Adjuvanzien bei der peripheren Regionalanästhesie der oberen Extremität - Eine Netzwerkmetaanalyse mit Fokus auf dem Endpunkt Motorik

Anesthesia and analgesia are an essential part of all surgical procedures. Continous progress in the area of general anesthesia is being made. The process of inducing and maintaining general anesthesia keeps getting better and safer for patients. Regional anesthesia is lacking such progress. The process of administering and maintaining regional anesthesia has been almost the same for many years, which reduces its significance drastically, even though there are many advantages over general anesthesia. Patients don’t have to take the risks that come with general anesthesia, they can have easier outpatient treatment and be mobilized sooner postoperatively. The quick restoration of patient autonomy is especially desirable. Two components are needed – minimum pain and maximum control of motor function. Many studies have been conducted in the past to further improve regional anesthesia. These studies have examined the effect of adjuvants added to local anesthetics on block characteristics. The present analysis has limited the search to upper extremity regional anesthesia, conducted via single-shot. The main parameters investigated are duration of analgesia, onset of sensory and motor block and duration of sensory and motor block. To be able to compare the literature, it was decided to conduct a network metaanalysis, which includes every available study up to december 2020. First of all, the inclusion and exclusion criteria had to be defined. Only RCT were permitted, which included patients with a mean age of at least 18, who needed a brachial plexus block. Furthermore, the search was limited to single-shot technique, which included at least one adjuvant compared to another or placebo. The search for literature was done using Embase, Central, Web of Science and Medline. The search came up with 511 references, of which 191 were included in the final analysis. The search, as well as data extraction and possible conversions, were done in accordance to the principle of dual control. The analysis was done using the program R, which came up with networks for all endpoints. As expected, the analysis showed high heterogeneity and inconsistency. However, the result was that dexamethasone had the highest impact on the duration of analgesia, with the block lasting more than twice the time compared to placebo. Dexmedetomidine, opiates and clonidine also showed significant effects on the parameter of duration of analgesia. With the exception of ketamine and hyaluronidase, every adjuvant prolonged the duration of motor block. The collection of data presented the same problem in almost every parameter: depending on the study author, different methods and timepoints were used to measure the parameters. Overall, there was significant heterogeneity and inconsistency in the data, which doesn’t make the results of the analysis less credible, especially considering that a different network metaanalysis has reached the same conclusions and results. Regional anesthesia is a gentle procedure for patients, which deserves to be developed further, much like general anesthesia. Prospective studies should be conducted, using the same methods and timepoints for data collection in order to be able to do a reliable analysis of the results. Furthermore, the use of different substances to prolong regional anesthesia should be investigated. Despite heterogeneity and inconsistency in our network metaanalysis, the results seem clinically plausible and should find clinical use.