Abstract This review is an update of anaesthesia for common elective paediatric ear, nose and throat (ENT) procedures. ENT is the most frequently performed surgery in children. These often-complex procedures are increasingly booked as day cases but judicious selection of suitable children is important. Suitability may be determined by preoperative assessment of co-morbidities, consequences of …
Abstract Echocardiography is the most widely used minimally invasive investigation to diagnose heart disease. Transoesophageal echocardiography (TOE) was first introduced perioperatively in the 1980s and is now an important monitoring tool for patients undergoing cardiac surgery. Because of the close proximity of the oesophagus to the heart, TOE facilitates the acquisition of high-resolution i…
Abstract Patients who have undergone previous organ transplantation represent a considerable therapeutic challenge to the anaesthetist. Although a transplant may have restored normal or near-normal function for that organ, the original underlying pathology often persists. In addition, undesirable effects of immunosuppressant drugs, particularly calcineurin inhibitors, may give rise to damage t…
Abstract The water contained in the body is divided amongst compartments of differing sizes and compositions. The dynamic balance across these compartments is an essential component of normal physiology. Here, the calculation of these volumes by measuring the dilution of markers able to permeate specific compartments is considered. Furthermore, the potential disadvantages to the approach are …
Abstract The immune system provides the body with both non-specific and specific defence against pathogens. It can recognize foreign from self. The immune system is composed of lines of defence and can mount responses by cellular and humoral mechanisms. It also has memory, allowing a quicker and heightened response on subsequent exposure. It achieves these effects by a complex interaction betw…
Abstract Epidural blocks can be performed at any level from the cervical spine down to the sacral hiatus. A lumbar epidural can provide surgical anaesthesia and postoperative analgesia for sub-umbilical surgery, whereas a thoracic epidural will provide effective analgesia but not anaesthesia for thoracic and upper abdominal surgery. A bolus epidural injection will last 2e4 hours, using a long-…
Abstract Suction devices have widespread uses in the clinical environment. The process of suction is the removal of fluid or other debris using a vacuum, and the properties of suction devices are governed by the physics of the flow of fluid through a tube. The rate of flow is dependent on the radius, length and pressure difference across the ends of the tube. A pump is used to create the vacuu…
Abstract Spinal anaesthesia is the injection of local anaesthetic into the subarachnoid space. It is a simple technique that can be used to provide surgical anaesthesia for procedures involving the abdomen, pelvis and lower limbs. To perform the technique safely it is important to understand the physiology of the block and the pharmacology of the drugs commonly used. Although serious complicat…
Abstract An awareness of what may constitute neglect or ill treatment to children and young people is important for all healthcare staff, and prevention of harm is everyone’s business. Whilst it is relatively unusual to see serious signs of abuse in a routine surgical context, anaesthetists also see children in many different settings and should be able clearly to communicate their concerns…
Abstract Patients who survive critical illness experience reduced health-related quality of life (HRQOL), impaired physical and cognitive functioning as well as psychological morbidity. These changes may be inter-connected and in part may relate to the loss of physical function at the time of critical illness. Rehabilitation of critically ill patients has largely focused on the post-acute and…
Abstract Regurgitation and aspiration remains one of the major complications of general anaesthesia. Aspiration is defined as oropharyngeal or gastric content entering the airway below the level of the vocal cords. This can cause morbidity and mortality by direct effects of the particulate, acidrelated damage and bacterial pneumonia. It occurs largely in patients with risk factors although occ…
Abstract Many surgical patients are taking drugs that impair normal coagulation, and this causes concern about the risk of perioperative bleeding events. The anaesthetist is particularly concerned about compressive vertebral canal haematomas, which may occur after spinal or epidural anaesthetic techniques. Fortunately, the risk of this complication is very low. The major risk factors are coagu…
Abstract It is possible to establish and maintain targeted blood and effect-site drug concentrations with reasonable accuracy using a ‘bolus, elimination, transfer’ (BET) infusion regimen. Simulation software that employs pharmacokinetic models can be used to drive infusion pumps or to design manually controlled BET infusions. Prolonged infusions can result in prolonged recovery times. How…
Abstract Cardiac surgical outcomes in the UK have consistently improved despite increasing procedure complexity and ‘sicker’ patients. Numerous anaesthetic techniques are employed with no definitive evidence clearly demonstrating superiority of one particular technique. Patient safety is paramount and various monitoring techniques used to enhance safety and ensure effective anaesthesia ar…
Abstract Venous thromboembolism is a major cause of perioperative morbidity and mortality. Immobilized medical patients are also at risk. Long-term sequelae represent a chronic health burden. Hospitalized patients should be assessed for their risk of thromboembolism and bleeding at regular intervals. Risk stratification, using recommended models can be used to guide the choice of thromboprophy…
Abstract Patients presenting for cardiac surgery pose many challenges for the anaesthetist. The clinician has to manage both the presenting cardiac pathophysiology and, increasingly, significant co-morbid disease. Thorough preoperative assessment, investigation and preparation allow identification of those patients at higher risk of perioperative complications, and permits development of indiv…
Abstract Paediatric anaesthesia can be challenging but careful preoperative assessment and preparation can make the process positive and successful for the child and their parents and rewarding for the anaesthetic team. During the preoperative assessment, we aim to gather information to plan our anaesthetic technique, assess risk, provide explanations and establish rapport. We describe below t…
Abstract Premedication is any drug or therapy administered before surgery. In the past this has mainly been used for the control of autonomic responses to anaesthetic agents, and for facilitating gas induction when this was the norm. Premedication declined from being almost universal until the 1980s to a much lower level today. The decline has been associated with a change in the type of preme…
Abstract Postoperative nausea and vomiting (PONV) remains a common clinical problem that increases patient morbidity, healthcare costs and affects patient satisfaction. This article outlines the physiology, reviews the available drugs and suggests a structure using risk stratification that helps to plan sensible clinical management. Keywords Antiemetics; nausea; risk stratification; vomiting
Abstract Most patients are ready to be transferred to a ward after 24e48 hours on a cardiac intensive care unit (CICU); however, several potential complications can occur during this period. The risks during transfer from theatre to CICU increase if a long distance is involved. A thorough handover to nursing staff is mandatory. Problems with blood pressure and arrhythmias are common on the CIC…
Abstract The physiology of nausea and vomiting is poorly understood. The initiation of vomiting varies and may be due to motion, pregnancy, chemotherapy, gastric irritation or postoperative causes. Once initiated, vomiting occurs in two stages, retching and expulsion. The muscles responsible for this sequence of events are controlled by either a vomiting centre or a central pattern generator,…
Abstract Patient recovery is the time from the end of anaesthesia/surgery to regaining full control of airway reflexes. During recovery immediate postoperative complications may arise. Major complications arise in 3e17% of inpatient surgical procedures. These complications should be managed either in theatre or in a designated recovery area (post-anaesthesia care unit). Keywords PACU; post-…
Abstract Anaesthesia inhibits a variety of the protective mechanisms which are usually in place to protect us from harm and prevent damage to vulnerable tissues. In addition, anaesthesia may impose physiological stresses on these tissues. Patients are often required to assume positions for surgery which would be intolerable without anaesthesia; these positions may introduce hazards which can l…
Abstract This article first outlines definitions and descriptions of key terms that will be used in the discussions that follow including osmolarity, osmolality, osmotic and oncotic pressure. The physicochemical properties of water, ions and organic molecules are discussed in terms of their biological roles. Similarly, the interactions of amphipathic molecules and their three-dimensional struc…
Abstract Solid organ transplant offers the hope of disease cure for hundreds of thousands of patients worldwide. Not only does it increase life expectancy and improve the quality of life, it unburdens health services and offers long-term financial savings. The clinician’s role in early identification and management of potential donors ensures that the maximum number of people can benefit fro…
Abstract Nosocomial infection in the intensive care unit (ICU) is associated with increased mortality, morbidity and length of stay. It is defined as infection that begins 48 hours after admission to hospital. The most common types are ventilator-associated pneumonia (VAP), central line-associated bloodstream infection (CLABSI), urinary catheter-related infection and surgical site infection. …
Abstract Medical gas production, storage and delivery is a complex process. Design of such a system must ensure that gas delivery is safe, convenient and cost-effective. This article reviews the production, storage and delivery of commonly used anaesthetic gases, following the gases from production to delivery. Keywords Cylinders; manifolds; medical gases; medical gas pipeline systems; vacu…
Abstract Mechanical support of the heart can be offered to patients who are refractory to pharmacological treatment, therapy for coronary or valvular disease or resynchronization therapy. Ventricular assist devices enable end-organ perfusion in the setting of heart failure. This can be temporary (as a bridge to recovery or transplantation) or permanent (destination therapy). Devices can be ex…
Abstract In the perioperative period patients tend to lose heat and become hypothermic. An understanding of the causes and prevention of heat loss is therefore important to the anaesthetist. Heat and temperature are measures of energy. Heat is a measure of the total kinetic energy (joules, J) of a body, and depends on the size of the body and its specific heat capacity. Temperature is a measur…
Abstract Severe sepsis is a heterogenous condition affecting multiple organ systems, and is commonly encountered in the hospital setting due to both community and nosocomial infections. Although the incidence of severe sepsis has increased over the past decades, there is evidence that mortality in developed world settings has improved. Management of the septic patient involves rapid evaluation…
Abstract Inotropes are a heterogenous group of drugs that modify calcium handling and alter the force of myocardial contraction. Catecholamines, and their synthetic analogues, increase intracellular calcium by activating cyclic adenosine monophosphate (cAMP) or inositol triphosphate (IP3). Phosphodiesterase inhibitors block phosphodiesterase 3, which in turn reduces catabolism of cyclic nucleo…
Abstract Injury or foreign invasion will instigate a cascade of events directed at eliminating the intruder and augmenting the healing process. This involves the uniting of two separate process (inflammatory and immune processes) to provide an effective host defence. Chemical mediators converge on the site of tissue damage and exert local and distant effects. The immune response is divided int…
Abstract General anaesthesia is a temporary state of unconsciousness that is induced to facilitate a therapeutic procedure. Induction is the first stage of a sequential process. It commences with patient preparation and assessment away from theatre, and continues in the safe and monitored environment of the anaesthetic room or operating theatre, where the administration of drugs and airwa…
Abstract Understanding the interaction of foreign tissue with the recipient immune system is key to improving results from organ transplantation. Responses are mediated by the humoral and cellular arms of the host immune system towards the tissues of the transplant. Unchecked this can lead to rejection of the graft. Improvements in immunosuppressive therapy have countered these reactions to a …
Abstract The immediate response to infection involves the innate immune system, which consists of many cell types and factors. The cells of the innate immune system include the different types of white blood cells and tissue residing cells such as macrophages and mast cells. This immediate response to infection involves an inflammatory response which locally causes vasodilation and increased v…
Abstract There is conclusive evidence that regional anaesthesia provides better postoperative analgesia than systemic opioid techniques. Regional anaesthesia also has the potential to improve the functional outcome from surgery, although proving this in a clinically relevant way is challenging; many studies are inconclusive with methodological weaknesses making comparison difficult and offerin…
Abstract Critical care clinicians are central to the organ transplantation process and therefore should be aware of the myriad ethical issues it raises. Organ donation can transform the lives of transplant recipients. However, it also warrants particular ethical scrutiny. Organ procurement is a procedure that cannot physically benefit the patient upon whom it is performed. Moreover, the poten…
Abstract Emergence and extubation are times of increased risk during anaesthesia. More complications occur then than at induction. The majority of problems are airway related due to airway obstruction, hypoxia, aspiration, airway trauma or post-obstructive pulmonary oedema. Other problems include a delayed recovery of consciousness, cardiovascular instability and delirium. Prompt identificatio…
Abstract The prescription of intravenous fluids is common in hospitalized patients and is increasingly ecognized as a potential source of harm if administered inappropriately. The recently published NICE guideline seeks to provide a simple and consistent approach to assessing, prescribing and reevaluating fluid status in sick patients. There has been a long-running debate regarding the optim…
Abstract Humidification is a process of adding water vapour to a volume of one or more gases. Natural humidification is achieved in the nasal cavity, but this process is often bypassed during anaesthesia and critical care. Various devices are used for artificial humidification, the most common is heat and moisture exchanger combined with a microbial filter. Electrically heated water baths may…
Abstract Anaemia is common in the ICU patient and is usually due to the interplay between many different factors. Although often this can be safely managed conservatively, red cell transfusion is commonly required. Patients who refuse blood products and patients with critical bleeding pose a particular management challenge. Coagulopathy is also frequently encountered in ICU. It is critical to …
Abstract Airway management provides gas exchange, protects the lungs from injury and permits treatment. This requires safe, effective and reliable use of equipment, often in combination. A management plan with backup plans is essential, but a sequence of logical plans forming an airway management strategy is better. Correct equipment use needs correct knowledge, skill and attitudes. There are …
Abstract There have been considerable developments in the equipment and monitoring available for paediatric anaesthesia over the past 3 years. Advances in airway management have come about primarily through the increased use of videolaryngoscopes. Numerous second-generation supraglottic airway devices are also now available with features aimed at improving both their safety profile and utilit…
Abstract Safe and effective drug therapy in neonates, infants and children require detailed knowledge about the ontogeny of drug disposition and action as well how these interact with genetics and co-morbidity of children. Recent advances in developmental pharmacology in children follow the increased understanding of the impact of growth and development on drug disposition (ADME: absorption, d…
Abstract The airway develops from the primitive foregut at four weeks’ gestation. Congenital anomalies may result when this process is abnormal. The anatomy of the airway at birth is uniquely different from older children and adults with a large tongue, long floppy epiglottis, large occiput and cephalad larynx. These features affect the technique required for facemask ventilation, supraglott…
Abstract Consent must be fully informed and freely given by a competent individual. Where the patient is a child, they can give their own consent provided they are competent to do so, otherwise it must be sought from someone with parental responsibility. This article discusses consent in children for both treatment and research. Keywords Capacity; children; competence; consent; parental re…
Abstract More than 7000 cardiopulmonary transplants were carried out worldwide in 2012 across the 388 centres reporting to the International Registry. The Registry of the International Society for Heart and Lung Transplantation reported 4196 heart transplants and 3812 lung transplants worldwide in 2012. The 100,000th heart transplant mark has been passed. Heart transplantation is a proven surg…
Abstract The primary function of the cardiopulmonary bypass (CPB) machine is maintaining systemic perfusion while the heart is under manipulation, its chambers are open or it suffers severe dysfunction. The CPB circuit consists of a reservoir, blood pump, oxygenator, heat exchanger, arterial filter, cardioplegia delivery device and cannulae, interconnected by various-sized tubing. Venous cannu…
Abstract The concept of brain and brain stem death developed from the observation of patients in apnoeic coma. Specific pre-conditions must be met before the diagnosis can be made through the clinical testing of brain stem function. Although the exact definition of brain death and some of the details for testing vary across the globe, the majority of tests carried out are similar. We define br…
Abstract Children with acute and chronic associated medical conditions often present for surgical and radiological procedures. An understanding of the implications of these conditions for anaesthesia is important in preventing perioperative adverse events. In this article, we outline the relevant clinical features of some of the commonly encountered associated medical conditions and provide g…