Balanced Anesthesia

Balanced anesthesia is a commonly performed form of general anesthesia. General anesthesia refers to conventional general anesthesia (Greek nàrkosi: to put to sleep), which forms a very large subspecialty of the field of anesthesiology. The definition of balanced anesthesia is not narrowly defined. Generally, it is understood to be a combination of inhalation anesthesia and intravenous anesthesia. The desired anesthetic qualities of hypnosis, analgesia (painlessness), muscle relaxation (muscle slackening), and the shielding of autonomic reflexes are achieved by a “balanced” combination of different drugs. These result in very good analgesia and are also characterized by less effect on the cardiovascular system than total intravenous anesthesia (TIVA).

Indications (areas of application)

Balanced anesthesia is a standard procedure and is used for long and intermediate length surgical procedures in adults. Furthermore, this form of anesthesia is recommended in cardiac risk patients (patients with preexisting cardiovascular disease).

Contraindications

  • Increased intracranial pressure – increase in pressure within the skull (under certain circumstances, volatile anesthetics may be used in cases of compensated intracranial pressure
  • Propensity for malignant hyperthermia – Malignant hyperthermia is a life-threatening metabolic derailment caused by a genetic dysregulation within skeletal muscle. In addition to numerous symptoms, a sharp increase in body temperature occurs.

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

In addition to preparation and thorough anamnestic exploration of the patient to rule out risks, medications are of key importance. The overall effect of anesthesia is characterized by the synergistic effects of these drugs. This principle is referred to as combination anesthesia and results in lower doses of the drugs as well as more targeted use of them. For balanced anesthesia, a combination of the following different drugs is used:

  • Volatile inhalation anesthetic – An anesthetic is considered “volatile” when it is administered through a vaporizer of the anesthetic apparatus and inhaled by the patient.
  • Opioid – Opioids, such as morphine, are powerful analgesics (pain relievers) that are administered intravenously.
  • Muscle relaxants (muscle relaxants).
  • Oxygen
  • If necessary nitrous oxide (nitrous oxide)

As mentioned above, balanced anesthesia is a mixed form of inhalation anesthesia and intravenous anesthesia. Depending on the weighting of the medication, opioid-supplemented inhalation anesthesia (inhalation anesthesia is in the foreground, supported by opioids) and inhalation-supplemented intravenous anesthesia (intravenous anesthesia is in the foreground, supported by inhalation anesthetics) can be distinguished. Thus, balanced anesthesia is an extremely flexible procedure.The airway must be kept open for the administration of oxygen: Intubation anesthesia allows the airway to be secured by an endotracheal tube (called a tube for short; it is the breathing tube, a hollow plastic probe inserted into the trachea (windpipe)). Another option is mask ventilation through a face mask. In this case, ventilation takes place via a mask that is placed over the mouth and nose. The laryngeal mask is placed over the larynx for ventilation in the pharynx. This form of ventilation is rarely used and then only for procedures of short duration.

After the procedure

After balanced 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 – heartbeat too slow: < 60 beats per minute.
  • Blood pressure drop
  • 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