An electrical probe of the phonon mean-free path spectrum

Most studies of the mean-free path accumulation function (MFPAF) rely on optical techniques to probe heat transfer at length scales on the order of the phonon mean-free path. In this paper, we propose and implement a purely electrical probe of the MFPAF that relies on photo-lithographically defined heater-thermometer separation to set the length scale. An important advantage of the proposed technique is its insensitivity to the thermal interfacial impedance and its compatibility with a large array of temperature-controlled chambers that lack optical ports. Detailed analysis of the experimental data based on the enhanced Fourier law (EFL) demonstrates that heat-carrying phonons in gallium arsenide have a much wider mean-free path spectrum than originally thought

Patient Priorities Care increases Long-Term Service and Support Use: Propensity Match Cohort Study

OBJECTIVES: Patient priorities care (PPC) is an evidence-based approach designed to help patients achieve what matters most to them by identifying their health priorities and working with clinicians to align the care they provide to the patient\u27s priorities. This study examined the impact of the PPC approach on long-term service and support (LTSS) use among veterans. DESIGN: Quasi-experimental study examining differences in LTSS use between veterans exposed to PPC and propensity-matched controls not exposed to PPC adjusting for covariates. SETTING AND PARTICIPANTS: Fifty-six social workers in 5 Veterans Health Administration (VHA) sites trained in PPC in 2018, 143 veterans who used the PPC approach, and 286 matched veterans who did not use the PPC approach. METHODS: Veterans with health priorities identified through the PPC approach were the intervention group (n = 143). The usual care group included propensity-matched veterans evaluated by the same social workers in the same period who did not participate in PPC (n = 286). The visit with the social worker was the index date. We examined LTSS use, emergency department (ED), and urgent care visits, 12 months before and after this date for both groups. Electronic medical record notes were extracted with a validated natural language processing algorithm (84% sensitivity, 95% specificity, and 92% accuracy). RESULTS: Most participants were white men, mean age was 76, and 30% were frail. LTSS use was 48% higher in the PPC group compared with the usual care group [odds ratio (OR), 1.48; 95% CI, 1.00-2.18; P = .05]. Among those who lived \u3e2 years after the index date, new LTSS use was higher (OR, 1.69; 95% CI, 1.04-2.76; P = .036). Among nonfrail individuals, LTSS use was also higher in the PPC group (OR, 1.70; 95% CI, 1.06-2.74; P = .028). PPC was not associated with higher ED or urgent care use. CONCLUSIONS AND IMPLICATIONS: PPC results in higher LTSS use but not ED or urgent care in these veterans. LTSS use was higher for nonfrail veterans and those living longer. The PPC approach helps identify health priorities, including unmet needs for safe and independent living that LTSS can support

Neuraxial and peripheral nerve blocks in patients taking anticoagulant or thromboprophylactic drugs: challenges and solutions

Jinlei Li, Thomas Halaszynski Department of Anesthesiology, Yale University, Yale New Haven Hospital, New Haven, CT, USA Abstract: Incidence of hemorrhagic complications from neuraxial blockade is unknown, but classically cited as 1 in 150,000 epidurals and 1 in 220,000 spinals. However, recent literature and epidemiologic data suggest that for certain patient populations the frequency is higher (1 in 3,000). Due to safety concerns of bleeding risk, guidelines and recommendations have been designed to reduce patient morbidity/mortality during regional anesthesia. Data from evidence-based reviews, clinical series and case reports, collaborative experience of experts, and pharmacology used in developing consensus statements are unable to address all patient comorbidities and are not able to guarantee specific outcomes. No laboratory model identifies patients at risk, and rarity of neuraxial hematoma defies prospective randomized study so “patient-specific” factors and “surgery-related” issues should be considered to improve patient-oriented outcomes. Details of advanced age, older females, trauma patients, spinal cord and vertebral column abnormalities, organ function compromise, presence of underlying coagulopathy, traumatic or difficult needle placement, as well as indwelling catheter(s) during anticoagulation pose risks for significant bleeding. Therefore, balancing between thromboembolism, bleeding risk, and introduction of more potent antithrombotic medications in combination with regional anesthesia has resulted in a need for more than “consensus statements” to safely manage regional interventions during anticoagulant/thromboprophylactic therapy. Keywords: antithrombotics, novel oral anticoagulant, regional, neurologic dysfunction, hematoma, peripheral nerve blockad

Perioperative Multimodal Anesthesia Using Regional Techniques in the Aging Surgical Patient

Background. Elderly patients have unique age-related comorbidities that may lead to an increase in postoperative complications involving neurological, pulmonary, cardiac, and endocrine systems. There has been an increase in the number of elderly patients undergoing surgery as this portion of the population is increasing in numbers. Despite advances in perioperative anesthesia and analgesia along with improved delivery systems, monotherapy with opioids continues to be the mainstay for treatment of postop pain. Reliance on only opioids can oftentimes lead to inadequate pain control or increase in the incidence of adverse events. Multimodal analgesia incorporating regional anesthesia is a promising alternative that may reduce needs for high doses and dependence on opioids along with any potential associated adverse effects. Methods. The following databases were searched for relevant published trials: Cochrane Central Register of Controlled Trials and PubMed. Textbooks and meeting supplements were also utilized. The authors assessed trial quality and extracted data. Conclusions. Multimodal drug therapy and perioperative regional techniques can be very effective to perioperative pain management in the elderly. Regional anesthesia as part of multimodal perioperative treatment can often reduce postoperative neurological, pulmonary, cardiac, and endocrine complications. Regional anesthesia/analgesia has not been proven to improve long-term morbidity but does benefit immediate postoperative pain control. In addition, multimodal drug therapy utilizes a variety of nonopioid analgesic medications in order to minimize dosages and adverse effects from opioids while maximizing analgesic effect and benefit

When the Statistics Steal the Show

International audienc

An electrical probe of the phonon mean-free path spectrum.

Most studies of the mean-free path accumulation function (MFPAF) rely on optical techniques to probe heat transfer at length scales on the order of the phonon mean-free path. In this paper, we propose and implement a purely electrical probe of the MFPAF that relies on photo-lithographically defined heater-thermometer separation to set the length scale. An important advantage of the proposed technique is its insensitivity to the thermal interfacial impedance and its compatibility with a large array of temperature-controlled chambers that lack optical ports. Detailed analysis of the experimental data based on the enhanced Fourier law (EFL) demonstrates that heat-carrying phonons in gallium arsenide have a much wider mean-free path spectrum than originally thought

Levobupivacaine 0.125% and Lidocaine 0.5% for Intravenous Regional Anesthesia in Volunteers

Background: Levobupivacaine, a long acting, amino-amide, local anesthetic, may offer advantages over lidocaine for intravenous regional anesthesia (IVRA). The objective of this investigation was to compare levobupivacaine to lidocaine for IVRA. Methods: After institutional review board approval and informed consent, eight unpremedicated male American Society of Anesthesiologists (ASA) I-II volunteers received 40 ml of levobupivacaine 0.125% or lidocaine 0.5% for IVRA on separate days. Onset and regression of sensory anesthesia by pinprick, transcutaneous electrical stimulation (TES), and of motor function were tested before, during, and after release of the tourniquet. Central nervous system and cardiac side effects were evaluated after local anesthetic administration and tourniquet release. The tourniquet remained inflated for 30 -45 min. Results: Intravenous regional anesthesia with either agent provided surgical anesthesia. Sensory anesthesia to pinprick (lateral antebrachial cutaneous nerve) was faster with lidocaine at median 1.5 min. versus 12.5 min with levobupivacaine. Loss of sensation to TES occurred at median 22.5 and 27.5 min for lidocaine and levobupivacaine, respectively. Loss of motor function occurred earlier after lidocaine administration. After release of the tourniquet, return of sensation to TES, pinprick (ulnar nerve), and return of motor function occurred later with levobupivacaine at median 25, 15, and 21.25 versus 10, 4.5, and 10 min with lidocaine. Central nervous system side effects were absent in volunteers given levobupivacaine, but five of eight volunteers given lidocaine experienced mild side effects. No cardiac events were noted. Conclusions: Levobupivacaine 0.125% may be an alternative to lidocaine 0.5% for IVRA. Longer lasting analgesia after release of the tourniquet may be caused by a more profound and prolonged tissue binding effect of levobupivacaine