Textbook of Critical Care

Severe asthma exacerbation in adults

Magnitude of the problem and risk factors Each year in the United States, acute asthma accounts for approximately 1.8 million emergency department (ED) visits, 190,000 hospitalizations, and 3500 deaths. Although death rates have decreased slightly over the last 20 years,…

Aspiration pneumonitis and pneumonia

Aspiration is defined as the misdirection of oropharyngeal or gastric contents into the larynx and lower respiratory tract. The consequent pulmonary syndromes that follow depend on the quantity and nature of the aspirated material, frequency and chronicity of aspiration, and…

Drowning

Definition Drowning is the process of experiencing respiratory impairment from submersion or immersion in liquid. This process can be fatal, nonfatal with complications, or nonfatal without complications. This definition is increasingly used in the medical, professional, and research literature to…

Acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a common problem in the intensive care unit (ICU) that can complicate a wide spectrum of critical illnesses. First described by Ashbaugh and colleagues in 1967, the syndrome was initially termed adult respiratory distress…

Intensive care unit imaging

Recent advances in ICU imaging Modern advancements in imaging modalities continue to provide an ever-increasing amount of diagnostic and interventional capabilities to aid in the care of critically ill patients. Continued advancement of bedside ultrasound (US) technology and training has…

Adjunctive respiratory therapy

Many critically ill patients are unable to effectively clear secretions that accumulate in the central and peripheral airways. This failure can be the result of factors such as increased secretion production, impaired cough reflex, weakness, and pain. An endotracheal tube…

Weaning from mechanical ventilation

The concept of liberation and extubation Weaning from mechanical ventilation refers to the transition period from total ventilatory support to spontaneous breathing. Approximately 70% of intubated mechanically ventilated patients are extubated after the first spontaneous breathing trial (SBT), either by…

Advanced techniques in mechanical ventilation

Introduction Physiologic closed-loop controlled (PCLC) systems run the gamut from simple negative feedback controllers to fully automated control of airway pressure, tidal volume (V T ), minute ventilation (V E ), fraction of inspired oxygen (FiO 2 ), and positive…

Noninvasive positive-pressure ventilation

Noninvasive ventilation is defined as the provision of ventilatory assistance to the lungs without an invasive artificial airway. Noninvasive ventilators consist of a variety of devices, including negative- and positive-pressure units. Until the early 1960s, negative-pressure ventilation in the form…

Patient–ventilator interaction

Clinical management of patients with acute respiratory failure is based on the concept that significant changes in respiratory mechanics, respiratory muscle performance, and control of breathing are the underlying mechanisms responsible for acute respiratory failure. The effects of mechanical ventilation…