Prevalence of iron deficiency on ICU discharge and its relation with fatigue: a multicenter prospective study

Abstract

IntroductionPrevalence of iron deficiency (ID) at intensive care (ICU) admission is around 25 to 40%. Blood losses are important during ICU stay, leading to iron losses, but prevalence of ID at ICU discharge is unknown. ID has been associated with fatigue and muscular weakness, and may thus impair post-ICU rehabilitation. This study assessed ID prevalence at ICU discharge, day 28 (D28) and six months (M6) after and its relation with fatigue.MethodsWe conducted this prospective, multicenter observational study at four University hospitals ICUs. Anemic (hemoglobin (Hb) less than 13 g/dL in male and less than 12 g/dL in female) critically ill adult patients hospitalized for at least five days had an iron profile taken at discharge, D28 and M6. ID was defined as ferritin less than 100 ng/L or less than 300 ng/L together with a transferrin saturation less than 20%. Fatigue was assessed by numerical scale and the Multidimensional Fatigue Inventory-20 questionnaire at D28 and M6 and muscular weakness by a hand grip test at ICU discharge.ResultsAmong 107 patients (men 77%, median (IQR) age 63 (48 to 73) years) who had a complete iron profile at ICU discharge, 9 (8.4%) had ID. At ICU discharge, their hemoglobin concentration (9.5 (87.7 to 10.3) versus 10.2 (92.2 to 11.7) g/dL, P =0.09), hand grip strength (52.5 (30 to 65) versus 49.5 (15.5 to 67.7)% of normal value, P =0.61) and visual analog scale fatigue scale (57 (40 to 80) versus 60 (47.5 to 80)/100, P =0.82) were not different from non-ID patients. At D28 (n =80 patients) and M6 (n =78 patients), ID prevalence increased (to 25 and 35% respectively) while anemia prevalence decreased (from 100% to 80 and 25% respectively, P <0.0001). ID was associated with increased fatigue at D28, after adjustment for main confounding factors, including anemia (regression coefficient (95%CI), 3.19 (0.74 to 5.64), P =0.012). At M6, this association disappeared.ConclusionsThe prevalence of ID increases from 8% at discharge to 35% six months after prolonged ICU stay (more than five days). ID was associated with increased fatigue, independently of anemia, at D28.

Implementing a blood management protocol during the entire perioperative period allows a reduction in transfusion rate in major orthopedic surgery: a before–after study

“…In addition, there is accumulating evidence that iron deficiency per se, independently of anemia, is associated with fatigue in different patient populations and also with muscle weakness . Treatment of iron deficiency may be indicated particularly in case of heart failure .…”

“…21 Our results are also in accordance with a recent randomized controlled trial in TKA patients with a postoperative Hb level of not more than 12 g/dL showing that postoperative IV iron infusion reduces the proportion of patients with low Hb at discharge compared to oral iron. 43 In addition, there is accumulating evidence that iron deficiency per se, independently of anemia, is associated with fatigue in different patient populations [44][45][46] and also with muscle weakness. [47][48][49] Treatment of iron deficiency may be indicated particularly in case of heart failure.…”

Carence martiale en réanimation : diagnostic et traitement

“…Enfin, et surtout, des données récen-tes ont confirmé cet intérêt chez les patients souffrant d'insuffisance cardiaque avec notamment une amélioration significative du test de marche de 6 minutes chez les patients recevant du carboxymaltose ferrique intraveineux par rapport au placebo [55]. Nous avons observé que les patients ayant une carence martiale à la sortie de réanimation avaient des scores de fatigues plus importants à 1 mois de leur sortie [23]. Toutefois, il n'existe pas de données montrant l'intérêt du traitement de la CM sur la fatigue ou la récupération des patients de réanimation.…”

“…En outre, dans une étude prospective observationnelle récente, nous avons retrouvé que la carence martiale pouvait également être importante à distance de la réanimation. Sur une centaine de patients suivis au décours de leur séjour en réanimation, nous avons observé une augmentation de la prévalence de la CM de 9 % à la sortie (en utilisant seulement la ferritine) jusqu'à 35 % à 6 mois [23]. La prévalence de la CM est donc variable, mais pourrait concerner 20 à 40 % des patients, selon les critères diagnostic utilisés.…”

Association of Serum Phosphate Levels and Anemia in Critically Ill Surgical Patients

“…Iron deficiency is the leading cause of anemia worldwide, 12 – 14 with prevalence as high as 25%–40% in the ICU 15 . Several other nutrition factors, such as vitamins B and D, have also been linked to the risk of anemia in the general population as well as in critically ill patients 16 – 18 .…”