HEART LESIONS & PHYSIOLOGY
A hole between the atria is called this.
What is an ASD (atrial septal defect)?
In a child with a structurally normal heart, we usually aim to keep SpO₂ at or above about this percentage.
What is about 92–94%
Increasing PEEP can improve oxygenation but may reduce this type of blood return to the heart.
What is venous return?
This blood test provides pH, PaO₂, and PaCO₂ and is often drawn from an arterial line.
What is an arterial blood gas (ABG)?
After cardiac surgery, this common lung problem shows up as patchy or lobar collapse on x‑ray and often improves with recruitment and positioning.
What is atelectasis?
A large VSD causes a left‑to‑right shunt, which primarily increases blood flow to this circulation.
What is the pulmonary circulation (lungs)?
In many Glenn or Fontan patients, typical target saturations are lower than normal, often in this general range.
What is roughly 80–92%
In a fragile cardiac patient, a sudden drop in blood pressure after a PEEP increase is most likely due to this hemodynamic effect.
What is decreased venous return and reduced cardiac output?
ETCO₂ is usually lower than PaCO₂. A widening gap between them often suggests this kind of problem.
What is a perfusion/low cardiac output problem (increased dead space)?
Two common triggers of a pulmonary hypertensive crisis are low oxygen and high CO₂. We call these conditions this.
What are hypoxia and hypercarbia?
In Tetralogy of Fallot, “tet spells” are usually caused by decreased blood flow to this organ.
What is the lungs (leading to hypoxemia)?
In single ventricle patients, pushing sats toward 100% can worsen this balance between lungs and body.
What is the balance between Qp and Qs (too much Qp, not enough Qs)?
Hyperventilating a patient (dropping PaCO₂ too low) generally does this to PVR, which can be harmful in some single ventricle patients.
What is it decreases PVR, increasing pulmonary blood flow and potentially stealing flow from the systemic circulation?
A rising lactate and dropping mixed venous saturation (SvO₂) together suggest this overall issue with systemic circulation.
What is decreased systemic perfusion or low cardiac output?
In a suspected pulmonary hypertensive crisis, the RT’s first ventilator priorities include adjusting FiO₂ and rate to correct these three things.
What are hypoxia, hypercarbia, and acidosis (optimize oxygenation, normalize CO₂, and support pH)?
In single ventricle physiology (e.g., Norwood), the same ventricle supplies both pulmonary and systemic blood flow. We call these two flows by these abbreviations.
What are Qp (pulmonary blood flow) and Qs (systemic blood flow)?
In a large left‑to‑right shunt with pulmonary overcirculation, high FiO₂ can further lower this vascular resistance, driving more flow to the lungs.
What is pulmonary vascular resistance (PVR)?
In a patient with pulmonary undercirculation (e.g., TOF with significant RV outflow obstruction), your vent strategy should support oxygenation by adjusting these two key settings carefully.
What are FiO₂ (increase as needed for sats) and PEEP (use moderate levels to recruit without significantly dropping venous return)?
In a mixing lesion, SpO₂ alone may not fully describe oxygenation. This ABG value tells you the actual partial pressure of oxygen in arterial blood.
What is PaO₂?
Inhaled nitric oxide (iNO) primarily lowers pressure in this vascular bed and is delivered through this route.
What is the pulmonary circulation, delivered via inhalation into the lungs?
In a Glenn circulation, systemic venous blood from the upper body drains directly into this structure without passing through the ventricle first.
What is the pulmonary artery (via the superior vena cava–to–pulmonary artery connection)?
Name one lesion or situation where your team might intentionally accept SpO₂ in the mid‑70s to mid‑80s, and briefly say why.
Single ventricle/Norwood or Glenn patient, because lower sats help keep Qp and Qs balanced and preserve systemic perfusion.
A post‑op cardiac child is on pressure control ventilation. You see rising PaCO₂ and low tidal volumes while pressures are unchanged. Name one likely cause and one RT action.
Likely cause: decreased lung compliance (atelectasis, edema) or increased resistance. RT action: perform recruitment maneuvers as appropriate, suction, adjust pressures, or notify team.
a sustained drop in cerebral NIRS after a vent change suggests what about cerebral oxygen delivery, and what should you do?
What is decreased cerebral oxygen delivery (possible reduced systemic perfusion); RT should reassess vent settings (FiO₂, PEEP, PaCO₂), check BP and other monitors, and alert the team.
A child on iNO is being weaned. List one sign that the patient is not tolerating the wean and one RT action.
Sign: rising pulmonary pressures, desaturation, increased work of breathing, or hemodynamic instability. RT action: notify team, consider returning to previous iNO dose, ensure adequate oxygenation and ventilation.