Coping with unpredictable environments: fine-tune foraging microhabitat use in relation to prey availability in an alpine species.

Microhabitat utilisation holds a pivotal role in shaping a species' ecological dynamics and stands as a crucial concern for effective conservation strategies. Despite its critical importance, microhabitat use has frequently been addressed as static, centering on microhabitat preference. Yet, a dynamic microhabitat use that allows individuals to adjust to fine-scale spatio-temporal prey fluctuations, becomes imperative for species thriving in challenging environments. High-elevation ecosystems, marked by brief growing seasons and distinct abiotic processes like snowmelt, winds, and solar radiation, feature an ephemeral distribution of key resources. To better understand species' strategies in coping with these rapidly changing environments, we delved into the foraging behaviour of the white-winged snowfinch Montifringilla nivalis, an emblematic high-elevation passerine. Through studying microhabitat preferences during breeding while assessing invertebrate prey availability, we unveiled a highly flexible microhabitat use process. Notably, snowfinches exhibited specific microhabitat preferences, favoring grass and melting snow margins, while also responding to local invertebrate availability. This behaviour was particularly evident in snow-associated microhabitats and less pronounced amid tall grass. Moreover, our investigation underscored snowfinches' fidelity to foraging sites, with over half located within 10 m of previous spots. This consistent use prevailed in snow-associated microhabitats and high-prey-density zones. These findings provide the first evidence of dynamic microhabitat use in high-elevation ecosystems and offer further insights into the crucial role of microhabitats for climate-sensitive species. They call for multi-faceted conservation strategies that go beyond identifying and protecting optimal thermal buffering areas in the face of global warming to also encompass locations hosting high invertebrate densities.

Mechanical cardiopulmonary resuscitation in microgravity and hypergravity conditions: A manikin study during parabolic flight.

INTRODUCTION: Space travel is expected to grow in the near future, which could lead to a higher burden of sudden cardiac arrest (SCA) in astronauts. Current methods to perform cardiopulmonary resuscitation in microgravity perform below earth-based standards in terms of depth achieved and the ability to sustain chest compressions (CC). We hypothesised that an automated chest compression device (ACCD) delivers high-quality CC during simulated micro- and hypergravity conditions. METHODS: Data on CC depth, rate, release and position utilising an ACCD were collected continuously during a parabolic flight with alternating conditions of normogravity (1 G), hypergravity (1.8 G) and microgravity (0 G), performed on a training manikin fixed in place. Kruskal-Wallis and Mann-Withney U test were used for comparison purpose. RESULTS: Mechanical CC was performed continuously during the flight; no missed compressions or pauses were recorded. Mean depth of CC showed minimal but statistically significant variations in compression depth during the different phases of the parabolic flight (microgravity 49.9 ± 0.7, normogravity 49.9 ± 0.5 and hypergravity 50.1 ± 0.6 mm, p < 0.001). CONCLUSION: The use of an ACCD allows continuous delivery of high-quality CC in micro- and hypergravity as experienced in parabolic flight. The decision to bring extra load for a high impact and low likelihood event should be based on specifics of its crew's mission and health status, and the establishment of standard operating procedures.

Hypothermic Cardiac Arrest With Full Neurologic Recovery After Approximately Nine Hours of Cardiopulmonary Resuscitation: Management and Possible Complications.

We describe full neurologic recovery from accidental hypothermia with cardiac arrest despite the longest reported duration of mechanical cardiopulmonary resuscitation (CPR) and extracorporeal life support (8 hours, 42 minutes). Clinical data and blood samples were obtained from emergency medical services (EMS) and the intensive care department. A 31-year-old man experienced a witnessed hypothermic cardiac arrest with a core temperature of 26°C (78.8°F) during a summer thunderstorm; he received mechanical CPR for 3 hours and 42 minutes, followed by 5 hours of extracorporeal life support. The use of a standard operating procedure that integrates a technical mountain rescue performed by EMS, optimizes prolonged CPR to the hub hospital, and enables prompt placement of extracorporeal life support is described and discussed. Three months postaccident, the patient had recovered completely (Cerebral Performance Category score of 1) and resumed normal daily life. Neurologically intact survival from hypothermic cardiac arrest is common, suggesting that aggressive resuscitation measures are warranted. There is a need for the establishment of a clear standard operating procedure and multiteam education and training to further optimize the patient survival chain from on-site triage and treatment to inhospital extracorporeal life support and postresuscitation care.

Mortality in Multicenter Critical Care Trials: An Analysis of Interventions With a Significant Effect.

OBJECTIVES: We aimed to identify all treatments that affect mortality in adult critically ill patients in multicenter randomized controlled trials. We also evaluated the methodological aspects of these studies, and we surveyed clinicians' opinion and usual practice for the selected interventions. DATA SOURCES: MEDLINE/PubMed, Scopus, and Embase were searched. Further articles were suggested for inclusion from experts and cross-check of references. STUDY SELECTION: We selected the articles that fulfilled the following criteria: publication in a peer-reviewed journal; multicenter randomized controlled trial design; dealing with nonsurgical interventions in adult critically ill patients; and statistically significant effect in unadjusted landmark mortality. A consensus conference assessed all interventions and excluded those with lack of reproducibility, lack of generalizability, high probability of type I error, major baseline imbalances between intervention and control groups, major design flaws, contradiction by subsequent larger higher quality trials, modified intention to treat analysis, effect found only after adjustments, and lack of biological plausibility. DATA EXTRACTION: For all selected studies, we recorded the intervention and its comparator, the setting, the sample size, whether enrollment was completed or interrupted, the presence of blinding, the effect size, and the duration of follow-up. DATA SYNTHESIS: We found 15 interventions that affected mortality in 24 multicenter randomized controlled trials. Median sample size was small (199 patients) as was median centers number (10). Blinded trials enrolled significantly more patients and involved more centers. Multicenter randomized controlled trials showing harm also involved significantly more centers and more patients (p = 0.016 and p = 0.04, respectively). Five hundred fifty-five clinicians from 61 countries showed variable agreement on perceived validity of such interventions. CONCLUSIONS: We identified 15 treatments that decreased/increased mortality in critically ill patients in 24 multicenter randomized controlled trials. However, design affected trial size and larger trials were more likely to show harm. Finally, clinicians view of such trials and their translation into practice varied.

Full recovery after prolonged cardiac arrest and resuscitation with mechanical chest compression device during helicopter transportation and percutaneous coronary intervention.

BACKGROUND: Despite early cardiopulmonary resuscitation (CPR) by bystanders and early advanced cardiac life support (ACLS) maneuvers, some patients present to the emergency department with persistent cardiac arrest caused by a coronary artery occlusion. Although emergency percutaneous intervention (PCI) has been shown to be effective in improving survival, transporting patients in cardiac arrest to the hospital is not considered to be effective, due to the poor quality of CPR in the ambulance. In the case reported here, a mechanical chest compression device was used while transporting the patient by helicopter emergency medical services (HEMS). CASE REPORT: A mechanical chest compression device was used to deliver chest compressions to a 53-year-old man in cardiac arrest. This device permitted the transfer of the patient by HEMS helicopter to the catheterization laboratory facility for a PCI. Return of spontaneous circulation was achieved 115 min after cardiac arrest and the patient survived without any neurological deficit. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The mechanical chest compression device has permitted safe and effective CPR during helicopter transportation. Although this is only a single case, it may present a new perspective for the treatment of prehospital cardiac arrest that is refractory to ACLS therapies.

Brain emboli distribution and differentiation during cardiopulmonary bypass.

OBJECTIVE: Cardiopulmonary bypass (CPB) is a lifesaving practice in cardiac surgery, but its use frequently is associated with cerebral injury and neurocognitive dysfunctions. Despite the involvement of numerous factors, microembolism occurring during CPB seems to be one of the main mechanisms leading to such alterations. The aim of the present study was to characterize the occurrence of cerebral microembolism with reference to microembolic amount, nature, and distribution in different combinations of cardiac procedures and CPB on the microembolic load. DESIGN: A retrospective observational clinical study. SETTING: A single-center regional hospital. PARTICIPANTS: Fifty-five patients undergoing elective cardiac surgery with CPB. INTERVENTIONS: Bilateral detection of the patients' middle cerebral arteries using a multifrequency transcranial Doppler. MEASUREMENTS AND MAIN RESULTS: Patients were divided into 3 groups depending on the CPB circuit used (open, open with vacuum, or closed). There was a significant difference between the number of solid and gaseous microemboli (p<0.001), with the solid lower than the gaseous ones. The number of solid microemboli was affected by group (p< 0.05), CPB phase (p<0.001), and laterality (p<0.01). The number of gaseous microemboli was affected only by group (p<0.05) and CPB phase (p<0.001). Generally, the length of CPB phase did not affect the number of microemboli. CONCLUSIONS: Surgical procedures combined with CPB circuits, but not the CPB phase length, affected the occurrence, nature, and laterality of microemboli.

Pump flow changes do not impair sublingual microcirculation during cardiopulmonary bypass.

OBJECTIVE: The flow rate of the cardiopulmonary bypass (CPB) pump used in cardiac surgery often undergoes inherent fluctuations ranging from 10% to 20% of its theoretic value. However, the effects of such alterations remain unknown. In the present study, the authors investigated whether such variations could induce changes in the microvascular flow, which is considered a primary indicator of poor perfusion. DESIGN: A prospective, observational, clinical study. SETTING: A university-affiliated teaching hospital. PARTICIPANTS: Thirty adult patients undergoing elective cardiac surgery with CPB. INTERVENTIONS: Analysis of the sublingual microcirculation during CPB using a pump flow rate of 80% or 100% of the theoretic value. MEASUREMENTS AND MAIN RESULTS: Sidestream dark field (SDF) imaging was used to record 2 video clips of the sublingual microcirculation in each patient. The videos were recorded at the same site at 80% and 100% of the theoretic flow rate. Microvascular analysis displaying the De Backer score, the microvascular flow index, the total vessel density, the perfused vessel density, and the proportion of perfused vessels was performed. Moreover, the mean arterial pressure (MAP), SvO(2), and PaCO(2) were evaluated. No significant changes in the measured parameters were noted at the 2 different flow rates. CONCLUSIONS: Changes in the CPB pump flow rate within 20% (80%-100%) of its theoretic value do not alter the sublingual microcirculation. Thereafter, it is conceivable that during perioperative adjustments of the CPB pump rate, blood flow autoregulation mechanisms are activated so that limited changes in the pump flow can be considered safe not only at the sublingual site but also for the entire microcirculation.

Analysis of road traffic accidents involving standing electric scooters reported in newspapers in Italy.

OBJECTIVE: As the use of electric scooters increased in Italy in the last years, we aimed to estimate the burden of accidents caused by this micro-mobility vehicle and identify characteristics, severity, and type of injuries. METHODS: We conducted a case series analysis of news reports about electric scooter crashes occurring in Italy from January 1, 2019 to September 30, 2020. Events were included when a road traffic accident involved an electric scooter and caused damages or injuries to the driver or others. RESULTS: We identified 96 road accidents involving electric scooters in Italy. The mean age of patients was 30 ± 16 years, and 79% (n = 71/90) were male. Of the 96 patients, only two (2%) were driving an electric scooter with a helmet, and three (3%) were driving while intoxicated. In 68% (n = 62/94) of cases, the incident was caused by a collision with another vehicle or a pedestrian, and 30% (n = 18/96) were transported with life-threatening injuries to the emergency department. In 15% (n = 14/96), the emergency medical service physician was dispatched to the scene. Head trauma was the most common injury (60%, n = 32/53). Patients who had life-threatening conditions were more likely to have head trauma than those who did not (82% [n = 9/11] vs. 55% [n = 23/42], P = 0.10). Polytrauma was significantly more common in patients with life-threatening conditions than in patients with no life-threatening conditions (36% [n = 4/11] vs. 5% [n = 2/42], P < 0.01). Fifteen percent of patients (n = 12/81) were admitted to the intensive care unit; only one death was reported. CONCLUSION: Road traffic accidents involving electric scooters often result in serious injuries, including head trauma and polytrauma, necessitating the involvement of an emergency medical service physician and intensive care unit admission in a non-negligible percentage of instances.

Implementation of a mechanical CPR device in a physician staffed HEMS - a prospective observational study.

In this prospective, observational study we describe the incidence and characteristics of out of hospital cardiac arrest (OHCA) cases who received mechanical CPR, after the implementation of a mechanical CPR device (LUCAS 2; Physio Control, Redmond, WA, USA) in a physician staffed helicopter emergency medical service (HEMS) in South Tyrol, Italy. During the study period (06/2013-04/2016), 525 OHCA cases were registered by the dispatch centre, 271 (51.6%) were assisted by HEMS. LUCAS 2 was applied in 18 (6.6%) of all HEMS-assisted OHCA patients; ten were treated with LUCAS 2 at the scene only, and eight were transported to hospital with ongoing CPR. Two (11.1%) of the 18 patients survived long term with full neurologic recovery. In seven of eight patients transferred to hospital with ongoing CPR, CPR was ceased in the emergency room without further intervention. Retrospectively, all HEMS-assisted OHCA cases were screened for proposed indication criteria for prolonged CPR. Thirteen patients fulfilled these criteria, but only two of them were transported to hospital. Based on these results, we propose a standard operating procedure for HEMS-assisted patients with refractory OHCA in a region without hospitals with ECLS capacity.

Effect of mild hypothermic cardiopulmonary bypass on the amplitude of somatosensory-evoked potentials.

BACKGROUND: Several neurophysiological techniques are used to intraoperatively assess cerebral functioning during surgery and intensive care, but the introduction of hypothermia as a means of intraoperative neuroprotection has brought their reliability into question. The present study aimed to evaluate the effect of mild hypothermia on somatosensory-evoked potentials' (SSEPs) amplitude and latency in a cohort of cardiopulmonary bypass (CPB) patients as the temperature reached the steady-state. MATERIALS AND METHODS: The amplitude and latency of 4 different SSEP signals--N9, N13, P14/N18 interpeak, and N20/P25--were evaluated retrospectively in 84 patients undergoing CPB during normothermic (36°C±0.43°C) and mild hypothermic (32°C±1.38°C) conditions. SSEPs were recorded in normothermia immediately after the induction of anesthesia and in hypothermia as the temperature reached its steady-state, specifically, when the nasopharyngeal temperature was equivalent to the rectal temperature (±0.5°C). A paired-samples t test was performed for each SSEP to test the differences in latencies and amplitudes between normothermic and hypothermic conditions. RESULTS: Compared with normothermia, hypothermia not only significantly increased the latency of all SSEPs, N9 (P<0.001), N13 (P<0.001), P14/N18 (P<0.001), and N20/P25 (P<0.001), but also the amplitude of N9 (P<0.001) and N20/P25 (P<0.001). CONCLUSIONS: The increased amplitude in particularly of cortical SSEPs (N20/P25), detected specifically during steady-state hypothermia, seems to support the clinical utility of this methodology in monitoring the brain function not only during cardiac surgery with CPB, but also in other settings like therapeutic hypothermia procedures in an intensive care unit.

Haemodynamics and oxygenation improvement induced by high frequency percussive ventilation in a patient with hypoxia following cardiac surgery: a case report.

INTRODUCTION: High frequency percussive ventilation is a ventilatory technique that delivers small bursts of high flow respiratory gas into the lungs at high rates. It is classified as a pneumatically powered, pressure-regulated, time-cycled, high-frequency flow interrupter modality of ventilation. High frequency percussive ventilation improves the arterial partial pressure of oxygen with the same positive end expiratory pressure and fractional inspiratory oxygen level as conventional ventilation using a minor mean airway pressure in an open circuit. It reduces the barotraumatic events in a hypoxic patient who has low lung-compliance. To the best of our knowledge, there have been no papers published about this ventilation modality in patients with severe hypoxaemia after cardiac surgery. CASE PRESENTATION: A 75-year-old Caucasian man with an ejection fraction of 27 percent, developed a lung infection with severe hypoxaemia [partial pressure of oxygen/fractional inspiratory oxygen of 90] ten days after cardiac surgery. Conventional ventilation did not improve the gas exchange. He was treated with high frequency percussive ventilation for 12 hours with a low conventional respiratory rate (five per minute). His cardiac output and systemic and pulmonary pressures were monitored.Compared to conventional ventilation, high frequency percussive ventilation gives an improvement of the partial pressure of oxygen from 90 to 190 mmHg with the same fractional inspiratory oxygen and positive end expiratory pressure level. His right ventricular stroke work index was lowered from 19 to seven g-m/m2/beat; his pulmonary vascular resistance index from 267 to 190 dynes•seconds/cm5/m2; left ventricular stroke work index from 28 to 16 gm-m/m2/beat; and his pulmonary arterial wedge pressure was lowered from 32 to 24 mmHg with a lower mean airway pressure compared to conventional ventilation. His cardiac index (2.7 L/min/m2) and ejection fraction (27 percent) did not change. CONCLUSION: Although the high frequency percussive ventilation was started ten days after the conventional ventilation, it still improved the gas exchange. The reduction of right ventricular stroke work index, left ventricular stroke work index, pulmonary vascular resistance index and pulmonary arterial wedge pressure is directly related to the lower respiratory mean airway pressure and the consequent afterload reduction.

Microembolic signals and strategy to prevent gas embolism during extracorporeal membrane oxygenation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) supplies systemic blood perfusion and gas exchange in patients with cardiopulmonary failure. The current literature lacks of papers reporting the possible risks of microembolism among the complications of this treatment.In this study we present our preliminary experience on brain blood flow velocity and emboli detection through the transcranial Doppler monitoring during ECMO. METHODS: Six patients suffering of heart failure, four after cardiac surgery and two after cardiopulmonary resuscitation were treated with ECMO and submitted to transcranial doppler monitoring to accomplish the neurophysiological evaluation for coma.Four patients had a full extracorporeal flow supply while in the remaining two patients the support was maintained 50% in respect to normal demand.All patients had a bilateral transcranial brain blood flow monitoring for 15 minutes during the first clinical evaluation. RESULTS: Microembolic signals were detected only in patients with the full extracorporeal blood flow supply due to air embolism. CONCLUSIONS: We established that the microembolic load depends on gas embolism from the central venous lines and on the level of blood flow assistance.The gas microemboli that enter in the blood circulation and in the extracorporeal circuits are not removed by the membrane oxygenator filter.Maximum care is required in drugs and fluid infusion of this kind of patients as a possible source of microemboli. This harmful phenomenon may be overcome adding an air filter device to the intravenous catheters.