Platelet mitochondrial dysfunction in critically ill patients: comparison between sepsis and cardiogenic shock

Area of Science:

• Critical care medicine
• Hematology
• Mitochondrial biochemistry

Background:

• Platelet mitochondrial respiratory chain enzymes are inhibited in sepsis.
• It is unknown if these changes occur in other critical illnesses or affect platelet function.
• This study investigated platelet mitochondrial enzymes in sepsis versus cardiogenic shock and their relation to platelet responsiveness.

Purpose of the Study:

• Compare platelet mitochondrial respiratory chain enzyme activity in sepsis and cardiogenic shock.
• Examine the association between enzyme activity and platelet aggregation/secretion in sepsis.

Main Methods:

• Prospective, observational, case-control study.
• Isolated platelets from 16 sepsis, 16 cardiogenic shock patients, and 16 healthy controls.
• Measured mitochondrial enzyme activity and platelet aggregation/secretion in response to agonists.

Main Results:

• Patients with sepsis or cardiogenic shock showed reduced activity in multiple mitochondrial respiratory chain enzymes (NADH, complex I, I+III, IV) compared to controls.
• Sepsis patients exhibited hypo-responsiveness in platelet aggregation and secretion.
• Lower activity of specific mitochondrial enzymes correlated with reduced platelet aggregation.

Conclusions:

• Platelet mitochondrial respiratory chain enzymes are similarly inhibited in sepsis and cardiogenic shock.
• Mitochondrial dysfunction in sepsis is associated with impaired platelet responsiveness.