Going under the knife? What to know about anaesthesia before surgery

Deciding on anesthesia before surgery can be a complex process, leaving many patients bewildered by the choices beyond the familiar general anesthesia (GA). While GA induces complete unconsciousness, regional anesthesia (RA) offers an alternative by numbing a specific part of the body, such as through spinal anesthesia or a peripheral nerve block, depending on the surgical site.

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More complex procedures, such as major abdominal or chest surgeries, often require GA.

Senior consultants from Tan Tock Seng Hospital (TTSH) explain that GA is typically necessary for more extensive procedures like major abdominal or chest surgeries. However, for operations focused on a particular area, such as an arm, leg, or the lower body, RA might be a more suitable option. Dr. Fong Wee Kim, who heads TTSH’s Anaesthesiology, Intensive Care and Pain Medicine, advises that RA can also be a beneficial choice for patients whose existing medical conditions pose higher risks with GA.

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RA can also be a good option for patients who may face higher risks with GA because of existing medical conditions.

Dr. Joanne Yeo, a consultant at Changi General Hospital’s Department of Anaesthesia and Surgical Intensive Care, notes that these medical considerations can include a patient's overall health, past reactions to medications, previous surgical experiences, and specific risks associated with different anesthetic types. Understanding these factors is crucial before making an informed decision.

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They temporarily reduce communication between different parts of the brain producing unconsciousness, reducing awareness, and reducing perception of pain.

During GA, an anesthesiologist typically administers an intravenous agent like propofol, which temporarily alters brain activity to induce unconsciousness and reduce pain perception. Strong painkillers are also given. An inhalational anesthetic is then used to maintain unconsciousness, though propofol infusions can sometimes suffice. The anesthesiologist's role extends to continuously monitoring vital signs like blood pressure, heart rate, and oxygen levels throughout the procedure.

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For instance, desflurane is particularly unpleasant to smell and is a lung irritant.