Micronutrient deficiencies in critically ill patients receiving continuous renal replacement therapy

Area of Science:

• Nephrology
• Critical Care Medicine
• Nutritional Science

Background:

• Continuous renal replacement therapy (CRRT) is vital for acute kidney injury (AKI) in critical illness.
• CRRT effluent leads to significant micronutrient loss.
• Existing data shows low micronutrient levels in CRRT patients, but lacks comparison to non-CRRT critically ill groups.

Purpose of the Study:

• To compare micronutrient and carnitine deficiencies in critically ill patients at high malnutrition risk, with and without CRRT exposure.
• To identify specific micronutrient deficiencies prevalent in CRRT patients.

Main Methods:

• Retrospective chart review of intensive care unit (ICU) patients from 01/01/2017-12/31/2018.
• Inclusion of patients with checked levels of carnitine, copper, zinc, selenium, and vitamins B1, B6, B9, and C.
• Definition of deficiencies as below reference range; carnitine deficiency defined by acyl to free carnitine ratio (ACFR) >0.4.

Main Results:

• 90% of CRRT patients had at least one micronutrient deficiency versus 61% of non-CRRT patients (p=0.002).
• Higher prevalence of copper (p<0.001) and carnitine (p<0.001) deficiencies in CRRT patients.
• Increased zinc deficiencies observed in non-CRRT patients (p=0.001).

Conclusions:

• The majority of CRRT patients exhibit micronutrient deficiencies.
• Clinicians must recognize the elevated risk of copper, carnitine, and vitamin B6 deficiencies in CRRT patients.
• Further research, including prospective trials, is necessary to define this malnutrition category and evaluate supplementation strategies.