Studying the drip, drip effect
Perhaps the most innocuous medical aids in today’s modern hospital units of high-tech machines and medical devises is the humble drip. Intravenous drips first came into prominence in the makeshift hospital units of World War One. On those battlefields, as in current day intensive care units, the ability to inject a simple hydrating solution into the vein helps to maintain body fluid, aid the output of the heart, and stabilises and maintains blood pressure.
The use of different drip solutions have for several years been of interest to researchers at The George Institute. There are many subtlety different forms of the drip that are used in the intensive care setting but the two main groups can be divided into crystalloids like saline, which dissolve in water, and colloids like starch, that suspend in water.
The CHEST trial is asking fundamental questions about the benefits of a starch verses saline drip solution in the intensive care environment. Saline has the benefit of being cheap, with a history of effectiveness, whereas the more expensive starch appears to have a faster-acting effect in improving factors like patient blood pressure and blood flow to body and organs.
Yet, some clinicians believe a potential consequence of a starch solution is that it can collect in kidney cells, damaging the kidney in the long term. There are also fears that starch inhibits immune cells and can accumulate in the skin to cause itchiness.
Surprisingly, there has never been a large clinical trial to vigorously prove the benefits or safety of a starch verses a saline drip. Intravenous fluids do not undergo the same strenuous clinical trial evaluations that are required before most medicines come into routine use. For this and many other reasons the CHEST trial is deemed by many as the most important study in intensive care medical research in the last 30 years.
Based on similar principles to a previous successful George Institute trial called ‘SAFE’, which found the use of a an expensive colloid solution called ‘albumin’ to be harmful for those with traumatic brain injury, researchers plan to recruit 7,000 patients in 32 intensive care units (ICU) in Australia and New Zealand by the end of 2011. Results are due to be published at the end of 2012.
The trial has three possible outcomes, all of which will have an impact on intensive care medicine around the world. The trial has been designed to find out if there is any difference between treatment with starch or saline in patient survival 90 days after receiving ICU care. The trial will also examine any difference between kidney function, brain haemorrhage and length of recovery. Cost-effectiveness and patient quality of life will also be examined. One or other of the intravenous treatments may have better results or the result may be similar for both treatments.
Whatever the results of the trial, the findings will provide importance evidence for clinical practice in intensive care units around the world contributing significantly to the improvement in the survival and recovery of millions of people that receive intensive care every year.