The effect of epinephrine on the perfusion index during ultrasound-guided supraclavicular brachial plexus block: a randomized controlled trial

Abstract

The perfusion index (PI) is an objective tool used to assess a successful nerve block. Epinephrine is a widely used adjuvant to local anesthetics, and it may affect PI values because of the vasoconstrictive property. The aim of this study was to investigate the influence of epinephrine on PI as an indicator of a successful block in ultrasound-guided supraclavicular brachial plexus block (SCBPB). In this randomized controlled trial, 82 adult patients underwent upper limb surgery under SCBPB were recruited between July 2018 and March 2019 in a single tertiary care center. Participants were randomly assigned to one of two groups: non-epinephrine group (n = 41) or epinephrine group (5 mcg ml −1 , n = 41). The primary outcome was the comparison of the "PI ratio 10," which was defined as the ratio of the PI 10 to the baseline. Receiver operating characteristic (ROC) curves were constructed to determine the accuracy of the PI in predicting the block success at each time interval. The PI ratio 10 was 2.7 (1.9-4.0) in non-epinephrine group and 3.3 (2.2-4.4) in epinephrine group (median difference: 0.4; 95% confidence interval [CI] − 1.1 to 0.2; P = 0.207). The ROC curves compared without group identification were not significantly different over time. The cutoff value for the PI and PI ratio at 5 min (PI ratio 5) were 7.7 (area under the ROC [AUROC]: 0.89, 95% CI 0.83-0.94) and 1.6 (AUROC: 0.94, 95% CI 0.90-0.98), respectively. The perineural epinephrine did not affect the PI following a SCBPB. The PI ratio 5 > 1.6 might be considered as a relatively accurate predictor of a successful SCBPB. Trial registration: This study was registered at the Clinical Trial Registry of Korea (https ://cris.nih.go.kr. CriS No. KCT0003006).

Optimal dose of perineural dexmedetomidine to prolong analgesia after brachial plexus blockade: a systematic review and Meta-analysis of 57 randomized clinical trials

“…In order to prolong the time of single nerve block analgesia, more and more anesthesiologists add adjuvants to local anesthetics (LAs) [ 3 ]. Over the past decade, adjuvants of local anesthetics such as opioids [ 4 ], epinephrine [ 5 ], clonidine [ 6 ], magnesium [ 7 ], midazolam [ 8 ], dexamethasone [ 9 ], buprenorphine [ 10 ] and dexmedetomidine (DEX) [ 11 ] have been proved to prolong the analgesic time of nerve block, and have achieved varying degrees of success. Among these different kinds of adjuvants, DEX is more widely used.…”

Perfusion index: Physical principles, physiological meanings and clinical implications in anaesthesia and critical care

“…A recent work showed that PI performances for detection of regional block success were not different when using epinephrine as an adjuvant to local anaesthetics [43].…”

Adjuvant Drugs for Peripheral Nerve Blocks: The Role of NMDA Antagonists, Neostigmine, Epinephrine, and Sodium Bicarbonate

“…Eighty-two patients were placed in 2 groups where one group received 12.5 mL of 2% lidocaine, 12.5 mL of 0.75% ropivacaine, and 0.1 mL of normal saline in the nonepinephrine group while the other group received 12.5 mL of 2% lidocaine, 12.5 mL of 0.75% ropivacaine, and 5mcg/mL of epinephrine in the epinephrine group. Using a pulse oximeter to assess the perfusion index, the study found the addition of epinephrine did not affect the perfusion index or perfusion index ratio during the block (P = 0.894 and P = 0.079, respectively) (61). All clinical studies are summarized below in Table 1.…”