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.

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Introduction: Pain following orthopaedic surgical procedures remains undertreated due to inadequate analgesic options. One possible solution is a novel device currently under investigation. The RELAY system (Gate Science, Moultonborough, NH) is comprised of a basic catheter-over-needle device to allow ultrasound-guided percutaneous insertion, leaving a perineural catheter after simple withdrawal of the internal needle. A single-injection bolus of local anesthetic may be quickly administered. Following surgery, the catheter may be attached to a portable infusion pump to provide an ambulatory continuous peripheral nerve block. Unlike previously described perineural catheters, the RELAY has an embedded wire and integrated pulse generator that permit stimulation of the targeted peripheral nerve(s) for up to 28 days. We here provide the first description of this novel device when used to provide postoperative analgesia. Case Report: A 67-year-old woman undergoing unilateral (right), primary reverse total shoulder arthroplasty provided written, informed consent and had a RELAY inserted under ultrasound guidance with a single pass. A single-injection nerve block was induced with lidocaine 2% (10 mL) and bupivacaine 0.5% (10 mL), both with epinephrine. A ropivacaine 0.2% infusion was initiated with a portable infusion pump via the catheter. Following surgery, the patient reported no surgical pain and her pulse stimulator initiated with a current of 2.2 mA. She was discharged home with the device in situ. Postoperative day (POD) 1 her maximum and average pain measured with a numeric rating scale (NRS) were 3 and 1. During her ropivacaine infusion her worst and average pain scores were 1 and 0, respectively. Following POD 4 (ropivacaine reservoir exhaustion on POD 3) she experienced no pain with active stimulation. The catheter/lead was removed at home by her caretaker without difficulty on POD 7. Conclusions: This new device represents a feasible intervention for postoperative pain management in ambulatory settings and further investigation is warranted.

Low-intensity focused ultrasound is a non-invasive neuromodulation technique that delivers mechanical forces to a deep location within the body through acoustic pressure waves without affecting tissue between the transducer and focal target. Preliminary studies involving healthy volunteers suggest focused ultrasound reversibly prevents action potential formation similar to a local anesthetic nerve block, but the modality has not been used in patients with existing pain. The current randomized pilot study was undertaken to 1) determine the feasibility and optimize the protocol for a subsequent definitive clinical trial; and 2) monitor for related complications of focused ultrasound when treating knee osteoarthritis pain.

Posttraumatic stress disorder (PTSD) is associated with poor hippocampal function and disrupted pattern recognition. Cannabis use is highly prevalent in individuals with PTSD, yet the impact on these cognitive functions is poorly understood. Participants (n = 111) with a range of PTSD symptoms with and without regular cannabis use completed the mnemonic similarity task. We hypothesized that regular use would be associated with alterations in pattern separation ability in individuals with PTSD symptoms. High PTSD symptoms were associated with reduced pattern separation performance in minimal users. Regular users with high PTSD symptoms showed greater pattern separation, but reduced pattern separation with low PTSD symptoms. These results suggest that regular cannabis use may disrupt pattern separation and similar hippocampal-dependent processes, while it may improve pattern separation in individuals with high PTSD symptoms. These cross-sectional results require longitudinal follow-up studies to evaluate the causal effects of regular cannabis use on cognitive function in PTSD.

Objectives Percutaneous auricular neuromodulation involves implanting electrodes around the ear and administering an electric current. A device is currently available in the United States, cleared to treat symptoms from opioid withdrawal, with multiple reports suggesting 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 following total hip arthroplasty. Methods Adults undergoing unilateral, primary, total hip arthroplasty received an auricular neuromodulation device (NSS-2 BridgeTM, Masimo, Irvine, California) applied following surgery. Participants were randomized to five days of either electrical stimulation or sham in a double-masked fashion and discharged home with their devices in situ. Participants or their caretakers removed the devices at home. Results One participant randomized to active treatment removed the device the morning of postoperative day one and withdrew from the study prior to any data collection. The remaining 29 participants were included in the analysis. For the first primary outcome measure, the median (IQR) pain level in the first five days for those receiving active stimulation (n=14) was 2.5 (1.0, 3.8) versus 3.0 (1.9, 4.0) for the sham group (n=15) (P=0.721). Concurrently, the median oxycodone use for the active stimulation group was 3.5 mg (0.1, 9.5) compared to 9.0 mg (2.0, 15.3) for the sham group (P=0.263). No statistically significant differences between treatments were identified for any of the secondary outcome measures. The protocol was successful regarding participant recruitment, intervention administration, data collection, outcomes assessment, and analysis. Six participants (three from each treatment group) removed their device prior to postoperative day five due to either difficulty sleeping while using the device or pain at one of the electrode sites. Conclusions While this randomized, controlled pilot study demonstrated the feasibility of using percutaneous auricular nerve stimulation following total hip arthroplasty for both the inpatient and outpatient portions of the postoperative period, it failed to identify improvements in analgesia, opioid-sparing, or pain interference in psychological and physical functioning. Therefore, it remains unclear whether a definitive clinical trial is warranted to investigate its use following total hip arthroplasty. Further research is advisable, possibly with a different auricular neuromodulation device and larger sample sizes.

BACKGROUND: Nonthermal, pulsed shortwave (radiofrequency) therapy (PSWT) is a nonpharmacologic, noninvasive modality that limited evidence suggests provides analgesia. Its potential favorable risk-benefit ratio stems from its lack of side effects and significant medical risks, applicability to any anatomic location, long treatment duration, and ease of application by simply affixing it with tape. Even with a relatively small treatment effect, PSWT might contribute to a multimodal analgesic regimen, similar to acetaminophen. However, widespread clinical use is hindered by a lack of systematic evidence. The current randomized, controlled pilot study was undertaken to determine the feasibility and optimize the protocol for a subsequent definitive investigation and estimate the treatment effect of PSWT on postoperative pain and opioid consumption. METHODS: Within the recovery room following primary knee and hip arthroplasty, cholecystectomy, hernia repair, and non-mastectomy breast surgery, we applied 1-3 PSWT devices (Model 088, BioElectronics Corporation, Frederick, Maryland) over the surgical bandages. Participants were randomized to 28 days of either active or sham treatment in a double-masked fashion. The outcomes of primary interest were the cumulative opioid consumption and the mean of the average and worst daily pain measured with the Numeric Rating Scale over the first 7 postoperative days. RESULTS: During the first 7 postoperative days, oxycodone consumption in participants given active treatment (n = 55) was a mean (SD) of 21 mg (24) versus 17 mg (26) in patients given sham (n = 57): difference 4 (95% CI, -5 to 13), p = 0.376. During this same period, the average daily pain intensity in patients given active treatment was 2.4 (1.6) versus 2.6 (1.7) in sham: difference -0.2 (95% CI -0.8 to 0.5), p = 0.597. Concurrently, the worst/maximum pain for the active group was 4.6 (2.0) versus 4.7 (2.1) in sham: difference -0.1 (95% CI -0.8 to 0.7), p = 0.888. No device-related systemic side effects or serious adverse events were identified. CONCLUSIONS: Pulsed shortwave (radiofrequency) therapy did not reduce pain scores and opioid requirements to a statistically significant or clinically relevant degree during the initial postoperative week in this pilot study. These results must be replicated with a subsequent study before being considered definitive. Data from this preliminary study may be used to help plan future trials.