An overview of the cardiovascular and respiratory changes that occur from pregnancy and of sepsis

Pregnancy induces complex physiologic changes from as early as 5–8 weeks in virtually every organ system, the most important being the cardiovascular and respiratory system as a consequence of mediators like oestrogen, prostacyclin and nitric oxide.*

These changes can mask the presence of sepsis and so a composite graphical record of key maternal and fetal data during labour, using a partogram combined with close observations from a medical professional such as Dr Gary Swift who is a leading Gold Coast based Obstetrician, is important for early recognition of any complications.

Let’s look at the cardiovascular and respiratory changes in a little more detail –

 

Cardiovascular changes

Some of the cardiovascular changes experienced during pregnancy may include a fall in blood pressure, an increase in heart rate, about a 50% increase in blood volume, an increase in cardiac output, the compression of the abdominal aorta (which is the largest artery in the abdominal cavity) and the compression of the posterior vena cava, which is the large vein that carries deoxygenated blood from the lower half of the body into the right atrium of the heart

Some of the cardiovascular changes experienced from sepsis is reduced peripheral vascular resistance, widening of the blood vessels, heart rate exceeding the normal range and a fall in systemic blood pressure,

The cardiovascular changes from pregnancy, combined with septic shock, can result in rapid haemodynamic collapse, which is a failure in blood circulation. This can result in the death of the cells of an area of the heart muscle due to oxygen deprivation.

 

Respiratory changes

Some of the respiratory changes experienced during pregnancy may include low pulmonary vascular resistance, an increase in the amount of air a person breathes in a minute, an increase in the amount of air a person takes during each breath (otherwise known as tidal volume) and alkalosis, which the reduction of hydrogen ion concentraion of the arterial blood plasma.

Respiratory changes from sepsis may include acute lung injury, enhanced pulmonary microvascular pressure and the flow whole cells in and out of the blood vessel.

The respiratory changes from pregnancy combined with septic shock may result in increased susceptibility to fluid accumulation in the air spaces and parenchyma of the lungs otherwise known as pulmonary oedema, a rapid decline in oxygenation, widespread inflammation of the lungs otherwise known as adult respiratory distress syndrome and a decreased ability to buffer metabolic acidosis, which is the condition of the body producing too much acid.

Much of these complications can be avoided by working closely with a medical professional such as Dr Gary Swift , who is a leading Obstetrician on the Gold Coast. To arrange a pregnancy plan with Dr Gary Swift you can contact the clinic by phone on 07 5564 6017 or online via this link.
references

*Duvekot JJ, Peeters LLH. Very early changes in cardiovascular physiology. In: Chamberlain G, Pipkin FB (eds). Clinical physiology in obstetrics. Blackwell Scientific, Oxford, 1998; 3–32.
**Andrew ML. Pregnancy and Critical Care Medicine Part 1: Normal Physiologic Changes in Pregnancy. Critical Care (Alert) 2011; 18: 89–93.
***Edward R, Yeomans Larry C. Gilstrap III. Physiologic changes in pregnancy and their impact on critical care. Crit Care Med 2005 33: S256–258.