Anaesthesiology is a medical speciality that allows the patient to benefit from a surgical procedure or an invasive medical treatment safely and painlessly.
This consists of creating a deep artificial sleep and suppressing any sensations of pain using an intravenous injection and/or by breathing in anaesthetic drugs under continuous medical supervision.
The doctor will inject a drug that will lead to a loss of consciousness (hypnotic), a pain relief medication (powerful morphine derivatives) and, where necessary, a drug for muscle relaxation (curare).
This allows for only the part of the body operated on to be put to sleep without any loss of consciousness. It can be used on its own for surgery, together with a general anaesthesia, or exclusively for the management of postoperative pain.
The principle is to inject a longer or shorter lasting local anaesthetic near the nerves in order to prevent the transmission of the pain signal to the brain.
There are different types of local/regional anaesthesia:
- Medullary anaesthesia (epidural or spinal): by injecting a local anaesthetic near the spinal cord. This technique allows for the lower part of the body to be put to sleep, for example, for gynaecological or urological surgery;
- Peripheral block: by injecting a local anaesthetic near a nerve or a nerve plexus. This technique allows for a single limb to be put to sleep to carry out an operation on that limb, for example, for orthopaedic surgery.
The anaesthesia technique is chosen by the anaesthetist during the preoperative anaesthesia consultation. Ensuring the comfort and safety of patients is the main objective in this line of care. The medical specialist makes their decision based on the surgical procedures and the risk assessment relating to the patient, as well as the patient’s own desires.
During the procedure, the anaesthetist will use equipment that allows the patient’s vital functions to be monitored throughout the operation. An intravenous catheter will be positioned, which allows the drugs to be administered through the vein. Subsequently, the anaesthetist will implement the anaesthetic technique decided upon in consultation with the patient.
Throughout the operation, the anaesthetist, or a nurse anaesthetist, stays with the patient to ensure a sufficient quantity of anaesthesia during the procedure, as well as the patient’s safety.
At the end of the operation, the doctor will wake the patient. If the patient was under general anaesthesia, they will be accompanied to the recovery room for postoperative monitoring, where the patient will remain until fully awake.
The administration of different analgesics for the postoperative treatment of pain will occur in post-anaesthesia care units.
Only once the patient is fully awake, their vital functions stable and their pain under control will the anaesthetist authorise the patient’s return to their room.
Anaesthesia allows for surgical procedures to be performed in the safest way possible. However, they are not completely free of risk. Risks will depend mainly on the patient’s general health, age, the urgency of the operation and the type of anaesthesia. At present, anaesthetic risks have significantly decreased and the number of serious complications is estimated at one case in every 100,000 patients.
Side effects are generally minor in healthy patients. Under general anaesthesia, patients may present nausea and vomiting upon waking or over the next few hours. However, in the majority of cases, symptoms can be avoided by preventively administering anti-nausea medication. During intubation, a dental injury may occur. Fortunately, this unwelcome complication is rare (it affects only one patient in every 2000).
Risk factors include a wobbly tooth and difficulties when inserting the tube into the throat. After intubation, up to 40% of patients may experience sore throats, which go away naturally within a few days. Finally, during the recovery stage, patients may experience chills. The main reason for this is the decrease in preoperative body temperature. However, it may also occur as a result of pain and stress. Therefore, the anaesthetist will always ensure that the loss of heat during the operation is as little as possible. Medications may also be administered to stop these chills. The majority of these side effects are transitory and go away naturally within a few hours.
During local/regional anaesthesia, although rare, the main risk is nerve damage in the form of impaired sensitivity or a loss of strength. In most cases, these disorders can be reversed. A drop in blood pressure, headaches and difficulty passing urine may also be experienced in the postoperative period. These are corrected with suitable treatment.