A roadmap to Renewable Adaptive Recyclable Environmental (R.A.R.E.) architecture

R.A.R.E. stands for Renewable Adaptive Recyclable Environmental Architecture; the acronym expresses a demand that is becoming increasingly important today in the eyes of designers and clients. The paper draws on the contents and the pedagogical methods applied in a Building Technology Unit (SRT 450) – at forth year level – at the School of Architecture and Building, Deakin University, Australia. The unit is basically structured upon eight subjects derived as relevant to the research and development for a R.A.R.E. Architecture: Sustainable Site & Climate Analysis; Flexible & Adaptive Structural Systems; Renewable Adaptive & Environmental Building Materials; Modular Building Systems; Innovative Building Envelope Systems; Renewable or Non-conventional Energy Systems; Innovative Heating, Ventilation & Air Conditioning; Water Storage & Systems. The overall objective of the unit is to present a comprehensive overview of all these Sustainable Building Categories (SBCs) so that the students can produce a guide towards the design of a R.A.R.E. Architecture. The push towards a holistic and integrated approach will contribute to the definition of an innovative architecture, which is both progressive and sustainable.

Advanced fabric energy storage systems in Australia

There is a growing interest in the use of advanced fabric energy storage (FES) systems in Australia. The influence of slab thickness and ventilation rate on the annual thermal load, and maximum heating and cooling demands for an office module using a ventilated hollow core concrete slab system has been investigated by simulation. Airflow through the panels was set at 1, 2 or 4 air changes per hour (ACH) for slab thicknesses of 205, 220 and 300 mm. These configurations were simulated using two different FES operational strategies for six capital cities in mainland Australia. The simulations show that FES systems can offer either energy and/or peak load savings in almost all locations investigated. Overall, compared to a conventional AC system, the tempering of incoming fresh air combined with night flushing of the FES system appears to be the most successful operational strategy.

Solar heating systems for recirculation aquaculture

The literature over the past 25 years indicates that there has been a continued interest in using passive and active solar technologies to reduce the conventional energy required to maintain water temperatures in small recirculation aquaculture systems. Although all of the experimental systems reviewed report favourable results, there is little information available to guide system designers. This paper describes the use of a simulation model to predict the annual conventional energy consumption of a 10.6 m3 RAS enclosed in a double layer polyethylene greenhouse in two different climates. The water was maintained at 22.5 °C and the recirculation rate was 10% of tank volume per day. Simple unglazed solar collectors have also been combined with the greenhouse to further reduce energy consumption. The effect of increasing collector area on the solar fraction and utilization of useful energy was predicted. Finally, the model was used to investigate the relationship between the occurrence of condensation on the inner cover, ventilation rates and energy use. It was found that in a hot dry climate, the greenhouse alone was sufficient to reduce the conventional energy requirements by 87%; while in the cooler temperate climate reductions of 66% were possible. When solar collectors were added to the system, conventional energy requirements were reduced further and depended on the area of collector used. For example, in the temperate climate location, conventional energy requirements were reduced to 23% of a RAS enclosed in a non-solar building when 26 m2 of solar collector inclined at the optimum angle for winter energy collection were used. Although condensation could be successfully reduced by ventilation of the greenhouse, this increased conventional energy requirements because the potential for evaporation was increased. Covering the tanks at night was found to be a more effective strategy because it reduced condensation and conventional energy use simultaneously.

Performance of a 120 m2 solar air heater for a commercial building in Victoria

The operation of two 60 m² solar air heaters serving a large studio teaching space has been monitored for a twelve month period. The solar contribution of the heaters was found to be less than 5%, and in some instances the heaters actually contributed to the space heating load. A validated mathematical model of the studio and it’s heating, ventilation and air conditioning system was used to investigate performance improvement strategies. It was found a different control strategy and recommissioned control sensors would substantially improve the solar air heater performance.

Sedation and analgesia management for mechanically ventilated adults: literature review, case study and recommentations for practice.

The quality of sedation management in mechanically ventilated patients has been a source of concern in recent years. This paper summarises the literature on the principles of optimal sedation, discusses the consequences of over and undersedation, highlighting the importance of appropriate pain management, and presents a case study using the results of an audit of 48 mechanically ventilated adults. As a result of the review and audit, we are implementing changes to practice.

The most important recommendations from the literature are the use of a sedation scale, setting of a goal sedation score, appropriate pain management and implementation of a nurse initiated sedation algorithm. Other recommendations include use of bolus rather than continuous sedative infusions and recommencing regular medications for anxiety, depression and other phychiatric disorders as soon as possible. A recommendation arising from our audit was the need to identify patients at high risk of oversedation and undersedation and adopt a proactive rather than reactive approach to management. The practice goal is to provide adequate and appropriate analgesia and anxiolysis for patients. This will improve patient comfort while reducing length of mechanical ventilation and minimising risk of complications.

A critical review of daily sedation interruption in the intensive care unit

Background. Daily sedation interruption (DSI) has been proposed as a method of improving sedation management of critically ill patients by reducing the adverse effects of continuous sedation infusions.

Aim. To critique the research regarding daily sedation interruption, to inform education, research and practice in this area of intensive care practice.

Design. Literature review.

Method. Medline, CINAHL and Web of Science were searched for relevant key terms. Eight research-based studies, published in the English language between 1995–December 2006 and three conference abstracts were retrieved.

Results. Of the eight articles and three conference abstracts reviewed, five originated from one intensive care unit (ICU) in the USA. The research indicates that DSI reduces ventilation time, length of stay in ICU, complications of critical illness, incidence of post-traumatic stress disorder and is reportedly used by 15–62% of ICU clinicians in Australia, Europe, USA and Canada.

Conclusions. DSI improves patients' physiological and psychological outcomes when compared with routine sedation management. However, research relating to these findings has methodological limitations, such as the use of homogenous samples, single-centre trials and retrospective design, thus limiting their generalisability.

Relevance to clinical practice. DSI may provide clinicians with a simple, cost-effective method of reducing some adverse effects of sedation on ICU patients. However, the evidence supporting DSI is limited and cannot be generalised to heterogeneous ICU populations internationally. More robust research is required to assess the potential impact of DSI on the physical and mental health of ICU survivors.

A time for real building performance measurement

The Mobile Architecture and Built Environment Laboratory (MABEL) was conceived upon the principle of investigating building environmental performance in situ. MABEL provides the first means of integrated, on-site measurement of the key aspects of internal built environments; energy, lighting, air quality, ventilation, acoustics and comfort using state-ofthe- art technology and instrumentation. The intention of this paper is to explain the how and what need to be measured in our buildings if we are to search of a genuine performance answer as well as the information to provide a solution. Several results of real building measurement are provided here, suggesting that a national program on 'as performing' is required if we are to proceed in a sustainable manner.

Lateral positioning for critically ill adult patients

We aim to assess the effect of the lateral position compared to other body positions on patient outcomes (mortality, morbidity and clinical adverse events during and following positioning) in critically ill adult patients. We will examine the single use of the lateral position (that is on the right or left side) and repeat use of the lateral position(s) in a positioning schedule (that is lateral positioning). We plan to undertake subgroup analysis for primary disease and condition, severity of illness, the presence of assisted ventilation and angle of lateral rotation.

Does an evidence-based sedation protocol improve practice and patient outcomes in critical care?

Learning Objective 1: compare protocol-directed sedation management with traditional non-protocol-directed practice in mechanically ventilated patients in an Australian critical care.

Learning Objective 2: explain the contrasting international research findings on sedation protocol implementation.
Minimization of sedation in critical care patients has recently received widespread support. Professional organizations internationally have published sedation management guidelines for critically ill patients to improve the use of research in practice, decrease practice variability and shorten mechanical ventilation duration. Innovations in practice have included the introduction of decision making protocols, daily sedation interruptions and new drugs and monitoring technologies. The aim of this study was to compare protocol-directed sedation management with traditional non-protocol-directed practice in mechanically ventilated patients in an Australian critical care setting.

A randomized, controlled trial design was used to study 312 mechanically ventilated adult patients in a general critical care unit at an Australian metropolitan teaching hospital. Patients were randomly assigned to receive protocol directed sedation management developed from evidence based guidelines (n=153) or usual clinical practice (n=159).

The median (95% CI) duration of ventilation was 58 hrs (44–78 hrs) for patients in the non-protocol group and 79 hrs (56–93) for those patients in the protocol group (p=0.20). Results were not significant for length of stay in critical care or hospital, the frequency of tracheostomies, and unplanned extubations. A Cox proportional hazards model estimated that protocol directed sedation management was associated with a 22% decrease (95% CI: 40% decrease to 2% increase, p=0.07) in the occurrence of successful weaning from mechanical ventilation.

Few randomized controlled trials have evaluated the effectiveness of protocol-directed sedation outside of North America. This study highlights the lack of transferability between different settings and different models of care. Qualified, high intensity nursing in the Australian critical care setting facilitates rapid, responsive decisions for sedation management and an increased success rate for weaning from mechanical ventilation.

Tracheostomy decannulation failure rate following critical illness : a prospective descriptive study

Background : Tracheostomy is a well established and practical approach to airway management for patients requiring extended periods of mechanical ventilation or airway protection. Little evidence is available to guide the process of weaning and optimal timing of tracheostomy tube removal. Thus, decannulation decisions are based on clinical judgement. The aim of this study was to describe decannulation practice and failure rates in patients with tracheostomy following critical illness.

Methods : A prospective descriptive study was conducted of consecutive patients who received a tracheostomy at a tertiary metropolitan public hospital intensive care unit (ICU) between March 2002 and December 2006. Data were analysed using descriptive and inferential tests.

Results : Of the 823 decannulation decisions, there were 40 episodes of failed decannulation, a failure rate of 4.8%. These 40 episodes occurred in 35 patients: 31 patients failed once, 3 patients failed twice and 1 patient failed three times. There was no associated mortality. Simple stoma recannulation was required in 25 episodes, with none of these patients readmitted to ICU. Translaryngeal intubation and readmission to ICU took place for the remaining 15 episodes. The primary reason for decannulation failure was sputum retention. Twenty-four patients (60%) failed decannulation within 24 h, with 14 of these occurring within 4 h.

Conclusions : Clinical assessments coupled with professional judgement to decide the optimal time to remove tracheostomy tubes in patients following critical illness resulted in a failure rate comparable with published data. Although reintubation and readmission to ICU was required in just over one third of failed decannulation episodes, there was no associated mortality or other significant adverse events. Our data suggest nurses need to exercise high levels of clinical vigilance during the first 24 h following decannulation, particularly the first 4 h to detect early signs of respiratory compromise to avoid adverse outcomes.

Improving comfort levels in Darwin houses through passive design

Darwin`s climate is hot and humid and as a result the use of residential air-conditioners is high. Although this technology allows the occupant to achieve thermal comfort, its use contributes directly to an increase in the emission of greenhouse gases. More environmentally-friendly ways of achieving residential thermal comfort in this climate need to be investigated. One method is to improve the home`s passive design. The aim of this research was to increase the thermal comfort of typical Darwin homes without the use of air conditioning. Temperature data from two houses (lightweight elevated and concrete) was recorded over a nine-day period and used to validate a TRNSYS simulation model of each house. Simulations were run using these validated models and three months of climatic data (January—March) to evaluate various passive design strategies. The success of three strategies was analysed using PMV and PPD indicators. As a single strategy, it was found that ventilation and air velocity by far increased the level of thermal comfort for occupants of both houses. Although the passive design strategies of increased shading and insulation were beneficial, Darwin`s ovemight low temperature and humidity are still too high to reduce these levels within the house significantly without air conditioning.

Oxygen delivery to patients after cardiac surgery : a medical record audit

OBJECTIVE: To describe how intensive care nurses manage the administration of supplemental oxygen to patients during the first 24 hours after cardiac surgery.
METHODS: A retrospective audit was conducted of the medical records of 245 adult patients who underwent cardiac surgery between 1 January 2005 and 31 May 2008 in an Australian metropolitan hospital. Physiological data (oxygen saturation measured by pulse oximetry and respiratory rate) and intensive care unit management data (oxygen delivery device, oxygen flow rate and duration of mechanical ventilation) were collected at hourly intervals over the first 24 hours of ICU care.
RESULTS: Of the 245 patients whose records were audited, 185 were male; mean age was 70 years (SD, 10), and mean APACHE II score was 17.5 (SD, 5.14). Almost half the patients (122, 49.8%) were extubated within 8 hours of ICU admission. The most common oxygen delivery device used immediately after extubation was the simple face mask (214 patients, 87%). Following extubation, patients received supplemental oxygen via, on average, two different delivery devices (range, 1-3), and had the delivery device changed an average of 1.38 times (range, 0-6) during the 24 hours studied. Twenty-two patients (9%) received non-invasive ventilation or high-flow oxygen therapy, and 16 (7%) experienced one or more episode of hypoxaemia during mechanical ventilation. A total of 148 patients (60%) experienced one or more episodes of low oxygenation or abnormal respiratory rate during the first 24 hours of ICU care despite receiving supplemental oxygen.
CONCLUSION: These findings suggest that the ICU environment does not protect cardiac surgical patients from suboptimal oxygen delivery, and highlights the need for strategies to prompt the early initiation of interventions aimed at optimising blood oxygen levels in cardiac surgical patients in the ICU.

Patients and nurses' perspective on oxygen therapy : a qualitative study

Aim. This paper is a report of a study to describe patients' and nurses' perspectives on oxygen therapy.
Background. Failure to correct significant hypoxaemia may result in cardiac arrest, need for mechanical ventilation or death. Nurses frequently make clinical decisions about the selection and management of low-flow oxygen therapy devices. Better understanding of patients' and nurses' experiences of oxygen therapy could inform clinical decisions about oxygen administration using low-flow devices.
Methods. Face-to-face interviews with a convenience sample of 37 adult patients (17 cardio-thoracic: 20 medical surgical) and 25 intensive care unit nurses were conducted from February 2007 to September 2007. Interviews were audio-taped, transcribed verbatim and then analysed using a thematic analysis approach.
Findings. The patients identified three key factors that underpinned their compliance with oxygen therapy: (i) device comfort; (ii) ability to maintain activities of daily living; and (iii) therapeutic effect. The nurses identified factors, such as: (i) therapeutic effect, (ii) issues associated with compliance, (iii) strategies to optimize compliance, (iv) familiarity with device, (v) triggers for changing oxygen therapy devices, as being key to the effective management of oxygen therapy.
Conclusion. Differences between the patients' and nurses' perspective of oxygen therapy illustrate the variety of factors that impact on effective oxygen administration. Further research should seek to provide a further in-depth understanding of the current oxygen administration practices of nurses and the patient factors that enhance or hinder effectiveness of oxygen therapy. Detailed information about nurse and patient factors that influence oxygen therapy will inform a sound evidence base for nurses' oxygen administration decisions.

Exposure to fumes and gases during welding operations

The exposure to fumes and gases is one of the hazards associated with welding operations. Apart from research conducted on the mechanism of fume and gas formation and the relationship between fume formation rates and common welding parameters, little is known about the exposure process during welding. This research project aimed to identify the factors that influence exposure, develop an understanding of their role in the exposure process and through this understanding formulate strategies for the effective control of exposure during welding. To address these aims a literature review and an experimental program was conducted The literature review surveyed epidemiological, toxicological and exposure data. The experimental program involved three approaches, the first, an evaluation of the factors that influence exposure by assessing a metal inert gas/mild steel welding process in a workshop setting. The second approach involved the study of exposure in a controlled environment provided by a wind tunnel and simulated welding process. The final approach was to investigate workplace conditions through an assessment of exposure and control strategies in industry. The exposure to fumes and gases during welding is highly variable and frequently in excess of the health based exposure standards. Exposure is influenced by a number of a factors including the welding process, base material, arc time, electrode, arc current, arc voltage, arc length, electrode polarity, shield gas, wire-to-metal-work distance (metal inert gas), metal transfer mode, intensity of the UV radiation (ozone), the frequency of arc ignitions (ozone), thermal buoyancy generated by the arc process, ventilation (natural and mechanical), the welding environment, the position of the welder, the welders stance, helmet type, and helmet position. Exposure occurs as a result of three processes: the formation of contaminants at or around the arc region; their transport from the arc region, as influenced by the entry and thermal expansion of shield gases, the vigorous production of contaminants, thermal air currents produced by the heat of the arc process, and ventilation; and finally the entry of contaminants into the breathing zone of the welder, as influenced by the position of the welder, the welders stance, helmet type, and the helmet position. The control of exposure during welding can be achieved by several means: through the selection of welding parameters that generate low contaminant formation rates; through the limitation of arc time; and by isolating the breathing zone of the welder from the contaminant plume through the use of ventilation, welder position or the welding helmet as a physical barrier. Effective control is achieved by careful examination of the workplace, the selection of the most appropriate control option, and motivation of the workforce.