Question: I'm curious if it is recommended to take blood sugar readings on VSA patients? If a blood sugar is taken on a VSA patient, and the reading is < 4mmol/L (which may be quite common due to the sample being capillary and CPR not perfusing sugar to the extremities), do we treat with Glucagon or D50? What if we suspect the patient is VSA due to a diabetic event? Does the answer change whether I'm a PCP or an ACP? Thanks!
Thanks for asking this question. It is definitely one of our frequent questions we receive each year at recertification time. The challenge here is knowing whether or not a capillary blood glucose reading (or one taken from an IV catheter from a peripheral source) in a patient suffering from a cardiac arrest can be considered reliable and truly reflective of the serum glucose. If the patient is poorly perfused, glucose is consumed by the cells and then no further glucose is delivered peripherally due to the lack of circulation. Taking a sample during a cardiac arrest therefore may lead to a falsely low number when truly the patient is/was not hypoglycemic.
Other complicating factors in this would be: if we do get a low number and decide to treat, how effective is IM Glucagon in a patient who has arrested and is no longer well perfused OR if we decided to treat with IV dextrose, is there a risk in doing so? In an anoxic and poorly perfused brain that is typical in a patient suffering from a cardiac arrest, it is unclear that a high solute load of dextrose suddenly infused into the circulation is desirable.
The 2010 AHA Guidelines state in Part 9: Post-Cardiac Arrest Care "The post€“cardiac arrest patient is likely to develop metabolic abnormalities such as hyperglycemia that may be detrimental. Evidence from several retrospective studies suggests an association of higher glucose levels with increased mortality or worse neurological outcomes." Circulation.2010; 122: S768-S786
So, to answer your question specifically, the SWORBHP Medical Council believes that the practice of routine blood glucose determination during a medical cardiac arrest is not indicated and may lead to unreliable results. As well, there is experimental evidence that suggests hyperglycemia is not without a negative consequence to a patient suffering from a cardiac arrest and therefore empiric dextrose administration is also not indicated.
Bottom line: In the setting of a medical cardiac arrest, whether you are a PCP or an ACP, please follow the Medical Cardiac Arrest Medical Directive as listed in your protocol book. Routine glucose sampling does not form part of that medical directive at this time.