The dynamics of perioperative serum albumin before and after total knee arthroplasty.

BACKGROUND

Previous studies have evaluated preoperative serum albumin (SA) for predicting postoperative complications of total knee arthroplasty (TKA). This study aimed to investigate the dynamics of perioperative SA and changes in SA (ΔSA) and identify any influential patient or surgical factors.

METHODS

In total, 381 patients (483 knees) undergoing primary TKA were recruited. SA values preoperatively (SA), 1 week postoperatively (SA), and 4 weeks postoperatively (SA) were investigated. SA values were converted to a percentage of SA and differences between timepoints were calculated and expressed as follows: ΔSA, ΔSA-, and ΔSA. Patient and surgical factors previously identified or with the potential to influence SA were evaluated.

RESULTS

The median values of SA, SA, and SA were 4.4, 3.8, and 4.2 g/dL, respectively; SA was significantly different between groups (p < 0.001). The incidence of low SA (<3.5 g/dL) was less than 1 %. Median ΔSA values were -13.7 %, 9.6 %, and -4.5 % for ΔSA, ΔSA- and ΔSA respectively; ΔSA was significantly different between groups (p < 0.001). SA recovered to 95.5 % of SA with less than 2 % of patients having low SA (<3.5 g/dL). Multiple regression analyses showed SA concentration at each timepoint was significantly associated with the other SA timepoint values; age was significantly associated with SA and SA (all p < 0.001).

CONCLUSIONS

We identified SA and age as significant factors affecting SA dynamics in the perioperative period. Low SA (<3.5 g/dL) was uncommon both preoperatively and at 4 weeks postoperatively; therefore, conventional cutoff values and preventive measures for low SA may need reconsideration.