The first 24 to 48 hours immediately following surgery is a critical time period. Many things need to happen in order to safely recover. A patient needs to awaken from anesthesia, vital signs need to be stable, and the patient must start to ambulate and eat. Occasionally, the patient’s vital signs are not stable and low blood pressure occurs. This is commonly referred to as shock.
Hypovolemic Shock
Hypovolemic shock, or low volume shock, occurs when there is not enough blood in the system to meet the requirements of the body. Low blood pressure occurs because the heart does not have enough blood to pump. Along with low blood pressure, the patient’s pulse rate will go up and urinary output will decrease. Blood loss during surgery or continued bleeding causes hypovolemic shock. According to “Sabiston Textbook of Surgery,” a hemorrhage is the most frequent cause of hypovolemic shock, and prompt recognition of the problem is required.
Cardiogenic Shock
Cardiogenic shock occurs because the heart's ability to contract is impaired and it cannot maintain adequate blood flow to the body. The most common cause of cardiogenic shock is the occlusion of a coronary artery that causes a myocardial infarction, or heart attack. When a part of the heart muscle dies because of lack of blood flow, the heart's ability to contract is compromised. According to “Sabiston Textbook of Surgery,” 7 to 10 percent of patients with a new onset heart attack develop cardiogenic shock. Death occurs in 40 to 70 percent of patients who experience cardiogenic shock. Treatment may require cardiac bypass surgery, intravenous fluids and medications that will keep the blood pressure within a normal range.
Septic Shock
Sepsis occurs when an overwhelming infection creates a severe inflammatory response in the body. This inflammatory response causes the arteries to dilate, resulting in not having enough blood in the vascular system to fill the capacity of the arteries and not enough resistance in the arteries to push blood back to the heart. Low blood pressure, fast heart rate and fever due to infection occur. According to “Sabiston Textbook of Surgery,” 700,000 patients were hospitalized in 2001 with sepsis; 210,000 of them died. Treating septic shock requires large volumes of fluid, drugs to help maintain pressure and antibiotics to treat the infection.
References
- “Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice”; Courtney Townsend, M.D., et al.; 2008
- MedlinePlus: Shock


