How Anesthesia Machines Work

How Anesthesia Machines Work

The use of anesthesia machines is common in many types of major and minor surgery, dental work, medical treatments, and even childbirth. Yet few people outside the medical community know anything about the way anesthesia and anesthesia machines work, even though many of us have been administered anesthesia before.

There are several types of anesthesia and several ways in which nerve impulses are blocked in order to limit the perception of pain. Therefore, there are several different anesthesia tools, ways to administrate it, and effects.

What anesthesia is: anesthesia is a drug-induced state of unawareness or unconsciousness that results from blocking sensation in all or part of the body. The pathways between the nervous system and the brain are cut off so that patients can receive treatments that would otherwise be too painful to endure.

Types of anesthesia: There are four different types of anesthesia that include local, regional, general, and dissociative. There are also sub-types of anesthesia such as spinal and epidural anesthetic.

•Local anesthesia: This type of anesthesia is “localized” to one small part of the body such as a tooth or finger. The patient remains conscious but has a reduced level of pain and sensation in the targeted area.

•Regional anesthesia: Regional anesthesia is a nerve block that affects a larger part of the body such as a limb or the lower half of the body as with epidural anesthesia. As with local anesthesia, the patient remains conscious but feels little to no sensation in the part of the body where nerve signals are blocked.

•General anesthesia: General anesthetic is given to send patients into a medical coma for the purposes of performing major surgery and other medical treatments. General anesthetic has a number of effects, which include loss of consciousness, motor skills, skeletal reflexes, memory, and the sensation of pain.

•Dissociative anesthesia: This type of anesthesia uses a dissociative drug to lower impulses in the brain and induce a trance-like or euphoric state while blocking signals between different parts of the brain to inhibit pain.

Administering Anesthesia

Anesthesia can be administered intravenously, breathed in, delivered by a machine, given orally, or by a combination of techniques. An anesthesiologist is normally the person responsible for administering general and regional anesthesia, while a doctor or dentist may give local anesthesia to their patients themselves. Veterinarians and nurse anesthesiologists are other people who may administer various types of anesthesia.

•Administering local anesthetic: Most often, a numbing agent is injected into the targeted area. In some cases a numbing agent may be applied topically.

•Administering regional anesthetic: Anesthetic is given intravenously or the nerve block is performed intravenously.

•Administering general anesthetic: General anesthetic is given with anesthetic machines.

•Administering dissociative anesthesia: Dissociative anesthesia is usually given orally, intravenously, or it is inhaled.

Using Anesthesia Machines to Administer General Anesthesia

A cocktail of gases is the most common anesthesia technique used to achieve the controlled state of unconsciousness and loss of sensation that results from general anesthesia. Sometimes techniques are combined to reduce side effects in certain patients or to better achieve the desired effect.

Gases are delivered to patients through an oxygen mask that fits over the patient’s mouth and nose. Patients breathe in the mixture of oxygen, nitrous oxide, and other gases that’s combined and regulated by the anesthesia machine. The machine also captures, purifies, and reuses or releases the gases that are exhaled by the patient. Here’s how the different parts work together to make an anesthesia machine function.

Vaporizers: Anesthesia machines keep patients sedated and breathing by delivering a mix of gases that includes oxygen and nitrous oxide. The anesthesiologist controls the level of sedation through the vaporizer which mixes the gases.

Ventilators: Ventilators keep patients breathing during sedation and help maintain good blood composition. Modern ventilators have multiple settings to help regulate the breathing patterns of different types and ages of patients.

Flowmeters: Flowmeters control the levels of gases as the anesthesiologist administers them. New, low-flow machines are just as effective but help maintain the patient’s core temperature at the same time.

Breathing Circuits: These devices effectively breathe for patients as they send the mix of anesthetic gases to the lungs and exhale the CO2 byproduct. Circular breathing units administer a low flow of continuous gases to patients for best results.

Scavenging Systems: These systems expel the gases the patient releases from their lungs. In an active scavenging system, suction is used to remove the gases from the patient’s lungs. In a passive system a tube sends gases out to a ventilation system for purification.