bluuebunny/crossref_metadata_2025 huggingface dataset:
Sedatives and anti-anxiety agents in critical illness
Authors: Sessler Curtis N. , Muzevich Katie M.
Published: April 2016

Sedative and anti-anxiety agents are administered to many mechanically-ventilated intensive care unit (ICU) patients. While commonly considered supportive care, suboptimal administration of sedatives has been linked to longer duration of mechanical ventilation and longer ICU length of stay. The use of a structured multidisciplinary approach can help improve outcomes. The level of consciousness, as well as the presence and severity of agitation should be routinely evaluated using a validated sedation–agitation scale. The approach to delivery of sedation should be based upon specific goals, particularly mechanical ventilation, while maintaining the lightest possible level of sedation. Selection should be based upon clinical circumstances and patient characteristics, however, when continuous infusion sedation is required, experts suggest using non-benzodiazepine agents. A variety of strategies for sedation management have been demonstrated to be effective in clinical trials including use of protocols, targeting light sedation, preference of analgesics for initial therapy, use of intermittent, rather than continuous drug delivery when possible, and daily interruption of sedation. Finally, light sedation should be linked to performance of spontaneous breathing trials, as well as early mobilization.
Inhalational anaesthetic agents in critical illness
Authors: Beydon Laurent , Duc Flavie
Published: April 2016

Inhalational anaesthetic agents have limited applications in the intensive care unit (ICU), as their delivery requires specific equipment, which are not routinely available. Sevoflurane and isoflurane are the two agents eligible for this purpose. They both show good clinical tolerance and versatility, but may raise cerebral blood flow above 1 minimum alveolar concentration. This property makes them unsuitable for sedation in patients suffering from acute brain injury. Sevoflurane is known to be partly metabolized via the cytochrome pathway in inorganic fluoride. This latter accumulates in a dose- and time-dependent manner, especially in a closed circuit with soda lime. However, no clinical renal injury has been proven, despite several studies reporting on sevoflurane in ICUs. A fresh gas flow above 2 L/min is required to limit inorganic fluoride build-up. Halogenates have been proven to allow efficient sedation in ICU patients for up to several days. They may be considered as therapeutic agents especially in refractory status asthmaticus. Insufficient data exist to recommend halogenates to treat status epilepticus. Nitrous oxide, in 50% oxygen, may serve to allow sedation/analgesia for short and moderately procedures. Xenon, an inert gas that discloses anaesthetic properties with extremely fast onset and recovery, and also has no haemodynamic side effects remains confined to the operating theatre. It requires specific anaesthetic machines and is, at present, too expensive to represent a routine inhalational anaesthetic agent.
Cardiac massage and blood flow management during cardiac arrest
Authors: Perkins Gavin D.
Published: April 2016

When cardiac arrest occurs, blood flow to the vital organs diminishes rapidly. Chest compressions are an essential element of cardiopulmonary resuscitation (CPR), yet they achieve, at best, one-third of the normal cardiac output. The speed of initiating CPR, as well as its quality is critical to patient outcomes. Optimal chest characteristics of compressions are defined as pushing hard (depth > 5 cm) and fast (compression rate 100–120/min). Pressure should be released fully between sequential chest compressions and interruptions in chest compressions should be minimized. Even short interruptions in CPR around the time of attempted defibrillation can be harmful. CPR feedback and prompt devices can be used to monitor the quality of CPR. Studies have shown these devices can improve the quality of CPR, but do not improve overall survival. Mechanical chest compression devices may be usefully deployed when it is difficult or unsafe to perform manual CPR, but there is no evidence that the routine deployment of these devices improves outcome. Vasoactive drugs improve coronary perfusion pressure and increase the chances of return of spontaneous circulation. However, there is no definitive evidence that they improve long-term survival. Recent data have raised the possibility that adrenaline may worsen long-term outcomes.
Management after resuscitation from cardiac arrest
Authors: Nolan Jerry P. , Parr Michael J. A.
Published: April 2016

Systemic ischaemia during cardiac arrest and the reperfusion response after return of spontaneous circulation (ROSC) cause the post-cardiac arrest syndrome (PCAS). The severity and duration of this syndrome is determined by the cause and duration of cardiac arrest, quality of resuscitation, and interventions after ROSC. Four key clinical components are recognized—post-cardiac arrest brain injury, myocardial dysfunction, other organ ischaemia/reperfusion (e.g. liver, kidney), and potential persistence of the precipitating pathology causing the cardiac arrest. The interventions applied after ROSC impact significantly on the quality of survival. All components of the PCAS need to be addressed if outcome is to be optimized; treatment should start immediately after ROSC. An ‘ABCDE’ (Airway, Breathing, Circulation, Disability, Exposure) systems approach is used to identify and treat physiological abnormalities and organ injury. All survivors of out-of-hospital cardiac arrest should be considered for urgent coronary angiography unless the cause of cardiac arrest is clearly non-cardiac or continued treatment is considered futile. Targeted temperature management (mild hypothermia and avoidance of hyperthermia) should be considered for those patients who remain comatose after ROSC. If targeted temperature management has been used, early prognostication on outcome is unreliable and should be delayed until 3 days after return to normothermia; it should not rely on just one modality.
Pulse oximetry and capnography in the ICU
Authors: Lee Richard
Published: April 2016

The estimation of arterial oxygen saturation by pulse oximetry and arterial carbon dioxide tension by capnography are vital monitoring techniques in critical care medicine, particularly during intubation, ventilation and transport. Equivalent continuous information is not otherwise available. It is important to understand the principles of measurement and limitations, for safe use and error detection. PETCO2 and oxygen saturation should be regularly checked against PaCO2 and co-oximeter SO2 obtained from the blood gas machine. The PECO2 trace informs endotracheal tube placement, ventilation, and blood flow to the lungs. It is essential their principles of estimation, the information gained and the traps in interpretation are understood.
Gas exchange principles in the critically ill
Authors: Wagner Peter D.
Published: April 2016

Pulmonary gas exchange in the critically-ill patient is almost always impaired. The reasons are usually multiple and complex, with causes both internal and external to the lung. To understand the relative contributions of these many factors in a given patient requires an understanding of the basic principles of gas exchange. This becomes even more important when a patient’s condition changes quickly, which happens commonly in the critically ill. The purpose of this chapter is to lay out those principles and discuss the several causes of arterial hypoxaemia (and hypercapnia) on the basis of those principles. The key principle that governs gas exchange (in the steady state) is conservation of mass, and writing straightforward mass transport equations that express this principle allows gas exchange to be analysed quantitatively. This chapter is intended to serve as a guide to support appropriate application of tests of pulmonary gas exchange, which are laid out in the chapter that immediately follows it.
Respiratory muscle function in the critically ill
Authors: Vassilakopoulos Theodoros , Roussos Charis
Published: April 2016

The inspiratory muscles are the diaphragm, external intercostals and parasternal internal intercostal muscles. The internal intercostals and abdominal muscles are expiratory. The ability of a subject to take one breath depends on the balance between the load faced by the inspiratory muscles and their neuromuscular competence. The ability of a subject to sustain the respiratory load over time (endurance) depends on the balance between energy supplied to the inspiratory muscles and their energy demands. Hyperinflation puts the diaphragm at a great mechanical disadvantage, decreasing its force-generating capacity. In response to acute increases in load the inspiratory muscles become fatigued and inflammed. In response to reduction in load by the use of mechanical ventilation they develop atrophy and dysfunction. Global respiratory muscle function can be tested using maximum static inspiratory and expiratory mouth pressures, and sniff pressure. Diaphragm function can be tested by measuring the transdiaphragmatic and twitch pressures developed upon electrical or magnetic stimulation of the phrenic nerve.
Indications for mechanical ventilation
Authors: MacIntyre Neil R.
Published: April 2016

Mechanical ventilation is indicated when the patient’s ability to ventilate the lung and/or effect gas transport across the alveolar capillary interface is compromised to point that harm is imminent. In practice, this means addressing one or more of three fundamental pathophysiological processes—loss of proper ventilatory control, ventilatory muscle demand-capability imbalances, and/or loss of alveolar patency. A fourth general indication involves providing a positive pressure assistance to allow tolerance of an artificial airway in the patient unable to maintain a patent and protected airway. The decision to initiate mechanical ventilation usually involves an integrated assessment that should include mental status, airway protection capabilities, ventilatory muscle load tolerance, spontaneous ventilatory pattern, and signs of organ dysfunction from either acidosis and/or hypoxaemia. Providing mechanical ventilatory assistance can be life-sustaining, but it is associated with significant risk, including ventilator-induced lung injury, infection, and need for sedatives/paralytics, and must be applied only when indications justify the risk.
Setting rate, volume, and time in ventilatory support
Authors: Oliver Charles M. , Moonesinghe S. Ramani
Published: April 2016

Ventilator rate, volume, and time parameters are interrelated directly, mechanically, and physiologically, and interactions between intrinsic pulmonary physio-mechanics, pathology and the effects of mechanical ventilation complex. The physiological consequences of mechanical ventilation and risks of ventilator-induced trauma may be exacerbated by lung pathology. Programming of ventilator parameters should be considered within the context of an individualized ventilatory strategy to achieve adequate gas exchange, while minimizing attendant risks of mechanical ventilation. Recommended strategies should be modified within accepted limits to mitigate disease-specific risks. Parameters should subsequently be titrated against blood gas- and ventilator-derived targets, and other clinical variables.
Pathophysiology and causes of airflow limitation
Authors: Tuxen David V.
Published: April 2016

Exacerbations of asthma or chronic obstructive pulmonary disease (COPD) can be life-threatening emergencies, and require careful management to minimize the risks of morbidity and mortality. Prompt, full bronchodilator therapy, careful observation and appropriate mechanical ventilation technique is required. Dynamic hyperinflation of the lungs occurs in all patients, and must be careful assessed and regulated. Excessive dynamic hyperinflation can result in respiratory tamponade, hypotension, circulatory failure, pneumothoraces and, in severe cases, cardiac arrest. Intravenous or continuous nebulized salbutamol commonly causes lactic acidosis that should be detected and managed. Prolonged paralysis during difficult mechanical ventilation can result in severe necrotizing myopathy. Pneumothoraces in ventilated patients with asthma are usually under tension, redistribute ventilation to the contralateral lung, and risk a second tension pneumothorax. Patients surviving mechanical ventilation for asthma and COPD have an increased risk of recurrence and death. All these problems require awareness, avoidance or detection and management
Pathophysiology and therapeutic strategy of respiratory acidosis
Authors: Gattinoni Luciano , Lissoni Alfredo
Published: April 2016

Out of 15–30 × 10–3 moles/day of protons derived from the hydration of CO2 only 40–60 × 10–9 moles/day remain unbounded in the plasma. If the CO2 production exceeds the excretion, the CO2 content in plasma and tissue rises (respiratory acidosis) until a new equilibrium is reached. In fact, doubling the PCO2 may compensate the halving of alveolar ventilation with unchanged excretion of the CO2 metabolically produced. Body reacts to respiratory acidosis increasing the secretion of chloride associated with ammonium. The process leads to an increase of bicarbonate in the plasma with an associated increase of pH. All the steps described may be altered in critically-ill patients due to hyper-metabolism, decreased excretion, decreased content of buffering proteins and impaired kidney response. Several options are available for therapy, from mechanical ventilation to artificial lung, up to lung transplant, depending on the severity of clinical conditions and their possible reversibility.
Pathophysiology and causes of haemoptysis
Authors: Blasi Francesco , Tarsia Paolo
Published: April 2016

The main goal of management of pleural effusion is to provide symptomatic relief removing fluid from pleural space and the options depend on type, stage and underlying disease. The first diagnostic instrument is the chest radiography while ultrasound can be very useful to guide thoracentesis. Pleural effusion can be a transudate or an exudate. Generally a transudate is uncomplicated effusion treated by medical therapy, while an exudative effusion is considered complicated effusion and should be managed by drainage. Refractory non-malignant effusions can be transudative (congestive heart failure, cirrhosis, nephrosis) or exudative (pancreatitis, connective tissue disease, endocrine dysfunction), and the management options include repeated therapeutic thoracentesis, indwelling pleural catheter for intermittent external drainage, pleuroperitoneal shunts for internal drainage, or surgical pleurectomy. Parapneumonic pleural effusions can be divided in complicated when there is persistent bacterial invasion of the pleural space, uncomplicated and empyema with specific indications for pleural fluid drainage. Malignancy is the most common cause of exudative pleural effusions in patients aged >60 years and the decision to treat depends upon the presence of symptoms and the underlying tumour type. Options include indwelling pleural catheter drainage, pleurodesis, pleurectomy and pleuroperitoneal shunt. Hemothorax needs to be differentiated from a haemorrhagic pleural effusion and when is suspected the essential management is the intercostal drainage. It achieves two objectives to drain the pleural space allowing expansion of the lung and to allow assessment of rates of blood loss to evaluate the need for emergency or urgent thoracotomy.
Central venous pressure monitoring in the ICU
Authors: Magder Sheldon
Published: April 2016

Central venous pressure (CVP) is at the crucial intersection of the force returning blood to the heart and the force produced by cardiac function, which drives the blood back to the systemic circulation. The normal range of CVP is small so that before using it one must ensure proper measurement, specifically the reference level. A useful approach to hypotension is to first determine if arterial pressure is low because of a decrease in vascular resistance or a decrease in cardiac output. This is done by either measuring cardiac output or making a clinical assessment blood flow. If the cardiac output is decreased, next determine whether this is because of a cardiac pump problem or a return problem. It is at this stage that the CVP is most helpful for these options can be separated by considering the actual CVP or even better, how it changed with the change in cardiac output. A high CVP is indicative of a primary pump problem, and a low CVP and return problem. Understanding the factors that determine CVP magnitude, mechanisms that produce the components of the CVP wave form and changes in CVP with respiratory efforts can also provide useful clinical information. In many patients, CVP can be estimated on physical exam.
Pulmonary artery catheterization in the ICU
Authors: Orenbuch-Harroch Efrat , Sprung Charles L.
Published: April 2016

Haemodynamic monitoring is a significant component in the management of critically-ill patients. Flow-directed pulmonary artery catheters (PAC) are a simple and rapid technique for measuring several continuous or intermittent circulatory variables. The PAC is helpful in diagnosis, guidance of therapy, and monitoring therapeutic interventions in various clinical conditions, including myocardial infarction and its complications, non-cardiogenic pulmonary oedema and severely ill patients.The catheter is inserted through a large vein. The PAC is advanced, after ballooninflation with 1.5 mL of air, through the right ventricle across the pulmonary valve and into the pulmonary artery (PA). Finally, the catheter is advanced to the ‘wedge’ position. The pulmonary artery wedge pressure (PAWP) is identified by a decrease in pressure combined with a characteristic change in the waveform. The balloon should then be deflated and the PA tracing should reappear. Direct measurements include central venous pressure, pulmonary artery pressure, and PAWP, which during diastole represents the left ventricular end-diastolic pressure and reflects left ventricular preload. Cardiac output can be measured by thermodilution technique. Other haemodynamic variables can be derived from these measurements. Absolute contraindications are rare. Relative contraindications include coagulopathy and conditions that increase the risk of arrhythmias.
Measurement of extravascular lung water in the ICU
Authors: McAuley Danny F. , Craig Thelma Rose
Published: April 2016

The accumulation of fluid in the interstitium and alveolar space is known as extravascular lung water (EVLW). EVLW is associated with increased morbidity and mortality in critically ill patients and is elevated in patients with cardiogenic pulmonary oedema, acute lung injury (ALI), and the acute respiratory distress syndrome (ARDS). Pulmonary oedema is a consequence of increased pulmonary capillary hydrostatic pressure and/or an increased capillary permeability. The quantity of pulmonary oedema fluid is dependent on the balance of fluid formation and clearance, and this contributes to the overall dynamic net lung fluid balance. Measurement of EVLW is therefore an indirect surrogate measurement of the alveolar epithelial and endothelial damage in ALI/ARDS. The single indicator transpulmonary thermodilution technique is an available bedside technique to measure EVLW.
Diagnosis and management of non-STEMI coronary syndromes
Authors: Erlinge David , Olivecrona Göran
Published: April 2016

Acute coronary syndromes are classified as ST segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI) or unstable angina. Most patients with NSTEMI present with a history of chest pain that has subsided spontaneously before or soon after arrival at the emergency room, but with positive cardiac markers (usually troponin T or I) indicative of myocardial infarction. NSTEMI has a risk of recurrent myocardial infarction of 15–20% and a 15% chance of 1-year mortality. Patients with non-STE-acute coronary syndromes are at similar risk as a STEMI patient at 1 year. The strongest objective signs of NSTEMI are a positive troponin and ST segment depression. NSTEMI should be acutely treated with aspirin, an adenosine diphosphate-receptor antagonist, and an anticoagulant (fondaparinux or low molecular weight heparins). NSTEMI should be investigated with coronary angiography within 72 hours. Curative treatment is percutaneous coronary intervention or coronary artery bypass grafting.
Diagnosis and management of ST-elevation of myocardial infarction
Authors: Erlinge David , Olivecrona Göran
Published: April 2016

ST-elevation myocardial infarction (STEMI) is generally caused by a ruptured plaque that triggers local thrombus formation, which occludes the coronary artery. STEMI should be diagnosed rapidly, based on the combination of ST-segment elevation and symptoms of acute myocardial infarction. The main treatment objective is myocardial tissue reperfusion as quickly as possible. The preferred method of reperfusion is primary percutaneous coronary interventionif transport time is below 2 hours, and thrombolysis if longer STEMI patients with acute onset cardiogenic shock should be evaluated by echocardiography to exclude mechanical complications, such as flail mitral insufficiency, ventricular septal defect or tamponade. Secondary prevention includes aspirin, adenosine diphosphate receptor antagonists, statins, beta-blockers, angiotensin-converting enzymeinhibitors, and lifestyle changes.
Pathophysiology of shock
Authors: Kimmoun Antoine , Levy Bruno
Published: April 2016

Shock remains a major cause of intensive care unit admission. Initially categorized into hypovolaemic, cardiogenic, and distributive shock, understanding of the pathophysiology has recently evolved such that tissue hypoperfusion in all shock states leads to a dysregulated inflammatory response. After 24 hours, septic shock and ischaemiareperfusion related to hypovolaemic and cardiogenic shock share similar haemodynamic and pro-inflammatory profiles. Vascular hyporesponsiveness to catecholamines is a major consequence of this common pathophysiology, which is focused upon activation of NF-κ‎b with subsequent NO overproduction. Myocardial dysfunction is a frequent complication of the cytokine storm that follows septic shock and ischaemiareperfusion. It may worsen haemodynamic status, but nevertheless, remains transient and totally reversible.
Causes and diagnosis of valvular problems
Authors: Deen Jason F. , Stout Karen K.
Published: April 2016

While valvular heart disease encountered in developing countries is primarily rheumatic in aetiology, in industrialized countries it is largely comprised of degenerative valvular disease. Although less prevalent than ischaemic heart disease, its prevalence increases with older age and increased life expectancy, and therefore represents significant disease burden in aging populations. Transthoracic echocardiography remains the imaging modality of choice for timely delineation of the anatomy and severity of the lesion,although, once identified, may not correlate with symptoms due to clinical latency of disease onset to disease manifestation. Variations of disease severity, which may not meet criteria for intervention, lead to chronicity of disease, while clinically silent lesions may remain undiagnosed—both of these situations may lead to acute illness requiring intensive care management. Stabilization through medical intervention may be required, although many patients with severe disease will need emergent surgical repair, therefore collaborative involvement between intensivists, cardiologists, and cardiovascular surgeons is needed to minimize patient mortality and morbidity.
Management of severe hypertension in the ICU
Authors: Levy Jerrold H.
Published: April 2016

Hypertensive urgencies and emergencies have not been sufficiently studied, but are important clinical problems in critically-ill patients. A hypertensive emergency episode can lead to further end-organ dysfunction or death. One of the biggest challenges in managing a hypertensive emergency is determining and maintaining the ideal range of blood pressure (BP), and avoiding overshoot for each individual patient. Haemodynamic instability including overshoot hypotension may also lead to organ ischaemia and adverse outcomes—to avoid these problems, appropriate and careful BP control is critical. This notion has always been perceived as important, but increasing evidence supports the role for appropriate therapy.
Diarrhoea and constipation in the critically ill
Authors: Dobb Geoffrey J.
Published: April 2016

The diagnosis of intra-abdominal hypertension (IAH)/abdominal compartment syndrome (ACS ) relies on accurate IAP measurement. The current gold standard for measurement is intermittently every 4–6 hours via the bladder. IAP monitoring should be performed in all critically-ill or injured patients exhibiting ≥1 risk factors for the development of IAH, and continued until risk factors are resolved and intra-abdominal pressure (IAP) has remained normal for 24–48 hours. IAH and ACS cause organ dysfunction through direct compression of the heart, compression of both arterial and venous perfusion of the abdominal organs, and abdomino-thoracic pressure transmission. All organ systems are affected by IAH-induced injury. Standard surgical treatment of established ACS not responding to non-invasive management consists of decompressive laparotomy via midline or transverse incision. Promising alternative surgical strategies are being developed to avoid the complications of the open abdomen.
Management of acute or chronic hepatic failure in the critically ill
Authors: O’Brien Alastair
Published: April 2016

Acute on chronic liver failure is characterized by an acute deterioration of liver function in a patient with previously compensated cirrhosis secondary to a precipitating event. It is most commonly associated with a very poor prognosis and early identification of the precipitating cause is essential to successfully attempt to reverse decompensation. The most common precipitant is infection and a high index of suspicion is required. Other management is largely supportive with close attention to renal dysfunction being particularly important. All patients admitted to the intensive care unit with complications of cirrhosis warrant consultation with a transplant centre to determine whether they fulfil the criteria for transplantation and for expert advice.
Imaging the urinary tract in the critically ill
Authors: Lewington Andrew , Weston Michael
Published: April 2016

Imaging the urinary tract of patients in the intensive care unit (ICU) may assist identifying the cause of acute kidney injury (AKI). By the nature of their illness patients on ICU will often be clinically unstable and this will restrict the choice of imaging. Ultrasound is the most commonly used non-invasive imaging technique used, and is essential for assessing renal anatomy, determining kidney size and the presence of obstruction. New developments hold much promise and there are a number of centres now using this technology. Doppler ultrasonography has become increasingly popular to assess intrarenal blood flow. CT scanning can be used with or without contrast when ultrasonography is non-diagnostic and is very useful in identifying calcification within the renal tract. However, the patient must be stable enough for transfer to the radiology department. It is important to consider the risk of iodinated contrast-induced AKI (CI-AKI) in critically-ill patients and minimize potential renal injury. Magnetic resonance imaging may be preferred where there is risk of CI-AKI, but the logistics may prove even more demanding. Renal arteriography is rarely performed, but may be required for diagnostic and interventional procedures for renal artery stenosis or sites of active haemorrhage.
The effect of renal failure on drug handling in critical illness
Authors: Munar Myrna Y. , Olyaei Ali J.
Published: April 2016

The kidneys play an important role in the elimination of many drugs. In chronic kidney disease and acute kidney injury several pharmacokinetic processes are altered. Thus, patients with impaired renal function require adjustment of medication dosing. Many drugs require a loading dose to rapidly achieve therapeutic plasma concentrations. Subsequently, the dose or dosing interval may have to be adjusted as appropriate for the degree for renal function. The most common method to estimate renal function is use of the Cockcroft–Gault (CG) equation. It has been well validated, is easy to remember, and is fairly accurate in estimating kidney function. Most drugs are dosed based on the patient’s weight (mg/kg), which makes the CG method easier to use for most estimates. Other methods are available and a patient’s renal function should always be estimated based on the best available evidence for that specific patient. Patients with chronic kidney disease are at great risk of developing kidney injury from drugs or diagnostic agents. Exposure to nephrotoxins should be avoided as much as possible.
Intracranial pressure monitoring in the ICU
Authors: Rhodes Jonathan K. J. , Andrews Peter J. D.
Published: April 2016

Intracranial pressure (ICP) measurement is an established monitoring modality in the ICU and can aid prognostication after acute brain injury. ICP monitoring is recommended in all patients with severe traumatic brain injury (TBI), and an abnormal cranial computed tomographic (CT) scan and the ability to control ICP is associated with improved outcome after TBI. The lessons from TBI studies can also be applied to other acute pathologies of the central nervous system where ICP can be increased. ICP measurement can warn of impending disaster and allow intervention. Furthermore, measurement of ICP allows the calculation of cerebral perfusion pressure (CPP) and maintenance of CPP may help to ensure adequate cerebral oxygen delivery. Various systems exist to monitor ICP. A recent trial in two South American countries suggested that ICP-guided management and management guided by clinical examination and repeated imaging produced equivalent outcomes. Although this trial currently provides the best evidence regarding the impact of monitoring ICP on outcome following TBI, but because of the inadequate power and questionable external validity, the generalizability of the results remain to be confirmed.
Pathophysiology and therapeutic strategy for sleep disturbance in the ICU
Authors: Harder Louise , Malhotra Atul
Published: April 2016

Robust data have shown that sleep disruption and inadequate sleep duration in the general population impact neurocognitive function and produce cardiometabolic sequelae. Despite widespread recognition of the importance of sleep as an essential homeostatic function, there are relatively few data regarding the importance of sleep in critically-ill patients. Obstructive sleep apnoea is a common respiratory condition that is prevalent in the ICU and can be particularly problematic pre-intubation, post-extubation, and in the peri-operative setting. Considerable discussion regarding the impact of sleep versus sedation has occurred, with some insights emerging from improvements in our understanding of basic neurobiology. Sleep disturbance may also have an impact in critically-ill mechanically-ventilated patients by contributing to the development of delirium, which is associated with poor outcomes. However, further data are required to determine the ideal strategy to optimize sleep in the ICU and whether such strategies will in turn improve hard outcomes of critically-ill patients.
Non-pharmacological neuroprotection in the ICU
Authors: Nielsen Niklas , Seder David B.
Published: April 2016

After control of the primary process causing acute neurological injury, further control of secondary injury pathways can be achieved by manipulating brain temperature, and achieving biochemical and metabolic homeostasis. Surgical techniques are routinely used to remove blood or trapped cerebrospinal fluid, control mass effect, or repair unstable vascular abnormalities. Therapeutic temperature management to a defined target can be achieved and maintained using cold fluids, ice packs, body surface cooling pads, and surface and intravascular devices with servo (feedback) mechanisms. Successful temperature management requires attentive surveillance and control of shivering and other potential complications, such as bleeding, infection, cardiac arrhythmias, and electrolyte and metabolic disturbances. Extremes of oxygenation and ventilation are associated with worse long-term functional outcomes, and should be avoided.
Epidemiology, diagnosis, and assessment of neuromuscular syndromes
Authors: Orlikowski David , Sharshar Tarek
Published: April 2016

Admission to ICU with severe limb weakness, or the occurrence of a respiratory or motor deficit, and failure to wean from mechanical ventilation while in the intensive care unit are common presentations of a neuromuscular disease. Neuromuscular diseases include neuronopathies, neuropathies, myasthenic syndromes, and myopathies. An accurate neurological examination and complementary investigations are necessary for both diagnosis and for evaluating the severity of the disease. Assessment of respiratory muscle function is a key step in deciding the need for mechanical ventilation and subsequently its weaning. Hypercapnia often indicates an impending respiratory arrest, but normocapnia, which can be seen in a patient with severe reduction in vital capacity is not reassuring. Hypoxaemia can be due to hypercapnia, pulmonary injury (atelectasis or pneumonia), or pulmonary embolism. Cardiac evaluation is important as cardiomyopathies are frequent in myopathies.
Blood product therapy in the ICU
Authors: Qu Lirong , Triulzi Darrell J.
Published: April 2016

Transfusions are among the most common medical procedures in the intensive care unit. Several randomized controlled trials (RCT) indicate that restrictive red cell transfusion practice using a haemoglobin of <7g/dL is safe in critically-ill patients. Although similar RCT are not available for plasma or platelet transfusion guidelines, a large body of observational studies suggest that plasma transfusion for an invasive procedure has not been shown to be of benefit in patients with INR <2.0. Similarly, in thrombocytopenic patients, the target platelet count for bleeding or for an invasive procedure is 50,000/µl. Viral transmission risk has become exceedingly low. Other risks such as transfusion-associated circulatory overload and, to a lesser extent, transfusion-related acute lung injury, are much more common. Storage of red cells does not seem to be associated with adverse clinical outcomes. Alternatives using haemostatic agents, salvaged blood, and adherence to evidence-based transfusion guidelines probably reduce the need for transfusion in critically-ill patients.
Definition, epidemiology, and general management of nosocomial infection
Authors: Landelle Caroline , Pittet Didier
Published: April 2016

Nosocomial infection or ‘healthcare-associated infection’ (HAI), is one of the most common medical complications affecting patients in intensive care units (ICUs). The prevalence of HAI generally exceeds 25% in ICUs worldwide and ICU-acquired HAI accounts for more than 20% of all HAI in general. HAI depends on the patient’s underlying disease, the presence of invasive devices, use of antimicrobial therapy, type of ICU, and workload and training of healthcare workers. Surveillance has a major impact on the incidence of infections. HAI rates are used to assess patient safety and healthcare systems’ effectiveness, but adjustment for case-mix and standardization of surveillance method are needed. Prevention must be guided by the measurement of indicators, such as HAI rates, structure indicators, process indicators, and audits using checklists to assess if correct procedures and equipment are in place. Routine hand hygiene is the most important feature of infection control. Although the optimal approach to reducing HAI in critically-ill patients remains unclear, recent studies and large quality improvement initiatives have shown that education-based strategies with multimodal interventions, including some bundle approaches, can decrease HAI rates in ICUs.
Diagnosis, prevention, and treatment of device-related infection in the ICU
Authors: Zingg Walter , Harbarth Stephan
Published: April 2016

Many patients in the intensive care unit (ICU) suffer from health care-associated infections. Age, immunosuppression, neutropenia, or multi-organ failure are preconditions, but health care-associated infections are largely related to the use of medical devices. Breaches of aseptic technique are the most important risk factor. Central line-associated bloodstream infections, ventilator-associated pneumonia, and catheter-associated urinary tract infections represent up to 75% of all health care-associated infections in the ICU. Ease of diagnosis and effective prevention strategies make the central line-associated bloodstream infection a model of how to diagnose, treat, and prevent health care-associated infections. Identification of ventilator-associated pneumonia is less straightforward and suffers from inconsistent definitions, making surveillance and benchmarking difficult. Catheter-associated urinary tract infection is underestimated in the ICU because clinical signs cannot be assessed in sedated patients. Antibiotic overuse in the ICU selects for multidrug-resistant micro-organisms and thus, broad-spectrum antibiotics must be used to offer empiric treatment of health care-associated infections. Accurate microbiology testing aiming at isolating causative micro-organisms is key to de-escalate antibiotic therapy. Health care-associated infections are preventable, many factors. Successful prevention programmes offer a comprehensive protocol, follow a multidisciplinary approach in preparation, and a multimodal training and education programme in implementation.
Assessment of sepsis in the critically ill
Authors: Idahosa Osamudiamen , Huang David T.
Published: April 2016

Sepsis is the presence of a known or suspected infection and a systemic inflammatory response. Severe sepsis is sepsis with acute organ dysfunction. Septic shock is a subset of severe sepsis characterized by systemic arterial hypotension or occult hypoperfusion. Severe sepsis is common, affecting more than 750 000 individuals in the United States each year with a hospital mortality of about 30%.Severe sepsis is a medical emergency that requires early identification, prompt evaluation, and treatment. The signs and symptoms of sepsis are influenced by the virulence of the pathogen, the portal of entry, the degree of organ dysfunction as well as the susceptibility and response of the host.
Innate immunity and the inflammatory cascade
Authors: Parlato Marianna , Cavaillon Jean-Marc
Published: April 2016

Inflammation results from a complex interaction between a large number of mediators able to induce each other and to favour the generation of other inflammatory molecules (e.g. free radicals, lipid mediators, and proteases). The perpetuation of inflammation by these cascades of mediators is favoured by their ability to induce coagulation, leukocyte recruitment, and cell and tissue alteration (apoptosis, necrosis, and barrier disruption). Other cascades of mediators occur to generate anti-inflammatory mediators favouring the healing process. A neuroendocrine loop and neuromediators from central and peripheral nervous system are also involved in the process, allowing a return to homeostasis.
Brain injury biomarkers in the critically ill
Authors: Kochanek Patrick M. , Berger Rachel P.
Published: April 2016

A variety of biomarkers of brain injury are being developed in neurocritical care to study secondary injury pathways or aid in diagnostic, prognostic, and/or theragnostic applications. This chapter focuses largely on brain injury biomarkers that can be detected in serum or cerebrospinal fluid samples from patients with acute critical brain injury of various causes. Much of the work has been carried using biomarkers of proteins that are relatively unique to the brain, and that reflect damage to important cellular constituents such as neurons, astroycytes, or axons. Novel approaches that employ a panel of markers or novel analytic methods such as trajectory analysis may optimize the utility of these biomarkers in clinical practice. We anticipate that there will soon be one or more protein biomarkers of brain injury available for clinical use.
The host response to hypoxia in the critically ill
Authors: Raju Raghavan , Chaudry Irshad H.
Published: April 2016

The hypoxic response of the host is complex. While the oxygen-sensing intracellular machinery attempts to restore cellular homeostasis by augmenting respiration and blood flow, events such as severe haemorrhage lead to whole body hypoxia and decreased mitochondrial function. Immunological perturbations following severe haemorrhage may result in multiple organ dysfunction and sepsis, while impaired perfusion may lead to microvascular injury and local hypoxia. Trauma-haemorrhage or hypoxic exposure in animals causes a systemic inflammatory response, decreased antigen presentation by peritoneal macrophages, hypoxaemia and initiation of endoplasmic reticulum stress. In response, the protein level of the oxygen-sensing transcription factor, hypoxia inducible factor (HIF)-1 increases; this leads to the regulation of expression of a number of genes resulting in decreased mitochondrial ATP production, but enhanced glycolytic processes, thus shifting the energy balance. In addition, sustained tissue hypoxia leads to increased free radical production and cellular apoptosis. Though the initial host response to hypoxia may be protective, sustained hypoxia becomes detrimental to the tissues and the organism as a whole.
Management of acetaminophen (paracetamol) poisoning
Authors: Levine Michael
Published: April 2016

Acetaminophen overdose remains common, and is one of the most frequent reasons for liver transplant in the United States. Toxicity results from the metabolism to a toxic metabolite, N-acetyl-para-benzoquinoneimine. This chapter begins with a brief discussion of the history and epidemiology of acetaminophen overdose, followed by a discussion on the pharmacokinetics and pharmacodynamics. The risk factors, clinical presentation, and treatment strategies presented.
Management of limb and pelvic injuries
Authors: Sabri Omar , Bircher Martin
Published: April 2016

Pelvic ring injuries can be life and limb threatening. The mechanism of injury can often be a good indicator of the type of injury; the Young & Burgess classification deploys that concept to full effect. Early identification based on mechanism of injury and improved prehospital care can play a major role in the outcome following such injuries. Pelvic ring injuries can lead to significant haemorrhage. Mechanical measures to stabilize the pelvis, in addition to modern concepts of damage control resuscitation (DCR), have been shown to be effective in early management of potentially life-threatening haemorrhage. Emphasis is now entirely on protecting the primary clot following a pelvic ring injury. Mechanical disturbance by log rolling the patient or springing of the pelvis are strongly discouraged. Early radiological clearance of the pelvis is encouraged. The lethal triad of coagulopathy, acidosis, and hypothermia should be corrected simultaneously to improve outcome. A traffic light system for monitoring venous lactate as an indicator of the patients’ physiological state can help the intensive care practitioner and the surgeon identify optimum timing for surgery. Pelvic ring injuries are associated with significant concomitant injuries. Limb trauma can also be life or limb threatening. Early identification, splinting, and resuscitation follow the same guidelines as pelvic ring injuries. Open long bone fractures should be managed by senior orthopaedic and plastic surgeons.
Assessment of traumatic brain injury
Authors: Andrews Peter J. D. , Rhodes Jonathan K. J.
Published: April 2016

Traumatic brain injury (TBI) accounts for the majority of traumatic deaths and most disability due to trauma in people aged less than 40 years old. Current trends suggest this burden of disease will increase dramatically over the next 20 years. Successful management of patients after traumatic brain injury requires recognition of patients at risk of deterioration, appropriate investigation, including imaging, and prevention of systemic and intracranial secondary injury processes. Unlike trauma affecting other body systems, outcome from TBI has not improved in the last 10–15 years. Assessment of a patient with traumatic brain injury includes clinical examination and diagnostic imaging both of which can be quantified or graded using scores such as the Glasgow Coma Score (GCS) and the Marshall score for grading cranial computed tomographic (CT) scans. Clinical examination and diagnostic imaging can both aid in prognostication (http://www.crash.lshtm.ac.uk/Risk%20calculator/).
Ongoing management of the tetraplegic patient in the ICU
Authors: Flower Oliver , Raper Raymond
Published: April 2016

This chapter focuses on the intensive care management of patients who have suffered cervical spinal cord injury (CSCI). This includes new CSCI, following initial resuscitation and stabilization, and the common issues faced when managing longstanding tetraplegic patients who require critical care. For patients with a new diagnosis of CSCI, a comprehensive systems-based approach is suggested covering topics including terminology, the standardized neurological examination, muscle spasticity, neuropathic pain, venous thromboembolism prophylaxis, as well as renal, gastrointestinal, and pressure care considerations. Particular attention should be paid to respiratory care, including ventilation strategies, tracheostomy, and the management of respiratory complications. The importance of early rehabilitation and appropriate psychosocial support is discussed. Common critical care issues affecting patients with chronic tetraplegia include autonomic dysreflexia, respiratory failure, peri-operative care, sepsis and complications of indwelling intrathecal devices.
Pathophysiology and management of drowning
Authors: Modell Jerome H. , Kiley Sean
Published: April 2016

Drowning is a process beginning with airway submergence under a fluid medium, progressing to aspiration, and ultimately death in the absence of intervention. Aspiration of both fresh- and saltwater can cause pulmonary oedema, decreased compliance, intrapulmonary shunting, and severe hypoxia. Devastating neurological injury resulting from prolonged cerebral hypoxia is proportional to the duration of submersion and delay in effective resuscitation and oxygenation. Victims presenting to the emergency department awake and alert, or even stuporous, are likely to have a good neurological outcome with follow-up intensive care. Those presenting comatose are much more likely to have severe neurological deficits. Keys to survival are: timely rescue from the water, immediate initiation of aggressive supportive care regarding airway, cardiovascular and pulmonary function, and optimization of tissue oxygenation.