Canterbury study into cardiac arrest

Hypothermia may be a way to give cardiac arrest patients a more than 10 per cent chance of survival, a study hopes to prove.

University of Canterbury PhD student Azurahisham Sah Pri is studying the affects of lowering cardiac arrest patients' body temperature below 35 degrees Celsius and its impact on their metabolism.

Sah Pri says hypothermia is an emerging treatment for cardiac arrest, an ailment which statistics show has a survival rate of about 10 per cent in New Zealand.

But cardiac arrest patients also suffered from high blood sugar levels, and hypothermia could 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 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 benefited from tight glycemic control.''

He had studied 47 patients from Christchurch Hospital's intensive care unit who were treated with hypothermia soon after admission and had high blood sugar.

Patients undergoing hypothermic treatment had significantly lower insulin sensitivity levels during the earlier cool period than the later warm after period, and were also more variable, which is what made 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 suggested 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 was contrary to common procedure.

The Canterbury University research, supervised by Geoff Chase and Chris Pretty, analyses the dynamics of post-cardiac arrest patients treated with hypothermia, and is the first study to show the metabolic impact of hypothermic treatment on the level, range and variability of insulin sensitivity.

The results had the potential to change metabolic treatment of patients and the therapy required to safely treat cardiac arrest patients.

The Press