Complications of general anesthesia

Specific risks in maxillofacial surgery

Interventions in the maxillofacial region (MFR) are accompanied by specific working conditions for the anesthesiologist and an increased risk of complications.

• Respiratory failure: In the postoperative period, there is a high threat of upper airway obstruction. This condition is provoked by soft tissue edema of the floor of the mouth and tongue, accumulation of wound discharge, and changes in normal tissue anatomy.
• Massive blood loss: Abundant vascularization of the face and neck, as well as the specific structure of the venous and arterial systems, create a threat of rapid bleeding. Standard mechanical hemostasis in this area is often insufficient, requiring timely and complete replenishment of the circulating blood volume (CBV).
• Metabolic disorders: Surgical trauma causes shifts that require strict monitoring of water-electrolyte balance and acid-base status.
• Monitoring complexity: Because the patient's face is covered with a sterile drape, the physician is unable to assess the depth of anesthesia using classic ocular reflexes. This requires the highest level of specialist qualification.

Complications associated with the choice of anesthetics

Incorrect selection of drugs for anesthesia induction can provoke life-threatening conditions. It is categorically inappropriate to use general anesthetics that increase the reflex excitability of the upper respiratory tract mucosa.

Such agents include:

1. Cyclopropane.
2. Chloroform.
3. Ethyl chloride.
4. Ketamine (Ketaminum).

If these drugs are used during manipulations on the larynx or oropharynx, the risk of reflex laryngospasm or bronchospasm increases manifold. This leads to severe impairment of pulmonary ventilation and requires immediate intervention.

Autonomic and systemic reactions

The lack of adequate autonomic stabilization before surgery (especially in patients with endocrine or cardiovascular pathology) leads to severe stress responses to surgical trauma.

Among the possible systemic complications are:

• Hard-to-control arterial hypertension.
• Myocardial ischemia and tachyarrhythmia.
• Vagal bradycardia, syncope, and collapse.
• Stress-induced hyperglycemia.

Competent premedication is necessary to prevent these conditions. There is also a risk of allergic reactions to the components of anesthesia. Patients with a burdened allergic history are indicated for specific prevention: H₁-receptor antagonists are prescribed one day before the intervention, and H₂-receptor antagonists 1–2 hours before surgery.

Prevention of respiratory complications and aspiration

To reliably protect the patient from severe complications, endotracheal anesthesia is widely used. It is strictly indicated when there is a threat of airway obstruction due to changes in the anatomy of the naso- and oropharynx. The most important function of tracheal intubation is the prevention of aspiration of blood, saliva, or foreign bodies into the bronchi.

In addition, the transition to multi-component combined anesthesia using muscle relaxants makes it possible to reduce the dosages of each individual drug. This decreases their toxic effect on the body, improves gas exchange by reducing "dead" space, and ensures rapid induction of anesthesia without the dangerous excitement stage.

Specific complications in pregnant women

A special risk group during surgical and obstetric interventions consists of pregnant patients with preeclampsia and eclampsia. Severe forms of these conditions can be complicated by convulsive seizures and fetal respiratory distress syndrome.

To prevent seizures and normalize blood flow, magnesium sulfate (Magnesii sulfas) is used, which has a mild narcotic, hypotensive, and anticonvulsant effect, and also reduces intracranial pressure. In critical conditions, the issue of transporting such patients to level III hospitals is decided on a strictly individual basis. It is important to remember that active bleeding is an absolute contraindication to transportation.

Class and exam questions

What else to study on this topic

• Indications and contraindications for endotracheal anesthesia
• Goals and pharmacological agents for premedication
• Types of combined general anesthesia (ataralgesia, neuroleptanalgesia)
• Scoring of operative and anesthetic risk
• Intensive care and anesthesia in severe preeclampsia

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