What is the definition of hemodynamic instability?

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Last updated: April 18, 2025View editorial policy

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From the Guidelines

Hemodynamic instability is defined as a condition where a patient's systolic blood pressure is less than 90 mmHg with evidence of skin vasoconstriction, altered level of consciousness, and/or shortness of breath, or greater than 90 mmHg but requiring bolus infusions/transfusions and/or vasopressor drugs and/or admission base excess greater than -5 mmol/l and/or shock index greater than 1 and/or transfusion requirement of at least 4-6 Units of packed red blood cells within the first 24 hours, as stated in the 2019 guidelines for kidney and uro-trauma by the World Journal of Emergency Surgery 1.

Key Characteristics of Hemodynamic Instability

  • Systolic blood pressure less than 90 mmHg
  • Evidence of skin vasoconstriction, such as cool, clammy skin and decreased capillary refill
  • Altered level of consciousness
  • Shortness of breath
  • Requirement for bolus infusions/transfusions and/or vasopressor drugs
  • Admission base excess greater than -5 mmol/l
  • Shock index greater than 1
  • Transfusion requirement of at least 4-6 Units of packed red blood cells within the first 24 hours

Pediatric Considerations

In pediatric patients, hemodynamic stability is considered a systolic blood pressure of 90 mmHg plus twice the child’s age in years, with an acceptable hemodynamic status being a positive response to fluid resuscitation, including 3 boluses of 20 mL/kg of crystalloid replacement, leading to heart rate reduction, cleared sensorium, return of peripheral pulses, normal skin color, increase in blood pressure and urinary output, and an increase in warmth of the skin in the extremities, as noted in the same 2019 guidelines 1.

Importance of Clinical Judgment

Clinical judgment is fundamental in evaluating children, as the definition of hemodynamic instability may vary depending on the individual patient's condition and response to treatment, highlighting the need for careful assessment and monitoring in pediatric cases 1.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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