An 81-year-old nursing home resident is brought to the emergency department due to a day of progressive lethargy and shortness of breath. The patient has a medical history of hypertension and Alzheimer dementia. Blood pressure is 97/45 mm Hg and pulse is 120/min. Auscultation of the chest reveals reduced breath sounds and crackles in the right infrascapular region. There is a 2/6 systolic ejection murmur heard at the right upper sternal border. Invasive hemodynamic monitoring reveals a cardiac index of 4.4 L/min/m2 (normal, 2.5-4.2 L/min/m2), right atrial pressure of 4 mm Hg (normal, 2-10 mm Hg), and pulmonary capillary wedge pressure of 6 mm Hg (normal, 6-15 mm Hg). The systemic vascular resistance is decreased. Which of the following is a likely additional finding in this patient?
This patient with likely pneumonia (eg, reduced breath sounds and crackles in the right lung) has signs of septic shock, including hypotension and tachycardia.
Patients with septic shock develop hypotension from peripheral vasodilation (which leads to decreased systemic vascular resistance) and capillary leak with loss of intravascular volume into the surrounding tissues (which leads to borderline-low right atrial pressure and pulmonary capillary wedge pressure [PCWP]). To compensate for intravascular hypovolemia, the cardiac index and stroke volume increase, leading to an increased pulse pressure (systolic minus diastolic pressure), which can manifest as bounding peripheral pulses.
The finding of bounding peripheral pulses is seen in the early phase of sepsis, known as the hyperdynamic phase. Without treatment, this can progress to the more severe hypodynamic phase, with patients developing cool and clammy extremities due to decreased blood supply as blood is preferentially shunted to the vital organs; this phase is associated with decreased cardiac output and increased (rather than decreased) systemic vascular resistance (Choice B).
(Choice C) A patient with distended neck veins likely has pooling of blood in the venous system, which can occur in states of volume overload (eg, congestive heart failure). On invasive hemodynamic monitoring, these patients will have elevated PCWP and right atrial pressures due to intravascular overload, with decreased cardiac index due to decreased cardiac contractility in the setting of cardiac muscle stretch from volume overload.
(Choice D) Pulsus paradoxus occurs when there is a ≥10 mm Hg drop in systolic blood pressure with inspiration. It is most commonly seen in patients with cardiac tamponade. On invasive monitoring, these patients have increased pulmonary vascular resistance and right atrial and ventricular pressures with equalization of the right atrial pressure, right ventricular end-diastolic pressure, and PCWP.
(Choice E) In most cases, the presence of a third heart sound, or S3 gallop, indicates early congestive heart failure and intravascular overload. This patient, however, has early septic shock with associated peripheral vasodilation and capillary leak leading to intravascular hypovolemia. Her systolic ejection murmur is more consistent with aortic stenosis or sclerosis.
Educational objective:
Early septic shock is associated with a hyperdynamic cardiovascular state that occurs in response to peripheral vasodilation with capillary leak and intravascular hypovolemia. This leads to an increase in stroke volume, heart rate, and pulse pressure, which results in bounding peripheral pulses.