Oxygen And Carbon Dioxide Transport Pathway Flashcards
What are the different steps included in the oxygen transport pathway?
Ventilation of alveoli Diffusion of oxygen across the alveolar capillary membrane Perfusion of the lungs Biochemical reaction of oxygen with the blood Affinity of oxygen with Hb Cardiac Output (CO) Integrity of the peripheral circulation Oxygen extraction at tissue level
What factors affect metabolic demand?
Gravitational stressors (positioning)
Exercise
Psychological stressors
The oxygen transport pathway ensures an adequate supply of oxygen to meet the demand of working tissues. The carbon dioxide pathway ensures this primary by product of metabolism is eliminated
What factors influence oxygen transport from the atmosphere to tissues?
Ventilate alveoli
Diffusion across alveolar capillary membrane
Lungs need to be perfumed with blood
Affinity of oxygen and haemoglobin
Adequate cardiac output
Strength and integrity of peripheral circulation to deliver the blood to the tissues
Tissues should be able to extract the oxygen
The transport pathway ensures an adequate supply of oxygen meets the demands of the working tissues
True or false-
Optimum cardiopulmonary function and gas exchange rely on optimal matching of oxygen demand and supply
True
How can demand meet supply?
A well integrated system between the heart and the lungs so they work as a unit,
A CARDIOPULMONARY UNIT
Why is this CARDIOPULMONARY UNIT relevant to physiotherapy?
Mobilisation and exercise involves the application of progressive exercise to elicit acute cardiopulmonary and cardiovascular responses to enhance oxygen transport and improve gas exchange.
Physios may have an affect on heart or airways, we need to understand how they work so we can justify our interventions Better.
How is the o2 transport pathway more efficient in healthy patients compared to ill patients?
In health, oxygen delivery (DO2) is about 4 times greater than oxygen consumption (VO2).
This provides a considerable reserve which can be drawn upon during periods of increased metabolic demand such as exercise, stress, illness and repair.
How can this capacity become compromised during acute and chronic pathological conditions?
Acute- of abrupt onset or an illness that is so short duration, progresses rapidly and is in need of urgent care.
Chronic- lasts a long time. It lasts 3 months or more. Subacute lays in between.
What is the name for something that causes disruption to oxygen transport
Cardiopulmonary dysfunction
What are the 4 main factors that contribute to cardiopulmonary dysfunction and impaired oxygen transport?
Underlying disease pathophysiology
Extrinsic factors imposed by medical care eg Lines, monitoring, intubation and ventilation
Intrinsic factors relating to the patient - age, obesity, previous medical history
Bed Rest/ Recumbency/ immobility
What disease factors and pathophysiology can compromise or threaten O2 transport?
Pneumonia- affects lungs in airways, inflammatory exudate appears in alveoli and occupies the space that oxygen needs to pass to capillaries COPD BRONCHIECTASIS FRACTURED RIBS ATELECTASIS POST OPERATIVELY ACUTE ASTHMA
The oxygen transport pathway
Oxygen is transported from the atmosphere to tissues along the heart and the efficiency of each step determines the efficiency of O2 transport overall.
Eg oxygen transport is affected by the amount of secretions the physio removes
In regards to pulmonary rehab, exercise will improve lower limb muscle functioning
Breakdown of oxygen transport pathways
O2 moves from atmosphere through airways to heart and ultimately to the tissues. Each step in this pathway can be compromised by disease, surgery and immobility
Physios get involved during cardiopulmonary dysfunction…
Impairment of one step can be compensated for by another step but severe impairments results in…
Reduced arterial oxygenation, increases work of the heart and lungs, impaired tissue oxygenation, this causes multi-organ dysfunction/failure
