Before surgery, patient sedation is the responsibility of an anesthesiologist. Induction of anesthesia can occur from inhalation agents or intravenous anesthesia. IV anesthetics are drugs administered through an IV to put the patient to sleep for surgery. Some of the most commonly used IV induction agents include propofol, ketamine, barbiturates, and etomidate. These IV anesthetics have unique and overlapping side effects.
Most Common IV Anesthetics
The four main groups of intravenous anesthetics are barbituates, propofol, etomidate, and ketamine. Propofol is the most commonly used IV anesthetic. It is classified as a sedative-hypnotic agent, meaning it causes a sleep state. Thiopental and methexital are barbiturate anesthetics. These drugs also have anti-seizure activity. Etomidate is a sedative agent that is used primarily in patients with heart disease. Lastly, Ketamine is another drug used for induction of anesthesia. Ketamine is called a dissociative anesthetic, because patients may have their eyes open but are not aware of their surroundings.
Main Side Effects
All IV anesthetics have a variety of side effects that affect multiple body systems. Sodium thiopental can cause rash, abnormal heart rhythm, shivering, abdominal pain, and cough. In Phase IV trials of propofol, most patients report nausea, vomiting, a drop in blood pressure and heart rate. Many patients report a burning sensation or pain at the IV site soon after drug administration. Etomidate can cause nausea, vomiting, changes in blood pressure or heart rate, coughing and drowsiness. Some other adverse reactions associated with use of intravenous Etomidate are phelbitis, which is swelling of the vein where medicine is injected. It can also cause myoclonus, or intermittent muscle cramping. The most common side effects of Ketamine include blurry vision, a confused state, drowsiness, increased or decreased blood pressure or heart rate, changes in mood, nausea and vomiting. Patients also report vivid dreams, illusions, and flashbacks several weeks after surgery, according to the Department of Anesthesia at Stanford University Medical Center.
Although these drugs have side effects, they also have many benefits that make them useful. IV anesthetics are useful because they allow the patient to be asleep during and unaware during the surgical procedure and have no memory upon awakening.
Most side effects from IV anesthesia are mild and self limiting. Some of these adverse reactions can be prevented from occurring with medication and preplanning. Nausea and vomiting is common after all anesthesia. During the procedure, your doctor may administer a drug called an anti-emetic, which helps prevent these symptoms. Shivering, another common symptom after surgery, can be prevented by keeping the patient warm during surgery with warm IV fluids, blankets, etc.
These IV anesthetics have similar and varied side effects in the perioperative period. Always report your past medical history and social history to your physician. Patients who use alcohol, medications, illicit drugs, or who have a family history of adverse reactions to anesthesia may have more complications from IV anesthesia.