Limitations in manpower in health care facilities both in civilian and in military settings can severely affect patient safety as well as overall outcomes. One challenge in the acute setting is the treatment of pain caused by trauma or by surgical procedures. Regional anesthesia via neural blockade is an effective means of managing uncontrolled acute pain. Uncontrolled acute pain has been associated with cardiopulmonary, endocrine, immunologic, and hematologic derangement in addition to the development to the development of potentially life-threatening coagulopathy. Training residents and junior attendings to perform these blocks in less than optimal environments (diminished staff availabilities, severe time and ergonomic environments) is often a function of performing enough repetitions of a procedural technique to gain proficiency.[1-4] We have designed a remote-controlled injection device that may expedite the performance of regional nerve blocks in these situations. The purpose of this study is to compare the device with more conventional or usual techniques, i.e., the two operator technique or the single operator technique using manual injection. The criteria to evaluate the device versus the usual techniques are the times to complete individual components of the nerve block.
Our design concept consists of a linear actuator able to provide automated forward and reverse movement of the syringe plunger in response to input from the anesthesiologist. Since the anesthesiologist has both his hands occupied by the US probe and needle, a more efficient method is a foot panel that allows the anesthesiologist to move his or her foot laterally in either direction to activate switches that activate dispensing or withdrawal of fluid via a syringe pump-catheter-needle system. We examined how the device affects the ability of the operator to act independently with respect to various block component times. This pilot trial examined 21 trainees at various levels in the Anesthesiology residency program at the University of Rochester (Rochester, NY). The outcomes examined were total time to perform the nerve block, time to visualize the block needle in the block phantom (gel); time of the needle to target embedded in the block phantom and time to injection. We examined the outcomes described above in each of the ergonomic settings and compared the classical approach (two operators), the single operator approach (needle released in order to control the injection syringe); and the foot-controller assisted approach.
Statistical analysis of our current data reveals that the no assistance or single operator model vs the classic two person model showed statistical significance in time to needle visualization (p ≤ 0.05) and near statistical significance (p≤ 0.051) between the same categories with respect to time of needle to the target, and total block time. (Table 2). For the non-inferiority trial in Tables 3A and 3B the null hypothesis is that the mean time in the foot-controlled setting is greater than the mean time of the classic method (margin 0.01), and the alternative hypothesis is that the mean time for performance of the nerve block in the foot-control is less than the mean time of the classic method+ margin (0.01). Since the p-value is 0.032, we reject the null hypothesis and conclude that the foot-control method is non-inferior to the classic method (up to a margin of 0.01).
1. Neal, J.M., et al., The ASRA evidence-based medicine assessment of ultrasound-guided regional anesthesia and pain medicine: Executive summary. Reg Anesth Pain Med, 2010. 35(2 Suppl): p. S1-9.
2. Delvi, M.B., Training in ultrasound guided blocks. Saudi J Anaesth, 2011. 5(2): p. 119-20.
3. Sites, B.D., J.M. Neal, and V. Chan, Ultrasound in regional anesthesia: where should the "focus" be set? Reg Anesth Pain Med, 2009. 34(6): p. 531-3.
4. Sites, B.D., et al., Characterizing novice behavior associated with learning ultrasound-guided peripheral regional anesthesia. Reg Anesth Pain Med, 2007. 32(2): p. 107-15.
5. Aziz, S., et al., Comparing Instructor and Trainee Preferences in Using a Foot Controlled Injection Device: An Initial Step in Standardizing Technical Instruction, in American Society Anesthesiologists Annual Meeting, A.S. Anesthesiologists, Editor. 2016, American Society of Anesthesiologists: Chicago, IL