Effect of preoperative hypoproteinemia on surgical prognosis in patients with open cardiac surgery
Authors: Chen Wei , Jiang Xinyi , Wang Yali , Wang Kuo , Pan Tuo , Wang Dong Jin 
Published: November 2023

Background: Hypoalbuminemia is a common complication in patients with heart disease, which is closely related to the treatment of patients. Especially for patients in department of cardiac surgery, failure to timely intervene in the treatment of hypoproteinemia can easily lead to deterioration of the condition, increase the risk of surgery, and affect the prognosis of patients.
Methods: The subjects of this experimental study were patients who underwent cardiac surgery in Nanjing Drum Tower Hospital, China, from October.2020 to October. 2022 .It was a retrospective study. Those patients were excluded from this study, including pregnant patients, patients aged<18 or>80 years, non thoracotomy patients, and patients with preoperative infection and unknown clinical data. A total of 421 patients were included in the study. The preoperative serum albumin level and prognosis of patients undergoing cardiac surgery and admitted to the intensive care unit were retrospectively analyzed. Collect clinical data of patients, as well as serum albumin level, brain natriuretic peptide level, preoperative left ventricular ejection fraction, surgical duration, extracorporeal circulation duration, intraoperative blood transfusion and bleeding volume, postoperative invasive mechanical ventilation time, postoperative brain natriuretic peptide level, postoperative left ventricular ejection fraction, new renal injury rate, new infection rate, secondary intubation rate, secondary thoracotomy rate, icu stay time Data such as total hospitalization time and hospital mortality. To analyze the impact of preoperative hypoproteinemia on the prognosis of patients undergoing cardiac surgery.
Results: Of the 421 patients included, 380 were non hypoproteinemia patients before operation, and 41 were patients with hypoproteinemia before operation, accounting for 9.7% of the total number of patients in the group. Except for hypertension, diabetes and chronic renal insufficiency, there was no significant difference between the two groups (P<0.05). The duration of surgery, cardiopulmonary bypass, postoperative mechanical ventilation, and stay time in the intensive care unit in the hypoproteinemia group were significantly longer than those in the normal group (P<0.05). The level of brain natriuretic peptide increased significantly after surgery (P<0.05), and the amount of intraoperative blood transfusion and bleeding in the hypoproteinemia group were significantly higher than those in the normal group (P<0.05). There was no clear correlation between preoperative hypoproteinemia and the occurrence of new infections (P>0.05). At the same time, there was no significant difference between the two groups in terms of new renal injury, secondary intubation, secondary thoracotomy, postoperative left ventricular ejection fraction, and hospital mortality (P>0.05). The above results suggest that preoperative hypoproteinemia can lead to the prolongation of the condition of patients undergoing cardiac surgery, but there was no statistical significance in the incidence of postoperative adverse events. By analyzing the impact of postoperative albumin content on prognosis, it was found that hypoalbuminemia significantly increased the incidence of adverse events in patients within 24 hours after surgery and prolonged the recovery time. There were significant differences between the two groups of patients in terms of new infection rate (53 (29.0%) vs. 38 (16.0%), P=0.001), new kidney injury (45 (24.6%) vs. 35 (14.7%), P=0.010), secondary thoracotomy (7 (3.8%) vs. 0, P=0.002), secondary intubation (10 (5.5%) vs. 4 (1.7%), P=0.032), hospitalization duration （20（16,25） vs. 16（14,20），P=0.000）, and ICU stay duration （72（48,120）vs. 50（45,72），P=0.000）.
Conclusion: 1. Preoperative hypoproteinemia can affect the duration of surgery, cardiopulmonary bypass, and icu stay in patients undergoing cardiac surgery. 2. Preoperative hypoproteinemia can lead to increased surgical bleeding and blood transfusion in patients undergoing cardiac surgery, as well as increased brain natriuretic peptide levels after surgery. 3. Preoperative hypoproteinemia had no significant impact on postoperative new infections, renal injury, secondary thoracotomy, mortality, and secondary intubation. 4. Hypoalbuminemia significantly increases the incidence of postoperative adverse events in patients within 24 hours after surgery and prolongs the recovery time.