Delayed Rewarming Thrombocytopenia (DRT): A Temperature-Dependent Platelet Aggregation Disorder

Area of Science:

• Hematology
• Physiology
• Biochemistry

Background:

• Hypothermia significantly impacts platelet function, inhibiting the second irreversible stage of aggregation.
• Platelet adhesion and the first reversible stage are augmented at temperatures below 32 °C.

Purpose of the Study:

• To investigate the mechanisms behind delayed rewarming thrombocytopenia (DRT) following hypothermia.
• To identify factors contributing to DRT and explore preventative strategies.

Main Methods:

• Observational study analyzing platelet aggregation and adhesion under hypothermic and rewarming conditions.
• Assessment of adenosine diphosphate (ADP) release from erythrocytes during rewarming.
• Evaluation of the efficacy of various interventions, including heparin, alcohol, aspirin, and platelet infusions.

Main Results:

• Rewarming triggers platelet de-aggregation, but adequate ADP levels can initiate the second aggregation phase, causing DRT.
• Erythrocytes release sufficient ADP within 24 hours to induce DRT.
• Heparin, alcohol, and aspirin demonstrate preventative effects by inhibiting platelet adhesion and/or aggregation.
• Platelet infusions stored without erythrocytes are an effective therapy for DRT.

Conclusions:

• DRT is a significant complication of hypothermia, particularly in cases of neonatal cold injury (NCI).
• Timely rewarming (within 24 hours) or therapeutic interventions can prevent DRT.
• Understanding the role of ADP and erythrocyte lysis is crucial for managing hypothermia-associated coagulopathy.