Analysis of the clinical characteristics and risk factors of postoperative atrial fibrillation in patients with critical burns

Objective To investigate the clinical characteristics and risk factors of postoperative atrial fibrillation (POAF) in patients with critical burns.

Methods A retrospective case series study was conducted. From January 2017 to December 2021, two hundred and twenty-seven critically burned aldult patients who met the inclusion criteria were admitted to Guangzhou Red Cross Hospital of Jinan University, including 173 males and 54 females, aged 19-83 (43±14) years. The admission years of patients were collected, and the percentage of patients complicated with POAF in each year was calculated. According to whether the patients were complicated with POAF or not, they were divided into POAF group (n=17) and non-POAF group (n=210). Following data were collected in patients in POAF group, including operation methods, duration of operation, intraoperative blood loss before occurrence of POAF each time, occurrence time and times of POAF, postoperative body temperature, blood pressure, hemoglobin, blood glucose, blood lactate, sepsis, and electrolyte, and type, duration, and treatment of POAF. General data of patients in the two groups including age, gender, burn reason, total burn area, full-thickness burn area, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) and sepsis-related organ failure evaluation (SOFA) scores on admission, combined with underlying diseases (hypertension, diabetes, and other types of arrhythmias), and sepsis were collected and analyzed. The mortality and factors influencing the prognosis of patients in the two groups such as mechanical ventilation time, operations times, and burn intensive care unit (BICU) length of stay were also collected and analyzed. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, chi-square test or Kruskal-Wallis H test. The multivariate logistic regression analysis was performed on the general data with statistically significant differences between the two groups, and the independent risk factors influencing the onset of POAF in 227 patients with critical burns were screened.

Results From 2017 to 2021, the percentage of critically burned patients complicated with POAF increased year by year. In POAF group, eschar debridement in limbs was the main surgical procedure prior to POAF complication, with the operation time of (3.5±1.2) h and the intraoperative blood loss volume of (365±148) mL.The POAF occurred 25 times in total in patients of POAF group, mostly within one week after the injury and within 6 hours after the operation with most of these patients having POAF only once. When POAF happened, the patients were often complicated with hypothermia, anemia, hyperglycemia, high blood lactate, sepsis, and electrolyte disturbance, and few patients had complications of hypotension. The POAF lasted (5±3) h, with all being paroxysmal atrial fibrillation, and most of POAF patients were reverted to sinus rhythm after amiodarone intervention. Most patients in the two groups suffered from flame burn, and the gender, age, and SOFA score on admission of patients in the two groups were similar (P>0.05); the APACHEⅡ score on admission, total burn area, full-thickness burn area, incidence proportion of sepsis, combined with diabetes and hypertension and other types of arrhythmias of patients in POAF group were significantly higher or larger than those in non-POAF group (t=3.47, with χ² values of 7.44, 10.86, 12.63, 14.65, 6.49, and 7.52, respectively, P<0.05 or P<0.01). The full-thickness burn area, combined with other types of arrhythmias, and sepsis were the independent risk factors for POAF in 227 critically burned patients (with odds ratios of 4.45, 0.04, and 3.06, respectively, with 95% confidence intervals of 2.23-8.87, 0.01-0.22, and 1.77-5.30, respectively, P<0.01). Compared with those in non-POAF group, the mechanical ventilation time, BICU length of stay, number of operations, and mortality rate of patients in POAF group were significantly increased (Z=3.89, Z=2.57, t=3.41, χ²=3.72, P<0.05 or P<0.01).

Conclusions POAF is a common postoperative complication in critically burned patients, and the incidence is increasing year by year, which seriously affects the prognosis of patients. The full-thickness burn area together with other types of arrhythmias and sepsis are the high-risk factors for POAF complication in patients with critical burns.