NU654 Unit 3 Competing Priorities, Aortic Stenosis Example

Perfusion First, at a Stated Price: A Competing Priorities Analysis of Hypotension, Severe Aortic Stenosis and Pneumonia in an 81-Year-Old Man

[Student Name]

Purdue University Global

NU654: AGACNP Acute Care Diagnosis and Management III

Unit 3 Competing Priorities Analysis

[Instructor Name]

[Date]

The patient is composite; values, doses and times are bracketed.

The Case

Mr. [H.] is an [81]-year-old man with severe calcific aortic stenosis, a valve area of [0.7] cm2 and a mean gradient of [46] mmHg on an echocardiogram last spring, awaiting evaluation for valve replacement. He was admitted with [three] days of fever and cough and a right lower lobe consolidation. On the second evening his mean arterial pressure fell to [58] mmHg, his heart rate rose to [112], his lactate was [2.9] mmol/L and his creatinine was [1.8] mg/dL, half again above his usual [1.2]. His saturation was [88] percent on [6] liters, with crackles to both scapulae.

The Conflict

A narrowed aortic valve fixes the heart's output. The left ventricle can push blood through it only if it is well filled, so it depends on preload, and the thickened muscle depends on diastolic pressure for its own coronary blood flow. Low blood pressure in severe aortic stenosis can start a spiral: less coronary flow, a weaker ventricle, lower output and lower pressure still. Tachycardia shortens diastole and worsens it, and vasodilation removes the pressure the coronaries need.

On the other side, his lungs are wet. Pneumonia has filled one lobe, and the crackles to both scapulae suggest pulmonary edema from a stiff ventricle that cannot accept more volume without raising left atrial pressure. Every milliliter that helps his preload may cost him oxygen.

The same liter of fluid is both the rescue for his heart and the threat to his lungs, and the plan has to say which it will accept.

The Choice: Perfusion

The plan protects coronary and organ perfusion first. The reasoning is that hypoperfusion in severe aortic stenosis can become irreversible within hours, while hypoxemia can be supported with oxygen and noninvasive ventilation, and intubation remains available if needed. Sepsis guidance recommends norepinephrine as the first vasopressor and a mean arterial pressure target of 65 mmHg (Evans et al., 2021). For this valve, a vasopressor that raises pressure without increasing heart rate or dilating vessels is particularly useful.

1. Norepinephrine started at [0.05] mcg/kg per minute through a central line, titrated to a mean arterial pressure of [65 to 70] mmHg, with an arterial line.

2. Small, measured fluid boluses of [250] mL, each followed by bedside ultrasound of the inferior vena cava and lungs and a repeat blood pressure, stopping when B-lines increase or pressure no longer responds.

3. No vasodilators, including no nitroglycerin for the pulmonary congestion while he is hypotensive.

4. Rate control only if atrial fibrillation appears; avoid drugs that lower pressure.

5. Antibiotics for severe community-acquired pneumonia continued.

The Price

Protecting perfusion will cost oxygenation, and the plan states the cost in advance. It accepts a saturation of [88 to 92] percent, instead of the usual higher target, while vasopressors and small boluses restore pressure. It accepts escalation from nasal oxygen to high-flow nasal oxygen or noninvasive ventilation, recognizing that the evidence for noninvasive ventilation is strongest in other forms of respiratory failure and that its use here is a bridge while pressure recovers (Rochwerg et al., 2017). It accepts that his work of breathing may rise for a few hours. What it does not accept is a saturation below [85] percent, rising carbon dioxide or confusion, any of which would end the trade-off.

The valve guideline notes that patients with severe symptomatic aortic stenosis are at high risk during acute illness and that definitive treatment of the valve should be considered once the acute problem is controlled (Otto et al., 2021). The price paid tonight buys time for that decision.

How the Night Will Be Watched

A plan that accepts a trade-off needs close watching, because the balance can shift quickly. Mr. [H.] moves to the intensive care unit with an arterial line, so pressure is seen beat to beat rather than every fifteen minutes. His lactate is repeated at [two] and [six] hours. His urine output is measured hourly through a catheter. Bedside ultrasound of the lungs and the inferior vena cava is repeated after each fluid bolus and at least every [four] hours, looking for more B-lines as the sign that the lungs have taken what the heart could not use. His saturation, respiratory rate and mental status are recorded hourly, and a blood gas is drawn if he becomes drowsy. Each of these measures belongs to one side of the trade-off, and reading them together shows whether the price is still the one the plan agreed to pay.

Talking With Him About the Trade-Off

Mr. [H.] is alert and able to take part in decisions. He was told that his blood pressure was low because of the infection and his valve, that the team would support his pressure with a medicine and small amounts of fluid, and that this might make his breathing harder for a while and could mean a mask to help him breathe. Asked about breathing support through a tube, should it become necessary, he said he would accept it for a short time to get through the infection. That answer is recorded, because one of the tripwires below leads to intubation.

Tripwires

The plan changes if any of these occur:

1. Mean arterial pressure below [60] despite norepinephrine above [0.2] mcg/kg per minute: add vasopressin, call cardiology about temporary support, and discuss urgent valve intervention.

2. Saturation below [85] percent or pCO2 rising above [50] mmHg on noninvasive ventilation: intubate, with a pressor running before induction and drugs chosen to avoid vasodilation.

3. Lactate rising at [two] hours or less than [40] mL of urine an hour for [two] hours: reassess volume with ultrasound and consider one more small bolus.

4. New atrial fibrillation with rapid rate: synchronized cardioversion if unstable, since loss of atrial contraction is poorly tolerated with this valve.

Why Not the Other Choice

Choosing oxygenation first would mean diuresis or no fluid at all and possibly vasodilators to relieve congestion. In a patient with a fixed outflow and falling pressure, that risks the coronary spiral that is hardest to reverse. The analysis does not claim the lungs do not matter; it claims that, tonight, the heart's failure would be less recoverable than the lungs', and it names the measurements that would prove that judgment wrong.

References

Evans, L., Rhodes, A., Alhazzani, W., Antonelli, M., Coopersmith, C. M., French, C., Machado, F. R., Mcintyre, L., Ostermann, M., Prescott, H. C., Schorr, C., Simpson, S., Wiersinga, W. J., Alshamsi, F., Angus, D. C., Arabi, Y., Azevedo, L., Beale, R., Beilman, G., . . . Levy, M. (2021). Surviving sepsis campaign: International guidelines for management of sepsis and septic shock 2021. Critical Care Medicine, 49(11), e1063-e1143. https://doi.org/10.1097/CCM.0000000000005337

Otto, C. M., Nishimura, R. A., Bonow, R. O., Carabello, B. A., Erwin, J. P., III, Gentile, F., Jneid, H., Krieger, E. V., Mack, M., McLeod, C., O'Gara, P. T., Rigolin, V. H., Sundt, T. M., III, Thompson, A., & Toly, C. (2021). 2020 ACC/AHA guideline for the management of patients with valvular heart disease. Circulation, 143(5), e72-e227. https://doi.org/10.1161/CIR.0000000000000923

Rochwerg, B., Brochard, L., Elliott, M. W., Hess, D., Hill, N. S., Nava, S., Navalesi, P., Antonelli, M., Brozek, J., Conti, G., Ferrer, M., Guntupalli, K., Jaber, S., Keenan, S., Mancebo, J., Mehta, S., & Raoof, S. (2017). Official ERS/ATS clinical practice guidelines: Noninvasive ventilation for acute respiratory failure. European Respiratory Journal, 50(2), Article 1602426. https://doi.org/10.1183/13993003.02426-2016