No domain in life is without risks, and complications do occur during patient care and treatment. In this regard, anesthesia is no more an exception. The complications can range from mild anaphylactoid reaction to death in the worst scenario. This chapter is an overview of complications that may arise during anesthetic care, and one should be aware of them. These are listed below:
Evidence suggests that perioperative mortality due to anesthesia is between 1 in 13,000 and 1 in 15,000 cases, but the incidence of mortality exclusive due to anesthesia is rare. Certain patient and procedure-related factors add to increased mortality:
Upper esophageal sphincter (UES): It is formed by cricopharyngeous muscle, which is striated in nature. A conscious individual has a tone of around 25 to 38 cm of H2O. Anesthetic agents except ketamine reduce the tone of the sphincter.
Lower esophageal sphincter (LES): It lies at the junction of the stomach and esophagus. The resting end-expiratory LES is approximately 8 to 20 cm of H2O higher (barrier pressure) than resting end-expiratory intragastric pressure. Since succinylcholine increases both the pressures, as a result, the barrier pressure is maintained.
Avoidance of positive pressure ventilation during conventional RSI precludes the ability of the clinician to check the airway and determine whether ventilation by the mask is possible. The failure to secure the airway during RSI may result in hypoxia, hypercarbia, and even death. Therefore, conventional RSI is modified. It consists of the following components:
Its main objective is to prevent aspiration by compressing the esophagus between the cricoid cartilage and body of C6 vertebra. The current recommendations regarding the amount of pressure are as follows:
Thrombolytic therapy (urokinase, streptokinase, alteplase, and reteplase): Thrombolytic therapy resolves the thrombi or emboli and restores the pulmonary circulation’s normal hemodynamic functioning, thereby reducing pulmonary hypertension and improving perfusion, oxygenation, and cardiac output.
Surgical management: A surgical “embolectomy” is rarely performed but may be indicated if the patient has a massive PE or hemodynamic instability or if there are contraindications to thrombolytic therapy.
Hypoxia is defined as the failure of oxygenation at the tissue level, while hypoxemia is defined as a condition where the arterial oxygen tension is below normal (normal PaO2 = 80–100 mm Hg). The hypoxemia can be of the following types:
The hypoxemia can occur due to the causes listed in Table 38.1.
Decreased minute ventilation in spontaneously ventilating patients due to drug-induced depression of the ventilatory response to CO2. Common agents are opioids, benzodiazepines, sedative-hypnotics (propofol), and halogenated inhalational agents.