Situation: The nurse is assigned to an adult intensive care unit where several clients have multi-system problems. Each item describes a different client. A 22-year-old man was admitted 2 hours ago after diving headfirst into shallow water. He cannot move his arms or legs. His blood pressure is 78/42 mmHg, heart rate 46/min, and his skin is warm and dry. Which mechanism explains this combination of findings?

A cervical spinal cord injury from a shallow-water dive can cause neurogenic shock: loss of sympathetic tone produces vasodilation (low systemic vascular resistance) and, with vagal tone unopposed, bradycardia. The result is hypotension with bradycardia and warm, dry skin.

Mechanism of hypotension with bradycardia after cervical SCI

A 22-year-old who dives headfirst into shallow water and presents with quadriplegia, hypotension, and bradycardia has a cervical spinal cord injury. The combination of BP 78/42 mmHg, HR 46/min, and warm, dry skin is the classic triad of neurogenic shock.

Neurogenic shock is a distributive shock caused by loss of sympathetic tone below the level of a spinal cord injury, most commonly at the cervical level. When the cervical cord is damaged, descending sympathetic pathways are interrupted. Below the injury, sympathetic outflow is lost, so blood vessels lose their baseline vasoconstrictor tone and dilate. This vasoplegia sharply reduces systemic vascular resistance, producing hypotension ^[1]. At the same time, the vagus nerve — which arises above the injury and remains intact — continues to slow the heart. With sympathetic input to the heart also interrupted, vagal tone is unopposed, resulting in bradycardia rather than the reflex tachycardia seen in other forms of shock. Because vasodilation is the primary problem, the skin stays warm and dry instead of cold and clammy ^[1][2].

The other options do not fit the clinical picture. Blood in the pericardial sac would produce cardiac tamponade, which causes hypotension but typically with tachycardia and distended neck veins. Internal bleeding causing hypovolemic shock also produces hypotension with tachycardia and cool, clammy skin. A vagal reflex from water inhalation would be transient and would not explain the quadriplegia.

Shock type	Heart rate	Skin	Key mechanism
Neurogenic shock	Bradycardia	Warm, dry	Loss of sympathetic tone below SCI; unopposed vagal tone
Hypovolemic shock	Tachycardia	Cool, clammy	Reduced circulating volume
Cardiogenic/tamponade	Tachycardia	Cool, clammy	Impaired cardiac output

Key point! Hypotension with bradycardia after trauma is a red flag for neurogenic shock until proven otherwise. The warm, dry skin helps distinguish it from hypovolemic shock, which also causes hypotension but with reflex tachycardia and cool skin.

Watch out! Neurogenic shock is not the same as spinal shock. Spinal shock refers to the temporary loss of reflexes and muscle tone below the injury; neurogenic shock refers specifically to the hemodynamic instability from sympathetic disruption. A patient can have both simultaneously ^[2].

The injury level matters. Cervical injuries are most likely to produce neurogenic shock because they interrupt sympathetic outflow to the heart and most of the vasculature. Injuries at T6 or above can also cause it, but the higher the lesion, the more profound the vasoplegia and bradycardia ^[1]. In this patient, the inability to move all four limbs confirms a cervical lesion, which is consistent with the hemodynamic findings.

Early management follows the ABCDE approach: stabilize the airway and breathing, support blood pressure, and immobilize the spine to prevent secondary cord injury ^[1]. The hypotension in neurogenic shock may respond poorly to fluids alone because the problem is vasodilation, not volume loss. Vasopressors with alpha-adrenergic activity are often needed to restore vascular tone, and atropine may be considered for symptomatic bradycardia ^[1][2]. The goal is to maintain spinal cord perfusion pressure and minimize secondary ischemic injury to the cord, which directly affects neurological outcome ^[2].