Researchers explore the evolution of regional anesthesia and the impact of technology on its development. Since the first general anesthesia (GA), anesthesia has seen a rapid evolution. In tandem with advances in pharmacology, anesthesia techniques were developed to facilitate surgical procedures and to increase patient safety.

Besides GA, regional anesthesia (RA) was introduced in the late 19th century when K. Koller used cocaine as a local anesthetic and W. Halsted performed the first peripheral nerve block (PNB) by infiltrating a local anesthetic (LA) solution around the nerve, making a transmission for sensation and pain impossible.

Anesthesia For Surgery

Since then, a fairly rapid evolution occurred in RA with the description of different PNBs, but also the spinal and epidural anesthesia. These RA techniques were, in the beginning, used as the sole anesthesia for surgery. 

Advances in pharmacology, electronics, and imaging techniques pushed the research in PNB to high levels and for use in daily practice. Soon some drawbacks appeared. All LA is limited in time, with the longest duration lasting between ten and 15 hours, as well as being limited in dose, due to toxicity. Evolution in clinical practice for efficacy and safety made the use of high-tech equipment inevitable. Security and privacy concerns made, and still, make, research more complex. 

Anatomy: the base of regional anesthesia

Research in chronic pain has focused on the interaction between the two nervous systems of the human body and, more specifically, the modulation of the autonomic system on the somatic nervous system. 

Advances in pharmacology

After the first use of cocaine in 1885, many different LAs made their appearance. Short-acting drugs, which were used for short and not too invasive surgical procedures, either by infiltration of the surgical site or for PNB at distance of the surgical site, had an active effect of a few hours. 

Furthermore, the proximity of the needle tip to the nerve could be assessed regarding the intensity of the electric current used to elicit the response the lower the current required, the closer the needle tip to the nerve. Now, with the use of ultrasound, this technique is used to reduce the risk of intraneural penetration of the needle.

The paresthesia, as well as stimulation techniques, had several disadvantages. However, both of these landmark-guided techniques, where the anesthesiologist determined his puncture site by looking at external anatomical characteristics on the skin or by palpation of different structures such as arteries or bony structures, were “blind” techniques.

Future research in regional anesthesia

However, some financial issues in social security systems might push research to other forms of pain relief, especially postoperative analgesia. Moreover, new techniques might block a nerve without the use of LA agents. These new nerve blocks could be variable over time and be modulated to the needs of analgesia. Future research has to focus on these new possibilities in the next few years.

They might be confronted with the risk of sending patients in pain, home, with the real possibility of evolution into chronic pain. This would increase the costs of the social security systems in two ways: firstly, due to an increase in health expenses to treat chronic pain; and secondly, due to long-term sick leave because of this chronic, invalidating pain.