Recent Advances in Anesthesia

By February 23, 2018Uncategorized

It is a formidable and near impossible task to discuss all pertinent advances in the field of anesthesia that have come to pass in the recent years, however it is interesting to look back and review a few of the changes that have reshaped our practice. Almost certainly there will be large omissions, particularly in subspecialties such as pediatrics and cardiac anesthesia; our focus will be on adult general anesthesia, from the perspective of practicing at a large academic institution.

New drug developments have always had the potential to alter the scope of our practice, but it is difficult to think of one that has had so much impact in recent years as the development and popularization of sugammadex. Instead of competitively reversing neuromuscular blockade by increasing acetylcholine levels as the acetylcholinesterase inhibitors do, sugammadex directly binds and inactivates the nondepolarizing neuromuscular blocker itself (most specifically rocuronium, but also vecuronium and pancuronium at a lower affinity; it has no action on succinylcholine or cisatracurium). Its action is dosage dependent, and its use is not limited by the number of twitches a patient has on nerve monitoring. Implications are vast and include a faster and more effective recovery from paralysis, which ensures improved post-operative respiratory mechanics and patient safety. Sugammadex also allows the anesthesiologist to keep the patient paralyzed for longer periods of time, optimizing surgical conditions during complex cases.  It is also effective at rescuing over-dosing of neuromuscular blocking drugs (whether unintentional or intentional, such as in rapid sequence inductions where succinylcholine is contraindicated). While Sugammadex must be used with caution in patients with renal disease, and may interact with oral contraceptives, its safety profile is overall reassuring.

In the realm of anesthesia equipment, one of the most notable advances has been transnasal humidified rapid-insufflation ventilator exchange (THRIVE), otherwise known by its trademark, Optiflow. Essentially comprised of a high flow oxygen source capable of delivering up to 60L/min of humidified, warmed oxygen, delivered by nasal cushion, the system provides a constant stream of oxygen with high enough flow to decrease anatomic dead space and provide PEEP, while partially washing out accumulating carbon dioxide. This concept of apneic oxygenation has recently been used in ENT procedures in paralyzed, apneic patients for procedures lasting 30-60 minutes without desaturation. Its duration is limited by carbon dioxide toxicity, and therefore patient selection is important to avoid complications such as the exacerbation of pulmonary hypertension. It has also become a useful tool for difficult airway management, providing better preoxygenation and a source of passive oxygen during airway management; however care must be taken in patients with airway obstruction such as large obstructive tumors, as barotrauma may develop.

Finally, there is a general shift away from narcotic-based general anesthetics to multimodal analgesia, and increasingly more regional and neuraxial techniques. Surgeries on extremities are being performed more and more under regional blocks, evidence for better outcomes has been forthcoming for neuraxial techniques for hip and knee replacements, and the American Pain Society recently released new guidelines advocating for the use of multimodal regimens including ketamine, lidocaine, non-steroidals, and physical modalities.

The field of anesthesia is constantly changing. In order to stay current and provide quality, effective perioperative care, anesthesia professionals should be able to adapt to new drugs, equipment and trends in anesthetic management.