What is permissive hypertension (high blood pressure)?

From the Guidelines

Permissive hypertension should be avoided in most clinical scenarios, and instead, a strategy of permissive hypotension with a target systolic blood pressure of 80-90 mmHg is recommended for patients without traumatic brain injury (TBI) or spinal injury. This approach is supported by recent meta-analyses of randomized controlled trials (RCTs) and retrospective studies, which have shown a decrease in mortality when using a restricted volume replacement and permissive hypotension concept compared to traditional aggressive fluid resuscitation 1. The rationale behind this strategy is to minimize the risk of exacerbating bleeding and promoting coagulopathy, while also reducing the need for transfusions and intensive care unit (ICU) stays.

Some key points to consider when implementing permissive hypotension include:

• The concept is contraindicated in patients with TBI and spinal injuries, as adequate perfusion pressure is crucial to ensure tissue oxygenation of the injured central nervous system 1.
• Elderly patients and those with chronic arterial hypertension may require careful consideration and potentially alternative strategies 1.
• Rapid bleeding control is of particular importance in patients with TBI and spinal injuries, and vasopressor administration may be necessary to achieve an adequate perfusion pressure 1.
• The currently available data should be interpreted with caution, and further confirmation in adequately powered prospective RCTs is needed to fully support this approach 1.

In terms of specific clinical scenarios, permissive hypotension may be beneficial in patients with penetrating trauma, as demonstrated by a RCT published in the 1990s 1. Additionally, a recent meta-analysis of RCTs found a decrease in mortality when using a restricted volume replacement and permissive hypotension concept in trauma patients without TBI 1. However, it is essential to carefully consider the individual patient's condition and tailor the approach accordingly, taking into account factors such as age, comorbidities, and the presence of other injuries.

From the Research

Permissive Hypertension

• Permissive hypertension is not directly addressed in the provided studies, however, the concept of blood pressure management and treatment of hypertension is discussed in several studies 2, 3, 4, 5.
• According to the study by 2, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) provides comprehensive guidelines on the diagnosis, classification, and management of hypertension and related CV conditions.
• The study by 3 discusses the combination of beta-blockers and ACE inhibitors in the treatment of hypertension and cardiovascular diseases, highlighting their complementary actions on the sympathetic nervous system and renin-angiotensin-aldosterone system.
• Another study by 4 recommends ACE inhibitors as a safe option for hypertension and congestive heart failure, due to their safety profile, absence of adverse metabolic effects, and positive cardiac and renal effects.
• The study by 5 provides a historical perspective and current insights on ACE inhibitors in hypertension, comparing their efficacy, tolerability, and safety to ARBs, and highlighting the contemporary issues surrounding ACE inhibitor use for HTN.

Treatment of Hypertension

• The studies suggest that ACE inhibitors, beta-blockers, and diuretics are potential first-step agents for the pharmacologic treatment of hypertension 2, 4.
• The combination of beta-blockers and ACE inhibitors is also recommended for the treatment of hypertension and cardiovascular diseases 3.
• The study by 5 suggests that ACE inhibitors and ARBs have an equal class of recommendation for first-line treatment for the management of HTN.

Blood Pressure Management

• The study by 6 discusses hypertensive emergencies, defining them as a blood pressure greater than 180/120 mmHg leading to end-organ damage, and recommends therapeutic intervention with short-acting, easily titratable, intravenous antihypertensive medication.
• The study by 2 highlights the importance of blood pressure reduction through lifestyle modification and/or antihypertensive therapy to dramatically reduce the risk for CVD.