Complications of inhalation anesthesia

The role of premedication in complication prevention

Premedication is the preliminary administration of medications before surgery. Its most important task is the prevention and reduction of potential complications, as well as the correction of pathological changes caused by concomitant somatic diseases.

Autonomic stabilization is of particular importance, which is critical for patients with cardiovascular and endocrine pathology. The lack of stabilization can lead to severe intraoperative and postoperative consequences:

• difficult-to-control arterial hypertension;
• tachyarrhythmia and myocardial ischemia;
• stress-induced hyperglycemia;
• vagal bradycardia, syncope, and collapse.

Patient preparation specifics and risks

Comprehensive preparation of the patient for anesthesia reduces the likelihood of adverse reactions. The mandatory minimum examination includes taking a medical history, measuring blood pressure, counting the pulse, and performing basic respiratory tests.

During the medical history taking, attention is paid to medications being taken, bad habits, concomitant pathologies, and the time of the last meal. Anesthesia is performed strictly on an empty stomach, no earlier than 4–5 hours after eating. Violation of this rule increases the risk of aspiration and vomiting. In women, the time of the last menstruation must be taken into account, as blood loss against the background of certain anesthetics can provoke vascular collapse.

Combined anesthesia and side effect minimization

To reduce toxic effects and prevent complications, combined general anesthesia is widely used, involving the simultaneous or sequential use of several drugs. This allows achieving a pronounced therapeutic effect and reducing adverse side effects.

Clinical practice utilizes:

• combinations of volatile anesthetics (halothane, enflurane, or sevoflurane) with nitrous oxide and oxygen;
• ataralgesia and neuroleptanalgesia (NLA), protecting against pain trauma;
• combinations of inhalation and intravenous anesthetics.

The cumulative use of several agents in small doses reduces the toxicity of each, improves gas exchange, and decreases the total amount of the administered anesthetic substance.

Assessment of Operative and Anesthetic Risk

Patient safety directly depends on proper risk assessment, which is composed of the patient's general condition, the scope of surgery, and the type of anesthesia. Different types of pain relief carry varying degrees of burden on the body:

1. Potentiated local anesthesia is rated as minimal.
2. Inhalation mask anesthesia with spontaneous breathing carries a moderate risk score.
3. Standard combined endotracheal anesthesia requires more careful monitoring.
4. Complex interventions with cardiopulmonary bypass or controlled hypotension represent the maximum risk level and require intensive care.

Class and exam questions

What else to study on this topic

• Sedation criteria and preservation of protective reflexes
• Pharmacological drug groups for premedication and amnesia
• Methodology of neuroleptanalgesia (NLA)
• Features of endotracheal anesthesia and the use of muscle relaxants
• Scoring scales for operative and anesthetic risk
• Advantages of non-inhalation anesthetics over inhalation ones

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.