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: To evaluate available evidence for the efficacy and safety of topical analgesics for neuropathic pain and to offer treatment guidance. METHODS: An expert panel searched PubMed (Medline) and reference lists of published articles for available literature assessing 8 categories of topical analgesics used to treat various neuropathic pain conditions. The panel rated the level of analgesic efficacy evidence for each treatment and considered safety, ease of use, and cost. The degree of consensus on the recommendations among the panelists was measured. RESULTS: There was strong evidence and high consensus that capsaicin 8% is effective for diabetic peripheral neuropathy and postherpetic neuralgia and that lidocaine is effective for postherpetic neuralgia. There was strong evidence and moderate consensus that capsaicin 8% could be effective for HIV-induced neuropathy. There was moderate evidence and high consensus that lidocaine is likely effective for diabetic peripheral neuropathy, idiopathic neuropathy, and postsurgical neuropathy and that capsaicin 8% might be effective for chemotherapy-induced peripheral neuropathy and complex regional pain syndrome. Evidence was weak for other topical medications, though the panel strongly agreed that antidepressants might help with postherpetic neuralgia, complex regional pain syndrome, postsurgical neuropathy, and post-traumatic neuropathy; that nonsteroidal anti-inflammatory drugs could help with postsurgical neuropathy; and that gabapentin might benefit vulvodynia. There was less agreement about whether antidepressants might benefit diabetic peripheral neuropathy, chemotherapy-induced peripheral neuropathy, and vulvodynia and whether capsaicin 8% could be effective for postsurgical neuropathy. CONCLUSIONS: Recommendations were based on a survey and grading of existing literature and, when strong evidence was lacking, the collective clinical expertise of panelists.

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.

Background: Intraoperative hypotension has been associated with postoperative complications, but its relationship with postoperative delirium remains debated. Methods: This single-centre retrospective cohort study included adults (≥60 yr) with ASA physical status score of 3 or 4 undergoing major noncardiac surgery, with documented Confusion Assessment Method assessments. Patients with a history of neurosurgery, stroke, dementia, or neurocognitive disorders were excluded. The primary exposure was the cumulative duration of a mean arterial pressure <65 mm Hg (minutes). The primary outcome was postoperative delirium within 7 days, diagnosed via Confusion Assessment Method. Multivariable logistic regression was used to assess the association between intraoperative hypotension and delirium, adjusting for confounders. Results: Among 5171 patients included from 2013-2024, 632 (11.8%) developed delirium. The median (Q1-Q3) duration of surgery and time with mean arterial pressure <65 mm Hg were 281 (199-430) min and 28 (9-61) min, respectively. In models adjusted for patient characteristics and perioperative factors, intraoperative hypotension was associated with increased odds of delirium (odds ratio per 60 min, 1.12; 95% confidence interval, 1.01-1.24; P=0.038). However, after adjusting for year of surgery, the association was attenuated and no longer statistically significant (odds ratio, 1.06; 95% confidence interval, 0.95-1.18; P=0.320). Both intraoperative hypotension exposure and delirium incidence declined significantly over the study period. Conclusions: Although intraoperative hypotension initially appeared to be associated with postoperative delirium, this association was no longer significant when accounting for temporal improvements in perioperative care. Intraoperative hypotension may represent a marker of historical practice patterns rather than an independent causal driver of delirium.