Why Blood Pressure Should Not Be the Therapeutic Target in Shock

Blood pressure is a routinely monitored parameter in patient care, whether ambulatory or inpatient.  It is continuously monitored in critically ill patients in an intensive care unit.  In these units, loud alarms are activated when such a patient’s blood pressure suddenly drops below the predetermined alarm threshold.  Critical Care nurses and physicians at once respond to the alarms and start to assess the patient and correct the situation.

In many cases, the patient has had earlier episodes of hypotension and has been successfully resuscitated with the appropriate treatments that were applied on those occasions. But in other cases, the root causality of the patient’s hypotension is not really known. There are several different underlying conditions that can produce hypotension. They have been categorized into 4 different etiologies:

1. Hypovolemia

2. Neurogenic conditions

3. Cardiogenic conditions

4. Overwhelming sepsis

Bottom line: Sudden hypotension by itself does not identify the underlying problem. There are four potential causes for such conditions:

Unfortunately, the response is usually flawed, as it seeks to correct the symptom but not the disease. That is, the initial clinical response is to administer vasopressors to increase the blood pressure reading.  However, such treatment does not actually fix the problem.  To treat any disease, it is necessary to evaluate and decide the nature of the condition responsible for it.  In the case of hypotension, there are different conditions in each of the four categories of hypotension.  Effective treatment requires specific management of the underlying condition.  I addressed this issue in “Understanding circulatory and non-circulatory shock” on this same website.