Association of blood lactate concentration and outcome in foals.

The researchers found a connection between the concentration of lactate in the blood of sick foals and their survival rates. The study was conducted on foals in a neonatal intensive care unit, and results showed that lower lactate levels correlated with higher chances of survival, while higher lactate levels were linked to unfavorable outcomes.

Research Design and Methodology

• The research involved 225 foals who were admitted consecutively to a Neonatal Intensive Care Unit.
• It was a retrospective case review study focusing on foals aged 30 days or less.
• The concentration of lactate in the blood was taken from either arterial or umbilical blood gas analysis at admission, 24, and 48 hours post-admission.
• Foals’ blood pressure, blood culture status, and outcome (survival versus nonsurvival at 96 hours and discharge) were recorded.
• ‘Change in lactate concentration over time’ (denoted as [LAC](BG)DeltaT in the study) was calculated based on the data gathered.

Research Findings

• Lower lactate levels in the blood at all measured times were observed in foals who survived, both up to 96 hours and until discharge.
• The ‘change in lactate levels over time’ was larger for the surviving foals.
• Increased lactate concentrations were associated with higher risks of mortality. Specifically, the likelihood of foals surviving decreased by 18, 39, 53 and 22, 38, and 47% respectively, at each sample time, for every 1 mmol/L increment in blood lactate levels.
• On the contrary, the odds of survival increased by 156% for every 1.0/day increment in the change of blood lactate levels from the time of admission to 24 hours.
• No correlation was found between blood pressure and lactate levels initially, but a significant relationship was observed after removing certain foals (those with mean arterial pressure below 60 mmHg, and whose lactate levels at admission were less than 5.5 mmol/L).
• Presence of bacteria in the blood, also known as bacteremia, showed no association with blood lactate levels.

Suggested Admission Cut-Points

• The researchers proposed that future studies should use an admission lactate concentration cut-point of 6.5 mmol/L for a forecast of 96-hour survival and a cut-point of 5.5 mmol/L for survival up to discharge.

Conclusions and Recommendations

• The researchers concluded the study by emphasizing the need for further prospective research examining the associations between lactate concentration, its change over time, and the suggested cut-points on the survival rates of sick foals.