A nurse is caring for a patient in the emergency department who presents with signs of distributive shock. Which assessment finding would be the MOST important priority for the nurse to monitor continuously?
1Urine output every 2 hours
2Blood pressure and mean arterial pressure✓ 정답
3Oxygen saturation levels
4Level of consciousness using Glasgow Coma Scale
해설
In distributive shock, continuous monitoring of blood pressure and mean arterial pressure is the highest priority because distributive shock is characterized by massive vasodilation leading to relative hypovolemia and inadequate tissue perfusion despite normal or increased cardiac output.
Distributive shock is a critical condition where massive vasodilation leads to relative hypovolemia and inadequate tissue perfusion. It is characterized by inadequate tissue perfusion despite normal or increased cardiac output. The main types of distributive shock include septic shock, anaphylactic shock, and neurogenic shock, all of which share the common pathophysiology of severe vasodilation.
Monitoring blood pressure and mean arterial pressure (MAP) is the highest priority because distributive shock primarily affects vascular tone. Massive vasodilation causes blood to pool in the peripheral circulation, dramatically reducing venous return and effective circulating blood volume. This leads to severe hypotension and can rapidly progress to cardiovascular collapse. Mean arterial pressure is particularly important as it represents the driving pressure for organ perfusion, and a value below 65 mmHg generally indicates inadequate organ perfusion.
Continuous blood pressure monitoring allows for immediate detection of hemodynamic deterioration and guides critical interventions such as fluid resuscitation and vasopressor therapy. Patients with distributive shock often require aggressive fluid resuscitation and vasopressors like norepinephrine or dopamine to restore vascular tone and maintain adequate perfusion pressure.
Pathophysiologically, the release of inflammatory mediators or other substances causes widespread vasodilation. In septic shock, bacterial endotoxins trigger a massive inflammatory response; in anaphylactic shock, histamine and other mediators cause severe vasodilation; and in neurogenic shock, loss of sympathetic tone leads to unopposed parasympathetic activity, resulting in vasodilation.
Distributive shock can rapidly progress from compensated to decompensated shock, making early recognition and continuous monitoring of blood pressure changes essential. The body's compensatory mechanisms may initially maintain blood pressure through increased heart rate and contractility, but in severe cases, these mechanisms are quickly overwhelmed.
Clinical Judgment
The core of distributive shock is relative hypovolemia due to widespread vasodilation. Cardiac output may initially be normal, but extremely low vascular resistance leads to severe hypotension. Therefore, continuous monitoring of blood pressure and mean arterial pressure (MAP) is most critical. MAP directly reflects the driving pressure for organ perfusion, and a value below 65 mmHg is a warning sign of organ ischemia. While other indicators are important, a sudden drop in blood pressure can lead to a life-threatening situation requiring immediate vasopressor administration and aggressive fluid resuscitation.
Memory Tip: Distributive shock is a shock where blood pressure drops because "the vessels are relaxed." Blood pressure is the first to fall and the most dangerous. Remember it as "Vessel relaxation → BP ↓."
KR vs US: In Korea, you may be more familiar with non-invasive blood pressure measurement, but in NGN/US clinical settings, continuous blood pressure monitoring via an arterial line is standard for unstable patients like those with distributive shock. This is essential for capturing moment-to-moment changes and precisely titrating vasopressor effects.
임상 시나리오
Clinical Practice Guide
When managing patients with distributive shock (septic, anaphylactic, neurogenic), hemodynamic monitoring is the top priority. Establish continuous blood pressure and MAP monitoring via an arterial line. The core of initial management is aggressive fluid resuscitation and rapid initiation of vasopressors (e.g., norepinephrine).
Caution: In SATA (Select All That Apply) questions asking "what to monitor in distributive shock," all options may seem important. However, pay attention to keywords like "MOST important priority" or "continuously." Blood pressure/MAP requires second-by-second observation, whereas urine output is typically assessed every 1-2 hours and level of consciousness periodically.
핵심 개념
Distributive Shock — Distributive shock. Shock that occurs when blood pools in the peripheral vascular system due to widespread vasodilation. It results in a relative hypovolemic state and includes septic, anaphylactic, and neurogenic shock.
Mean Arterial Pressure — Mean arterial pressure. The average pressure within the arteries during the entire cardiac cycle. It is the best indicator of the driving pressure for organ perfusion, and generally should be maintained at 65 mmHg or above.
Vasodilation — Vasodilation. A phenomenon where the smooth muscle of blood vessels relaxes, widening the vessel diameter. It is the core pathophysiology of distributive shock, causing a sudden drop in vascular resistance leading to hypotension.
Vasopressor — Vasoconstrictors. Drugs that constrict blood vessels to raise blood pressure (e.g., norepinephrine, dopamine). They are the main pharmacological treatment for distributive shock.
Relative Hypovolemia — Relative hypovolemia. A condition where blood vessel volume is normal, but excessive vasodilation leads to insufficient effective circulating blood volume. It is a characteristic of distributive shock.