In the present study, multivariate linear regression analysis showed that serum albuminitial was closely related to LOS of patients with AHF. Trend test and smooth curve fittings suggested that LOS was gradually shorten when serum albumininitial level was gradually increased (based on serum albumin being less than its maximum; maximum albumininitial: 5.1g/dl). in our subgroups, sepsis and serum albumininitial had an interactive effect on LOS (P = 0.036), and there was significantly different between AHF patients with sepsis (β:-1.927; 95%CI:-3.823, -0.030) and without sepsis(β: -1.412; 95%CI:-1.737, -1.087) .
The nutritional status of patients with AHF in ICU significantly affects their prognosis and LOS, albumin not only maintains the colloidal osmotic pressure, but also plays an important role in their nutritional status. Hypoalbuminemia, occurred commonly in patients with AHF in ICU, might be related to their poorer heart function and more underlying diseases, and it could result in serious adverse events. Previous studies showed that hypoalbuminemia significantly affected prognosis and LOS of various diseases, such as patients for severe sepsis, acute decompensated chronic obstructive pulmonary disease and requiring surgery.[10–13] But none of them proposed the specific relationship between albumin and LOS. In the present study, negative relationships between serum albumin and LOS in patients with AHF was found, and elevation of serum albumin level could reduce the LOS. Serum albumin could maintains the colloidal osmotic pressure, the proper serum albumin is beneficial to the recovery oh AHF patients, however, with the levels of serum albuminas increasing, heart load will inevitably be aggravated, the topic on the optimical value of serum albuminas has not been widely explored. the further increases of albumin might weight the heart load, which may be not conducive to the prognosis of patients with AHF. Therefore, the above findings were based on the fact that albumin is less than 5.1g/dl.
Currently, several studies had suggested that serum albumin level < 3.5g/dL was an independent risk factor for prolonged LOS,[12–14] Clinicians are more inclined to treat moderate and severe hypoalbuminemia, but albumin level are divided into normal albumin levels (≥ 3.5g/dl), mild hypoalbuminemia (3.0g/dl-3.5g/dl), moderate hypoalbuminemia (2.5g/dl-3.0g/dl) and severe hypoalbuminemia (< 2.5g/dl). The present study found that compared with low albumin level, high albumin level could significantly reduce the LOS. Therefore, the treatment of mild albuminemia is also vital to shorten the LOS.
Age and gender are important indicators for risk stratification and treatment of patients with AHF. Previous literature demonstrated that age not only was an independent risk factor for mortality of various diseases, but also determined the length of their hospital stay, and with age increasing, LOS was prolonged.[15–17] This might be because the elderly in ICU often had multiple organ failure, including poor heart function and other serious underlying diseases, which lead to poor prognosis and long LOS. For gender, women may be closely related to longer LOS.[18] Compared with men, female had higher systolic blood pressure, and the article published by redfield et al. on circulation thought as patients grew older, female could have heavier arteriosclerosis.[19, 20] Severe coronary arteriosclerosis reduced blood supply of heart, and made prognosis of patients with AHF worse. In our study, neither of different age and gender had an impact on the relationship between serum albumin and LOS.
For AHF patients with malignancy, liver cirrhosis, nephrotic syndrome, chronic kidney disease and sepsis, these comorbidities can affect the synthesis and concentration of albumin.[21–24] In subgroup analysis, it can be found that only sepsis had an impact on the relationship between serum albumin and LOS. Sepsis is systemic infectious disease that often leads to dysfunction of various organs of the body. Demissei et al. pointed out AHF patients often had elevated inflammation indicators and had poor prognosis,[25] but there is currently no clear guideline for the treatment of AHF patients with sepsis.[26] In the present study, we found that compared to without sepsis, serum albumin can significantly reduce the LOS in AHF patients with sepsis, which might guide clinical practice. Explanation from the clinical mechanism, serum albumin enhances immunity, regulates inflammation and reduces oxidative damage, which are beneficial to reduce the damage of sepsis to various organs of the body.
The present study found that high serum albumin level was beneficial to shorten LOS of AHF patients, and the result could guide clinicians to reduce LOS of AHF patients by changing albumin levels. However, our study also have some limitations. Firstly, The maximum serum albumininitial level included in our study was 5.1g/dl. When the albumin level is greater than 5.1g/dl, whether the relationship between serum albumin and LOS is still negative has not been studied. Secondly, the study was a single-center retrospective design, the numbers of patients included are not large, and the selected population is relatively limited. Finally, we might not adjust other potential confounding factors.