School of Medicine

Introduction: Low tidal-volume ventilation (LTVV), defined as a maximum tidal volume of 8 milliliters per kilogram (mL/kg) of ideal body weight, is a key component of lung protective ventilation. Although emergency department (ED) initiation of LTVV has been associated with improved outcomes, disparities in LTVV application exist. In this study our aim was to evaluate whether rates of LTVV are associated with demographic and physical characteristics in the ED.

Methods: We conducted a retrospective observational cohort study using a dataset of patients who underwent mechanical ventilation at three EDs in two health systems from January 2016–June 2019. Demographic, mechanical ventilation, and outcome data including mortality and hospital-free days were abstracted by automatic query. A LTVV approach was defined as a tidal volume ≤8 mL/kg ideal body weight. We performed descriptive statistics and univariate analysis as indicated, and created a multivariate logistic regression model.

Results: Of 1,029 patients included in the study, 79.5% received LTVV. Tidal volumes of 400-500 mL were used in 81.9% of patients. Approximately 18% of patients had tidal volumes changed in the ED. Female gender (adjusted odds ratio [aOR] 4.17, P< 0.001), obesity (aOR 2.27, P< 0.001), and first-quartile height (aOR 12.2, P < 0.001) were associated with receiving non-LTVV in multivariate regression analysis. Hispanic ethnicity and female gender were associated with first quartile height (68.5%, 43.7%, P < 0.001 for all). Hispanic ethnicity was associated with receiving non-LTVV in univariate analysis (40.8% vs 23.0%, P < 0.001). This relationship did not persist in sensitivity analysis controlling for height, weight, gender, and body mass index. Patients who received LTVV in the ED had 2.1 more hospital-free days compared to those who did not (P = 0.040). No difference in mortality was observed.

Conclusion: Emergency physicians use a narrow range of initial tidal volumes that may not meet lung-protective ventilation goals, with few corrections. Female gender, obesity, and first-quartile height are independently associated with receiving non-LTVV in the ED. Using LTVV in the ED was associated with 2.1 fewer hospital-free days. If confirmed in future studies, these findings have important implications for achieving quality improvement and health equality.

INTRODUCTION:  Diagnostic testing represents a significant portion of healthcare spending, and cost should be considered when ordering such tests.  Needless and excessive spending may occur without an appreciation of the impact on the larger health care system. Knowledge regarding the cost of diagnostic testing among Emergency Medicine residents has not previously been studied.

METHODS: A survey was administered to 20 Emergency Medicine residents from a single ACGME-accredited three-year EM residency program, asking an estimation of the patient charges for 20 commonly ordered laboratory tests and 7 radiological exams. Responses were compared between residency classes to evaluate whether there was a difference based on level of training.

RESULTS: The survey completion rate was 100% (20/20 residents).  Significant discrepancies were noted between the median resident estimates and actual charge to patient for both laboratory and radiological exams.  Nearly all responses were an underestimate of the actual cost. The group median underestimation for laboratory testing was $114, for radiographs $57, and for computed tomography (CT) exams was $1058.   There was statistically significant improvement in accuracy with increasing level of training.

Gentle stroking that activates C-tactile afferents is typically pleasant, calming and pain relieving. Deep pressure touch frequently elicits similar affective responses. However touch is often less pleasant for individuals with chronic pain. It is important to understand the reasons for this clinical difference because of the close relationship of pain with reduced social connection, and the widespread use of touch-based therapies for pain relief. It is not known whether differences in touch perception in chronic pain relate to pain-specific processes or to comorbid affective symptoms. The current study compared affective touch perception in adults with the chronic pain condition fibromyalgia (FM) and no-pain (NP) controls, and the contributions of pain, depression, anxiety and trauma history to differences in touch perception. We hypothesized that deep pressure - like gentle stroking - would be less pleasant in FM and that these differences would be associated with depression and trauma history. Touch was rated as significantly less pleasant and more intense in FM. Chronic pain intensity best predicted reductions in touch pleasantness, whereas preferences for brushing versus tapping (affective touch preference) were positively predicted by depression and anxiety scores. In contrast heat pain unpleasantness was significantly predicted only by depression and anxiety. These results suggest that blunted touch pleasantness in FM is best explained by pain-specific processes, whereas pain unpleasantness is more closely associated with affective processes. KEY POINTS: Pleasant touch perception is often reduced in chronic pain, but the reasons for this are not clear. Patients with fibromyalgia (FM) and no-pain controls rated their perception of gentle stroking, deep pressure and heat pain. All touch types were less pleasant and more intense in FM participants. Chronic pain intensity predicted reductions in touch pleasantness, whereas affective symptoms predicted affective touch preference and heat pain unpleasantness. Findings suggest that blunted touch pleasantness in FM is more related to pain processes than to comorbid affective symptoms.

OBJECTIVE: Strategies are needed for patients with chronic pain who are using opioids to safely and effectively wean opioids without worsening of pain. The objective was to measure associations between medical cannabis authorization (MCA) and opioid milligram equivalents (OME) in patients with chronic non-cancer pain. DESIGN: A longitudinal, retrospective cohort analysis from July 2016 to August 2019. SETTING: Electronic health record data were analyzed. SUBJECTS: Adult patients (≥18 years) seen in a university-based pain clinic. METHODS: Longitudinal multilevel modeling with maximum likelihood estimation. RESULTS: Average overall OME at the final time point was 33.4 mg/day (SE = 1.18) with increase over time of 0.45 mg/day per quarter (not statistically significant). Average OME in those without MCA was 32.60 mg/day (SE = 1.11) versus 38.51 mg/day (SE = 4.81) in those with MCA, not significantly different. Medical cannabis consultation predicted a nonsignificant decrease of 14.25 mg/day OME. Long-term opioid use was a significant predictor with a mean OME of 85.34 mg/day, 63 mg/day higher than the rest of the cohort at the final quarter (t = 5.77, SE = 10.93, P < 0.0001). CONCLUSIONS: In this longitudinal study of electronic health record data, MCA was not associated with a statistically significant decrease in OME over time. However, patients with long-term opioid use diagnostic code demonstrated a significantly higher endpoint OME. Future prospective research is needed to establish whether there are opioid-sparing effects of cannabis in humans.

Introduction: Percutaneous auricular neuromodulation involves implanting electrodes around the ear and administering an electric current. A device is currently available that is cleared to treat symptoms from opioid withdrawal, and multiple reports suggest a possible postoperative analgesic effect. This randomized, controlled pilot study aimed to (1) assess the feasibility of a postoperative auricular neuromodulation protocol and (2) provide an estimate of its treatment effects on postoperative pain and opioid consumption. Methods: Adults undergoing unilateral or bilateral ambulatory breast surgery with anticipated moderate-severe pain and a single-injection paravertebral nerve block(s) received an auricular neuromodulation device (NSS-2 Bridge, Masimo) following surgery. Participants were randomized to 5 days of electrical stimulation or sham in a double-masked fashion. Results: In the first 5 days, the median pain for those receiving active stimulation (n = 15) was 0 (interquartile range [IQR] = 0, 0.5] versus 1.5 (IQR = 0, 3.8) for the sham group (n = 15, P = 0.084). Concurrently, the median oxycodone use for active stimulation was 0 mg (IQR = 0, 2.5) compared to 0 mg (IQR = 0, 3) for the sham group (P = 0.905). Various secondary outcomes reached statistical significance, including maximum and average daily pain scores. Conclusions: This pilot study demonstrates that percutaneous auricular neuromodulation is a feasible approach for managing pain in ambulatory surgical procedures and shows potential as an effective analgesic following discharge. Considering its ease of application, absence of systemic side effects, and lack of significant complications, conducting a definitive clinical trial seems justified because the current study was underpowered, which possibly resulted in the lack of statistical significance for the primary outcome.Registry: Clinicaltrials.gov NCT05521516.

BACKGROUND: Tobacco use, obesity, and type 2 diabetes are risk factors for colorectal cancer, but whether they generate distinct tumor mutation patterns is unclear. Tobacco is a known mutagen, while obesity and diabetes may act through metabolic and inflammatory pathways. METHODS: We analyzed colon cancer patients from the University of California Health Data Warehouse, linking clinical sequencing data to diagnosis-based indicators of tobacco dependence, obesity, and type 2 diabetes. For each gene-behavior pair, we conducted reverse logistic regressions and calculated a combined score reflecting the strength and specificity of association adjusting for demographic covariates and cancer stage. Multidimensional scaling and clustering assessed behavioral differentiation. RESULTS: Of 981 gene-behavior tests, 87 pairs exhibited a behavioral association at p < 0.001 in adjusted models. Of these, 60 tobacco, 12 obesity, and 9 diabetes pairs had affinity ≥0.5; 48 tobacco pairs exceeded 1.0. Mean (SD) combined scores were 1.39 (0.79) for tobacco, 1.24 (0.88) for obesity, and 0.74 (0.39) for diabetes. Exemplars included KEAP1 and CDKN2A (tobacco), ASPSCR1 and PGR (obesity), and a smaller diabetes signal led by MAF. CONCLUSIONS: Tobacco dependence is associated with a more mutagenic and distinct somatic mutation profile in colon cancer, suggesting fundamental differences in behavioral mechanisms of carcinogenesis.

Purpose of ReviewArtificial intelligence (AI) offers a new frontier for aiding in the management of both acute and chronic pain, which may potentially transform opioid prescribing practices and addiction prevention strategies. In this review paper, not only do we discuss some of the current literature around predicting various opioid-related outcomes, but we also briefly point out the next steps to improve trustworthiness of these AI models prior to real-time use in clinical workflow.Recent FindingsMachine learning-based predictive models for identifying risk for persistent postoperative opioid use have been reported for spine surgery, knee arthroplasty, hip arthroplasty, arthroscopic joint surgery, outpatient surgery, and mixed surgical populations. Several machine learning-based models have been described to predict an individual’s propensity for opioid use disorder and opioid overdose. Natural language processing and large language model approaches have been described to detect opioid use disorder and persistent postsurgical opioid use from clinical notes. Summary AI holds significant promise in enhancing the management of acute and chronic opioids, which may offer tools to help optimize dosing, predict addiction risks, and personalize pain management strategies. By harnessing the power of AI, healthcare providers can potentially improve patient outcomes, reduce the burden of opioid addiction, and contribute to solving the opioid crisis.

Introduction/Objectives Patients undergoing surgical procedures for peripheral artery disease and carotid artery stenosis are recommended to undergo surveillance imaging at regular intervals. With > 250,000 patients undergoing interventions for both annually, the number of patients requiring interval surveillance increases in parallel, placing strain on an already overburdened health system. In this study we evaluated the performance of a novel ultrasound platform prototype built for remote ultrasound surveillance. Methods The prototype duplex ultrasound device was developed by a team of engineers and utilizes color flow images to detect the vessel for flow velocity measurements. The device was tested on 28 healthy volunteers. The results of spectral flow from the device were compared to standard of care ultrasound measurements of the CFA, SFA, ICA and CCA. Results The mean absolute difference between the prototype ultrasound and standard of care device for peak systolic velocity of the CFA, SFA, CCA, and ICA were 3.06 cm/s, 2.27 cm/s, 3.51 cm/s, and 3.55 cm/s, respectively. There were no significant differences between measurements recorded by the prototype and the standard of care device. Conclusion It is feasible to make a small, wearable ultrasound device that can collect accurate waveform and flow velocity data from healthy volunteers. Such a device has the potential to expand access to vascular imaging to low resource regions and improve the surveillance of patients after vascular surgery procedures.

Colorectal cancer is a leading cause of morbidity and mortality worldwide. This study investigates the association between GLP-1 receptor agonists (GLP-1 RAs) and five-year mortality in patients with primary colon cancer, considering BMI. Using data from the University of California Health Data Warehouse, 6,871 patients were analyzed. Five-year mortality was 15.5% for GLP-1 RA users compared to 37.1% for non-users. Analyses showed significantly lower odds of five-year mortality with GLP-1 RA use (OR = 0.38, 95% CI: 0.21-0.64). This benefit persisted after adjusting for confounders, including disease severity, but was found to only extend to high obese patients (BMI > 35) in stratified modeling.

ABSTRACT: Mindfulness meditation, a slow breathing practice that is predicated on cultivating nonreactive awareness, also reduces pain. The existing literature has been mixed in demonstrating whether mindfulness meditation is more effective than slow breathing alone (ie, sham-mindfulness meditation) at reducing pain. Furthermore, smaller sample sizes in prior work have hindered a clear understanding of how respiration rate and state anxiety contribute to analgesia during meditation. This study pooled data from 5 randomized controlled trials using paralleling interventions and methodologies in 245 healthy, pain-free, meditation-naïve individuals. Noxious heat (49°C; right calf) was used to test whether changes in respiration and state anxiety mediate the effects of (1) mindfulness meditation (n = 113), (2) a slow-breathing sham-mindfulness meditation technique (n = 73), and (3) a book-listening control (n = 60) on pain intensity ratings ("0" no pain; "10" worst pain imaginable). Three separate 3 (group) × 2 (pre- vs postmanipulation) repeated-measures analysis of variances assessed whether mindfulness and sham-mindfulness meditation significantly reduced pain, anxiety, and respiration, respectively. Mediation analyses examined whether changes in state anxiety and respiration, respectively, mediated analgesia during meditation. Mindfulness meditation produced significantly greater analgesia when compared with sham-mindfulness meditation and controls. Slower respiration rate partially mediated analgesia for mindfulness and sham-mindfulness meditation as compared with controls. Both meditation techniques significantly lowered anxiety, but these improvements did not mediate pain relief. The present findings demonstrate that mindfulness meditation is more effective than slow-breathing (sham-mindfulness) meditation at reducing pain and highlight the role of slower breathing in the direct modulation of acutely evoked pain by meditation.