Biochemical response to treatment of bone hyperresorption in chronically critically ill patients

Study objective: The chronically critically ill (CCI) are a subgroup of cri tically ill patients who have survived an acute critical illness but remain profoundly debilitated and ventilator dependent, We have previously shown that CCI patients have a very high prevalence of bone hyperresorption. The objective of this present study was to determine the biochemical response o f bone hyperresorption in CCI patients to treatment with either calcitriol alone or calcitriol and pamidronate. Design: Retrospective survey. Setting: Respiratory care step-down unit (RCU) at a tertiary-care leaching hospital, Patients: Fifty-five ventilator-dependent CCI patients transferred from ICU s within the same institution who had elevated urine N-telopeptide (NTx) le vels at RCU admission, who were treated with either calcitriol alone (n = 4 4) or calcitriol and pamidronate (n = 11), and who had urine NTx levels rem easured following treatment. Intervention: None. Measurements and results: Patients treated with calcitriol alone had a sign ificant reduction in serum parathyroid hormone (PTII; 93 +/- 145 pg/mL vs 4 0 +/- 28 pg/mL; p = 0.02) but not in urinary NTx (187 +/- 146 nmol bone col lagen equivalents [BCE]/mmol creatinine [Cr] vs 178 +/- 123 nmol BCE/mmol C r, p = 0.59). In contrast, patients treated with both calcitriol and pamidr onate had a significant decrease in urine NTx at follow-up (329 +/- 238 to 100 +/- 85 nmol RCE/mmol Cr; p < 0.01) but not in serum PTH (36 +/- 29 to 5 3 +/- 51 pg/mL; p = 0.44). Conclusion: The bone hyperresorption of CCI patients is PTII independent an d biochemically responds to treatment with calcitriol and pamidronate but n ot calcitriol alone.