Advanced Life Support Systems Research Articles

International comparison of prehospital trauma care systems

Given the recent emphasis on developing prehospital trauma care globally, we embarked upon a multicentre study to compare trauma patients' outcome within and between countries with technician-operated advanced life support (ALS) and physician-operated (Doc-ALS) emergency medical service (EMS) systems. These environments represent the continuum of prehospital care in high income countries with more advanced prehospital trauma care systems. Five countries with ALS-EMS system and four countries with Doc-ALS EMS system provided us with de-identified patient-level data from their national or local trauma registries. Generalised linear latent and mixed models was used in order to compare emergency department (ED) shock rate (systolic blood pressure (SBP) <90mmHg) and early trauma fatality rate (i.e. death during the first 24h after hospital arrival) between ALS and Doc-ALS EMS systems. Logistic regression was used to compare outcomes of interest among different countries, accounting for within-system correlation in patient outcomes. After adjustment for patient age, sex, type and mechanism of injury, injury severity score and SBP at scene, the ED shock rate did not vary significantly between Doc-ALS and ALS systems (OR: 1.16, 95% CI: 0.73-1.91). However, the early trauma fatality rate was significantly lower in Doc-ALS EMS systems compared with ALS EMS systems (OR: 0.70, 95% CI: 0.54-0.91). Furthermore, we found a considerable heterogeneity in patient outcomes among countries even with similar type of EMS systems. These findings suggest that prehospital trauma care systems that dispatch a physician to the scene may be associated with lower early trauma fatality rates, but not necessarily with significantly better outcomes on other clinical measures. The reasons for these findings deserve further studies.

Microbial detection and monitoring in advanced life support systems like the International Space Station

Microbial detection and monitoring in advanced life support systems like the International Space Station

Canopy structure and imaging geometry may create unique problems during spectral reflectance measurements of crop canopies in bioregenerative advanced life support systems

AbstractHuman exploration missions to the Moon or Mars might be helped by the development of a bioregenerative advanced life-support (ALS) system that utilizes higher plants to regenerate water, oxygen and food. In order to make bioregenerative ALS systems competitive to physiochemical life-support systems, the ‘equivalent system mass’ (ESM) must be reduced by as much as possible. One method to reduce the ESM of a bioregenerative ALS system would be to deploy an automated remote sensing system within plant production modules to monitor crop productivity and disease outbreaks. The current study investigated the effects of canopy structure and imaging geometries on the efficiency of measuring the spectral reflectance of individual plants and crop canopies in a simulated ALS system. Results indicate that canopy structure, shading artefacts and imaging geometries are likely to create unique challenges in developing an automated remote sensing system for ALS modules. The cramped quarters within ALS plant growth units will create problems in collecting spectral reflectance measurements from the nadir position (i.e. directly above plant canopies) and, thus, crop canopies likely will be imaged from a diversity of orientations relative to the primary illumination source. In general, highly reflective white or polished surfaces will be used within an ALS plant growth module to maximize the stray light that is reflected onto plant canopies. Initial work suggested that these highly reflective surfaces might interfere with the collection of spectral reflectance measurements of plants, but the use of simple remote sensing algorithms such as 760/685 band ratios or normalized difference vegetation index (NDVI) images greatly reduced the effects of the reflective backgrounds. A direct comparison of 760/685 and NDVI images from canopies of lettuce, pepper and tomato plants indicated that unique models of individual plants are going to be required to properly assess the health conditions of canopies. A mixed model of all three plant species was not effective in predicting plant stress using either the 760/685 or NDVI remote sensing algorithms.

宇宙食における乳酸菌による腸内環境調節

We scope space exploration beyond the low Earth orbit, such as manned activities on Moon and Mars. The advanced life support system is required to create and maintain living environment in outer space by providing foods, cloths and habitat. We shall prepare effective measures for promoting health and preventing illness, as well. Since astronauts would be exposed to various stressful situation, it is highly requested to feed them healthy meal with a good balance of its nutrients, which maintain inner environment of digestive organ at its proper condition. It is also important to prevent diarrhea and constipation, or to enhance willpower and physical strength of astronauts, by feeding them with good nutritious and ingestible materials. The lactic acid bacterium beverage (containing 80 billion Lactobacillus casei shirota) was given, every day for one month, to 10 healthy female subjects (20.4 ± 0.51 years old) who suffer constipation, together with another 10 subjects for the control with dead bacteria in the same beverage. Status of their constipation was examined by their reporting of number of evacuation, shape of the evacuation, their self awareness on their status. The average stool frequency increased in both the experiment and the control group from the first week of administration. In the experiment group, six among ten subjects showed improvement of clear constipation. Since seven out of ten control subjects did not show improvement in their constipation, administration of live lactic acid bacterium is effective for improving constipation. The L-casei shirota lactic acid bacterium stock helps the action of Bifidobacterium bifidum to keep bowels in normal state. Without proper population of Bifidobacterium bifidum, such conditioning is not effective. Administration of both bacterium species is required in such case. In the future space missions, intake of the lactic acid bacterium would be one of effective measures to maintain astronaut's bowel in good condition and contribute to enhance their health and productivity in their task of space exploration.

Effect of different waste recovery systems on the overall waste generation rates for an Advanced Life Support System

This work demonstrates how studies of life support systems can be used to advance the understanding of environmental principles. Efficient waste recovery systems that are developed for the Advanced Life Support System used in space explorations can be utilised on Earth. As an example, we explored three different ALSS scenarios, each having different waste recovery technologies. The results are compared in terms of the overall waste generation rates. It is concluded that physicochemical waste recovery systems, with their low level of uncertainty in operating conditions and high recovery efficiencies, are the best choice for a 600 day mission to Mars.

Menu Optimization for an Earth-based Advanced Life Support System (ALSS) Test Bed Considering Crop Cultivation Scheduling

Menu Optimization for an Earth-based Advanced Life Support System (ALSS) Test Bed Considering Crop Cultivation Scheduling

Hypobaric Conditions Affect Gas Exchange, Ethylene Evolution, and Growth of Lettuce for Advanced Life Support Systems (ALS)

Hypobaric Conditions Affect Gas Exchange, Ethylene Evolution, and Growth of Lettuce for Advanced Life Support Systems (ALS)

Exposure ofArabidopsis thalianato Hypobaric Environments: Implications for Low-Pressure Bioregenerative Life Support Systems for Human Exploration Missions and Terraforming on Mars

Understanding how hypobaria can affect net photosynthetic (P (net)) and net evapotranspiration rates of plants is important for the Mars Exploration Program because low-pressured environments may be used to reduce the equivalent system mass of near-term plant biology experiments on landers or future bioregenerative advanced life support systems. Furthermore, introductions of plants to the surface of a partially terraformed Mars will be constrained by the limits of sustainable growth and reproduction of plants to hypobaric conditions. To explore the effects of hypobaria on plant physiology, a low-pressure growth chamber (LPGC) was constructed that maintained hypobaric environments capable of supporting short-term plant physiological studies. Experiments were conducted on Arabidopsis thaliana maintained in the LPGC with total atmospheric pressures set at 101 (Earth sea-level control), 75, 50, 25 or 10 kPa. Plants were grown in a separate incubator at 101 kPa for 6 weeks, transferred to the LPGC, and acclimated to low-pressure atmospheres for either 1 or 16 h. After 1 or 16 h of acclimation, CO(2) levels were allowed to drawdown from 0.1 kPa to CO(2) compensation points to assess P (net) rates under different hypobaric conditions. Results showed that P (net) increased as the pressures decreased from 101 to 10 kPa when CO(2) partial pressure (pp) values were below 0.04 kPa (i.e., when ppCO2 was considered limiting). In contrast, when ppCO(2) was in the nonlimiting range from 0.10 to 0.07 kPa, the P (net) rates were insensitive to decreasing pressures. Thus, if CO(2 )concentrations can be kept elevated in hypobaric plant growth modules or on the surface of a partially terraformed Mars, P (net) rates may be relatively unaffected by hypobaria. Results support the conclusions that (i) hypobaric plant growth modules might be operated around 10 kPa without undue inhibition of photosynthesis and (ii) terraforming efforts on Mars might require a surface pressure of at least 10 kPa (100 mb) for normal growth of deployed plant species.

Termination of Resuscitation in Out-of-Hospital Cardiac Arrest

To the Editor: We do not believe that Morrison et al. (Aug. 3 issue)1 focused on the right question in the Termination of Resuscitation (TOR) trial. If saving lives is the issue, the question is: What can early, adequate advanced cardiac life support achieve? Basic life support — as provided in this study — will never result in “good” cardiopulmonary resuscitation, and transportation of the patient to the emergency department during basic life support is thus futile. With physician-staffed advanced cardiac life support systems, 40 to 50% of patients with out-of-hospital cardiac arrest have a return of spontaneous circulation, and 10 to 15% survive with good neurologic outcomes.2-4 In the study reported by Morrison and colleagues, the rates of return of spontaneous circulation and hospital discharge were substantially lower — by a factor of 10 and 5, respectively — than those associated with physician-staffed systems.1 Thus, implementation of the proposed rule may result in Russian roulette for patients with out-of-hospital cardiac arrest. Would anyone ask about survival after motor vehicle accidents involving patients without safety belts in their cars? Why not just use cars with safety belts, even if doing so is more expensive? Let’s think differently and send the advanced cardiac life support know-how of the emergency department — that is, experienced physicians — to our patients undergoing out-of-hospital cardiac arrest. Education and organization, not termination, make the difference.2-4

Removal of Natural Steroid Hormones from Wastewater Using Membrane Contactor Processes

Growing demands for potable water have strained water resources and increased interest in wastewater reclamation for potable reuse. This interest has brought increased attention to endocrine-disrupting chemicals (EDCs) as emerging water contaminants. The effect of EDCs, and in particular natural steroid hormones, on humans is of heightened interest in the study of wastewater reuse in advanced life support systems (e.g., space missions) because they are excreted in urine and have high endocrine-disrupting potencies. Direct contact membrane distillation (DCMD) and forward osmosis (FO) are being investigated for wastewater treatment in space. Retention of two natural steroid hormones, estrone and 17beta-estradiol, by these two processes was evaluated in the current investigation. DCMD provided greater than 99.5% hormone rejection; DCMD also provided constant flux, greater than 99.9% urea and ammonia rejection, and high water recovery. FO provided from 77 to 99% hormone rejection depending on experiment duration and feed solution chemistry.

Microbial functions in space: Mars transit to early planetary base exploration missions

Microbial processing of liquid and solid wastes may play a role in the advanced life support systems of nearer term human exploration missions such as transit vehicles to Mars or initial surface bases on either the Moon or Mars. Recycling wastewater (urine, atmospheric condensate, hygiene water) is a critical component of reducing storage and resupply requirements on such missions, and microbial treatment of all or part of the waste stream may improve overall treatment efficiency. As small-scale plant systems (i.e., 5– 10 m 2 person - 1 ) are used to supplement food storage, microbial processing of both wastewater and edible plant material will facilitate nutrient and water recycling through the biomass production systems.

Microbial detection and monitoring in advanced life support systems like the international space station

Potentially pathogenic microbes and so-called technophiles may form a serious threat in advanced life support systems, such as the International Space Station (ISS). They not only pose a threat to the health of the crew, but also to the technical equipment and materials of the space station. The development of fast and easy to use molecular detection and quantification methods for application in manned spacecraft is therefore desirable and may also be valuable for applications on Earth. In this paper we present the preliminary results of the SAMPLE experiment in which we performed molecular microbial analysis on environmental samples of the ISS as part of an ESA-MAP project.

Biosynthesis Genes in Arabidopsis thaliana

The NASA Advanced Life Support (ALS) System for space habitation will likely operate under reduced atmospheric pressure (hypobaria). There are engineering, safety, and plant growth advantages in growing crops under low pressure. In closed production environments, such as ALS, excessive plant-generated ethylene may negatively impact plant growth. Growth of lettuce (Lactuca sativa) in the Low Pressure Plant Growth (LPPG) system was enhanced under low pressure (25kPa), due in part to decreased ethylene production. Under reduced pO2, ethylene production decreased under low as well as ambient conditions (He et al., 2003). During hypobaria, the expression of genes encoding ethylene biosynthesis enzymes, namely ACC synthase (ACS) and ACC oxidase (ACO), is not known. The primary objective of this research was to characterize the expression of ACS and ACO genes in response to hypobaria. Three-week-old Arabidopsis was used to determine the effects of hypobaria (25 kPa) and reduced O2 (12 kPa pO2) at the molecular level. Candidate gene expression was tested using quantitative real-time PCR at different times after treatment. Under low pressure, ACO1 expression is induced in the initial 12 hours of treatment, gradually decreasing with increased exposure. At 12 kPa pO2, ACO1 was induced under ambient conditions, suggesting that plants under low pressure may be more tolerant to hypoxic stress. The mechanism for enhanced growth of lettuce under hypobaric conditions will be studied further by analysis of the ACS and ACO gene families, and stress-responsive genes, namely late-embryogenesis abundant (LEA) proteins and dehydrins.

(147) Effect of Hypobaria, Oxygen, and Carbon Dioxide on Gas Exchange, Ethylene Evolution, and Growth of Lettuce Plants for NASA Advanced Life Support Systems

There are engineering and payload advantages in growing plants under hypobaric (reduced atmospheric pressure) conditions in biomass production for extraterrestrial base or spaceflight environments. Objectives of this research were to characterize the influence of hypobaria on growth, gas exchange, and ethylene evolution of lettuce (Lactuca sativa L. cv. Buttercrunch). Elevated levels of the plant hormone, ethylene, occur in enclosed crop production systems and in space-flight environments—leading to adverse plant growth and sterility. Lettuce plants were grown under variable total gas pressures [25 (low) or 101 kPa (ambient)]. During short growth periods of up to 10 days, growth was comparable between low and ambient pressure plants. Regardless of total pressure, plant growth was reduced at 6 kPa pO2 compared to 12 and 21 kPa pO2. At 6 kPa pO2 there was greater growth reduction and stress with ambient (101 kPa) than low (25kPa) pressure plants. Plants at 25/12 kPa pO2 had comparable CO2 assimilation and a 25% lower dark-period respiration than 101/21 kPa pO2 (ambient) plants. Greater efficiency of CO2 assimilation/dark-period respiration occurred with low pressure plants at 6 kPa pO2. Low pressure plants had a reduced CO2 saturation point (100 Pa CO2) compared with ambient (150 Pa CO2). Low pO2 lowered CO2 compensation points for both 25 and 101 kPa plants, i.e., likely due to reduced O2 competing with CO2 for Rubisco. Ethylene was 70% less under low than ambient pressure. High ethylene decreased CO2 assimilation rate of 101/12 kPa O2 plants. The higher dark-period respiration rates (higher night consumption of metabolites) of ambient pressure plants could lead to greater growth (biomass production) of low pressure plants during longer crop production cycles.

Preventing death and disability through the timely provision of prehospital trauma care

Injury remains a major cause of death and disability worldwide, and places an enormous burden on countries with limited resources. The optimal way to reduce life-threatening injuries is through primary prevention efforts that decrease the incidence and severity of injuries. When prevention fails, however, it is often possible to minimize the consequences of injury through effective prehospital and hospital-based trauma care. Unfortunately, much of the world's population does not have access to prehospital trauma care, particularly in low income countries. In many parts of the world, few victims receive treatment at the scene and fewer still receive safe transport to the hospital in an ambulance. Transport, when available, is usually provided by relatives, untrained bystanders, commercial drivers (minibus, taxi or truck drivers), or by public safety officers (police and firefighters). Many high-income countries have developed technically complex and costly prehospital trauma care systems to provide care for acutely ill or injured patients. While these systems are impressive and they undoubtedly benefit some patients, there is little evidence that they are inherently superior to less costly systems that provide a more basic level of prehospital care. The start-up and maintenance costs of advanced life support systems place them out of the reach of all but a few countries, effectively eliminating them as a practical, sustainable option in many parts of the world. Expensive systems are not necessarily the best. With few exceptions, most advanced prehospital interventions have not been scientifically proven to be effective because the necessary randomized trials have not been conducted. In fact, most of the benefits of prehospital trauma care can be readily realized if basic, vital interventions are quickly and consistently applied, utilizing a country's existing resources and health-care infrastructure. Considerable good may be accomplished by ensuring that victims receive life-sustaining care within a few minutes of injury. Even in countries with limited resources, many lives may be saved and disabilities prevented by teaching individuals what to do at the scene of an injury. The foundations of an effective prehospital system can be laid by recruiting carefully selected volunteers and non-medical professionals, and providing them with training as well as the basic supplies and equipment they need to provide effective prehospital care. Most severely injured patients who die in the first few hours after injury succumb to airway compromise, respiratory failure or uncontrolled haemorrhage. All of these conditions can be treated using basic first aid measures. The challenge, however, is to promote sustainable and affordable prehospital trauma care systems that provide services to everyone. To do this, each system must be defined by local needs and capacity and must be developed with due regard for local culture and health-care capacity. …

Etomidate Versus Midazolam for Out-of-Hospital Intubation: A Prospective, Randomized Trial

The primary objective of this study is to compare the intubation success rates of etomidate and midazolam when used for sedative-facilitated intubation, without paralytics, in out-of-hospital adult patients. This prospective, double-blind, randomized trial was conducted with 2 ground out-of-hospital advanced life support systems (ALS); all patients aged 18 or older who required out-of-hospital sedative-facilitated intubation were eligible for participation. The ambulances were stocked with blinded numbered syringes containing either 7 mg of midazolam or 20 mg of etomidate. No paralytics were used. If sedation was not achieved with the study drug, medics could request additional sedation from a medical command physician; only midazolam or diazepam were available outside of the study. One hundred ten patients were enrolled in the study; 55 patients received midazolam and 55 patients received etomidate. The 2 groups were similar with regard to age, sex, initial vital signs, and reasons for intubation or sedation. The overall intubation success rate was 76% (95% confidence interval [CI] 68% to 84%); 75% (41/55) for midazolam (95% CI 64% to 86%) and 76% (42/55) for etomidate (95% CI 65% to 87%). There was also no difference in incidence of hypotension, number of intubation attempts, or perceived difficulty of intubation. Additional sedation was requested almost equally for the 2 groups: 14 patients in the midazolam group and 12 patients in the etomidate group. A benzodiazepine was successful for rescue of a failed etomidate intubation 10 of 12 times (83%; 95% CI 62% to 100%). When used for rescue of failed midazolam intubations, benzodiazepines were effective in only 5 of 14 (36%, 95% CI 11% to 61%) attempts. There were no observed differences between midazolam and etomidate in sedation-facilitated intubation success rates; we could not fully evaluate global outcomes of these agents or the sedative-facilitated intubation strategy itself.

Application of Membrane Bioreactors in the Preliminary Treatment of Early Planetary Base Wastewater for Long Duration Space Missions

Membrane bioreactors (MBRs) are the preferred technology for the preliminary treatment of Early Planetary Base Wastewater (EPBW) because of their compact configuration and promising treatment performance. For long-duration space missions, irreversible membrane biofouling resulting from the strong attachment of biomass and the formation of biofilms are major concerns for the MBR process. In this study, a MBR was operated for 230 days treating synthetic EPBW. The reactor demonstrated excellent treatment performance, in terms of chemical oxygen demand removal and nitrification. Filtration resistance is mainly caused by concentration polarization, reversible fouling, and irreversible fouling. Analysis of the microbial communities in the planktonic and corresponding sessile biomass suggested that the microbial community of the planktonic biomass was significantly different from the one of the sessile biomass. This study provides valuable information for the development of the water reuse component in the National Aeronautics and Space Administration's (Washington, D.C.) Advanced Life Support system for long-term space missions.

Nile tilapia Oreochromis niloticus as a food source in advanced life support systems: Initial considerations

Maintenance of crew health is of paramount importance for long duration space missions. Weight loss, bone and calcium loss, increased exposure to radiation and oxidative stress are critical concerns that need to be alleviated. Tilapia are currently under evaluation as a source of food and their contribution to reducing waste in advanced life support systems (ALSS). The nutritional composition of tilapia whole bodies, fillet, and carcass residues were quantitatively determined. Carbon and nitrogen free-extract percentages were similar among whole body (53.76% and 6.96%, respectively), fillets (47.06% and 6.75%, respectively), and carcass (56.36% and 7.04%, respectively) whereas percentages of N, S, and protein were highest in fillet (13.34, 1.34, and 83.37%, respectively) than whole body (9.27, 0.62, and 57.97%, respectively) and carcass (7.70, 0.39, and 48.15%, respectively). Whole body and fillet meet and/or exceeded current nutritional recommendations for protein, vitamin D, ascorbic acid, and selenium for international space station missions. Whole body appears to be a better source of lipids and n-3 fatty acids, calcium, and phosphorous than fillet. Consuming whole fish appears to optimize equivalent system mass compared to consumption of fillets. Additional research is needed to determine nutritional composition of tilapia whole body, fillet, and carcass when fed waste residues possibly encountered in an ALSS.

Replicability of Bacterial Communities in Denitrifying Bioreactors as Measured by PCR/T-RFLP Analysis

Bioreactors hold great promise for treating graywater in an advanced life support system for space applications. However, questions remain regarding the reproducibility and reliability of biological systems for long-term use. Although there have been numerous studies on ground-based biological systems, most studies focus on a single reactor or a simple (single carbon) waste stream. There have been very few studies on microbial communities in replicate reactors using a nonsterile, complex waste stream. In this report, we describe the characterization of five replicate denitrifying reactors receiving a complex feed, including urine and limb washes from donors at Johnson Space Center over a 100-day period. Denitrifying conditions were employed because of the ease in adding a terminal electron acceptor to the bioreactor. Bacterial populations were tracked by 16S rRNA and nosZ genes T-RFLP analysis to target the total and denitrifying microbial communities. The results demonstrated reproducible biological communities with nearly identical performance that slowly changed with time and exhibited low variability with respect to the bacterial community (T-RFLP peak area) in all reactors. These results suggest that, when designed for replication, bioreactors are not stochastic systems exhibiting chaotic behavior, but are biological systems that can be highly reproducible and reliable.

Magnetically Assisted Filtration for Solid Waste Separation and Concentration in Microgravity and Hypogravity

Development of efficient means for the recovery of valuable resources from solid waste materials is a critical requirement for future advanced life-support systems that will be needed to support long-duration manned missions in space. Of particular importance are technologies that may be used in hypogravity and microgravity environments. Gradient magnetically assisted fluidized-bed (G-MAFB) technology, which uses magnetic forces to compensate for the absence of gravity, is under development to serve as an operating platform for fluidized-bed and related operations in the space environment. In this study, the G-MAFB is used as a renewable filter in which granular ferromagnetic filtration media are magnetically consolidated into a packed bed. The filtration media attains a substantially different structure from that of an ordinary packed bed, when consolidated under the influence of the magnetic field gradient. This directly influences filtration rates. The fully loaded bed is then regenerated by magnetically controlled fluidization, thereby releasing a concentrated slug of solids, which may be further processed by a variety of treatment schemes. Filtration experiments have shown that G-MAFB-based methods can successfully separate suspended inedible plant biomass waste particles from a recirculating liquid stream. A mathematical model that describes the filtration process in the G-MAFB is presented. Correlations for estimation of the accumulation and detachment coefficients, based on hydrodynamic conditions and geometry of the filtration system, have also been developed. Model predictions are compared with experimental results obtained in the G-MAFB while operated under Earth's gravity conditions (1 g). The experimental data are in good agreement with the theoretical predictions.