UC studying use of hypothermia to treat cardiac arrest
UC studying use of hypothermia to treat cardiac arrest patients
July 24, 2013
A University of Canterbury (UC) PhD student is studying the use of hypothermia, or lowering body temperature below 35C degrees, to treat cardiac arrest patients and its impact on metabolism in these patients.
Statistics show the survival rate of cardiac arrest in New Zealand is around 10 percent. UC PhD researcher Azurahisham Sah Pri says hypothermia is an emerging treatment for these patients that can improve survival rates. However, these patients also suffer from high blood sugar levels and hypothermia can affect the doctor’s ability to control it.
``High blood sugar levels are prevalent in critical care which increases the risks of further complications and mortality. Tight glycemic control (TGC) has shown its potential in reducing mortality. Cardiac arrest patients, who have low survival rates and often experience high blood sugar, are one group who have benefitted from tight glycemic control.
``We have studied patients from Christchurch Hospital’s intensive care unit who were treated with hypothermia soon after admission and had high blood sugar.
``We found that patients undergoing hypothermic treatment have significantly lower insulin sensitivity levels during the earlier cool period than the later warm after period, and were also more variable, which is what makes their blood sugar levels particularly difficult to control.
``Our research results let us predict that, during treatment, the insulin sensitivity levels for patients will be very low during the cool period and increase over time which means we can see the future to an extent and provide safe control of blood sugar levels.
``Clinically, our results have significant implications for managing glycaemia in these patients. The results suggest that proposed protocols should seek to try to regulate insulin usage particularly during the cool period in the first 15 to 24 hours of intensive care, which is contrary to what is often done.’’
The UC research, supervised by Professor Geoff Chase and Dr Chris Pretty, analysed the dynamics of post-cardiac arrest patients treated with hypothermia. It is the first study to show the metabolic impact of hypothermic treatment on the level, range and variability of insulin sensitivity.
The results have significant potential clinical impact on the metabolic treatment of patients and the changes in therapy required to safely treat patients as they transition in each period of the treatment.