bluuebunny/crossref_metadata_2025 huggingface dataset:
When bad things happen
Authors: Khursandi Diana C Strange
Published: November 2020

When bad things happen, good communication skills and honesty are of supreme importance. Breaking bad news to patients, relatives or staff is never easy. Anaesthetists are most familiar with imparting bad news when they are working in a critical care unit, where the possibility of bad news is implicit. The necessity to do so in anaesthetic practice arises relatively infrequently. When patients are acutely unwell, elderly or frail prior to surgery, the patient and his or her family may be met with beforehand to signal a possible or probable unfavourable outcome related to natural disease processes. If the worst does happen, the patients and relatives will be somewhat prepared. Adverse incidents following anaesthesia require anaesthetists to be skilled in communicating honestly to the patient and relatives. These incidents can range from an unanticipated but treatable complication—for example, dural puncture—to an unexpected major mishap in theatre resulting in a serious adverse outcome (disability or death). Effective communication is as important when the issue is a more minor adverse outcome or side effect as it is when an adverse event has had disastrous consequences. Major mishaps in anaesthesia create stressful and difficult situations, since anaesthetists are required to communicate the bad news. Why is one anaesthetist’s day in court another anaesthetist’s invitation to dinner at a patient’s home? The good news is that breaking bad news is a skill that can be learned and taught. The initial ‘breaking bad news’ communication to the patient and/or relatives about the series of events in a serious adverse outcome will be more thoroughly followed up in the subsequent disclosure process. An investigation into the contributing factors in such events (root cause analysis) may need to occur, and staff members involved in the incident must be supported (critical incident support). Each department or group of anaesthetists should consider designating one of their number to respond to major adverse events. The ‘duty anaesthetist’ may be caught up with other clinical duties, and additional senior support will be required. One anaesthetist will be needed to manage ongoing clinical work, while another will be required to manage the aftermath.
Teaching and research
Authors: Richmond Susie , Smith Andrew F
Published: November 2020

This chapter is designed to give an overview of a number of specific situations in teaching and research relating to anaesthesia where communication skills may be useful. Whilst there are many others, these have been chosen because, in the authors’ experience, they are often unfamiliar or poorly performed, or assumed to be part of the ‘tacit’ skill set that cannot be formally taught. Perhaps the most important interaction that occurs between anaesthetists is that which occurs during teaching. Communicating with trainees in order to bring about a change in knowledge, skills and attitude is probably the most sophisticated form of communication anaesthetists employ other than the context of therapeutic communication with patients. Scant attention is often paid to the unconscious way in which anaesthetics trainees learn. Anaesthesia, like surgery, is learnt, not taught. Much of the beliefs, behaviours and attitudes that trainees acquire comes implicitly as they observe and copy their mentors’ actions. Part of becoming an anaesthetist involves the acquisition of ‘anaesthetic culture’—the sense of professional identity which may be either a positive or a negative one. When working with trainees, not only should they be taught the knowledge and skills to do the job, but, more importantly, senior anaesthetists should be modelling, and explicitly teaching them, better ways to interact with colleagues. It is far beyond the scope of this chapter to address the issues surrounding education in anaesthesia. However, it is useful to explore one aspect of teaching—that is, feedback in order to highlight some basic principles. Everyone loves feedback—so long as it is positive! No-one likes to feel that they are being unfairly, or even fairly, criticized. So how can anaesthetists give the feedback our trainees so desperately crave? As in all communication the key lies in establishing a rapport. Most trainees spend long enough in a department to establish a reasonable relationship with at least one or two trainers. It is difficult to give feedback to a trainee whose baseline capabilities are uncertain. … ‘Does he always make a pig’s ear out of arterial cannulation or is he just having a bad day? ’ …
Examination of the musculoskeletal system
Authors: Zengeya Stanley Tamuka , Serane Tiroumourougane V
Published: November 2020

The musculoskeletal examination, as for other systems, is best done in correlation with the medical history. You may be asked to examine the whole system, the spine, or a single joint. A structured approach is required, both for a screening examination and individual joint examination. Practise a systematic approach for presenting your findings, even if the examination is carried out in a different sequence from the one outlined here. Key competence skills required in the musculoskeletal examination are given in table 12.1. Musculoskeletal cases commonly encountered in the MRCPCH Clinical Exam are listed in table 12.2. Stepwise examination of the musculoskeletal examination is performed as follows: • visual survey (head to toe inspection) • screening examination of the musculoskeletal system: gait, arms, legs, spine (pGALS) • Examination of individual joints (hands and wrists, elbows, shoulders, head and neck, hips, knee, foot and ankle, spine):… • look • feel • move • measurements • assessment of function • joint-specific tests…. These steps are repeated in every system to reiterate their importance and to help you recollect the initial approach of any clinical exam. Also refer to chapter 4. • On entering the examination room, demonstrate strict adherence to infection control measures by washing your hands or by using alcohol rub. • Introduce yourself both to the parents and the child. • Talk slowly and clearly with a smile on your face. • Establish rapport with the child and parents. • Expose adequately while ensuring their privacy. Ideally, the child should be undressed to their underwear. If possible, watch the child undress. • Ask three important questions:… • Do you have pain anywhere? • Can you dress completely without difficulty? • Can you walk up and down the stairs without difficulty?... • Positioning: early in the examination, it is preferable to examine a younger child on their parent’s lap rather than on a couch. Useful information can be obtained by watching the child walk and play. Depending on the joint, examine an older child either in the sitting or lying position.
Forced Moves or Just Good Moves? Rethinking Environmental Decision-Making among East African Intensive Cultivators
Authors: Davies Matthew I. J.
Published: November 2020

There has been a tendency in archaeology and in related social sciences and humanities to view human cultures as simply ‘adapted’ to or ‘in tune’ with ‘nature’ (Binford 1962; Butzer 1982; Steward 1955a; White 1959). Nature in this view is difficult to define and is principally considered in opposition to culture; it is not culture, it is external to humans, and it has an active causality of its own. This is often true even when researchers have been considering phenomena with a distinctly ‘human’ flavour such as population growth or technological development; both have often been seen as ‘natural’ aspects of human behaviour, as things which ‘just happen’. In such thinking, when human societies are impacted by nature (conceived of as a phenomenon emanating from outside of the human realm) their responsive action or behaviour is often considered to be ‘forced’, in the sense that there is only one way in which society can respond and therefore that the nature of the change is inevitable. The idea that alternative actions might be as appropriate and effective, and equally likely, is given little credence—the specific nature of the response is taken as requisite and the form of the response goes unquestioned: human agency (choice) is given little opportunity to make its mark. Cause and effect are favoured over choice, opportunism, innovation, and dynamic decision making, while the environment is seen as external to culture and shaped by natural rather than cultural forces. Moreover, this logic is self-fulfilling; things occur as they do because the result was inevitable and only one course of action was possible; ergo the problem is solved! Of course I am here describing an extreme position and most researchers today would see a much more dynamic interaction between humans and the natural world. However, unicausal thinking does remain pervasive in popular accounts (Diamond 2005, 1997; Fagan 2007: 16–17; Scarre 2005: 35) and in much influential academic work where technology, environment, and ecology remain prime mover explanations, at least partially at the expense of variable responses, individual agency, politics, and ideology (Algaze 2008: 151–4; Demarest 2004: 27–30; Pollock 1999: 22–5; Webster 2002: 327–43).
Nature, Identity, and Disaster: Prehistoric Lake Dwelling in Central Europe
Authors: Leckie Katherine
Published: November 2020

Exploring human–environment relations has been an area of great interest to archaeologists, especially for the purpose of reconstructing past environments and investigating methods of human adaptation in the face of changing climates. However, despite the great fruitfulness of such research, particularly in raising awareness of the diversity of human practices, archaeologists often do not account for the influence that preconceived notions of human– environment relationships have in such reconstructions. In fact, archaeology can play a part in constructing or reinforcing Western perceptions of the environment, and as such, sometimes tell us more about our own associations with the natural world rather than informing us about those in the past (see Stump, Chapter 10 and Armstrong Oma, Chapter 11 this volume for similar statements). Using the example of the prehistoric Swiss lake dwellings, this chapter argues that preconceived notions of human–environment relations affect how we interpret and present the archaeological record and past communities. As a consequence, these presentist preconceptions can influence interpretations of the past, creating research trajectories that are monopolized by influential historic debates and obscure the potential subtleties to human interactions with the natural world. This chapter maintains that the environment often shapes cultural and community identities, both now and in the past, with implications for how such communities deal with environmental change or disaster. In fact, environmental change and risk can itself become inscribed into the cultural identities of the communities that inhabit such landscapes (see Fiore et al., Chapter 4 and Chevalier, Chapter 5 this volume for further discussion of environment and identity). Archaeologists must therefore approach the question of past human–environment relations by considering the place of the environment in the construction of community identities through the daily process of ‘living with nature’. Cogent arguments have been made for the inextricable relationship between culture and the environment and particularly for the way in which the environment is perceived through the process of ‘dwelling’ within it (Ingold 2000). Such work has opened up new avenues of investigation particularly in relation to the mutually constituting association between an environment and its inhabitants.
Past Changes in Ocean Carbonate Chemistry
Authors: Zeebe Richard E. , Ridgwell Andy
Published: November 2020

Over the period from 1750 to 2000, the oceans have absorbed about one-third of the carbon dioxide (CO2) emitted by humans. As the CO2 dissolves in seawater, the oceans become more acidic and between 1750 and 2000, anthropogenic CO2 emissions have led to a decrease of surface-ocean total pH (pH T) by ~0.1 units from ~8.2 to ~8.1 (see Chapters 1 and 3). Surface-ocean pHT has probably not been below ~8.1 during the past 2 million years (Hönisch et al. 2009). If CO2 emissions continue unabated, surface-ocean pH T could decline by about 0.7 units by 2300 (Zeebe et al. 2008). With increasing CO2 and decreasing pH, carbonate ion (CO32–) concentrations decrease and those of bicarbonate (HCO-3) rise. With declining CO32– concentration ([CO32–]), the stability of the calcium carbonate (CaCO3) mineral structure, used extensively by marine organisms to build shells and skeletons, is reduced. Other geochemical consequences include changes in trace metal speciation (Millero et al. 2009 ) and even sound absorption ( Hester et al. 2008 ; Ilyina et al. 2010 ). Do marine organisms and ecosystems really ‘care’ about these chemical changes? We know from a large number of laboratory, shipboard, and mesocosm experiments, that many marine organisms react in some way to changes in their geochemical environment like those that might occur by the end of this century (see Chapters 6 and 7). Generally (but not always), calcifying organisms produce less CaCO3, while some may put on more biomass. Extrapolating such experiments would lead us to expect potentially significant changes in ecosystem structure and nutrient cycling. But can one really extrapolate an instantaneous environmental change to one occurring on a timescale of a century? What capability, if any, do organisms have to adapt to future ocean acidification which is occurring on a slower timescale than can be replicated in the laboratory? Simultaneous changes in ocean temperature and nutrient supply as well as in organisms’ predation environment may create further stresses or work to ameliorate the effect of changes in ocean chemistry.
The Ocean Acidification Challenges Facing Science and Society
Authors: Turley Carol , Boot Kelvin
Published: November 2020

Human development, inspiration, invention, and aspiration have resulted in a rapidly growing population, with each generation aspiring to greater wealth and well-being, so having greater needs than the previous generation. Amongst the resulting negative impacts are over-exploitation of planetary resources and the build-up of gases in the atmosphere and oceans to the extent that they are changing earth’s climate and ocean chemistry (IPCC 2007). However, the history of humanity’s relationship to the environment has shown that, if threatened, society can respond rapidly to environmental risks, introducing better practices, controls, regulations, and even global protocols, for example the reduction of city smog, the move from leaded to unleaded petrol, and reduction of chlorofluorocarbon (CFC) production to reduce loss of the ozone layer. Nearly all of these changes have led to direct and obvious positive gain to human health and well-being which has been a driving force in the production, agreement and implementation of the policies and laws that have brought them about. The spatial scale or ‘ecological footprint’ of these risks has increased with time, such that international agreements and protocols, like the Montreal Protocol for CFCs, have been increasingly necessary for reducing them. Along with the globalization of agriculture, business, industry, and financial markets and the expansion of the human population goes the globalization of risk to the environment. Climate change and ocean acidification are global issues with solutions that are only possible through global agreements and action. Substantial proportions of nations’ gross domestic product (GDP) were used to secure the banks and major industries in the economic crises that have swept the world in the last few years, far greater than the 1 to 2% per annum estimated to be required to mitigate climate change (Stern 2006). However, the response to the economic crisis does show that global society can react rapidly when it believes it is necessary. The question is, when do society and governments deem it necessary to act, and to act together? One issue may be time, the perceived immediacy of the crisis.
Interview Preparation
Authors: Watkin Sara , Vincent Andrew
Published: November 2020

This chapter focuses on the preparation you will need to go through to be successful at the consultant interview. Many candidates wrongly think that the key to interview success is to know about everything political that has ever happened to the NHS or their speciality. Unfortunately this belief sets them up to be unsuccessful. The key is to take time to learn as much about yourself as possible so that you can use every interview question as an opportunity to promote why you should be given the job. In this chapter we explore: • An appropriate preparation plan • Key sales techniques • Key rules for answering questions effectively • Key tips for answering specific types of question, e.g. the negative question or the opinion question The preparation needed for answering political questions is addressed in Chapter 9. Guidance on how to approach answering questions within the interview itself is addressed in Chapter 6, e.g. not understanding the question asked. It goes without saying that the purpose of the interview is for the interview committee to appoint the right person for the job. In general this will be the person who they feel: • Will most fit with the ethos of the team, service and Trust • Is a safe doctor • Will be both a leader and a team player • Will proactively develop the service • Will work collaboratively with Trust management However, not all interview committees want all of the above in all cases. For instance, although many Trusts are currently looking for proactive, business-focused goal achievers (because there is a shortage!), some may simply want a quiet, methodical clinical professional. At the pre-interview visit it is vitally important to get a sense of what the key players really do want so that at interview you can effectively promote the benefits you will bring to the post in that regard. It is equally true that not all panel members are the same. Many panels are made up of people with divergent requirements.
Mathematics
Authors: Magee Patrick , Tooley Mark
Published: November 2020

Graphs are used to represent pictorially or clarify a relationship between two variables, say x and y, or t and function (t). If x and y are related by the linear equation y = mx + c, then the graphical relationship is a straight line as in Figure 1.1, where m is the slope, a constant value for a straight line and c is the value of y when x = 0. Figure 1.2 shows the relationship when m and c take negative values. Note that if c = 0, the line passes through the origin, 0, of the x–y axes. Examples of other linear relationships that can be represented in this way include the following (the bracketed symbols are the variables equivalent to x and y above): v = u + a t; (variables are t and v), where u is the starting velocity of an object that is subjected to acceleration a for time t, after which its velocity is v.
Thermodynamics: Heat, Temperature and Humidification
Authors: Magee Patrick , Tooley Mark
Published: November 2020

In continuing the concepts of energy and work, heat is a form of energy, and heat and work are related by the laws of thermodynamics. The first law states that the amount of mechanical work achievable out of a thermodynamic system going through a cyclic process is proportional to the amount of heat put into it, which is intuitive. The second law states that the amount of work gained from the system is always less than the amount of heat put into it; in other words there is some energy wasted, which is also believable. Heating a substance gives its constituent molecules increased kinetic energy, which can be put to mechanical use, for example in driving a turbine. Such an increase in energy either raises its temperature or changes its state. The increasing energy causes increasing velocity of movement of molecules and eventually breaks intermolecular bonds, giving the molecules more freedom of movement. As characteristic temperatures are reached, e.g. melting point or boiling point, the energy increase goes into changing the substance’s state into a more energetic one, e.g. solid to liquid, or liquid to gas, without any associated temperature change. Loss of heat from a substance involves the reverse processes. The gas laws have their origin in this concept of the kinetic theory of gases, and are an inherent part of consideration of the effects of heating and cooling, compression and expansion of gases. Pressure has been defined in Chapter 7, but to understand the concept, one that is taken for granted, it is necessary to start with the idea of molecules of matter undergoing a change in momentum (the physical definition of momentum being mass × velocity, see Chapter 3). It is unnecessary here to deduce the following equation, but the proof can be found in any physics or engineering text [Macintosh et al. 1987; Dorrington 1989; Hill 1976]).
Cardiac Output Measurement
Authors: Magee Patrick , Tooley Mark
Published: November 2020

The pulmonary artery catheter was the mainstay of clinical cardiac output measurement for many years, but because of its relatively invasive nature and the lack of improvement of clinical outcome with its use, it is now seldom used in a modern clinical environment. Any perceived accuracy of the technique is now considered unnecessary in the face of the risks of its use, and with the introduction of newer non-invasive techniques. Nevertheless, it is worth describing, partly because of its historical interest, and partly because of the technologies involved. A catheter passed into the right atrium from an easily accessible central vein can be passed through the right ventricle and out into the pulmonary arterial tree while the vascular waveforms are visualised. Figure 13.1 shows the waveforms as they appear to the user. A small balloon at the tip of the catheter allows it to be flow directed and wedged in a pulmonary arterial vessel. At this point the pulsatile waveform is lost and the tip of the catheter is looking ahead, down the pulmonary arterial tree towards the left atrium, a system with a relatively low pressure drop from one end to the other, the flow in that vessel having been brought temporarily to a standstill. Thus the pulmonary artery occlusion pressure (PAOP) or pulmonary capillary wedge pressure (PCWP) can be considered a reasonably accurate representation of left atrial pressure or left ventricular filling pressure. This assumes that there is no pulmonary vascular disease, such as pulmonary hypertension, or mitral valve disease, in which case PAOP would not be an accurate representation of left atrial pressure. If the catheter is placed in the apical region of the pulmonary vascular tree, the excess of the alveolar pressure in inspiration over pulmonary capillary pressure becomes significant, and the latter is a less accurate reflection of left atrial pressure. The balloon should not be over-inflated for fear of rupturing the pulmonary artery, and this is one of its perceived risks that has led to less usage. Once the measurement has been made, the balloon should be deflated so that the pulmonary arterial waveform is once again visible, if necessary withdrawing the catheter a bit to achieve this; failure to do so would result in regional lack of perfusion and may result in ischaemia.
Respiratory Gas Analysers
Authors: Magee Patrick , Tooley Mark
Published: November 2020

The purpose of respiratory gas analysis during anaesthesia is to identify and measure the concentrations, on a breath by breath basis, of the individual gases and vapours in use. It may also be useful as a guide to cardiac function or to identify trace contaminant gases. Different techniques use different physicochemical properties of the gas or vapour. An understanding of the physical principle underlying each method is necessary in order to recognise the value and limitations of each. In terms of the device’s ability to respond on a breath by breath basis, there are two important components: the time taken for the gas to be sampled from the anaesthetic machine or breathing system, the delay time; then there is the time taken for the device to measure the gas concentration, the response time. This is depicted in Figure 16.1. Most of the delay occurs in the delay time or transit time and can be reduced either by analysing the gas sample close to the airway, or by using as short and thin a sampling tube and as high a sampling flow rate to the analyser as possible [Chan et al. 2003]; the sampling flow rate is usually of the order of 100 to 200 ml min−1. If minimal fresh gas flow rates are being used in a circle anaesthetic breathing system and the sampled gas is not returned to the breathing system, then a high gas sampling rate could represent a significant gas leak. Figure 16.1 shows a sigmoid curve of recorded gas concentration change in response to a square wave input change. The response of a gas analyser is often expressed as the time taken to produce a 90–95% response to a step or square wave input change. A square wave change in gas concentration can be produced by moving a gas sampling tube rapidly into and out of a gas stream, by bursting a small balloon within a sampling volume containing a gas sample, or by switching a shutter to a gas sample volume using a solenoid valve. An important part of the use of gas analysers is zeroing and calibration since they are all prone to drift in both zero and gain.
Monitoring Depth of Anaesthesia
Authors: Magee Patrick , Tooley Mark
Published: November 2020

There are, and have been, many monitors designed to monitor depth of anaesthesia and to give an indication of awareness during surgery, which use electrical signals obtained from the human body. Some have been designed as just research devices, some have been available commercially, but have been withdrawn, and some are still available. Most, but not all, are based on the spontaneous EEG and the AER. Some have been designed to use properties of the ECG. Although useful, all of the discussed monitors have some shortcomings, and not all are 100% sensitive and specific to discriminate between consciousness and unconsciousness, and none correlate exactly with clinical states and levels of anaesthesia. The design of the commercial monitor, the Cerebral Function Monitor (CFM) was based on simple time domain measures already discussed [Maynard et al. 1969]. The CFM took the EEG from a single pair of parietal electrodes. The signal was amplified and passed through a band-pass filter and differentiator, which had the effect of accentuating the gain of the higher end of the 2–15 Hz pass band. The output of this specialised filter was integrated to produce a voltage output, which varied with time. It was plotted on a logarithmic scale. The trace on the paper gave an indication of the power of the EEG and the width of the line gave an indication of the signal’s variability. A schematic of an example of a CFM trace is shown in Figure 19.1(a). The CFM although useful did have its problems [Sechzer 1977]. When used to monitor depth of anaesthesia, the machine was shown to be unreliable, especially when using inhalational agents. The response is biphasic, as has already been discussed in chapter 18. Also burst suppression, as already discussed, is smoothed out by the action of the filtering in the CFM, so effectively the burst suppression can artificially elevate the readings producing a paradoxical rise in cerebral function [Sinha 2007] The machine was further developed into the Cerebral Function Analysing Monitor (CFAM)[Maynard 1984]. This machine produced two chart recorder outputs, as shown in Figure 19.1. There was a chart similar to the CFM trace, and also a chart that produced frequency domain data consisting of the EEG displayed as traditional EEG frequency bands.
Pacemakers and Defibrillators
Authors: Magee Patrick , Tooley Mark
Published: November 2020

Cardiac pacemakers and defibrillators are used to stimulate cardiac muscle directly. The pacemaker corrects for abnormalities in the heart rate (this can be fast or slow). Defibrillators are used to restore a fibrillating or tachycardic heart, to sinus rhythm. These are normally external, battery or mains powered, but can be internal devices, which are called Implantable Cardiac Devices (ICDs). Pacemakers that deal with bradycardia will be considered first. Normally a slow or irregular heart rhythm is caused by three types of heart block: ◆ First degree, where the delay at the AV junction is increased beyond the normal 0.2 s; ◆ Second degree, where a proportion of the depolarisation wave fails to pass through the AV junction; ◆ Complete block, where none of the depolarisation waves pass through the AV junction, and ventricular electrical activity is independent of supraventricular activity. In all these cases, the ventricles will beat at a slower or irregular rate. Dizziness or loss of consciousness may occur. The simplest pacemaker consists of three major components: batteries, the pulse generator, and the electrode leads. The pulse generator is required to provide a rectangular pulse. Typical parameters are the duration of 1 ms, a voltage of 5 V and capable of delivering a current of 10 mA. The power needed per second (if the pacemaker is on all the time) would be I 2R = 50 mW, for an electrode tissue resistance of 500 Ω. If the pacemaker is operating at 1 Hz (60 beats per minute), then the average power consumption would be 50 μW, as the pulse width is 1 ms (the pacemaker is on for 1/1000 of a second, and so the power consumption will be divided by 1000). A typical small battery has a capacity of 1 A h, so that this battery could supply the average current (10 μA) for about 11 years. The circuitry would also absorb power so that the battery life would drop to around 5 years. The batteries used are now commonly lithium iodide. The output pulse is applied to the tissue via an electrode. The electrode tip, which can screw in (or more unusually, is sown in), can be made of platinum, silver, stainless steel, titanium as well as various alloys.
Gas Supply and the Anaesthetic Machine
Authors: Magee Patrick , Tooley Mark
Published: November 2020

In Europe and other advanced medical communities, medical gases are generally supplied by pipeline, with cylinders available as back up. Large hospitals usually have oxygen supplied and stored in liquid form, since one volume of it provides 840 volumes of gaseous oxygen at 15◦C. It is stored in a secure Vacuum Insulated Evaporator (VIE) on the hospital site. The arrangement is shown in Figure 22.1. The VIE consists of an insulated container, the inner layer of which is made of stainless steel, the outer of which is made of carbon steel. The liquid oxygen is stored in the inner container at about−160◦C (lower than the critical temperature of−118◦C) at a pressure of between 700 and 1200 kPa. There is a vapour withdrawal line at the top of the VIE, from which oxygen vapour can go via a restrictor to a superheater, where the gas is heated towards ambient temperature. Where demand exceeds supply from this route, there is also a liquid withdrawal line from the bottom of the VIE, from which liquid oxygen can be withdrawn; the liquid can be made to join the vapour line downstream of the restrictor and pass either through the superheater or back to the top of the VIE. The liquid can also be made to pass through an evaporator before joining the vapour line. After passing through the superheater, the oxygen vapour is passed through a series of pressure regulators to drop the pressure down to the distribution pipeline pressure of 410 kPa. It should be remembered that no insulation is perfect and there is a pressure relief valve on top of the VIE in case lack of demand and gradual temperature rise results in a pressure build up in the container. There is a filling port and there is usually considerable wastage in filling the VIE; the delivery hose needs to be cooled to below the critical temperature, using the tanker liquid oxygen itself to cool the delivery pipe. The whole VIE device is mounted on a hinged weighing scale and is situated outside the hospital building, protected by a caged enclosure, which also houses two banks of reserve cylinders.
Intravenous Pumps and Syringe Drivers
Authors: Magee Patrick , Tooley Mark
Published: November 2020

Many infusions are given by gravity assisted, drip sets that give a flowrate dependent on the height of the reservoir above the patient, the length of the tubing, the bore of the IV cannula, the density and viscosity of the fluid being delivered, and the patient’s venous pressure. However there is an increasing tendency to use programmable volumetric intravenous pumps and syringe drivers to deliver intravenous anaesthesia, fluids, patient controlled analgesia, epidural infusions and other drugs. Not only are they programmable, but they can also be adjusted to give desired flowrates or volumes. Some infusion devices are powered only by gravity, but the flowrate is controlled by a photoelectric drip rate detector in conjunction with a microprocessor controlled drip occlusion device. Other infusion devices use a stepper motor to control the rate of infusion. A stepper motor is designed so that the rotation is by a fixed amount per supplied electrical pulse, independent of the mechanical load it is carrying. The pulses are controlled by a microprocessor in the pump and the rate of infusion is dependent on the stepper motor’s output. Syringe drivers are designed to use a range of syringe sizes and some require special delivery tubing. The flow is a continuous, pulsatile flow and accuracy is 2–5%. Some syringe drivers are driven by clockwork motors, others by a battery powered motor that is intermittently on and off, depending on required flowrate. The driving mechanism is usually by a screw threaded rod connected to the syringe plunger. Other syringe drivers use a stepper motor connected to the screw threaded rod. Care should be taken not to position the syringe driver above the patient’s venous cannula or the syringe may siphon a drug additional to that programmed on the driver, by virtue of the weight of the column of fluid in the tubing above the patient. Care should also be taken to avoid any bubbles in the syringe reaching the patient. Modern syringe drivers are usually sufficiently accurate over the desired range of infusion [Stokes et al. 1990]. However, there may be a delay before the drug is delivered to the patient as the parts attached to the syringe take up slack [O’Kelly et al. 1992].
Imaging and Radiation
Authors: Magee Patrick , Tooley Mark
Published: November 2020

This chapter explains in simple terms the background physics of imaging using standard X-rays, computed axial tomography (CT), nuclear medicine (including positron emission tomography-PET), and magnetic resonance imaging (MRI). It covers the basics of ionising radiation, and also discusses lasers, which are a form of non-ionising radiation (imaging using ultrasound is covered in Chapter 10). X-rays, CT, aspects of nuclear medicine, and lasers are covered briefly. MRI is examined in more detail as this is a newer modality that is often difficult to comprehend, and in any case often involves the presence of the anaesthetist. Some isotopes are naturally occurring but many of the radioactive nuclides used in medicine are produced artificially by a nuclear reactor or cyclotron. Each of these will provide isotopes that are useful for different purposes. Unstable radioactive nuclides achieve stability by radioactive decay, during which they can lose energy. This occurs in a number of ways. For example, atoms can lose energy by ejection of an alpha particle (an extremely tightly bound basic atomic structure of 2 protons and 2 neutrons, which is equivalent to a helium nucleus). This occurs if they have too many nucleons (protons or neutrons) and results in the atomic number being reduced by two and the atomic mass by 4. Other ways that unstable radionuclides decay include: emission of an electron (β−) from the nucleus if the atoms have an excess of neutrons, or by, either emitting a positron (β+) or capturing an electron if they are neutron deficient. Normally isotopes produced by a reactor will be neutron rich and decay by emitting an electron and the cyclotron will tend to produce isotopes that are proton rich and the decay will then be by emitting a positron. This is illustrated in Table 29.1. The new nuclide formed by the decay process (the daughter nuclide) may be left in an excited nuclear state and can release this excess energy by emission of gamma (γ) radiation as shown in Figure 29.1. This example is where the electron (β−) has been emitted. The situation is more complex when a positron has been emitted.
Infectious Diseases
Authors: Gupta Pawan
Published: November 2020

An infectious disease, as the name implies, is caused by pathogenic microorganisms such as bacteria, viruses, parasites, and fungi, and it spreads from one person to another through various ways, directly or indirectly. Most, but not all, of such diseases present to the ED with fever. Septic shock, respiratory failure, or central nervous system involvement may occur following an infection and threaten life. Such a situation presenting with tachycardia, reduced BP, tachypnoea, or depressed GCS requires immediate assessment and resuscitation. Following the principles of ABCDE, promptly carry out airway protection, oxygenation, and IV access with collection of blood samples for investigations, and fluid resuscitation. The aetiology of fever may be wide ranging, but a careful history and a detailed physical examination should help in determining the cause in majority of cases presenting to the ED. In addition to this, the initial investigations may help further in establishing the diagnosis. In elderly patients, the source of such infections may be the respiratory system, the genitourinary system or the involvement of the soft tissues, and they are often serious. In the otherwise healthy younger patient, one must keep in mind the other systems such as the central nervous system, as well as abdominal and soft tissue infections. Patients may often present in septic shock. Even if the cause of a fever may not be evident at the outset, the best ‘guestimate’ often helps in determining which antibiotics to start with, which should be given as soon as the culture samples have been collected. One must make every effort to collect appropriate samples of body fluids (blood, urine, stool, sputum, etc.) to find the source of infection so that targeted antimicrobial therapy may be started if the empirical treatment has not worked. A discussion with the on-call microbiologist to properly direct the empirical antibiotic therapy is often most rewarding. A patient with an infectious disease may put others at risk as well, resulting in devastating effects, particularly in hospitals.
Environmental Emergencies
Authors: Gupta Pawan
Published: November 2020

Environmental emergencies comprise acute exposure of human beings to extremes of temperature, electrical, and radiation injuries, drowning and diving, and high-altitude sickness. Of these, hypothermia, electrical injuries, and drowning are slightly more commonly encountered. However, there are some parts of the UK where scuba diving incidents are more frequent. The story of a physician surviving a temperature of 13.7°C after a 9h resuscitation effort, or various war tragedies in which thousands of soldiers died during cold exposure, etc., are well known. Hypothermia occurs when the core body temperature drops below 35°C, and the compensatory mechanism in a healthy individual is overwhelmed by the extreme exposure. This may be sometimes hastened by various types of medications affecting the thermoregulation. The management in the ED starts with basics (ABCDE). While the ABC and D are taken care of, an accurate measurement of temperature is essential, and most EDs do so by measuring an oesophageal, rectal, or bladder temperature, while the patient is being warmed. The common rhythm in a cardiac arrest associated with hypothermia is asystole. But if the patient is in VF, defibrillation is usually unsuccessful until the core temperature is well above 28–30°C. Therefore, rewarming continues alongside resuscitation and as the core temperature rises, defibrillation attempts should continue according to the UK resuscitation guidelines. The approximate death rate from drowning in the UK is 0.72/100 000 population per year. In 2005, of 435 deaths from drowning, 39 cases were between the ages of 0 and 14 years. Alcohol consumption in the vicinity of water is a major risk factor for morbidity or death by drowning. During the initial assessment, important details surrounding the incident should be obtained rapidly. The outcome of patients in cardiac arrest, who are often hypothermic as well, largely depends on how quickly CPR is initiated. The duration of CPR remains controversial in the hypothermic drowned patient—a safe approach is to continue until the core temperature reaches 35°C. This chapter includes questions on hypothermia, drowning, and some other environmental emergencies to give the reader an insight into the latest management of these situations.
Wounds, Fractures, Orthopaedics
Authors: Gupta Pawan
Published: November 2020

A significant number of patients attending the ED are those who are often referred to as ‘minors’, ‘streamers’, ‘walking wounded’, etc. These include patients with minor injuries, wounds, fractures or other soft tissue injuries. Therefore, a basic knowledge of anatomy and its application in various circumstances is mandatory. The injuries mentioned above are rarely life-threatening, but they may be limb-threatening and severely disabling. So it is extremely important to avoid errors in diagnosis and management, and to know when to ask for help at the appropriate time. By following the key principles listed below, you will be able to avoid many problems with such patients: • In the history, a detailed description of the mechanism of injury and the patient’s complaint will help in predicting the type of injury sustained. • A careful and thorough physical examination can point to the site and type of injury, on the basis of which appropriate radiological images can then be requested. • A neurovascular examination must be completed and documented in every limb injury, before and after any reductions, and before and after immobilization. • Appropriate radiological imaging, accompanied by a thorough physical examination, can pick up injuries with a high degree of accuracy. Inadequate radiographic films should not be accepted. • Immobilize the patient if a fracture is clinically suspected even if the X-rays are negative. • In cases of dislocations or subluxations, X-rays should be done before and after reductions, except when a delay could be potentially harmful to the patient (for example, when a severe traumatic deformity of a joint threatens to jeopardize the viability of the overlying skin). • The patient should be able to mobilize safely before being discharged from the ED. • Patients should be given proper aftercare instructions before leaving the ED, including how to look after themselves and to recognize limb-threatening features, the follow-up arrangement, and to return if things go wrong. • Ask for senior help if you are not sure about an injury or its management.
Eastern and Central Mediterranean
Authors: O'Brien William
Published: November 2020

Copper objects first circulated on the Greek mainland during the fifth millennium BC and shortly after in the islands of the southern Aegean (Zachos 2007). The earliest metalwork of Late Neolithic date comprised small objects such as awls, beads, and bracelets. Metal use gradually expanded during the Chalcolithic stage that followed, with production of larger items such as axeheads. There are parallels with the development of early metallurgy in the Balkans, however there was much less copper in circulation. This may be explained by the absence of early copper mines comparable to Rudna Glava or Ai Bunar in either Greece or the Aegean islands. The use of metal in the Aegean expanded significantly during the third millennium BC, with the emergence of a flourishing culture that had extensive seafaring contacts (Renfrew 1972). The importance of maritime trade in this region dates from the Neolithic when the island of Melos was a major source of obsidian across the east Mediterranean. Lead isotope analysis confirms that the copper, lead, and silver used by the Cycladic culture of the Early Bronze Age came from ore sources on many of those islands (Stos-Gale 1989). These metals were traded widely across the Aegean, with supply also into mainland Greece. While no copper mines have been identified, lead/silver workings of this period are recorded at Lavrion and at Ayios Sostis on Siphnos (Wagner et al. 1980). There are numerous deposits of copper ore and other metals in mainland Greece. No prehistoric copper mines have been identified; however, the potential has been examined by lead isotope analysis. An examination of various ore deposits in northern Greece, including examples in Thrace and eastern Macedonia, Thasos, the Pangeon Mountains, and Chalkidki did not reveal any likely sources of copper in prehistory. Samples were also taken in east-central Greece, from mineralization in the Othrys Mountains where there are several indications of ancient mining. Radiocarbon dates indicate copper mining at various locations there during the first millennium BC (Gale and Stos-Gale 2002: table 3).
France and The Western Alps
Authors: O'Brien William
Published: November 2020

The use of copper was first established in the western Alps during the late fifth/ early fourth millennia BC. There were several metal-using groups in what is now modern Switzerland during the fourth millennium, including the Cortaillod and Pfyn cultures, followed in the third millennium BC by groups of the Saône-Rhône culture (Strahm 1994). The first direct evidence of copper production, however, only dates from the Late Bronze Age. This is based on the dating of smelting slag heaps in the valley of Oberhalbstein in the canton of Graubünden (Fasnacht 2004). These slags derive from the smelting of chalcopyrite ore derived from pillow lavas of the ophiolite geology in that area (Geiger 1984). The ability to smelt iron-rich copper ore involved a furnace technology that seems to have been first developed in the eastern Alps (see Chapter 7). No prehistoric mines are known; however, their existence may be inferred from the smelting of local ore at Late Bronze Age sites such as Savognin-Padnal and Marmorera-Stausees in the Oberhalbstein valley. Potential mining sites have been identified (see Schaer 2003), however, these have yet to be investigated in any detail. There are numerous deposits of copper mineralization in many parts of France. These occur in Brittany, the Pyrenees, the Corbières, on the margins of the Massif Central, the Maures, and the Alps. Research over the past 30 years has identified prehistoric copper mines in several of these areas. Further discoveries are possible in the difficult terrain of the Alps and Pyrenees, and also in areas where early copper mines have not been discovered, such as Brittany where deposits of steam tin and gold are also known. The oldest metal objects in France are recorded in the Paris Basin, where a small number of sheet copper beads date to the second half of the fourth millennium BC. These include the burial at Vignely (Seine-et-Marne) where a necklace of nine such beads was found with the burial of a five-year old child dated to 3499–3123 BC (Allard et al. 1998).