Laboratory Testing

Tongue swabs are presented as less invasive and more accessible than sputum collection. The Dieulafoy Reaction and Astra System are BUN assay methods, and both report BUN in mg/dL. The Jaffe Reaction and enzymatic procedure are creatinine assay methods, and both report creatinine in mg/dL. Total cholesterol alone is described as a low-value marker compared with inflammatory downstream markers. Including tongue swabs alongside sputum is significant because sputum collection can be difficult for some patient groups. The protocol uses 04:00 on postoperative day 1 as the primary melatonin peak sampling point. 25-hydroxy vitamin D testing is considered essential, with sun exposure preferred when feasible. Variability in testing may reflect differences in awareness, patient resources, access to testing, or practice norms. The final ratio is calculated by dividing BUN in mg/dL by creatinine in mg/dL. Both BUN and creatinine should be measured from serum rather than plasma. Patients should fast for 8–12 hours before diagnostic BUN-to-creatinine ratio testing. For iron, more than 60% used laboratory results to guide prescribing, with complete blood count the most commonly recommended test.…