2 Clinical Trials for Various Conditions
This is a pharmacokinetic study to determine risk of local anesthetic systemic toxicity of ropivacaine when used in erector spinae plane blocks for thoracic surgery. Through serial blood sampling and the use of NONMEM population pharmacokinetic analysis this risk will be determined for the study population and other populations as well. Pain and quality of recovery will also be assessed.The erector spinae plane (ESP) block was first described in 2016 as a novel fascial plane block that provided analgesia for thoracic neuropathic pain. Since then hundreds of articles have been published that have reported use of the ESP block for indications such as rib fractures, breast surgery, abdominal surgery, and even shoulder surgery. It has also been studied in thoracic surgery and clinical experience confirms that patients undergoing video-assisted thoracoscopic surgery (VATS) or robot-assisted thoracic surgery experience satisfactory analgesia with ESP blocks. Because the block location is further from the neuraxis than both epidural and paravertebral blocks, ESP blocks have been suggested as a safer alternative to these older blocks but safety data have not yet been generated. In particular, the risk of local anesthetic systemic toxicity (LAST) has not been studied in ESP blocks. While the pharmacokinetics of ropivacaine used for thoracic paravertebral blocks have been established, similar studies have yet to be performed for the newer ESP block. Of particular concern for ESP blocks are two factors not present in some other blocks with established safety: 1). significant intercostal spread has been noted in anatomical studies, which could put patients at risk for LAST and 2). some of the proposed dosing regimens involve the intermittent injection of large bolus doses of local anesthetic. While measurement of arterial plasma levels is useful and necessary to study the safety of ropivacaine given in ESP blocks, the measurements alone do not allow for prediction of plasma levels that would occur in populations as a whole. Nonmem is a population pharmacokinetic application that provides estimates of mean parameters and residual variability in pharmacokinetic values across populations and has been shown to generate better estimates than the two-stage approach. Nonmem will be used in this study to predict pharmacokinetics in populations with different characteristics than the one being studied here, which would create generalizable results.
Significant data exists to suggest that lipid emulsion administration in the setting of local anesthetic toxicity has the potential to be life-saving. Unfortunately, a variety of potential barriers exist to routine lipid emulsion administration for those performing regional anesthesia including drug availability, drug cost and drug location. Inadequate training or lack of established protocols also have the potential to negatively impact patient outcomes. A previous study by Toledo et al (Availability of lipid emulsion in United States obstetric units. Anesth Analg 2013;116:406-408.) evaluated lipid emulsion availability on obstetric units and found that it was nearly universally available. The Accreditation Council for Graduate Medical Education (ACGME) publishes a list of contact information for each anesthesia institution that engages in resident training. Investigators will contact these institutions by phone or email to obtain contact information for their regional anesthesia program director. In the absence of a program director, investigators will send a survey and consent information via email to the faculty physician most involved in regional anesthesia. Survey completion instructions (survey itself to be completed on Qualtrics Survey Hosting Service) and copy of the study consent form will be attached to the initial contact email. The study consent form will contain a description of the study itself. Survey participants will be allowed time to complete their survey in private at their discretion. Non-responders will receive two follow-up emails at one month intervals.