Dental General Anesthesia is a state of reversible unconsciousness of the central nervous system resulting in total analgesia and amnesia.
Some specific requirements, which must be met in order to legally and properly perform a procedure under the influence of a Dental General Anesthesia, are listed below:
1. The patient must have the procedure explained to him or her in detail and must fully understand its risks and benefits. All questions concerning the anesthesia and procedure should be answered for the patient.
2. The patient must sign a permit to have the procedure performed; It is considered to be an assault when a person’s body is invaded without prior permission. Completely worn off.
3. Sterile needles must be used at all times.
4. Instruments must be properly sterilized.
5. All equipment must be in good working order with functions checked prior to a procedure.
6. A patient’s preoperative evaluation, including a history and physical examination, should be performed.
7. All medications must be properly stored and utilized.
8. Resuscitative equipment must be nearby and in good working order.
9. Appropriate personnel must be present as required.
10. The procedure should take place in a hospital or hospital-like setting.
11. The patient may not leave the premises until the effects of the anesthetic have
The above guidelines should be followed with all dental procedures requiring Dental General Anesthesia in order to avoid malpractice, health hazards, complications, and legal actions.
There are four stages in the accomplishment of Dental General Anesthesia:
The first stage in Dental General Anesthesia is analgesia. This period extends from the time the anesthetic agent is administered to the time the patient loses consciousness. The patient becomes less aware of the surroundings and his or her muscle tone becomes flaccid (flabby, not finn).
(II) Excitement Stage
The second stage is the excitement stage. Here, the patient wifi have irregular respirations, muscle twitches, and indistinguishable speech. There may also be uncontrolled bowel or bladder function and dilated pupils.
(ill) Surgical Anesthesia
Surgical Dental General Anesthesia follows with the patient progressing into respiratory failure and into a deeper state of unconsciousness. Surgical anesthesia can be broken down into four separate stages or planes.
Plane one (light surgical) occurs when the gag reflex disappears and the eyelids lose their motion.
Plane two (mid-surgical) follows with the muscles losing tone and the eyes appearing to stare. The swallowing mechanism is lost.
Next, plane three (deep surgical) ensues as respiratory motion begins to dwindle. The muscle of respiration becomes frozen. The pupils do not respond to light stimuli.
Finally, in plane four (respiratory and circulatory failure), breathing further diminishes. Here, the patient’s airway must be especially maintained so there’s adequate oxygenation and perfusion of tissues.
(IV) Medullary or Respiratory Paralysis
The final stage of Dental General Anesthesia is called medullary or respiratory paralysis. In this state, the patient’s normal respirations have ceased, with the pulse becoming soft. At this point, the patient is completely anesthetized.
With the introduction and use of newer anesthetic agents, some of the specific stages of Dental General Anesthesia can no longer be observed since the time periods of many of them have been greatly reduced. The stages have been simplified into three general ones:
(i) Induction Period. The first stage is the induction period. This runs from the time the agent is administered to the time unconsciousness is accomplished.
(ii) Maintenance Stage. The second stage, the maintenance stage, runs from the time the patient is unconscious all the way through the surgical procedure.
(iii) Recovery Phase. Finally, the recovery phase includes the time from which the procedure ends until the patient is completely awake and the agents’ effects have worn off.
METHODS OF ADMINISTRATION
There are several ways to administer general anesthetics:
(A) Inhalational Agents
The inhalational Dental General Anesthesia take effect as the patient breathes them in through a face- mask. There are three systems that make their effect possible. In the first system, exhalations are introduced into tubing that connects to a reservoir bag. Here, some of the exhaled air remixes with the original agent while some of it is expulsed through a release valve. Mapleson theorized this system in 1954.
A second system, developed by Bain, is known as the “Bain Unit.” This system utilizes a tube within a tube. The gaseous agent is delivered to the patient’s mask through a tube while exhaled air is blown through the inner tube to the reservoir bag where it escapes through the escape valve. This system is convenient to use.
The third system is known as the circle breathing system. Here the gas flows freely to the patient through an inspiratory valve. As the patient exhales, the internal valve closes while an overflow valve opens, allowing carbon dioxide to be eliminated from the system.
There are four types of masks: the regular mask, the throwaway mask, the transparent mask, and the pediatric mask for the use in inhalational Dental General Anesthesia. Masks should be properly cleaned and fitted before commencing with any procedure.
One of the most commonly used inhalational agents is nitrous oxide. It’s advantageous to use this agent when possible because of the low potential for side effects and its rapid recovery phase.
Mother agent is halothane. There are some precautions when using this drug. These include the adverse effects on the cardiovascular system. Also the agent must be properly stored in special containers so it does not react with certain materials. The advantages of halothane are that it is non-flammable, has a rapid onset of action, has a rapid recovery rate, and has less incidence of stomach upset.
(B) Intravenous Agents
These agents are injected into a vein to induce Dental General Anesthesia. During the procedure various devices are used to continuously monitor the patient’s vital signs, heart rhythm, oxygenation, and respirations. The administration of intravenous medications is individualized and should be thoroughly understood before being performed. The patient should always have an open intravenous line in place in case resuscitative medications need to be rapidly administered.
There is a large selection of intravenous agents that can be utilized now-a-days. Benzodiazepines are commonly utilized but with higher doses than recommended in the treatment of anxiety. Examples of this class of medications include diazepam, lorazepam, and midazolam.
Diazepam takes a minute for its effects to be noticed, while midazolam takes 80 seconds.
Thiopental (Pentothal) and methohexital (Brevita) are other examples of intravenous agents. They are the shortest acting drugs of this group, with effects lasting approximately 10 minutes. Both have a rapid onset of action and a rapid recovery phase. These two agents are indicated for shorter procedures.
Other agents include ketamine, etomidate, propofol, and propanidid.
Occasionally, neuromuscular blocking agents are used to help prevent unwanted movements. It is important to understand that with any of these agents, patients must be continuously monitored to prevent complications.
There are specific instructions which need to be followed faithfully by a patient prior to coming in for a procedure requiring Dental General Anesthesia. It is helpful if these instructions are written out. Some of the important instructions are:
(i) The patient should not have anything to eat eight hours prior to surgery.
(ii) The bladder and bowels should be emptied since some of the Dental General Anesthesia may have an effect on these organ systems.
(iii) It is also wise for someone to spend time with the patient at home following the procedure in case of adverse reactions and to help the patient with any difficulties.
(iv) Patients should not wear any jewelry, accessories, or artificial prostheses on the day of the dental procedure. In addition, wearing makeup is unacceptable. This includes nail polish, shaving lotion, hair spray, perfumes or colognes, and lipstick. Instead, patients should be freshly bathed and wear clean and comfortable clothes.
The administration of Dental General Anesthesia requires specific equipment depending on whether it is theintravenous or inhalational type.
The intravenous equipment for Dental General Anesthesia is listed as follows:
— Reclining dental chair
— Rubber tubing
— Sterile syringes
— Sterile containers
— Intravenous poles
— Operating light
— Blood pressure cuff
— Sterile dressings
— Adhesive tape
– Sterilized surgical instruments which vary with the procedure
— Intravenous catheters
— Anesthetic medications
— Portable emergency unit
— Sterile needles of various gauges and lengths.
The inhalational equipment for Dental General Anesthesia should include the above items with the addition of the following:
— Oxygen tank (green in color)
— Inhalational agent tank
— Dispensing unit
— Clean masks in various sizes for children and adults.
As the procedure finishes and the stages of Dental General Anesthesia are reversed, the patient is continuously monitored until all bodily systems including respirations, heart rate, muscular reflexes, and vital signs are back to normal. It is very helpful to talk to the recovering patients, asking questions and having them perform simple commands. Patients should never be left unattended during this phase in case a problem should arise.
Other precautions include the prevention of aspiration or inhalation of gastric juices into the lungs. This can occur during vomiting and could result in aspiration pneumonia. Having the patient sit up in bed prevents it. The side rails of the bed should be raised to protect against falls. There should be a return of normal urinary and bowel functions. Finally, the vital signs are frequently monitored and recorded on the chart. Important warning signs here are a sudden change in respirations, heart rate, blood pressure, or temperature.
These instructions may vary greatly, depending on the procedure performed. Nevertheless, it is important for the patient to understand these instructions and follow them faithfully to ensure a rapid healing process. They are usually individualized for the patient with the following items given attention:
— Dietary restrictions
— Instructions for wound care
— The administration of pain medication and/or antibiotics
— Bed rest
— Calling the office if certain complications may occur
— Appointment for a recheck or suture removal
— A list of things which can be expected or which need to be recognized should they occur.
The best way to avoid complications in Dental General Anesthesia is to prevent them by performing a thorough medical and dental history and physical examination prior to the dental procedure. Complications are understood to be the potential adverse effects which may occur during or after a procedure. They can be minor or serious. Minor complications include headache, visual changes, nausea and vomiting, diarrhea, and weakness. Two serious complications which could occur in Dental General Anesthesia are respiratory failure (failure to breathe) and vascular (blood vessel) collapse.