Dyspnoea is a common complaint in pregnant women, and may occur as a result of the physiological changes in pregnancy or due to cardio-respiratory disease. A prospective observational study of 62 pregnant women identified that 76% experienced dyspnoea at some point during their pregnancy. Approximately half became symptomatic before 20 weeks’ gestation and the incidence increased until about 30 weeks’ gestation. It is important to be aware that some complications of pregnancy may produce dyspnoea in the previously well patient, so it is important to differentiate pathological conditions from this physiological dyspnoea. This chapter reviews the mechanisms of dyspnoea of pregnancy and the differentiation from pathological conditions.

Restrictive lung diseases are conditions characterized by a reduction in lung volume, and may be subdivided according to the anatomic location of the pathology. Diseases of the lung parenchyma itself reduce lung volumes due to the poor compliance (‘stiffness’) of the lungs. Examples include interstitial lung diseases such as pulmonary fibrosis, connective tissue diseases affecting the lung, sarcoidosis and hypersensitivity pneumonitis. A second anatomic group involves diseases of the chest wall, where lung volumes are reduced by abnormalities of the lining of the lung (pleural thickening), the skeletal chest wall (e.g. marked kyphoscoliosis) or weakness of the muscles generating breathing activity (e.g. neuromuscular diseases).

Day to day, critical care units in Western society provide highly resourced intense care to patients with complex medical problems or injuries. Typically a relatively small number of patients are managed by highly educated and specialised physicians (intensivists) in collaboration with a large team of health care workers (HCWs), skilled specifically in dealing with critically ill patients including: critical care nurses, respiratory therapists, nutritionists, physiotherapists, pharmacists and other allied HCWs. Critical care is comprised of three core components: intensive nursing care with a 1:1 or 1:2 nurse-to-patient ratio, the provision of life support measures, and invasive monitoring including devices such as arterial lines or pulmonary artery catheters. Life support in this context can include ventilatory support with positive pressure mechanical ventilation, circulatory support with medications to control/support blood pressure (e.g. dopamine) or mechanical support (e.g. intra-aortic balloon pump or temporary transvenous pacemaker), and renal replacement therapy.

Whilst the model of care described above is effective for day-to-day patient management, during a disaster, particularly biological disasters, this model of care is often not sustainable nor an efficient use of limited resources. The term biological disaster is used to refer to events such as infectious disease outbreaks (epidemics and pandemics) or bioterrorism attacks. This chapter will discuss issues related to providing critical care services during biological disasters including preparedness, organisational structure, communication, surge capacity, mass critical care, triage, infection control, and ethical challenges.