Parathyroid hormone serum concentration kinetic profile in critically ill patients undergoing continuous renal replacement therapies: a prospective observational study.

INTRODUCTION: Elevated serum parathormone (PTH) levels have been observed in acute kidney injury and are related to calcium-phosphate metabolism disturbance, decreased renal production of 1,25 dihydroxyvitamin D3, impaired renal PTH excretion, and other renal-independent factors. There are no data regarding PTH concentration kinetics in critically ill patients undergoing continuous renal replacement therapies (CRRT) in an intensive care setting. The primary objective of this study was to investigate trends in PTH serum levels in critically ill patients with multiorgan failure undergoing CRRT, by performing periodic PTH measurements in the acute phase of critical illness. MATERIAL AND METHODS: This was a single-centre, prospective, observational study conducted in an mixed, university-affiliated intensive care unit. Critically ill patients who fulfilled all of the following criteria were included: respiratory failure; circulatory failure; acute kidney injury treated by CRRT; and sequential organ failure assessment score (SOFA score) of 5 or more. Patients who met any of the following criteria were excluded: acute liver failure; hypercalcemia at admission (total calcium serum level > 10.6 mg/dL; total ionized calcium plasma level > 1.35 mmol/L); parathyroid gland disease; end-stage renal disease; patients undergoing therapeutic plasma exchange or extracorporeal membrane oxygenation procedures; aged under 18 years; pregnant; and life expectancy after admission to the intensive care unit anticipated to be less than 72 hours as assessed by the investigator. RESULTS: Thirty patients met the inclusion criteria. A statistically significant change in PTH over time was observed (Friedman ANOVA; p = 0.0001). The post-hoc test showed a statistically significant decrease in PTH: measurements 5-8 relative to measurement 1, and measurements 4-8 relative to measurement 2 (p < 0.05). No significant correlations between 25 hydroxyvitamin D3 deficiency, age, diagnosis, SOFA score, and PTH levels were observed. A statistical test indicated that serum concentrations of PTH were significantly higher in the de novo sepsis group (p < 0.05). CONCLUSIONS: The PTH serum concentration decreases during the course of CRRT in the majority of patients. When the course of the disease starts to be complicated by sepsis, PTH serum levels then remain high. A probable reason for this is the existence of the inflammatory state triggered by sepsis.

Vitamin D serum levels in multiorgan failure critically ill patients undergoing continuous renal replacement therapies.

INTRODUCTION: Severe vitamin D deficiency in critically ill patients is linked to mortality. There are no scientific data regarding vitamin D status in critically ill patients undergoing continuous renal replacement therapies. MATERIAL AND METHODS: We aimed to measure vitamin D serum levels in critically ill patients with multi-organ failure undergoing continuous renal replacement therapies. Vitamin D serum measurements in 12-hour time intervals were performed in 20 patients undergoing continuous renal replacement therapies through continuous veno-venous haemodiafiltration (the study group). The results were then compared with the historical control group (20 patients without renal replacement therapy). RESULTS: In the control group the median vitamin D level initially decreased, then stabilised around the fourth and fifth measurement, after which it appeared to increase unevenly. In the study group the median vitamin D level decreased considerably, and then stabilised around the third measurement. Although the differences between groups gradually increased for the last three measurements, there was insufficient evidence to indicate that they were statistically significant (P > 0.05). Significant correlations were found between the time of measurement and the level of vitamin D in the study (R = -0.31, P = 0.0002) and control groups (R = -0.18, P = 0.0341). CONCLUSIONS: Vitamin D serum levels decline rapidly during the course of critical illness in patients undergoing continuous renal replacement therapies. No statistically significant differences in the levels of vitamin D between the study and control groups were found.

[Trends in parathyroid hormone plasma concentration in critically ill patients: prospective observational study].

OBJECTIVE: Introduction: There is no data in the literature regarding trends in parathormone serum concentration assessment in critically ill patients. The aim: To assess the parathyroid hormone plasma concentrations and kinetics in critically ill patients admitted to the intensive care unit due to multiorgan failure. PATIENTS AND METHODS: Materials and methods: Thirty multiorgan failure (at least circulatory and respiratory failure) patients were included. Patients who met any of the following criteria were excluded: acute liver failure, end stage renal disease, hypercalcemia, parathyroid gland disease, severe vitamin D deficiency, admission from another ICU or readmission, age younger than 18 years, or lack of consent from relatives. We performed the parathyroid hormone plasma measurements in 12-hour time intervals. RESULTS: Results: The initial parathyroid hormone plasma concentration levels in the study group were rather variable and medians exceeded laboratory reference values. Especially in the acute kidney injury subpopulation treated with continuous renal replacement therapy these trends were emphasized. The initial parathyroid hormone plasma concentration levels in this group significantly exceeded laboratory reference values in 80% of patients. After initial spike we observed subsequent drop between second and third measurement. The distribution of plasma levels was rather variable between second and third measurement in this group of patients. CONCLUSION: Conclusions: The parathyroid hormone plasma concentration levels in the critically ill patients are variable. In the acute kidney injury subpopulation treated with continuous renal replacement therapy after initial significant spike we observed subsequent drop between second and third measurement.

Vitamin D kinetics in the acute phase of critical illness: A prospective observational study.

PURPOSE: The objective of this study was to assess the vitamin D kinetics in critically ill patients by performing periodic serum vitamin D measurements in short time intervals in the initial phase of a critical illness. MATERIALS AND METHODS: We performed vitamin D serum measurements: at admission and then in 12-hour time intervals. The minimum number of vitamin D measurements was 4, and the maximum was 8 per patient. RESULTS: A total of 363 patients were evaluated for participation, and 20 met the inclusion criteria. All patients had an initial serum vitamin D level between 10.6 and 39ng/mL. Nineteen patients had vitamin D levels between 10 and 30ng/mL, which means that they had vitamin D insufficiency or deficiency, and only one patient had a normal vitamin D serum plasma level. We observed that the median of the vitamin D level decreases until the fourth measurement then stabilizes around the 4th and 5th measurement and then appears to increase unevenly. The highest drop is at the very beginning. CONCLUSIONS: The vitamin D serum level is changeable in the initial phase of a critical illness. We hypothesize that the serum vitamin D concentration can mirror the severity of illness.