Evaluating the necessity of postoperative day 1 labs following laparoscopic radical nephrectomy (LRN)

Standard postoperative care following laparoscopic radical nephrectomy (LRN) typically includes routine blood tests. Recent studies have assessed the safety of omitting routine postoperative labs in minimally invasive surgeries to reduce hospital costs. Our primary objective was to evaluate if routine postoperative day 1 (POD1) labs were necessary following LRN.

We evaluated 650 consecutive LRN performed by a single surgeon. Patients on dialysis or that previously had a renal transplant were excluded from the study. Our final analysis included 478 LRN. We examined POD1 labs of potassium (K), sodium (Na), and hemoglobin (Hgb) and their associations to preoperative and postoperative outcomes. Abnormal K at POD1 was defined as less than 3.5 mEq/L or greater than 5.0 mEq/L. Abnormal Na at POD1 was defined as less than 135 mEq/L or more than 145 mEq/L. Abnormal Hgb at POD1 was defined as POD1 Hgb less than 8 g/dL or POD1 Hgb 3.0 g/dL or more decrease from preoperative Hgb.

One or more abnormal POD1 labs were observed in 32.4% (155/478) patients. Sixty-five patients had abnormal Hgb, 57 had abnormal Na, and 53 had abnormal K. Preoperative patient factors associated with abnormal labs included older age [odds ratio (OR) 0.461; 95% confidence interval (CI): 0.26-0.809], higher Charlson comorbidity index (CCI) (OR 1.671; 95% CI: 1.036-2.7), and increased intraoperative blood loss (OR 1.213; 95% CI: 1.069-1.39; all P<0.05). Intraoperative variables such as longer operative time and complications were not significantly associated with abnormal labs (P>0.05).

Abnormal labs on POD1 following LRN were found in 32.4% of patients. POD1 lab tests appear to be needed following LRN in older patients with more comorbidities.