Due to advances in modern technology, administering a cardiopulmonary test has become easier, while the possibilities for evaluation and diagnosis have increasedsignificantly. In this, our third special edition of cardiopulmonary exercise testing we would like to introduce our latest developments in this field as well as giving you further background information on topics such as: threshold determination and on testing with increased oxygen supplementation.

The role of the O2 transport/O2 utilisation system determining maximum O2 uptakehas been analysed in an integrative manner. The system responses to exercise in healthy subjects (athletes and sedentary) and in common pulmonary diseases have been examined.

The maintenance of blood gas homeostasis is dependent on the balance between respiratory drive and peripheral, mechanical and chemoreceptor responses. No single measurement encapsulates all aspects of this complex control system. Most investigators and clinical tests rely on relatively short-term changes in inspired gas concentrations and/or additional predominantly inspiratory mechanical loading to determine how the control system responds.

The aim of this chapter has been to describe the unique and clinically relevant information that forced oscillation technique (FOT) provides. This may be derived without mathematical mastery of technological principles of the equipment and/or of numerical models. It is emphasised that recognition of the change in respiratory mechanical parameters as a function of oscillation frequency is necessary to appreciate the outstanding value of FOT in its ability to assess peripheral airway function.

The discussion which follows describes the aspects of HFOV which affect oxygenation and ventilation (CO2 elimination) and how they are adjusted when managing infants with specific pathologies.

Objective: To compare a new transport ventilator to manual ventilation in terms of maintaining the respiratory and hemodynamic levels of critically ill patients.

Fetten und Eiweißen mit Sauerstoff (aerober Stoffwechsel). Neben der Nahrungsaufnahme muss der Körper demzufolge in der Lage sein, abhängig von der Belastung auch genügend Sauerstoff für diesen Verbrennungsprozess der Muskulatur zur Verfügung zu stellen. Wie bei jedem anderen Verbrennungsprozess entsteht hierbei auch Kohlendioxid (CO2), welches anschließend wieder aus den Muskelzellen und dann über die Atmung aus dem Körper eliminiert werden muss.

Lung function research is a relatively young science. Physicists have historically made an important contribution to the scientific development of lung function analysis due to the importance of topics such as elasticity, resistance, muscular strength and the work of breathing.

Although diagnosis always begins with a careful history and physical examination and a physician is obligated to consider more than the diseased organ, testing of lung function has become standard practice to confirm the diagnosis, evaluate the severity of respiratory impairment, assess the therapy response and follow-up patients with various cardio-respiratory disorders. Ventilation, diffusion, blood flow and control of breathing are the major components of respiration and one or more of these functional components can be affected by any disorder.

There is an inextricable link between hemodynamic characteristics and response to ventilation settings. Therefore, a careful evaluation of cardiovascular function in critically ill patients with pulmonary disease is an important aspect of their ventilatory management.

In this "overview", pulmonary gas exchange is considered in three sections. The first section (Normal values, Causes of hypoxaemia I, Respiratory failure) contains "basic" knowledge about pulmonary gas exchange, which is relevant to all who work in clinical medicine. The next section (Oxygen carriage in blood, Heterogeneity of ventilation and perfusion, Causes of hypoxaemia II) focuses on "intermediate" knowledge, with which all respiratory specialists should be familiar. The last section (Oxygen affinity in special situations, Diffusion, Inert gas transport) contains "advanced" knowledge, appropriate for staff in intensive care units, anaethesiology or rehabilitation, or those undertaking research.

During the past decade there has been remarkable progress in the field of infant and preschool lung function testing, with measurements once thought impossible to obtain below the age of 5–6 yrs now being performed regularly in children as young as 3 yrs. Commercially available equipment and international recommendations are now available for most routine infant lung function tests.

Assessment of respiratory mechanics can play a central role in the management of critically ill patients undergoing artificial ventilation because of acute respiratory failure (ARF). This assessment is of crucial importance to understand the pathophysiology of the disease underlying ARF and to improve the patient–ventilator interaction and the medical treatment of the disease.

Respiratory muscle weakness has serious clinical consequences. The assessment of respiratory muscle function and the detection of respiratory muscle weakness has a place in the clinical decision tree of many diseases, including lung disease, neuromuscular diseases and others.

Office spirometry in the primary care setting can be most helpful for the detection (case finding) and management of asthma and chronic obstructive pulmonary disease (COPD). The severity of asthma is underestimated by history and physical examination alone in some patients. Only spirometry has been shown to detect COPD in its early stages.

The main function of the lungs is to establish exchange of O2 and CO2 between the environment and the capillary blood. The gas transport across the alveolar-capillary membrane can be measured by the transfer of carbon monoxide (CO).

The aim of this chapter has been to describe the unique and clinically relevant information provided by whole-body plethysmography. Primary among this information is the measurement of absolute TGV.