Vasoconstrictors should not be used in?

SJH Nursing Officer - 2019

Pharmacology

Hard

Appeared in: SJH Nursing Officer - 2019

Explanation

Haemorrhagic shock is a form of hypovolemic shock caused by significant blood loss.
The primary problem is an 'empty tank'—insufficient blood volume to fill the vascular system.
The body's natural response is to trigger the sympathetic nervous system, causing intense vasoconstriction to maintain pressure and perfuse vital organs.
Adding vasoconstrictor drugs before replacing lost fluid volume further constricts already constricted vessels, severely cutting off blood supply to tissues (like kidneys and gut) and worsening organ damage.
Therefore, the priority treatment is rapid fluid and/or blood product administration to restore circulating volume, not vasoconstrictors.

Option A: This option is incorrect. Vasoconstrictors are a primary treatment for neurogenic shock.
Option C: This is a vague and less specific term. 'Secondary shock' can refer to the decompensated stage of any shock, but haemorrhagic shock presents a more direct and absolute initial contraindication to vasoconstrictors.
Option D: This option is incorrect. Vasoconstrictors are the standard treatment for hypotension caused by spinal anaesthesia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacological Management of Shock as background academic context rather than a clinical decision trigger.
The core nursing principle in managing haemorrhagic shock is 'volume first'. Nurses must prioritize establishing large-bore IV access for rapid infusion of fluids and blood products.
A key nursing assessment is monitoring for signs of end-organ perfusion, such as urine output, mental status, and skin temperature. Worsening of these signs after vasopressor administration (without volume) would indicate harm.
What if? If a patient in haemorrhagic shock has received massive fluid resuscitation but remains hypotensive, a vasopressor might then be considered as a last resort to maintain perfusion to the heart and brain, but this is after the primary problem of volume has been aggressively addressed.

How to Approach the Question

First, identify the negative framing of the question: it asks where vasoconstrictors should NOT be used.
Recall the basic pathophysiology of the different types of shock listed in the options.
For each option, ask: 'What is the primary problem?' Is it a loss of volume (hypovolemic), a failure of the pump (cardiogenic), or a problem with the pipes (distributive/vasodilatory)?
Haemorrhagic shock is a volume problem. Neurogenic shock and hypotension from spinal anaesthesia are 'pipe' problems (vasodilation).
Match the drug's action (vasoconstriction, i.e., narrowing the pipes) to the underlying problem. Narrowing already-constricted pipes in a volume-depleted patient is harmful. Narrowing overly-dilated pipes is helpful.
This logic identifies haemorrhagic shock as the condition where vasoconstrictors are initially contraindicated.

Concept Tested & Keywords

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E6 Physiology Guyton 4SAE Part 2A p. 30-32

E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 1 (1-214) p. 194-196