Question

Carlos Adams was involved in a motor vehicle accident and suffered blunt trauma to his abdomen. Upon presentation to the emergency department his vital signs are as follows: temperature, 100.9F; heart rstr, 20 breaths/min;and blood pressure, 90/54 mm Hg. His abdomen is firm, with bruising around the umblicus. He is alert and oriented, but complains of dizziness when changing positions. The patient is admitted for management of suspected hypovolemic shock.

The following orders are written for patient.

Place two large-bore IVs and infuse 0.9% NS at 125mL/hr/line

Obtain complete blood count serum electrolytes

Oxygen at 2L/min via nasal cannula

Type and cross for 4 units of blood

Flat plate of the abdomen STAT

a. Describe the pathologic sequence of events seen with hypovolemic shock

b. What the major goals of medical management in this patient

c. What is the rationale for placing two large-bore IVs

d. What are the advantages of using 0.9% NS in this patient

e. What is the rationale for placing the patient in a modified Trendelenburg position

Answer 1

Hypovolemic shock:

Etiology: It occurs due to the inadequate intravascular fluid volume resulting from the acute blood loss and fluid loss due to persistent diarrhea, vomiting, and dehydration.

a). Pathophysiology: In response to the decreased blood volume, the cardiovascular system, endocrine system, renal system and the hematologic system respond in different ways. The primary consequences of hypovolemia include,

• The hematologic system activates the coagulation cascade if bleeding occurs
• The cardiovascular system initially increases the heart rate and sympathetic response. As a result, the peripheral blood flow decreases to restore the circulation to the vital organs such as brain, heart, lungs, and kidneys. However, the overall drop in blood volume reduces the venous return and stroke volume. This results in reduced cardiac output and tissue perfusion.
• The renal system responds by stimulating the renin release. Renin stimulates aldosterone secretion and formation of angiotensin –II, both of which play a key role in the reversal of hemorrhagic shock.
• Endocrine system releases the ADH (anti-diuretic hormone) to reduce the fluid excretion through the kidneys.

b). The goals of medical treatment include restoration of fluid volume (lost through hemorrhage), blood pressure, and control of bleeding.

c). Placing two large bores IV (intravenous) allows the fluid administration continuously.

d). 0.9% NS (normal saline) is isotonic with the blood, so it is used to increase the fluid volume in cases of hypotension or hypovolemic shock

e). The patient is placed in a modified Trendelenburg position to improve the blood circulation to the heart and brain.