Neuro Monitoring

Question 1

Why is it important to avoid hyperglycaemia in the critically unwell?

Answer 1

Severe hyperglycaemia has been shown to have negative impact on the vascular, immune and haemodynamic systems. It is can lead to electrolyte imbalance, mitochondial injury and endothelial dysfunction

Question 2

Why do critically unwell adults develop hyperglycaemia?

Answer 2

Endogenous causes:

• release of counter-regulatory hormones
• elevated inflammatory cytokines
• increased insulin resistance
• reduced glucose uptake

Exogenous

• medications - glucocorticoids
• parenteral and enteral nutrition
• immobility

Question 3

Why do we target a glucose of 6-10 mmol/L

Answer 3

Van der Berghe et al in 2001 demonstrated that tight glycaemic control led to a reduced mortality in predominantly post-op surgical patients. However, this was a single centre RCT, and the large NICE-SUGAR RCT in 2008 a significantly higher mortality in the tight glycaemic control group, as well as a higher cardiovascular deaths and hypoglycaemic events. This has led to a transition to ‘good’ glycaemic control of BMs of 6-10.

Question 4

How is hypoglycaemia defined?

Answer 4

Blood glucose level under 3.9 as this correlates with the initial release of counter-regulatory hormones. Cognitive impairment begins at a blood glucose of 2.8. Severe is defined as glucose under 2.2

Question 5

How are glucocorticoids and mineralocorticoids different?

Answer 5

In addition to the anti-inflammatory and immunosuppressive effects, glucocorticoids mimic cortisol, a natural hormone produced by our body, essential for the utilization of carbohydrates, fat and protein as well as aiding in our normal response to stress.

Mineralocorticoids also play a role in anti-inflammatory and immunosuppressive therapy, but more importantly, they mimic aldosterone. Aldosterone is another hormone secreted by the adrenal glands, which plays a critical role in the regulation of sodium and water transport