Reliability of lithium dilution cardiac output in anaesthetized sheep

Background Cardiac output (CO) measurement with lithium dilution (COLD) has not been fully validated in sheep using precise ultrasonic flow probe technology (COUFP). Sheep generate important cardiovascular research models and the use of COLD has become more popular in experimental settings. Methods Ultrasonic transit-time perivascular flow probes were surgically implanted on the pulmonary artery of 13 sheep. Paired COLD readings were taken at six time points, before and after implantation of a left ventricular assist device (LVAD) and compared with COUFP recorded just after lithium injection. Results The mean COLD was 5.7 litre min−1 (range 3.8-9.6 litre min−1) and mean COUFP 5.9 litre min−1 (range 4.0-9.2 litre min−1). The bias (standard deviation) was 0.3 (1.0) litre min−1 [5.1 (16.9)%] and limits of agreement (LOA) were −1.7 to 2.3 litre min−1 (−28.8 to 39.0%) with a percentage error (PE) of 34.4%. Data to assess trending [rate (95% confidence intervals)] included a 78 (62-93)% concordance rate in the four-quadrant plot (n=27). In the half moon polar plot (n=19), the mean polar angle was +5°, the radial LOA were −49 to +35° and 68 (47-89)% of data points fell within 22.5° of the mean polar angle. Both tests indicated moderate to poor trending ability. Conclusion COLD is not precise when evaluated against COUFP in sheep based on the statistical criteria set, but the results are comparable with previously published animal studie

Reliability of lithium dilution cardiac output in anaesthetized sheep

BACKGROUND: Cardiac output (CO) measurement with lithium dilution (COLD) has not been fully validated in sheep using precise ultrasonic flow probe technology (COUFP). Sheep generate important cardiovascular research models and the use of COLD has become more popular in experimental settings. METHODS: Ultrasonic transit-time perivascular flow probes were surgically implanted on the pulmonary artery of 13 sheep. Paired COLD readings were taken at six time points, before and after implantation of a left ventricular assist device (LVAD) and compared with COUFP recorded just after lithium injection. RESULTS: The mean COLD was 5.7 litre min(-1) (range 3.8-9.6 litre min(-1)) and mean COUFP 5.9 litre min(-1) (range 4.0-9.2 litre min(-1)). The bias (standard deviation) was 0.3 (1.0) litre min(-1) [5.1 (16.9)%] and limits of agreement (LOA) were -1.7 to 2.3 litre min(-1) (-28.8 to 39.0%) with a percentage error (PE) of 34.4%. Data to assess trending [rate (95% confidence intervals)] included a 78 (62-93)% concordance rate in the four-quadrant plot (n=27). In the half moon polar plot (n=19), the mean polar angle was +5°, the radial LOA were -49 to +35° and 68 (47-89)% of data points fell within 22.5° of the mean polar angle. Both tests indicated moderate to poor trending ability. CONCLUSION: COLD is not precise when evaluated against COUFP in sheep based on the statistical criteria set, but the results are comparable with previously published animal studies. KEYWORDS

Climatic change and the Mediterranean

The temperature and precipitation scenarios for the Malta region developed by the Climate Research Unit of the University of East Anglia suggest that annual temperature will increase by 0.8 to 0.9°C per degree Celsius of global change and that there will be little if any change in the annual rainfall amounts around Malta. A statistical analysis of past meteorological data for Malta indicates an existing trend towards increasing extremes of temperature; namely an increase in the maximum and a decrease in the minimum temperatures. The mean annual temperature is also apparently increasing. These data also suggest a trend towards lower total annual rainfall; an increase in the atmospheric pressure; an increase in the number of days with thunderstorms; and decreases in cloud cover and the number of hours of bright sunshine. These trends suggest that a process of desertification is already occurring in Malta, and that there is an increase in the suspended particle concentration including pollutants, in the atmosphere over the island. The hydrological cycle will be significantly affected by global warming. In Malta, natural sources of freshwater account for about 37% of all potable water in the public supply and for 84% of all irrigation water. Global warming will affect the freshwater supply through changes to relative sea level, and through changes in rainfall and evapotranspiration. A eustatic rise in sea level of around 65 ± 35 cm by the year 2100 would adversely affect the existing extraction rates from Malta's principal aquifer and make it more vulnerable to sea water intrusion. In contrast, the direct climatic effect will be less pronounced, since only a small change in local precipitation is predicted to accompany global warming. Climate is a fundamental factor influencing the nature of the soils of Malta. Since an increase in temperature with little change in the total rainfall is anticipated, evapotranspiration will increase, leading to an increase in aridity, and to soil degradation mainly due to salinization and alkalinization. The anticipated increase in temperature; a shift in precipitation patterns; a decrease in soil water availability; and a rise in sea level, will have negative impacts on agriculture, natural vegetation and associated fauna, favouring an increase in xerophilic, thermophilic and halophilic species. Such species are likely to be introduced ones, thriving at the expense of native species. It is predicted that the character of the vegetation will change from that typical of Mediterranean coastal lowlands, to associations more typical of deserts. This shift in vegetation pattern would be enhanced by soil erosion and increased soil salinity. Remedial action at a local level could include measures to prevent soil erosion by gradually changing to crops and trees that stabilize soils and which tolerate the new climatic conditions. A change in temperature could possibly lead to an increase in agricultural pests, whilst sea level rise may cause inundation of low-lying agricultural land such as that at Pwales and of groves such as those at Salina Bay. The impacts on fisheries may be less dramatic but changes in migration patterns of important fish such as lampuki might happen; and the potentially adverse effects which competitive thermophilic seaweeds may have on the important Posidonia meadows may be of concern in the future. The effects on aquaculture are difficult to assess but may include an increase in pathogens. The control of pollutants and protection of the Posidonia meadows are recommended, together with development of more sustainable use of fisheries resources. The present coastal, near-shore and freshwater ecosystems are threatened by a number of anthropogenic, non-climatic changes. Any additional impacts on these ecosystems resulting from climatic changes will have to be assessed in the light of such nonclimatic effects, if the overall projections of future changes are to be accurate. Increased eutrophic conditions and increased water stratification are likely to occur under conditions of global change in certain localities already influenced by other non-climatic human activities. Non-linear biological responses to climatic changes are discussed and may prove to be quite significant but difficult to predict with the present state of knowledge. Coastal sandy beaches, sand dunes and saline marsh habitats are considered to be sensitive to predicted climate change impacts, through increased erosion, enhanced shoreline recession and increased environmental fluctuations. The extent of impacts on such habitats, under less severe climatic change scenarios, will depend largely on present and future land-use management practices. Given the coastal topography, present drainage patterns and negligible tectonic movements in Malta, the predicted rise in sea level will have coast and especially those in the main drainage basins will become more susceptible to periodic rainfall-induced flooding and anticipatory action will be needed to address the consequential economic and social disruption. Impacts on coastal settlements are expected as a result of tidal and storm surges rather than from permanent inundation. A rise in sea level may cause sewage systems to flood, and new systems may have to be developed to reduce public health risks from such a hazard, including the increased risk of epidemics of enteric disorders such as typhoid fever. Salt water intrusion into aquifers will reduce the quantity and quality of potable water resources. Temperature rise and an increased frequency of extreme high temperatures, especially when combined with high humidity, will put some population groups such as the elderly and infants at risk from heat stress. Diseases presently confined to the tropics may spread to higher latitudes, and tropical and sub-tropical vector borne diseases may become more widespread, partly because vector survival will increase and partly because the parasites may be able to complete their life cycle more easily. Malaria may reappear in Europe, whilst Leishmaniasis, which has been under control in the recent past, already seems to be on the increase, possibly as a result of recent increases in temperature and humidity. Increased exposure to the sun when combined with possible ozone layer depletion may result in a further rise in the incidence of both melanomas and non-melanotic skin cancers. Exposure to increased ultraviolet (UV) radiation is expected to cause damage to the cornea and lens and an increased incidence of cataracts. The effect of UVB radiation on the human immune system is far less well understood, but it is a well accepted fact however, that UV, possibly acting through DNA damage, is an important precipitating factor of the auto-immune condition, systemic lupus erythematosus. The tourist industry has, for many years, been one of the Islands' most important economic activities, employing 5.8% of the total working population. If the climate conditions of the Maltese Islands change, the tourist industry could suffer, causing disruption to the Maltese economy and hardship to the population. Sea level rise will certainly have an impact on this site-dependent and coastal industry, which would be adversely affected by the loss of sandy beaches and the reduction in potable water supply. The tourist industry, is by its very nature, fragile and susceptible to political, economic and social changes. Climate change will add another element of uncertainty to this sector. Transport in Malta depends entirely on roads, whilst a ferry service connects the islands of Malta, Gozo and Comino and is also used around the Grand Harbour area. Road traffic would suffer in the event of flooding of the main traffic arteries as a result of severe rain storms, which will probably increase along with the anticipated increase in autumn precipitation. Changes in climate are expected to have an effect on the patterns of energy demand to heat and cool buildings. Electricity generation, which accounts for almost two thirds of primary energy consumption, has grown on average by about 8.5% per year in recent years. The predicted average temperature increases would, theoretically, reduce the need to provide heating, thereby saving energy. Given the low thermal performance of Maltese buildings, an increase in ambient temperature may merely result in a more thermally comfortable interior, rather than a saving of energy. · In the commercial and industrial sectors, the interhal heat generated by the use of machinery is high and an increase in ambient temperature, may result in a need for cooling through increased ventilation and possibly an extension of the air conditioning season. The introduction of thermal insulation to the building envelope, would reduce both the heating demand in winter as well as the cooling demand in summer. The displacement of fossil fuels by renewable energy sources particularly biomass and hydro power would reduce carbon dioxide emissions. In Malta there is good potential for development of solar energy, although land availability is a major obstacle. There is less possibility of harnessing wind energy on a large scale although wind energy is already widely used for water pumping in agriculture.peer-reviewe

Comparative oncology and clinical translation of glyco protein conjugated gold nano therapeutic agent (GA-198AuNP) [abstract]

Nanoscience Poster SessionAs part of our efforts toward clinical translation of GA-198AuNP, our studies are focused on therapeutic efficacy of nanoparticulate GA198AuNP agent in dogs with prostatic carcinoma. The overall goal is to gain clinical insights on therapeutic efficacy of GA198AuNP in a large animal model. We have performed a phase I clinical trial using GA-AuNP administered intravenously or intratumorally by injection or infusion. CT scans were performed prior to injection and 24 hours post injection in 3 of the 4 dogs. Following injections, dogs were allowed further treatment as recommended by the primary attending clinician. Four dogs have been treated to date. Complications related to GA-AuNP treatment were not observed, and all 4 dogs received adjunctive treatment with radiation therapy and/ or chemotherapy. These preliminary studies have clearly provided compelling evidence on the therapeutic potential of biocompatible GA-AuNP for their utility as novel therapeutic agents in treating various types of inoperable solid tumors. Intra-tumoral and intravenous administration of GA-AuNP is safe in dogs with spontaneously occurring tumors. As further therapeutic efficacy studies continue, the outcome of this clinical trial in a large animal model will generate therapeutic efficacy data which will be used for filing IND application for Phase I clinical trial studies. This clinical translation effort provides significant advances in terms of delivering optimum therapeutic payloads into prostate cancers with subsequent reduction in tumor volume, thus may effectively reduce/eliminate the need for surgical resection. This presentation will include details of clinical translation of GA198AuNP in prostate tumor bearing dogs

Alternating one lung ventilation using a double lumen endobronchial tube and providing CPAP to the non-ventilated lung in a dog

INTRODUCTION: This case report describes the anaesthetic management of exploratory thoracoscopy and alternating one lung ventilation (OLV) in a dog with a pulmonary bulla, and the application of continuous positive airway pressure (CPAP) to the non-ventilated lung for preventing and treating hypoxia. CASE HISTORY: A 6-year-old, male castrated Border collie was scheduled for exploratory thoracoscopy to investigate spontaneous pnemothorax that had not resolved with repeated suction. Specific requirements for the thoracoscopy were alternating OLV to allow the surgical access to the right middle lobe and its removal, and the examination of the left hemithorax to rule out the presence of other lesions. DIAGNOSIS AND MANAGEMENT: Selective lung ventilation was performed with a double lumen endobronchial tube (DLT), inserted under endoscopic guidance. After a short period of two lung ventilation during preparation of the surgical field, alternating OLV was performed, combining CPAP, provided to the non-ventilated lung via a Mapleson D breathing system, and positive end-expiratory pressure (PEEP) applied to the ventilated lung. Left OLV occurred first and resection of the right middle pulmonary lobe was successfully performed; right OLV followed to allow the examination of the left hemithorax. DISCUSSION AND CONCLUSIONS: The combination of CPAP and PEEP resulted in a satisfactory intra-operative management of hypoxemia. Alternating OLV can be performed successfully by using a DLT. CPAP, commonly employed in human medicine, should be considered an important tool in the anaesthetic management of OLV in small animals