Objective To investigate the prevalence of vitamin D deficiency in medical intensive care unit (ICU) and its relationship with severity of disease and prognosis.Methods A prospective study was performed to evaluate vitamin D status in 216 patients admitted to the medical intensive care unit.The incidence of hypovitaminosis D was observed.Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score,days kept in ICU and on ventilator,main laboratory findings,and mortality rate were compared among patients with different serum 25-hydroxyvitamin D [25 (OH) D] levels.Potential risk factors for mortality were analyzed by multivariate logistic regression analysis.Results One hundred and fifty-three patients (70.8％) developed hypovitaminosis D.25 (OH) D deficiency was identified in 95 (44.0％),25 (OH) D insufficiency in 58 (26.8％),and 25 (OH) D sufficiency in 63 (29.2％) patients.APACHE Ⅱ score,positive blood culture,the incidence of multiple organ dysfunction syndrome(MODS),and mortality rate were higher in deficiency group compared with the other two groups [APACHE Ⅱ score:deficiency group 25 (20,28) score,insufficiency group 22 (17,26) score,sufficiency group 19 (18,20) score,P＜0.01 ; positive blood culture:deficiency group 18.9％,insufficiency group 13.8％,sufficiency group 3.2％,P=0.015 ; MODS:deficiency group 48.4％,insufficiency group 43.1％,sufficiency group 25.4％,P=0.025; mortality rate:deficiency group 40％,insufficiency group 24.1％,sufficiency group 15.9％,P =0.003].25 (OH)D levels were negatively correlated with APACHE Ⅱ score and mortality rate (r =-0.325,P＜0.01 ; r=-0.276,P＜0.01,respectively).Analysis by multiple logistic regression demonstrated that 25 (OH) D deficiency (OR =3.005,95 ％ CI 1.321-5.875,P =0.008) was independent risk factor for mortality.Conclusions This study demonstrates that vitamin D deficiency is highly prevalent among patients admitted into ICU.Vitamin D deficiency is associated with disease severity,and seems to be an independent risk factor for mortality.

The placement of the flexible ureteroscopic sheath during lithotripsy may injure the ureter. We have developed a double-tube flexible ureteral access sheath. Thirteen patients with renal calculi were treated with double-tube and flexible sheath in one stage. CT examination of 13 cases showed that the ureter was normal. The double-tube flexible ureteral access sheath makes the operation of sheathing easy, safe and effective.