Metabolic Changes in Patients Entering End of Life
At the end of life, patients experience significant metabolic changes including terminal hypometabolism, where normal amounts of energy and substrates may become excessive and induce metabolic distress rather than provide benefit. 1
Metabolic Changes by System
Energy Metabolism
- Decreased overall metabolic rate and energy requirements
- Shift from anabolic to catabolic state
- Reduced ability to utilize nutrients effectively
- Terminal hypometabolism where normal nutritional intake may cause metabolic distress 1
Glucose Regulation
- Altered glucose metabolism with potential for:
- Hyperglycemia due to stress response and reduced insulin sensitivity
- Hypoglycemia risk in patients on glucose-lowering medications 1
- Blood glucose levels between 200-300 mg/dL may be acceptable in hospice patients 1
Fluid and Electrolyte Balance
- Decreased thirst sensation
- Reduced kidney function affecting fluid and electrolyte balance
- Dehydration may occur but rarely causes discomfort in truly terminal patients 2
- Fluid overload may cause increased respiratory secretions and discomfort 2
Nutritional Status
- Decreased appetite and oral intake
- Reduced gastrointestinal motility and absorption
- Anorexia-cachexia syndrome in many terminal conditions
- Weight loss despite adequate caloric provision 1
Progression of Metabolic Changes by Stage
Stable End-of-Life Phase
- Patients may continue previous metabolic function with gradual decline
- Hyperglycemia risks include hyperosmolar hyperglycemic state, osmotic diuresis, recurrent infection, and poor wound healing 1
- Monitoring should focus on preventing hypoglycemia rather than tight glycemic control 1
Organ Failure Phase
- Renal and hepatic dysfunction affects medication metabolism
- Increased risk of hypoglycemia due to reduced clearance of medications
- Dehydration becomes more common and significant 1
- Reduced metabolism of medications requiring dose adjustments 1
Active Dying Phase
- Terminal hypometabolism - normal amounts of energy and substrates become excessive 1
- Minimal to no hunger sensation
- Thirst primarily related to dry mouth rather than true dehydration 1
- Metabolic needs dramatically decrease 1
Management Implications
Glucose Management
- For patients with diabetes:
- Type 1 diabetes: Maintain minimal basal insulin to prevent ketoacidosis
- Type 2 diabetes: Consider discontinuing all glucose-lowering medications 1
- Avoid strict glucose targets; focus on preventing symptomatic hyper/hypoglycemia 1
- Acceptable blood glucose range is wider (200-300 mg/dL may be appropriate) 1
Hydration Considerations
- Parenteral hydration unlikely to provide benefit for most dying patients 1
- Short-term limited hydration may be considered only for acute confusional states to rule out dehydration as a precipitating cause 2
- Oral care measures are more effective than IV hydration for dry mouth and thirst 2
Nutritional Support
- Little to no benefit from nutritional support in last weeks of life 1
- Focus on comfort rather than nutritional goals
- Small amounts of desired food may provide appropriate comfort 1
- Artificial nutrition should be discontinued when no longer providing benefit 1
Common Pitfalls in Managing End-of-Life Metabolic Changes
- Continuing strict glycemic control that increases risk of hypoglycemia without benefit
- Providing excessive hydration that may cause respiratory congestion and edema
- Continuing full nutritional support that may cause metabolic distress
- Failing to recognize that hunger is rare in imminently dying patients
- Treating laboratory values rather than patient symptoms
Key Considerations for Clinicians
- Focus on comfort and symptom management rather than metabolic parameters
- Recognize that metabolic needs decrease dramatically at end of life
- Understand that normal amounts of nutrition and hydration may cause distress
- Communicate with patients and families about changing metabolic needs
- Prioritize quality of life over laboratory values
By understanding these metabolic changes, clinicians can provide appropriate care that focuses on comfort and dignity at the end of life rather than attempting to maintain normal metabolic parameters that no longer serve the patient's best interests.