The generalization of a large clinical material made it possible to propose to distinguish the following types of response to standard physical activity (the basis for such an allocation is a combination of changes in the main hemodynamic parameters): 
 1. If immediately after loading the stroke volume of the left ventricle increases by 10–12%, the pulse rate increases by 12–15% and the reserve ratio increases by 0.3 (regardless of the initial value), then the reaction is regarded as normal or adequate. In this case, by the end of 3 minutes after the load comes full recovery of all hemodynamic parameters. 2.If there is no increase in stroke volume after the load, however, by increasing the heart rate, CD increases by 0.3, then the reaction is regarded as inadequate, but sufficient. 3. If the increase in the heart rate does not lead to an increase in the CR by 0.3, then the reaction is inadequate and insufficient. 4. As a paradoxical reaction is considered when, after exercise, there is a decrease in cardiac index,at the same time, even due to severe tachycardia, an increase in the CR to +0.3 is rarely achieved, as a rule, does not occur recovery of hemodynamic parameters by the end of the third minute after exercise. With a paradoxical and inadequate response, the dynamics of changes in vascular reactions is important. Reducing the performance of the heart to the load with an increase in vascular tone allows us to state left ventricular type heart failure. If the decrease in UI occurs when the vascular resistance of the pulmonary circulation decreases, in which the vascular tone of the small circle reflexively increases, which puts the right ventricle at disadvantageous conditions with a decrease in its performance, then on this basis only the registration of the left ventricular stroke volume (according to ITGT) allows regard this type of reaction as a manifestation of dynamic (i.e., detected under stress) right ventricular failure.

As the main criterion of functional operability, we use hemodynamic compensation of respiratory failure. Ultimately, all patients in this regard can be divided into three conditional groups. First, these are patients in whom the existing respiratory failure is fully compensated for by the hyperdynamic circulation regime, and functional stress tests reveal the presence of functional reserves. Experience shows that if the course of the operation and anesthesia are normal, no extraordinary situations developed, then almost always patients successfully complete the treatment with a good outcome.

The second, most numerous group is represented by patients with incomplete hemodynamic compensation of respiratory failure and limited reserve capacity of the cardiovascular system. These patients have special requirements for the operation and, especially, anesthesia. If pneumonectomy is planned, then spirometry must be performed separately. Simulation of this kind makes it possible to identify patients who are unable to provide full breathing and blood circulation in one lung. These patients are functionally inoperable. The rest in this group can have surgery, but its risk is extremely high, as well as the likelihood of various complications. Therefore, they require special management at all stages of treatment using the most modern means of monitoring, diagnostics,prevention and treatment.

The third group consists of patients in whom an uncompensated hemodynamically respiratory failure is detected in the absence of functional reserves of the circulatory system. In our opinion, these patients are functionally inoperable.