European Respiratory Society

Respiratory Emergencies

Edited by S. Nava and T. Welte
Respiratory Emergencies

Access to free airways is the first consideration in emergency situations, such as at the scene of an accident, and respiratory emergencies represent an important part of acute medicine in general. Respiratory problems also play a crucial part in critical care medicine and constitute an important share of the numerous problems in an intensive care unit. There is no clear forum for publishing scientific achievements within the field of respiratory emergencies, so this issue of the European Respiratory Monograph on respiratory emergencies will be welcome, and will help bridge the gap between specialists in respiratory and intensive care medicine. Different aspects of respiratory emergencies have been covered and this Monograph gives insights into acute respiratory events due to exacerbations of obstructive pulmonary diseases, infections, accidents, neuromuscular disorders and acute respiratory distress syndrome.

  • European Respiratory Society Monographs
  1. Page viii
  2. Page ix
  3. Page 1
    Abstract
    Correspondence: P. Ceriana, Respiratory Intensive Care Unit, Fondazione “S.Maugeri”, Via Ferrata 8, 27100 Pavia, Italy. Fax: ; E-mail: pceriana@fsm.it

    Respiratory failure is a condition in which the respiratory system fails in one or both of its gas exchange functions, i.e. oxygenation and clearance of carbon dioxide. Any condition in which the arterial oxygen tension is <7.3–8.0 kPa breathing room air is generally called hypoxic (or type I) respiratory failure, whereas hypercapnic respiratory failure is a condition in which arterial carbon dioxide tension is >6.5–6.6 kPa, with or without acidosis (arterial blood pH <7.36). The most important causes of hypoxaemia are impaired diffusion, ventilation/perfusion mismatch and shunt, whereas alveolar collapse, alveolar flooding and impaired hypoxic pulmonary vasoconstriction are the main pathological mechanisms. Alveolar flooding is generally the most important mechanism underlying severe hypoxaemic states such as acute cardiogenic pulmonary oedema (ACPO), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). The prevalence of hydrostatic (ACPO) or inflammatory (ALI, ARDS) mechanisms in pulmonary oedema deeply impacts upon clinical course and outcome.

    Most hypercapnic states result from inadequate clearance due to alveolar hypoventilation and increased dead space (dead space/tidal volume); this may happen in parenchymal diseases such as emphysema and in circulatory problems such as pulmonary embolism. Normally, the ventilatory drive adjusts the output of the muscular pump in proportion to metabolic activity, in order to maintain arterial blood pH within narrow limits (7.38–7.42). Causes of pump failure can be grouped into three major categories: central depression, mechanical defect of the ventilatory pump, and muscle fatigue. Exacerbation of chronic obstructive pulmonary disease is the most important cause of hypercapnic respiratory failure; the increased load of the respiratory system and reduced muscular force induce the patient to adopt a rapid shallow breathing pattern in order to preserve the ventilatory pump from fatigue and exhaustion.

  4. Page 16
    Abstract
    Correspondence: J.A. Wedzicha, Academic Unit of Respiratory Medicine, Royal Free & University College Medical School, Rowland Hill Street, London, NW3 2PF, UK. Fax: ; E-mail: j.a.wedzicha@medsch.ucl.ac.uk

    Exacerbations of the major obstructive lung diseases, asthma and chronic obstructive pulmonary disease (COPD), cause considerable morbidity, mortality, hospital admission and healthcare cost. Exacerbations of both conditions are largely caused by infection, resulting in heightened airway inflammation in association with a deterioration in symptoms and lung function.

    Although the nature of the inflammation in the two conditions is dissimilar, the principles of treatment and many of the agents used are the same. This review outlines the evidence for the available treatment modalities in the emergency treatment of exacerbations of both asthma and COPD. The review focuses on hospital management in the emergency department and ward setting, and does not specifically cover issues relating to endotracheal intubation and mechanical ventilation, or paediatric disease.

    The aim of emergency treatment is to support gas exchange and respiratory function until disease-modifying agents are able to act. The major therapies used in both conditions are inhaled bronchodilators (short-acting β2-agonists, with or without anticholinergics), systemic corticosteroids and controlled oxygen therapy. An important distinction between asthma and COPD is the benefit seen with antibiotics in those exacerbations of COPD associated with a change in the character of the sputum.

    For more severe exacerbations, a range of additional therapies are available. Many published guidelines exist for reviewing the management of exacerbations in these conditions, and adherence to protocols has been associated with improved patient outcomes. The development of newer and more specific therapies will no doubt result in the development of these guidelines over the course of the coming years.

  5. Page 34
    Abstract
    Correspondence: T. Welte, Dept of Respiratory Medicine, Hannover Medical School, Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany. Fax: ; E-mail: tobias.welte@gmx.de

    Mechanical ventilation is the treatment of choice in patients with acute, severe obstructive airway disease and respiratory insufficiency. The most frequent underlying diseases are chronic obstructive pulmonary disease and bronchial asthma.

    The therapeutic target of ventilation is to improve gas exchange, to unload the ventilatory pump and to relieve respiratory distress of the patient.

    Today, noninvasive ventilation (NIV) is the first-line treatment. NIV provides similar ventilatory support like invasive mechanical ventilation, but is associated with a significantly lower risk of ventilator-associated pneumonia, shorter periods of mechanical ventilation and shorter stay in the intensive care unit.

    Invasive ventilation allows the application of controlled ventilation with optimised ventilatory patterns to improve blood gases and to reduce hyperinflation. However, weaning procedures from invasive ventilation in patients with underlying lung diseases are difficult and time consuming.

  6. Page 49
    Abstract
    Correspondence: J.J. Haitsma, Interdepartmental Division of Critical Care, University of Toronto, St. Michael's Hospital, 30 Bond Street, Queen Wing 4-042, Toronto, ON, Canada M5B 1W8. Fax: ; E-mail: Jack.haitsma@utoronto.ca

    Acute respiratory distress syndrome (ARDS) is characterised by inflammation and increased permeability. The incidence of ARDS is still high with up to 60 cases per 100,000 person-yrs, as well as a mortality of 40%. Using the nearly 10-yr-old definition of ARDS, a multitude of clinical trials have addressed possible therapies and increased current knowledge.

    The only proven therapy in reducing mortality in ARDS patients is the use of lower tidal volumes (VTs), using the ARDS Network study as a guideline. Implementation of feedback and education concerning low VT ventilation, with special attention to closely adjusting VTs to predicted body weight, can help improve physician compliance in the use of this strategy. Additional therapies that can be taken into consideration in treating patients include: recruitment procedures to increase oxygenation, but these are not yet recommended; and, in severe ARDS (arterial oxygen tension/inspiratory oxygen fraction ratio <100), prone positioning can be contemplated. Furthermore, fluid management should be conservative, using the 2006 ARDS Network study as a guideline. Other therapies, such as exogenous surfactant, partial liquid ventilation and corticosteroids, are not recommended in ARDS.

  7. Page 64
    Abstract
    Correspondence: K. Raymondos, Dept of Anaesthesiology, University Hospital, Carl Neuberg Str. 1, 30625 Hannover, Germany. Fax: ; E-mail: kraymondos@aol.com

    Inhalation injury represents the major cause of death from burns and has a much greater influence on mortality than age or the extent of burned body surface. A total of 20–30% of all burn victims suffer from inhalation injury that increases mortality to >50% in severe burns. Inhalation injury plays a key role in recently developed outcome prediction models, reflecting its outstanding importance on mortality in burned patients. Traditional clinical signs include burns on the face, lips, in the mouth or on the pharyngeal or nasal mucosa, coughing, and soot in the sputum, nose or mouth. However, with flexible bronchoscopy, inhalation injury is diagnosed about twice as often compared with traditional clinical signs. As symptoms are often absent on admission, tight monitoring is mandatory. First of all, in all burn victims, carbon monoxide (CO) intoxication has to be considered and high inspiratory oxygen concentration has to be applied in order to accelerate CO elimination until CO intoxication can be ruled out.

    Acute upper airway obstruction occurs in ∼20–30% of hospitalised burn victims with inhalation injury. A minor pharyngeal oedema can rapidly develop into complete upper airway obstruction with subsequent asphyxia. Tracheobronchial hygiene therapy is essential after inhalation injury. Coughing, physiotherapy, early mobilisation, airway suctioning, therapeutic bronchoscopy and pharmacological agents mobilize and remove secretions and fibrin cast.

    Bacterial pneumonia represents the major complication of inhalation injury raising mortality to 60%. Primary endogenous pneumonia can be avoided with selective intestinal decontamination that decreases intensive care mortality by 75%. The intensive care course is often complicated by acute renal failure that represents one of the most important causes of death. Barotrauma represents the most prominent mechanical complication caused by a variety of injuries, especially with high peak inspiratory pressures in combination with valve-type obstructions. Late pulmonary complications include tracheal damage and tracheomalacia.

  8. Page 84
    Abstract
    Correspondence: A.K. Simonds, Royal Brompton & Harefield Trust, Sydney Street, London SW3 6NP, UK. Fax: 44 2073518911; E-mail: a.simonds@rbh.nthames.nhs.uk

    Acute ventilatory decompensation is an inevitable feature of some inherited neuromuscular diseases that involve the respiratory muscles, such as type I spinal muscular atrophy and Duchenne muscular dystrophy, and is a common cause of morbidity in others, including severe chest wall disease and central hypoventilation syndromes. It can complicate acquired neuromuscular disorders such as Guillain–Barré syndrome, motor neurone disease (amyotrophic lateral sclerosis) and polymyositis. An anticipatory care plan can be employed in which high-risk cases are identified, respiratory function assessed, and ventilatory failure treated promptly. Noninvasive ventilation, combined with cough-assist techniques, has considerably improved the outlook and reduced the need for invasive ventilation in these conditions, unless severe bulbar compromise is present. Patients should always be involved in decision making and advance care planning where possible.

  9. Page 95
    Abstract
    Correspondence: C.T. Bolliger, Respiratory Research Unit, Clinical Building, Faculty of Health Sciences, University of Stellenbosch, 19063 Tygerberg 7505, South Africa. Fax: 27 219323105; E-mail: ctb@sun.ac.za

    The expectoration of blood is a frightening experience for both patients and doctors. The definition of massive haemoptysis varies from 200–1,000 mL of blood per 24 h. In patients with underlying lung disease, even a small amount of haemoptysis can cause respiratory compromise. A stepwise approach to the management of life-threatening haemoptysis is needed. Careful history and examination are essential for both diagnostic as well as therapeutic work-up. Initial management consists of proper resuscitation, basic blood testing (haemoglobin) and chest radiograph. In the next step, bronchial artery angiography/embolisation is performed as the procedure of choice. Depending on its success and on an individual risk assessment for the recurrence of bleeding, a decision should be taken regarding the need for surgery. If surgery is needed, lung function assessment should be done to evaluate operability. If emergency surgery is needed, the history of the degree of dyspnoea prior to haemoptysis has to be relied on. An algorithm encompassing all necessary steps in the management of massive haemoptysis is proposed at the end of the current review.

  10. Page 108
    Abstract
    Correspondence: O. Dikensoy, Dept of Pulmonary Diseases, Gaziantep University, Gaziantep, 27035, Turkey. Fax: ; E-mail: dikensoy@yahoo.com

    Tracheobronchial aspiration syndromes are the most important causes of accidental morbidity and mortality worldwide, particularly in infants. Children aged <2 yrs and individuals of any age with one or more predisposing risk factors, such as dysphagia, are the most vulnerable groups. As most aspiration events are unwitnessed, timely diagnosis relies on a high index of suspicion. The clinical presentation and radiographic features can vary depending on the nature and amount of the aspirated material or object. While a foreign body aspiration or a relatively large volume of aspirated material can cause an acute or subacute presentation ranging from choking and sudden death to acute pneumonia, repeated aspiration of gastric acid in small amounts can gradually progress to recurrent pneumonia, bronchiectasis or pulmonary fibrosis. Management varies depending on the clinical appearance (e.g. hypoxaemia or signs of infection) and the nature of the aspirated material (e.g. foreign body, gastric content or hydrocarbon). Bronchoscopy has a major role in the diagnosis and management of cases of foreign body aspiration.

    Drowning is the third most common cause of accidental death worldwide. The pathophysiology of the damage incurred by the lung in near-drowning events may differ depending on the tonicity of the aspirated water. Respiratory failure is the most important consequence of near-drowning. However, injuries to other parts of the body, especially head or cervical spine injuries, should be suspected and evaluated. Victims of near drowning recover without any sequellae in most cases provided that irreversible hypoxic brain damage did not occur.

  11. Page 125
    Abstract
    Correspondence: D.A. Groneberg, Dept of Respiratory Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30623 Hannover, Germany. Fax: 49 5115323353; E-mail: groneberg.david@mh-hannover.de

    Drowning is one of the major causes of accidental paediatric death, and is also a relatively common accident in adulthood.

    Drowning can be defined as a loss of respiratory function due to submersion or immersion, with the main pathophysiological characteristic being hypoxia. Since prolonged hypoxia leads not only to respiratory but also to irreversible central nervous system symptoms, immediate and aggressive clinical management of drowning casualties is pivotal for optimal survival rates.

    In the present chapter, definitions, epidemiological and pathophysiological aspects, and management of drowning accidents are discussed.

  12. Page 136
    Abstract
    Correspondence: F. Reichenberger, University of Giessen Lung Centre, University Hospital Giessen, Klinikstrasse 36, 35392 Giessen, Germany. Fax: 49 6419942599; E-mail: Frank.Reichenberger@innere.med.uni-giessen.de

    Pulmonary embolism (PE) remains a frequent but often overlooked disease, despite improvements in diagnostic strategies, including clinical probability scores, the d-dimer test, and computed tomography or perfusion scintigraphy. Development of acute cor pulmonale has emerged as a risk factor for adverse outcome in PE.

    Therefore, risk evaluation has been attempted, based on clinical assessment, echocardiography and newly discovered biomarkers, in order to improve therapeutic decisions.

    The main therapeutic goal is still the rapid initiation of anticoagulation therapy, including unfractionated heparin, low-molecular-weight-heparins and heparinoids, which also improves overall outcome.

    Several studies have encouraged the expanded use of thrombolysis; however, further studies concerning short- and long-term outcome are required.

    Interventional and surgical embolectomy should be considered in precarious situations according to the clinical setting and local availability.

    The duration of anticoagulation therapy as secondary prophylaxis depends upon individual risk factors. Therefore, follow-up with clinical assessment and echocardiography is recommended for the early detection of long-term complications.

    The development of chronic thromboembolic pulmonary hypertension is observed more frequently than previously expected. The treatment of chronic thromboembolic pulmonary hypertension includes surgical and medical options; however, this should be assessed in specialised centres.

  13. Page 165
    Abstract
    Correspondence: M. Noppen, Interventional Endoscopy Clinic, Respiratory Division, University Hospital AZ-VUB, Laarbeeklaan 101, B-1090 Brussels, Belgium. Fax: ; E-mail: marc.noppen@az.vub.ac.be

    Spontaneous pneumothorax is frequently encountered in clinical practice. A distinction is made between primary (i.e. no known underlying lung disease, occurring in adolescents and young adults, in particular tall thin smoking males) and secondary disease (i.e. occurring in patients with underlying lung disease such as chronic obstructive pulmonary disease, tuberculosis, lymphangioleiomyomatosis and numerous others). Nevertheless, better and new visualisation techniques have shown that the underlying lung and/or visceral pleura are also diffusely damaged in primary spontaneous pneumothorax, and blebs and bullae are not always the cause or localisation of the air leak. Observation only is indicated in small, asymptomatic, first episodes. Manual aspiration is the established first-line treatment in first episodes of large and/or symptomatic disease. In cases of recurrence or persistence of pneumothorax, medical thoracoscopic talc poudrage (which has also been proven to be safe) and video-assisted thoracoscopic surgery are equally effective. The cornerstone of both treatments is effective pleurodesis. In secondary spontaneous pneumothorax, which is potentially more dangerous owing to the extent and type of underlying disease, a more aggressive approach is suggested, including a pleurodesis technique after the first episode.

    A bronchopleural fistula is a persistent communication between the bronchial tree and the pleural space. Thus, persistent spontaneous or traumatic pneumothorax can be considered a specific cause of bronchopleural fistula. However, complication of pulmonary resection is the most common cause by far. Bronchopleural fistulas are associated with significant morbidity and mortality, and represent a challenging management problem. Treatment includes various surgical and bronchoscopic techniques, the choice of which depends upon the underlying cause, the localisation and the size of the fistula. In high-risk surgical patients, bronchoscopic procedures may serve as a temporary bridge to definitive surgical treatment, while in others they may be the only treatment option. There are no prospective randomised trials comparing various approaches. Current treatment options seem to be complementary, and treatment should be individualised.

  14. Page 177
    Abstract
    Correspondence: FIRH T2123, St. Joseph's Healthcare, McMaster University, 50 Charlton Ave East, Hamilton, ON, L8N 4A6, Canada. Fax: 1 9055216132; E-mail: kolbm@mcmaster.ca

    Acute presentation as a respiratory emergency is very uncommon for interstitial and immunological lung diseases, unless severe diffuse pulmonary or alveolar haemorrhage is involved. However, patients with chronic interstitial and fibrotic lung diseases may have low respiratory reserves so that even a seemingly mild respiratory tract infection or minor subsegmental pulmonary embolism can be too much for these patients to tolerate. Abrupt changes in the clinical state of these patients should trigger an emergency awareness in their care.

  15. Page 183
    Abstract
    Correspondence: A. Torres, UVIR Hospital Clinic Servei de Pneumologia, Villarroel 170, 8036 Barcelona, Spain. Fax: 34 932279813; E-mail: Atorres@clinic.ub.es

    Community-acquired pneumonia (CAP) is a frequent cause of emergency room (ER) visits, and although its diagnosis is usually straightforward, certain aspects, such as the evaluation of severity and choice of antibiotic treatment influence the progress of the patient. The diagnosis of CAP is not usually difficult and the clinical picture includes fever, dyspnoea, cough with purulent expectoration, and sometimes pleuritic pain. Every effort should be made to isolate the aetiological micro-organism. These include a Gram stain, sputum and blood cultures, and Legionella and pneumococci urinary antigen tests, mainly in admitted patients. Once the patient has been diagnosed with CAP, the next step is to evaluate its severity and the risk of poor outcome, which has implications about where the patient must receive treatment, the diagnostic tests to be performed, and the initial, empirical treatment.

    In current clinical practice, the pneumonia severity index (PSI), the CURB score and its modifications, and the American Thoracic Society severity criteria are useful rules to predict severity and mortality risk of the CAP patient. The main limitation of the PSI is the great weight placed on the patient's age in the final scoring, which could hide important risks in younger patients and vice versa. The CURB score is a very easy tool to perform in the ER and the treatment site can be defined based on it. Severe CAP bears certain characteristics related to its incidence, aetiology, progression and prognosis that are sufficiently different from mild CAP to warrant a specific management plan.

    The early identification of patients with severe CAP is of great importance since it facilitates the initiation of prompt treatment oriented at likely pathogens as well as the establishment of monitoring and support measures. Ideally, the choice of antibiotic treatment should be based on microbiological findings; however, in current clinical practice, the choice is empirical (despite the current diagnostic tools, including invasive techniques) since the clinician can only establish an aetiological diagnosis in 50% of cases, and in even fewer in the ER.

  16. Page 200
    Abstract
    Correspondence: K. Dalhoff, Medizinische Klinik III, Medizinische Universität zu Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany. Fax: 49 4515006014; E-mail: klaus.dalhoff@uni-luebeck.de

    Pneumonia in the immunocompromised host is a frequent and life-threatening complication that requires rapid diagnosis and targeted treatment. Key points for assessing the aetiology include: 1) the underlying condition and type of immunodeficiency; 2) prophylaxis regimens or pre-emptive treatments already used; and 3) unusual or heavy exposure to respiratory pathogens (e.g. Aspergillus spp., Mycobacterium tuberculosis).

    Radiographic findings may be uncharacteristic and may quickly progress to respiratory failure. High-resolution computed tomography (CT) scan is the best tool for a timely recognition of infiltrates and for planning the diagnostic work-up.

    A rapid microbiological diagnosis is preferable regarding the broad spectrum of pathogens implicated. This is best accomplished by fibreoptic bronchoscopy with bronchoalveolar lavage, with or without transbronchial biopsy, early in the course of disease. Bronchoscopy also allows for identification of noninfectious processes associated with pulmonary infiltrates. In peripheral focal lesions, CT-guided fine-needle aspiration biopsy is an alternative diagnostic option.

    A standardised approach to initial treatment is recommended, generally consisting of broad-spectrum antibacterial therapy. This can be narrowed after identification of causative pathogens and has always to be adapted to the underlying condition and individual factors during the course of disease. Additional empirical antifungal, antipneumocystis or antiviral coverage may be warranted in high-risk populations for these aetiologies.

    In patients with respiratory failure, early noninvasive ventilation is advantageous compared with intubation and mechanical ventilation.

  17. Page 214
    Abstract
    Correspondence: J.Y. Paton, Division of Developmental Medicine, Yorkhill NHS Trust, Glasgow, G3 8SJ, UK. Fax: 44 1412010837; E-mail: J.Y.Paton@clinmed.gla.ac.uk

    Respiratory disorders account for approximately a half of hospital admissions and a significant number of deaths each year in children throughout the world. Structural and functional differences in the respiratory tract make children more vulnerable to respiratory failure than adults, and most cases of collapse in children have a respiratory component.

    Paediatric respiratory emergencies can be broadly grouped by site and pathological process, with the main categories being upper airway obstructions (croup), lower airway obstructions (asthma) and respiratory tract infections (pneumonia). A careful clinical evaluation, combined with objective measurements of respiratory and cardiac frequency and arterial oxygen saturation, is essential for accurate diagnosis and severity assessment. The precise management depends upon the diagnosis. The introduction of pulse oximetry for the noninvasive detection of hypoxaemia and the recognition that corticosteroids play an important role in the management of croup have been important advances.

  18. Page 241
    Abstract
    Correspondence: M. Cazzola, Unit of Pneumology and Allergology, Dept of Respiratory Medicine, A. Cardarelli Hospital, Via A. Cardarelli 9, 80131 Naples, Italy. Fax: 39 081404188; E-mail: mcazzola@qubisoft.it

    Acute respiratory failure, although a relatively uncommon complication of pregnancy, is associated with significant morbidity and mortality. Pregnancy is associated with several cardiac and respiratory physiological changes that impact upon the assessment and management of respiratory failure. Adequate knowledge of these changes is essential for ensuring optimal management of the pregnant patient.

    Acute respiratory failure in pregnancy may be caused by a variety of clinical conditions, which can be due to either obstetric complications or deterioration of underlying lung or other systemic diseases. Since there is an increase in intravascular volume and cardiac output during pregnancy, patients with underlying structural heart disease may present with cardiac decompensation and pulmonary oedema. Pulmonary oedema during pregnancy may also be caused by severe pre-eclampsia or administration of tocolytic therapy. Peripartum cardiomyopathy occasionally complicates the course of pregnancy during the peripartum or post-partum period.

    Acute lung injury and acute respiratory distress syndrome occur during pregnancy as a complication of underlying medical conditions, such as severe sepsis and pneumonia, or secondary to obstetric complications, such as amniotic fluid or venous air embolism. Hypercoagulability associated with pregnancy results in a marked increase in the incidence of thromboembolic disease such as acute pulmonary embolism. Asthma is one of the most common medical conditions that can complicate pregnancy. Although most pregnant subjects with asthma have an uneventful course during their pregnancy, a few may experience severe life-threatening exacerbations that require hospitalisation and intensive care management.

    Managing a pregnant patient with acute respiratory failure is challenging and requires a multidisciplinary approach. Although management of respiratory failure in this situation is similar to that in a nonpregnant patient with the same illness, the physiological changes that occur during pregnancy should be borne in mind in order to ensure maternal and foetal safety. Early identification and treatment of the underlying cause of respiratory failure are key to achieving a successful outcome. Implementation of maternal and foetal haemodynamic and oxydynamic monitoring is also of paramount importance.