# Evaluation of Chronic Kidney Disease Risk Factors after Radical Nephrectomy
## 4 Discussion
A rise in neutrophils count along with increased NLR has been found to be strongly associated with higher all-cause death with a hazard ratio of 1.14, including renal dysfunction (HR = 1.62, CI 1.21-2.17) [43]. NLR also has a prognostic impact on adverse effects after cardiac and non-cardiac surgery [44; 45]. Other publications have described that higher NLR is related with CKD upstage and poorer renal outcomes (from dialysis till death) among patients with 1 and 4 CKD stages (HR = 1.67, 95% CI 1.02-2.77) [46]. Cross-sectional data from [PERSON] et al. presented that every additional unit of NLR was related with a higher risk for CKD in obesity but not in patients with normal BMI (\(p\) = 0.03) [47]. Hypotension is an adverse reaction following general anesthesia during surgery and is defined by a systolic pressure of blood (SBP) of <90 mm Hg, mean arterial pressure (MAP) of <60 mm Hg or 20% lower in baseline SBP or MAP [48]. IOH is highly prevalent in non-cardiac, non-cesarea section surgery, with a minimum 1 MAP report \(\leq\) 65 mm Hg in 19.3% cases [49]. The pathophysiological mechanism of IOH includes decreased reperfusion of vital organs, including the heart and kidney. The longer duration of IOH during RN and PN is related with a higher risk of postoperative AKI, (OR = 1.14, CI 0.98-1.32); however, these results do not meet the criteria for clinically significant findings [14], although the results are more definitive for RN, as a study by [PERSON] et al. found that 20 min of IOH during RN is associated with AKI (OR = 1.30, \(p\) < 0.03) [16]. Time under 65 mm Hg MAP threshold increases the odds for postoperative AKI compared to patients not going under 65 mm Hg MAP during non-cardiac surgery (\(p\) < 0.001) [50]. However, there are few data about IOH as a causative factor for postoperative CKD. In our multivariate analysis, we found that longer IOH is a major risk factor associated with postoperative CKD 1 year after RN with odds of 1.09 (\(p\) < 0.01). Another important predictor of the development of CKD after RN is AKI [51]. Our definition of postoperative AKI \(\geq\) 1.5 times the baseline value 48 h after surgery was in line with practical guidelines [52]. The pathophysiological mechanisms behind the AKI effect on the progression of CKD are fairly well-studied and include inflammatory cell infiltration, matrix remodeling and angiogenesis impairment [53]. A recent study showed that hospitalized participants with AKI are at significant chance of new-onset CKD and further disease development. (HR = 2.67, CI 1.99-3.58) [54]. AKI is more prevalent in patients undergoing RN over PN (\(p\) < 0.001) and in those who were dehydrated or mildly dehydrated (\(p\) = 0.05) [51]. A retrospective study of non-cardiac surgery by [PERSON] et al. found that patients who developed AKI were at 2.8 times increased risk of developing CKD compared to patients without postoperative AKI [55]. This study confirmed findings by [PERSON] et al., who reported that half of RCC patients who suffered AKI after RN, ended up with CKD compared to 32% of patients who did not have AKI diagnosed after RN (\(p\) = 0.003) [56]. We conducted a prospective study in which we investigated the risk factors of developing CKD after RN. Our study may be invaluable for better prediction of postoperative CKD that allows better patient selection for surgical treatment, more individualized surgery and follow-up plans and risk management. This is the first study to evaluate IOH together with blood loss during RN as a risk factor of developing CKD 12 months postoperatively. However, our study has some limitations. First of all, a small study sample from a single hospital may produce inconclusive results and weaken some statistical analyses; therefore, a larger sample study is needed to achieve true representation for the population of patients. Furthermore, we used the IOH definition of <70 mmHg MAP measured by using a non-invasive monitoring technique. Different thresholds may achieve different results as there is no uniform IOH definition.