What is the significance of Systolic Blood Pressure (SBP)?

From the Guidelines

In geriatric trauma patients, a systolic blood pressure (SBP) of less than 110 mmHg is considered a critical cutoff value for predicting massive transfusion, especially in those taking antihypertensives, as indicated by a study published in 2024 1. When evaluating SBP in the context of geriatric trauma, it's essential to consider the patient's age, pre-existing medical conditions, and medications, as these factors can significantly impact the interpretation of SBP readings.

• A study published in the World Journal of Emergency Surgery in 2024 found that low systolic blood pressure at presentation was a significant risk factor for mortality in geriatric trauma patients 1.
• The same study highlighted that the odds of dying in trauma patients older than 74 years were higher compared to those aged 65-74 years, emphasizing the importance of careful monitoring and management of SBP in this population.
• Another study published in Hypertension in 2018 noted that isolated systolic hypertension is the predominant form of hypertension in older persons and that blood pressure lowering in this population can reduce the risk of fatal and nonfatal stroke, cardiovascular events, and death 1. Key considerations in managing SBP in geriatric trauma patients include:
• The potential for polypharmacy and comorbidities to impact SBP readings and treatment outcomes
• The need for careful titration of blood pressure lowering medications to avoid orthostatic hypotension and other adverse effects
• The importance of monitoring for signs of hemodynamic instability, such as a shock index (SI) greater than or equal to 1, which can indicate the need for transfusion or other interventions 1.

From the Research

Definition and Causes of SBP

• Spontaneous bacterial peritonitis (SBP) is a severe infectious complication in cirrhotic patients, and initial antibiotic therapy must be empirical 2.
• SBP is defined as bacterial infections that occur in patients with cirrhosis and ascites without any significant intraperitoneal infection, accounting for approximately 10-30% of bacterial infections in hospitalized patients 3.
• The most common cause of SBP is Gram-negative bacteria, such as Escherichia coli and Klebsiella species, and infections by Gram-positive bacteria are increasing 3, 4.

Diagnosis of SBP

• SBP is diagnosed by the presence of >250 polymorphonuclear leukocyte/mm3 in ascites after paracentesis 3.
• Paracentesis is the diagnostic modality of choice and should be performed in any patient with ascites and concern for SBP or upper gastrointestinal bleeding, or in those being admitted for a complication of cirrhosis 4, 5.
• An ascites absolute neutrophil count (ANC) ≥ 250 cells/mm3 is diagnostic of SBP 4.

Treatment and Management of SBP

• Empirical antibiotic therapy should be started immediately if SBP is diagnosed, and should distinguish between community acquired infections and nosocomial infections 3, 5.
• Third-generation cephalosporins, such as cefotaxime, are considered the agent of choice in the empiric therapy of SBP 2.
• Albumin infusion is associated with reduced risk of renal impairment and mortality 4.
• Management may also include the use of broad-spectrum antibiotics, such as carbapenem or piperacillin-tazobactam, in specific patient populations 4, 5, 6.

Prevention and Risk Factors

• Cirrhotic patients with gastrointestinal bleeding or low ascitic protein concentrations should consider primary prevention, and those who recover from SBP should consider secondary prevention 3.
• Acid suppressive and beta-adrenergic antagonist therapies are strongly associated with SBP in at-risk individuals 6.
• Withholding acid suppressive medication and discontinuing beta-adrenergic antagonist therapy in patients with end-stage liver disease and resistant ascites is standard care 6.