Cannabis Exposure Decreases Need for Blood Pressure Support During General Anesthesia in Orthopedic Trauma Surgery.

Introduction: As cannabis use continues to increase in popularity, it is important to investigate how it impacts public health in all sectors of the population, including patients undergoing anesthetic management. This retrospective study focuses on the orthopedic trauma population presenting through an emergency department (ED) and receiving a urine drug screen (UDS) with subsequent urgent surgical intervention. We aimed to evaluate differences in response to general anesthesia in patients with exposure to THC, a major cannabinoid, compared to controls that screened negative for THC. Materials and Methods: All ED visits at UC Irvine, a level 1 trauma center between November 4, 2017 and January 7, 2020, were evaluated in this study. Only adult patients who received a UDS and underwent urgent orthopedic trauma surgery within 48 h of ED visit were included in this study. Additional inclusion criteria required an anesthesia time greater than 1 h as well as anesthesia induction and intubation while in the operating room. Overall, we analyzed a total of 221 adult patients. Discussion: When adjusting for demographic variability, there were statistically significant differences in response to general anesthesia between these two groups. The THC-positive (THC(+)) group was less likely to receive intraoperative vasopressors, had higher mean arterial blood pressure and mean diastolic blood pressure, needed less total fluid input and had a lower overall fluid balance. Chronic exposure to THC has been shown to downregulate cannabinoid 1 receptors and cause alterations in endocannabinoid tone. These are two potential mechanisms by which the THC(+) group in our study may have become more resistant to the typically observed hypotensive effects of general anesthesia. Conclusion: The present study suggests that prior use of cannabis, objectively assessed by urinalysis, results in a decreased need for blood pressure support during general anesthesia. The physiological basis for this phenomenon is unclear, but possible causes might include the downregulation of vascular cannabinoid receptor 1 and/or altered endocannabinoid levels after exposure to cannabis.

A Prospective Observational Cohort Study of Calls for Help in a Tertiary Care Academic Operating Room Suite.

While significant literature exists on hospital-based "code calls," there is a lack of research on calls for help in the operating room (OR). The purpose of this study was to quantify the rate and nature of calls for help in the OR of a tertiary care hospital. For a 1-year period, all calls were recorded in the main OR at The University of California, Irvine Medical Center. The average rate of calls per 1000 anesthesia hours was 1.4 (95% CI, 1.1-1.8), corresponding to a rate of 5.0 (3.8-6.5) calls per 1000 cases. Airway (44%), cardiac (32%), and hemorrhagic (11%) emergencies were the most common etiologies. Thirty-day mortality approached 11% for patients who required a call for help in the OR.

Is There a Benefit for Liposomal Bupivacaine Compared to a Traditional Periarticular Injection in Total Knee Arthroplasty Patients With a History of Chronic Opioid Use?

BACKGROUND: Postoperative pain after total knee arthroplasty (TKA) poses a major challenge. It delays mobilization, increases opioid consumption and side effects, and lengthens hospitalization. This challenge multiplies when treating an opioid-dependent population. We examined whether a novel suspended release local anesthetic, liposomal bupivacaine (LB) would improve pain control and decrease opioid consumption after TKA compared to a standard periarticular injection in opioid-dependent patients. METHODS: Thirty-eight patients undergoing TKA were randomly assigned to receive either a periarticular injection (PAI) with LB (n = 20) or with a standard PAI (including a combination of ropivacaine, clonidine, Toradol, Epinepherine, and saline; n = 18) as part of a multimodal pain management approach. All periarticular injections were done by a single surgeon. Perioperative treatment was similar between groups. Postoperative information regarding pain level was evaluated by a pain visual analog scale score. Postoperative opioid consumption was recorded. RESULTS: After controlling baseline narcotic usage before surgery, no differences were found between groups in daily postoperative narcotic usage (P = .113), average daily pain score (P = .332), or maximum daily pain score (P = .881). However, when examining pain levels separately for each day, pain visual analog scale scores were reported higher in post operative day 1 in the LB group (P = .033). CONCLUSIONS: LB was not found to be superior to standard PAI in opioid-dependent patients undergoing TKA. This patient population continues to present a challenge even with modern multimodal pain protocols.