Introduction: Hypothermia is a promising therapeutic modality for neuro- protection in patients with acute stroke. Treatment goal temperature may be governed indirectly by foley bladder temperature (F) measurements. We describe a mathematical correlation between bladder (F) and cerebral temperature (Br).
Methods: In a retrospective analysis of prospectively collected data from 2008 to 2011, 54 patients underwent cerebral cortical temperature monitoring (Licox, Integra Sciences) and foley bladder temperature measurements before, during, and after hypothermia to goal of 33 degrees C. Normal cerebral tissue was targeted for cerebral probe implant site. Average time from induction to rewarm completion was 3.5 days. Nine patients (M:F = 4:5; avg age 51) underwent hypothermia for acute cerebral occlusive disease (stroke, vasospasm, dissection). A total of 510 hourly data points were analyzed. Only one patient had BMI greater than 30.
Results: Linear regression analysis demonstrated correlation of Br = 0.98F + 1.3 (Figure1). R2 was 0.82. Hourly temperature recordings are shown on Figure 2.
Conclusions: A high degree of hourly correlation is noted before, during and after hypothermia to 33 degrees C between bladder and cerebral temperature. An average of 1.3 degrees C separates bladder from cerebral temperature.
Patient Care: Identification of correlation between cerebral and systemic temperatures.
Learning Objectives: (1) Realize that most systemic hypothermia for cerebral protection currently do not use direct cerebral temperature measurements
(2) Realize a rough physiologic correlation between cerebral and foley temperature during, before, and after induction of hypothermia to 33 degrees Celcius