Evaluation of Quadratus Lumborum Block as Part of an Opioid-Free Anaesthesia for Canine Ovariohysterectomy

Quadratus lumborum block (QLB) is used to provide analgesia for abdominal surgery in humans. The aim of this study was to assess an anaesthetic protocol involving the QLB for canine ovariohysterectomy. Ten dogs were included. Anaesthetic protocol consisted of premedication with IM medetomidine (20 μg kg−1) and SC meloxicam (0.1 mg kg−1), induction with propofol to effect, and maintenance with sevoflurane in oxygen/medical air. QLB was performed injecting 0.4 mL kg−1 of 0.25% bupivacaine/iohexol per side. Computed Tomography (CT) was performed before and after surgery. Fentanyl was administered as rescue analgesia during surgery. The Short Form of The Glasgow Composite Pain Scale and thermal threshold (TT) at the level of the elbow, T10, T13 and L3 were assessed before premedication and every hour postoperatively. Methadone was given as rescue analgesia postoperatively when pain score was >3. A Yuen’s test on trimmed means for dependent samples was used to analyse the data (p < 0.05). CT images showed spreading of the contrast/block for a median (range) of 3 (2–5) vertebrae, without differences between preoperative and postoperative images. One dog needed rescue analgesia during surgery. Pain score was less than 4/24 in all the animals during the first 4 h after surgery. TT showed a significant increased signal in all the areas tested, apart from the humerus, 30 min after surgery. The QLB may provide additional analgesia for canine ovariohysterectomy. Further studies are needed to assess the specific contribution of the QLB in abdominal analgesia.

Polish Medical Air Rescue Crew Interventions Concerning Neonatal Patients

The purpose of the study was to present the characteristics of Helicopter Emergency Medical Service (HEMS) and Emergency Medical Service (EMS) interventions concerning newborns in Poland. The study involved a retrospective analysis of missions by Polish Medical Air Rescue crews concerning newborns, carried out in Poland between January 2011 and December 2020. Polish Medical Air Rescue crews were most commonly dispatched to urban areas (86.83%), for patient transfer (59.67%), using an airplane (65.43%), between 7 AM and 6:59 PM (93.14%), and in the summer (28.67%). Further management involved handing over the neonatal patient to a ground neonatal ambulance team. Most of the patients studied were male (58.02%), and the most common diagnosis requiring the HEMS or EMS intervention was a congenital heart defect (31.41%). The most common medical emergency procedure performed by Polish Medical Air Rescue crew members for the neonatal patients was intravenous cannulation (43.07%). The odds ratio for congenital malformations was higher in male newborns. The type of Polish Medical Air Rescue mission was associated with the location of the call, time of the call, ICD-10 diagnosis associated with the dispatch, selected clinical findings, most commonly performed medical emergency procedures, and mission duration and distance covered.

Effects of 7.5% Carbon Dioxide and Nicotine Administration on Latent Inhibition

Stratified medicine approaches have potential to improve the efficacy of drug development for schizophrenia and other psychiatric conditions, as they have for oncology. Latent inhibition is a candidate biomarker as it demonstrates differential sensitivity to key symptoms and neurobiological abnormalities associated with schizophrenia. The aims of this research were to evaluate whether a novel latent inhibition task that is not confounded by alternative learning effects such as learned irrelevance, is sensitive to (1) an in-direct model relevant to psychosis [using 7.5% carbon dioxide (CO2) inhalations to induce dopamine release via somatic anxiety] and (2) a pro-cognitive pharmacological manipulation (via nicotine administration) for the treatment of cognitive impairment associated with schizophrenia. Experiment 1 used a 7.5% CO2 challenge as a model of anxiety-induced dopamine release to evaluate the sensitivity of latent inhibition during CO2 gas inhalation, compared to the inhalation of medical air. Experiment 2 examined the effect of 2 mg nicotine administration vs. placebo on latent inhibition to evaluate its sensitivity to a potential pro-cognitive drug treatment. Inhalation of 7.5% CO2 raised self-report and physiological measures of anxiety and impaired latent inhibition, relative to a medical air control; whereas administration of 2 mg nicotine, demonstrated increased latent inhibition relative to placebo control. Here, two complementary experimental studies suggest latent inhibition is modified by manipulations that are relevant to the detection and treatment of schizophrenia. These results suggest that this latent inhibition task merits further investigation in the context of neurobiological sub-groups suitable for novel treatment strategies.

Exertional Desaturation in Idiopathic Pulmonary Fibrosis: The Role of Oxygen Supplementation in Modifying Cerebral-Skeletal Muscle Oxygenation and Systemic Hemodynamics

<b><i>Background:</i></b> In patients with idiopathic pulmonary fibrosis (IPF) with isolated exertional desaturation, there are limited data regarding the effectiveness of oxygen supplementation during exercise training; the underlying mechanisms that contribute to these responses are unknown. <b><i>Objectives:</i></b> To examine in these IPF patients the effects of oxygen supplementation during submaximal exercise (vs. medical air) on cerebral/skeletal muscle oxygenation and systemic hemodynamics. <b><i>Methods:</i></b> In this randomized, cross-over, placebo-controlled trial, IPF patients (<i>n</i> = 13; 63.4 ± 9.6 years) without resting hypoxemia but a significant desaturation during maximal cardiopulmonary exercise testing underwent 2 steady-state exercise trials (65% peak-work-load), breathing either oxygen-enriched or medical air. Cerebral/skeletal muscle oxygenation (near-infrared spectroscopy) and beat-by-beat hemodynamics (photoplethysmography) were monitored. <b><i>Results:</i></b> In the air protocol, from the initial minutes of submaximal exercise, patients exhibited a marked decline in cerebral oxygenated hemoglobin (O₂Hb) and an abrupt rise in deoxygenated hemoglobin (HHb). Oxygen supplementation alleviated desaturation, lessened dyspnea, and prolonged exercise duration (<i>p</i> &#x3c; 0.01). Oxygen supplementation during exercise (i) attenuated cerebral deoxygenation (cerebral-HHb: 0.7 ± 1.9 vs. 2.5 ± 1.5 μmol/L, O₂ and air protocol; <i>p</i> = 0.009) and prevented cerebral-Hb_difference decline (2.1 ± 2.7 vs. −1.7 ± 2.0 μmol/L; <i>p</i> = 0.001), (ii) lessened the decline in muscle O₂-saturation index, and (iii) at isotime exercise, it resulted in lower muscle-HHb (<i>p</i> = 0.05) and less leg fatigue (<i>p</i> &#x3c; 0.05). No differences between protocols were observed in exercise cardiac output and vascular resistance. <b><i>Conclusions:</i></b> IPF patients with isolated exertional hypoxemia exhibit an inability to increase/maintain cerebral oxygenation during submaximal exercise. Correcting desaturation with O₂ supplementation prevented the decline in brain oxygenation, improved muscle oxygenation, and lessened dyspnea, suggesting an efficacy of acute oxygen supplementation during exercise training in protecting brain hypoxia in these IPF patients.

Uncertainty Estimation of Biomedical Oximeters: Proposal for an Experimental Test-Bench

Paramagnetic oximeters are frequently used in clinical practice to measure and titrate the fraction of inspired oxygen (FiO2) administered to a hypoxic patient. Newborns are prone to several diseases leading to hypoxia but also to oxidative damage, therefore a precise measurement of administered oxygen is of paramount importance. In this study, we evaluated and compared the performance of four commonly used gas analyzers at a Neonatal Unit. A paramagnetic gas analyzer was considered the standard for reference. Gas mixing performed by blenders was also evaluated. We first assessed the stability and composition of O2 and medical air. A settling time study was conducted to estimate steady state. Results show how tested blenders underestimated the real measures when FiO2 was &lt;50% and overestimated them when FiO2 =50%. In all the tested oximeters the FiO2 was underestimated by 1.18%, but the overall agreement with the gold standard was very good.

Rewarding Subjective Effects of the NMDAR Antagonist Nitrous Oxide (Laughing Gas) Are Moderated by Impulsivity and Depressive Symptoms in Healthy Volunteers

Background Nitrous oxide (N2O) is an anesthetic gas with both therapeutic and abuse potential. Because N2O is an NMDA receptor (NMDAR) antagonist, its effects are expected to resemble those of the prototypical NMDAR antagonist, ketamine. In this study, we examined the subjective rewarding effects of N2O using measures previously employed in studies of ketamine. We also tested for moderation of these effects by bipolar phenotype, depressive symptoms, and impulsivity. Methods Healthy volunteers were randomly assigned to either 50% N2O (n = 40) or medical air (n = 40). Self-reported rewarding (liking and wanting), and alcohol-like effects were assessed pre-, peri- and post inhalation. Results Effect sizes for the various rewarding/alcohol-like effects of N2O were generally similar to those reported in studies of moderate-dose ketamine. Impulsivity moderated the subjective reinforcing (liking) effects of inhaled gas, while depressive symptoms moderated motivational (wanting [more]) effects. However, depression and impulsivity had opposite directional influences, such that higher impulsivity was associated with higher N2O liking, and higher depression, with lower N2O wanting. Conclusion To the extent that static (versus longitudinal) subjective rewarding effects are a reliable indicator of future problematic drug use, our findings suggests that impulsivity and depression may predispose and protect, respectively, against N2O abuse. Future studies should examine if these moderators are relevant for other NMDAR antagonists, including ketamine, and novel ketamine-like therapeutic and recreational drugs. Similarities between moderate-dose N2O and moderate-dose ketamine in the intensity of certain subjective effects suggest that N2O may, at least to some extent, serve as substitute for ketamine as a safe and easily implemented experimental tool for probing reward-related NMDAR function and dysfunction in humans.

The role of anxiety in the perception of pain: exploring the cumulative & temporal mechanisms of hypercapnic analgesia

ABSTRACTBackgroundAnxiety, evoked by continuous inspiration of a 5 – 8% CO2 mixture, has been found to have an analgesic eLect on self-reported pain. The precise mechanism whereby this effect obtains remains unknown.MethodsThe present study tested whether temporal summation, the psychological counterpart of wind-up, is involved in hypercapnic analgesia. 21 healthy participants received painful transcutaneous electrical stimuli of varied intensity, during continuous inhalation of 7.5% CO2 mixture and medical air, presented in a single-blinded counterbalanced order. Continuous pain ratings were acquired to measure the temporal development of the pain response. Several points and events of interest that characterise the pain response profile were extracted from the continuous data.ResultsMixed-eLects modelling demonstrated a reduction of all pain measures during inspiration of the anxiogenic mixture, but not air. This was accompanied by an increase in the psychological and physiological measures of anxiety. Analyses of the characteristic measures of temporal summation suggested that the hypercapnic mixture has an analgesic property evident from the start of the pain response. The same was true for the remainder of the response, the adaptation period, where pain ratings were also inhibited. The reduced pain ratings persisted during the remainder of the response. Anxiety was found to be a mediating factor for summative pain ratings but not the temporally sensitive TS measures, suggesting an overall, cumulative effect.ConclusionsThe findings provide an explanation for the previously observed low self-reported pain during the inhalation of an anxiogenic hypercapnic mixture.

Vibration Properties of Steel Constructed Hospital Elevated Helipads

Polish Medical Air Rescue helicopters facilitate the rapid transport of patients to large hospitals. The requirements of the space around the helipad and the safety of flight operations mean that hospitals closer to city centers create more elevated helipads than ground-based helipads. The helipads can vary in the way they are constructed and located - depending on the possibilities offered by hospital buildings and their surroundings.Vibroacoustics Laboratory of the Institute of Aviation measured the vibration properties of some elevated helipads. The goal of this research was to determine the vibration properties of the helipads itself and the transmission of vibrations to the construction of the helipads, the building and its equipment caused by the landing and taking-off of a helicopter.This article presents some of the results of measurements of vibrations of steel constructed elevated helipads with the use of a modal hammer and while landing and taking-off of a helicopter, as well as comparison of the vibration properties concerning various elevated concrete helipads.