According to anesthesiologist Wayne Kleinman in the 2006 edition of "Clinical Anesthesiology," anesthesiologists use spinal nerve blocks to support a range of applications in orthopedic, urologic, gynecologic, obstetric and sometimes vascular surgeries. An ITN block involves the injection of both narcotics, such as fentanil, and local anesthetics, such as lidocaine, into the spinal canal. As with any medical treatment, ITN spinal blocks sometimes cause side effects.
Back Pain
In order to perform a spinal nerve block, an anesthesiologist must insert a long, thin needle through the skin, muscles and ligaments of the back, as well as the thin membranes that line the spinal canal. Many people report back pain near the needle insertion site as the anesthetic starts to wear off. According to the American Society of Regional Anesthesia and Pain Medicine, back pain is typically mild and resolves on its own over the course of a few days. Alternating hot and cold compresses and limiting activity can help. Patients who have recently undergone an ITN spinal block should talk to their doctors before using over-the-counter medications such as acetaminophen.
Nausea and Vomiting
Nausea and vomiting are a common side effect of narcotic drugs that are used in ITN spinal blocks. Patients typically feel the urge to vomit a few minutes after opioids are injected by an anesthesiologist or, in the case of patient-controlled analgesia, a few minutes after the patient herself pushes the button. Anti-emetic medications such as trimethobenzamide and promethazine can help. Since oral drugs often make nausea and vomiting worse, anti-emetics are administered intravenously, intramuscularly, or as a rectal suppository.
Low Blood Pressure
Low blood pressure results when the drugs in a spinal block interfere with outflow from nerves in the sympathetic nervous system that maintain tone in the blood vessels. Patients experience low blood pressure as wooziness, fainting or, sometimes, nausea and vomiting. Unlike nausea and vomiting due to opioid drugs, nausea and vomiting due to low blood pressure follows the administration of local anesthetic drugs. Patients who experience low blood pressure require more aggressive monitoring both intraoperatively and postoperatively, in order to reduce the risk of complications such as cardiac arrest, respiratory failure and falls.
References
- "Clinical Anesthesiology, 4th edition;" G.E. Morgan et al. (eds); 2006
- American Society of Regional Anesthesia and Pain Medicine: Patient Informatio
- American Society of Anesthesiologists: Frequently Asked Questions
- MedlinePlus: Spinal and Epidural Anesthesia
