General anesthesia makes it possible to be in a state of artificial sleep thanks to the injection of anesthetic product or the inhalation of an anesthetic gas, making it possible to temporarily suppress the sensation of pain. When to do it? Fibroscopy? Colonoscopy? What risks? Directions and process.
General anesthesia is a state of deep sleep and artificial performed for certain medical operations and produced by the injection of anesthetic product or by the inhalation of anesthetic gas. How is it going? What are the risks of complications? How to prepare for it? And the following? Know everything.
Definition: what is general anesthesia?
The term anesthesia comes from a Greek word evoking “the absence of sensation”. The purpose of general anesthesia is toput the brain to sleep, so that it no longer incorporates the painful sensation transmitted by the nerves during the surgical operation. It is a state comparable to sleep. In practice, this consists to inject anesthetic products into the blood, which passes from the blood to the brain. It is done either by the intravenous injection of drugs or by the inhalation of an anesthetic gas using a mask. “Since pain constantly stimulates the areas of nerve endings, which will transmit information through the nerves to the brain, the brain must be put to sleep deeply so that it no longer integrates these signals.“, explains Doctor Aurélien Jacquemod, anesthesiologist.
Indications: when to perform general anesthesia?
General anesthesia may be indicated (according to the recommendations of the High Authority of Health) :
► Related to the general condition of the patient:
- behavioral conditions precluding awake oral assessment and/or treatment following failed attempts at chairside care;
- need for heavy and urgent oral conditioning before specific urgent medical and surgical treatments, for example: oncology, hematology, cardiology, organ transplant, etc.;
- limitation of mouth opening prohibiting immediate examination and/or treatment;
- pronounced gag reflexes.
► Related to the intervention:
- long, complex interventions, grouping of several acts in the same session;
- loco-regional infectious state requiring emergency intervention (for example: associated procedure of drainage and/or debridement extractions in the context of osteoradionecrosis).
► Related tolocal anesthesia :
- proven contraindications to local anesthesia, i.e. allergy confirmed by an allergology assessment and contraindications specified in the Marketing Authorization (porphyria, epilepsy not controlled by medication, etc.) )
- inability to achieve a local level of anesthesia
General anesthesia involves a preparatory anesthesia consultation several days before the medical act. During this consultation, the anesthesiologist asks the patient regarding his general state of health, his medical history and determines the type of anesthesia according to the operation or act, but also potential illnesses and treatments in progress. . An anesthetic questionnaire must also be completed. A little before the intervention, a new pre-anaesthetic consultation takes place (generally the day before for hospitalization or the same day for an intervention in ambulatory) to check that everything is fine.
Do you have to be fasting for general anesthesia?
It is necessary to remain on an empty stomach following your dinner the day before to limit the risk of regurgitation during the anesthesia.
Step by step: how is a general anesthesia performed?
► To start, the anesthetist sets up an infusionthen will realize pre-oxygenation of the patient : this consists of making him breathe a large quantity of oxygen for a short time. This will allow in a second time to carry out the artificial ventilation.
► Once the patient is pre-oxygenated, we move on to la phase d’induction. “This involves injecting different drugs into the patient: first hypnotic drugs (propofol in the majority of cases) then analgesic drugs, with painkiller effects (ketamine is the most commonly used) and if necessary, a drug of the type of muscle relaxants, which will cause significant muscle relaxation“, describes the anesthesiologist.
► Once the patient has lost consciousness, in the majority of cases, it will be necessary to put in place artificial ventilation. “This is necessary when the brain is so sleepy that it loses the ability to generate spontaneous breathing“, explains the specialist. Artificial ventilation is done either under oral-tracheal intubation (i.e. via a tube that goes through the mouth), or supraglottic, also called a laryngeal mask.
► Then we go into maintenance phase of anesthesia, which consists of making the patient sleep as long as desired. There are two ways: intravenous anesthesia, and volatile anesthesia. This consists of maintaining anesthesia through the respiratory tract. It is done by means of an evaporator which mixes an anesthetic drug in the air which the patient is made to breathe.
► “At the end of the intervention, it suffices to stop drug administrationexplains the doctor. Once the patient is awake, he will go to the recovery room to ensure that there are no immediate postoperative complications, and to check his vital functions and verify that there is no re- falling asleep“.
You don’t have to drive followingwards.
After the operation, the patient is taken to post-procedure monitoring room (recovery room) to monitor blood pressure, pulse, respiratory rate…until total recovery of consciousness. If the medical act required an intubation or a mask, it is possible to feel sore throat or temporary hoarseness. Transient memory problems or a decrease in the faculties of concentration can occur in the hours following the anesthesia. Also compressions of certain nerves or a feeling of numbness. Driving following general anesthesia is contraindicated. It is advisable to organize to be accompanied or to remain under surveillance for one night.
What are the risks and side effects of general anesthesia?
The most common side effects are the least serious, such as nausea and vomiting. But the more serious risks are mainly severe allergy. “This is because a large amount of medicine is injected directly into the blood. This can create a anaphylactic shock and jeopardize the vital prognosisexplains the doctor. But today, incidents of this type are on the order of 1 in 1 million, because we know very well how to deal with complications.“. Other risks are respiratory complications, because there can be the contents of the gastric liquid which goes up in the lungs when one is under artificial ventilation. There may also be mechanical complications when you are intubated, like damaging a vocal cord or break a tooth.
What are the contraindications of general anesthesia?
- Major anesthetic risks: necessary assessment of the risk-benefit.
- Refusal by patient and/or parents or legal representative.
Thanks to Dr Aurélien Jacquemod, anesthesiologist.
