Pure inhalation anesthesia is a subspecialty of general anesthesia. General anesthesia refers to conventional anesthesia or general anesthesia (Greek nàrkosi: to put to sleep). Pure inhalation anesthesia differs from balanced anesthesia in that the opioid (painkiller; e.g., morphine) administered intravenously is not used. Balanced anesthesia (combination of inhalation anesthesia and intravenous anesthesia) represents the more advanced form of inhalation anesthesia.
Indications (areas of application)
Balanced anesthesia is usually preferred over pure inhalation anesthesia. One indication is the use in pediatrics (pediatrics). Here, inhalation anesthesia is used primarily in children or infants when placement of venous access fails due to low cooperation. However, access must be placed after induction of anesthesia. An advantage of inhalation anesthesia is the good controllability of the depth of anesthesia by precise rationing of the supplied gases. However, postoperatively (after surgery), there is a very rapid decay of the analgesic (pain-reducing) effect.
Contraindications
- Intracranial (located inside the skull) pressure elevation.
- Circulatory instability
- Tendency to malignant hyperthermia (Malignant hyperthermia is a life-threatening metabolic derailment caused by genetic dysregulation within skeletal muscle. In addition to numerous symptoms, a severe increase in body temperature occurs. Volatile inhalational anesthetics and so-called depolarizing peripheral muscle relaxants can trigger this reaction).
- Severe liver damage
Before surgery
Before any surgery, the anesthesiologist (anesthesiologist) must conduct an educational interview with the patient to clarify questions, obtain a medical history, and inform the patient of risks and complications.The patient is often given premedication. This is administered about 45 minutes before the procedure and serves primarily to anxiolysis (anxiety resolution).Immediately before the induction of anesthesia, the anesthesiologist makes sure of the identity of the patient so that there is no confusion. It is obligatory to ask about the last food intake and to check the oral and dental status (also for forensic traceability in case of damage during intubation). Before any planned anesthesia, the patient must be fasting, otherwise the risk of aspiration (carryover of food residues into the airway) is increased. For emergency procedures performed on non-fasted individuals, a special form of anesthesia induction, Rapid Sequence Induction, is used to address the increased risk of aspiration.Medical monitoring is now begun, this includes: Electrocardiogram (ECG), pulse oximetry (measurement of pulse and oxygen content of the blood), venous access (for the anesthetic drugs and other medications), blood pressure measurement (if necessary, invasive arterial blood pressure measurement in high-risk patients).
The procedure
Pure inhalation anesthesia is an anesthetic procedure that is rarely used today. Balanced anesthesia is usually used. In both forms, mask anesthesia, intubation anesthesia, and anesthesia using a laryngeal mask (laryngeal mask) or a laryngeal tube (LT) can be performed. The LT is an airway protection device and is inserted blindly. Due to its design, the laryngeal tube almost always comes to rest in the esophagus (food pipe). In inhalation anesthesia, air (or nitrous oxide (laughing gas)), oxygen, a volatile inhalation anesthetic (an anesthetic is understood to be “volatile” if it is administered through a vaporizer of the anesthetic apparatus and inhaled by the patient), and usually muscle relaxants (muscle relaxants) are administered. The inhalation anesthetic is administered at a higher dose, in contrast to balanced anesthesia.
After the procedure
After inhalation anesthesia, extensive monitoring of the patient is indicated, usually performed in a recovery room by experienced skilled nursing staff. In addition to surgical follow-up, the focus is on monitoring the patient’s cardiovascular system.
Potential complications
- Anaphylactic (systemic allergic) reaction – e.g., to medications.
- Aspiration of stomach contents
- Awareness – intraoperative waking states
- Bradycardia – slowing of cardiac activity or heartbeat.
- Drop in blood pressure
- Blood loss
- Intubation damage – e.g., damage primarily to the anterior teeth when the tube is inserted, or further injury to the mouth and throat.
- Hypothermia (hypothermia)
- Air embolism – obstruction of a vessel by air bubbles that enter the vascular system during surgery
- Respiratory disorders
- Nausea (nausea)/vomiting