A 54-year-old woman is admitted with shock of unclear etiology. Placement of PA catheter reveals low cardiac output, elevated pulmonary artery pressure, and normal pulmonary capillary wedge pressure (PCWP).
The most likely etiology of her shock is:
A.Right ventricular infarct
B.Pulmonary embolism
C.Anaphylaxis
D.Pericardial tamponade
B is answer
Obstructive shock
Tamponade would not elevate PAP
A 55-year-old man is brought to the emergency department because of two hours of chest pain and difficulty breathing. Over the past week, he has felt increased shortness of breath upon exertion, with right-sided chest pain upon deep breathing. He has a cough productive of yellow-green sputum and intermittent chills. He is lethargic and only arousable with a forcible sternal rub. His temperature is 39°C (102.2°F), pulse is 110/min, respirations are 30/min, and blood pressure is 74/40 mm Hg. Pulse oximetry shows an oxygen saturation of 91% on 4 L of oxygen. A plain film chest radiograph shows multifocal consolidation opacities. Two liters of normal saline administered via pressure bag result in a blood pressure of 80/43 mm Hg. Blood cultures are obtained, and he is started on broad-spectrum intravenous antibiotic coverage. Which of the following corrections would most directly counteract the pathophysiology of this patient's condition?
A Decreasing heart rate
B Decreasing respiratory rate
C Decreasing systemic vascular resistance
D Increasing cardiac inotropy
E Increasing systemic vascular resistance
E. Septic shock is treated with a combination of intravenous fluid resuscitation to increase vascular preload and vasopressor medications to increase systemic vascular resistance.
TNF-α is the major mediator of septic shock. It is released when toll-like receptors on the surface of macrophages bind bacterial lipopolysaccharide, activating the signaling cascade allowing for its release.
This patient is in a state of distributive shock, specifically septic shock, secondary to a respiratory infection (probably pneumonia). Lipopolysaccharides (LPS) and other proteins, carbohydrates, and toxins produced by bacteria result in the activation of a variety of inflammatory mediators throughout the body. Large amounts of inflammation and immune activation can further induce systemic vasodilation and a large decrease in vascular resistance. The treatment for septic shock, aside from administering early antibiotics, is to help maintain adequate organ perfusion by providing increased intravascular volume (intravenous fluids) as well as increasing systemic vascular resistance. Vasoconstricting drugs, also known as "pressors," like norepinephrine, phenylephrine, and epinephrineare often used to help maintain adequate perfusion in patients with septic shock while antibiotics help to clear the source of infection (and the ultimate source of inflammation).
A 34-year-old man comes to the emergency
department by ambulance from a motor vehicle accident. He was riding in the bed
of a pickup truck and was ejected at a high speed. He has not received any
intravenous fluids. Physical examination shows an unresponsive man with an
absence of deep tendon reflexes and flaccid quadriplegia. Additionally, he has
dry, flushed, and warm skin with fecal incontinence and priapism. A cervical
spine MRI is obtained and shows traumatic spine injury above T6. A Swan-Ganz
catheter is inserted to assess hemodynamic variables. Which of the following
findings is most likely to confirm the diagnosis?
A. Beck's triad
B. Bradycardia
C. Discovery of a ruptured large artery
D. Increased pulmonary capillary wedge
pressure
E. Increased systemic vascular resistance
B
Major Takeaway
Neurogenic shock is
a type of distributive shock that is characterized by bradycardia, hypotension, and
other symptoms reflective of
the loss of sympathetic
nervous system stimulation
throughout the body. It
is often caused by traumatic injury to
the spinal cord above thoracic vertebrae number
6 (T6).
