Comparison of below-knee and above-knee amputations with demographic, comorbidity, and haematological parameters in patients who died.

Background: This study aimed to establish mortality predictive parameters with a higher contribution to mortality by comparing the demographic data, comorbid factors, and haematological values of patients who underwent below-knee and above-knee amputation and had died during the follow-up period.

Materials and methods: Between March 2014 and January 2022, 122 patients in a single centre who developed foot gangrene due to chronic diabetes and underwent below-knee or above-knee amputation were evaluated retrospectively. Patients who died of natural causes during the post-operative period were included in the study. Those who were amputated below the knee were assigned to Group 1, and those who were amputated above the knee were assigned to Group 2. The patients' age, gender, side of amputation, comorbid diseases, American Society of Anaesthesiologists (ASA) score, Charlson comorbidity index (CCI), death time, and haematological values at the time of first admission were compared between the two groups and statistical analyses were performed.

Results: Group 1 (n = 50) and Group 2 (n = 37) had similar distributions in terms of age, gender, side of operation, number of comorbidities, and CCI (p > 0.05). Group 2's mean ASA score and c-reactive protein (CRP) levels were statistically higher than those of Group 1 (p < 0.05). Death time, albumin value, and HbA1c levels were statistically lower in Group 2 than in Group 1 (p < 0.05). There were no significant differences between the groups in haemogram, white blood cells (WBC), lymphocytes, neutrophils, creatinine, and Na values at the time of first admission (p > 0.05).

Conclusion: A high ASA score, low albumin value, and high CRP value were significant predictors of high mortality. Creatinine levels and HbA1c values were quite ineffective in predicting mortality.

Level of evidence: Level 3, retrospective comparative study.