, monitors, and alarms. They are microprocessor-controlled and programmable, and regulate the volume, pressure, and flow of respiration.
  • Infusion pumpdevice that delivers fluids intravenously or epidurally through a catheter. Infusion pumps employ automatic, programmable pumping mechanisms to deliver continuous anesthesia, drugs, and blood infusions to the patient. The pump hangs from an intravenous pole that is located next to the patient's bed.
  • Crash cartalso called resuscitation cart or code cart. A crash cart is a portable cart containing emergency resuscitation equipment for patients who are "coding" (i.e., vital signs are in a dangerous range). The emergency equipment includes a defibrillator, airway intubation devices, resuscitation bag/mask, and medication box. Crash carts are strategically located in the operating room for immediate accessibility if a patient experiences cardiorespiratory failure.
  • Intra-aortic balloon pumpa device that helps reduce the heart's workload and helps blood flow to the coronary arteries for patients with unstable angina, myocardial infarction, or those awaiting organ transplants. Intra-aortic balloon pumps use a balloon placed in the patient's aorta. The balloon is on the end of a catheter that is connected to the pump's console, which displays heart rate, pressure, and electrocardiogram (ECG) readings. The patient's ECG is used to time the inflation and deflation of the balloon.

Patient monitoring equipment

Patient monitoring equipment includes the following:

  • Acute care physiologic monitoring systemcomprehensive patient monitoring systems that can be configured to continuously measure and display various parameters via electrodes and sensors connected to the patient. Parameters monitored may include the electrical activity of the heart via an ECG, respiratory (breathing) rate, blood pressure (noninvasive and invasive), body temperature, cardiac output, arterial hemoglobin oxygen saturation (blood oxygen level), mixed venous oxygenation, and end-tidal carbon dioxide.
  • Pulse oximetermonitors the arterial hemoglobin oxygen saturation (oxygen level) of the patient's blood with a sensor clipped over the finger or toe.
  • Intracranial pressure monitormeasures the pressure of fluid in the brain in patients with head trauma or other conditions affecting the brain (such as tumors, edema, or hemorrhage). Intracranial pressure monitors are connected to sensors inserted into the brain through a cannula or bur hole. These devices signal elevated pressure and record or display pressure trends. Intracranial pressure monitoring may be a capability included in a physiologic monitor.

Diagnostic equipment

The use of diagnostic equipment may be required in the operating room. Mobile x ray units are used for bedside radiography, particularly of the chest. These portable units use a battery-operated generator that powers an x ray tube. Handheld portable clinical laboratory devices, called point-of-care analyzers, are used for blood analysis at the bedside. A small amount of whole blood is required, and blood chemistry parameters can be provided much faster than if samples were sent to the central laboratory.

Other operating room equipment

Disposable OR equipment includes urinary (Foley) catheters to drain urine during surgery, catheters used for arterial and central venous lines to monitor blood pressure during surgery or withdraw blood samples), Swan-Ganz catheters to measure the amount of fluid in the heart and to determine how well the heart is functioning, chest and endotracheal tubes, and monitoring electrodes.

New surgical techniques

Minimally invasive surgery, also called laparoscopic surgery, is an operative technique performed through a few small incisions, rather than one large incision. Through these small incisions, surgeons insert a laparoscope (viewing instrument that displays the surgery on a computer screen for easier viewing) and endoscopic instruments to perform the surgery.

Robot-assisted surgery allows surgeons to perform certain procedures through small incisions. In robotic surgery, a surgeon sits at a console several feet from the operating table and uses a joystick, similar to that used for video games, to guide the movement of robotic arms that hold endoscopic instruments and an endoscope (small camera). The robotic arms allow the surgeon to perform precise, fine hand movements, and provides access to parts of the body that are difficult to reach manually. In addition, robotic surgery provides a three-dimensional image, and the surgical field can be magnified to a greater extent than traditional or minimally invasive surgery. The goal of robotic surgery is to decrease incision size and length of hospital stay, while improving patient comfort and lessening recovery time.

Lasers are "scalpels of light" that may offer a new alternative for some surgical procedures. Lasers can be used to cut, burn, or destroy abnormal or diseased tissue; shrink or destroy lesions or tumors; sculpt tissue; and seal blood vessels. Lasers may help surgeons perform some procedures more effectively than other traditional methods. Because lasers cause minimal bleeding, the operative area may be more clearly viewed by the surgeon. Lasers may also provide access to parts of the body that may not have been as easily reached manually.

Surgery centers

Freestanding surgery centers are available in many communities, primarily for the purpose of providing outpatient surgical procedures. The patient should make sure that the surgery center has been accredited by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), a professionally sponsored program that stimulates a high quality of patient care in health care facilities. There is also an accreditation option that is available for ambulatory surgery centers .

Choosing a surgery center with experienced staff is important. Here are some questions to consider when choosing a surgery center:

  • How many surgeries are performed annually and what are the outcomes and survival rates for those procedures?
  • How does the surgery center's outcomes compare with the national average?
  • Does the surgery center offer procedures to treat a particular disease?
  • Does the surgery center have experience treating patients in certain age groups?
  • How much does surgery cost at this facility?
  • Is financial assistance available?
  • If the surgery center is far from the patient's home, will accommodations be provided for caregivers?



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American Board of Surgery. 1617 John F. Kennedy Boulevard, Suite 860, Philadelphia, PA 19103. (215) 568-4000. <>.

American College of Surgeons. 633 N. Saint Clair Street, Chicago, IL 60611-3211. (312) 202-5000. <>.

American Society of Anesthesiologists. 520 N. Northwest Highway, Park Ridge, IL 60068-2573. (847) 825-5586. E-mail: <>.

Association of Perioperative Registered Nurses (AORN, Inc.). 2170 South Parker Road. Suite 300, Denver, CO 80231. (800) 755-2676 or (303) 755-6304. <>.

National Heart, Lung and Blood Institute. Information Center. P.O. Box 30105, Bethesda, MD 20824-0105. (301) 251-2222. <>.

National Institutes of Health. U.S. Department of Health and Human Services, 9000 Rockville Pike, Bethesda, MD 20892. (301) 496-4000. <>.

other <>.

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Angela M. Costello

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"Operating Room." Gale Encyclopedia of Surgery: A Guide for Patients and Caregivers. . 10 Dec. 2017 <>.

"Operating Room." Gale Encyclopedia of Surgery: A Guide for Patients and Caregivers. . (December 10, 2017).

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operating room

op·er·at·ing room (abbr.: OR) (Brit. operating theatre) • n. a room in a hospital specially equipped for surgical operations.

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"operating room." The Oxford Pocket Dictionary of Current English. . 10 Dec. 2017 <>.

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"operating room." The Oxford Pocket Dictionary of Current English. . Retrieved December 10, 2017 from