Chiefs’ Inquiry Corner – 12/9/19

December 9, 2019

Being an outstanding physician and lifelong learner requires stoking the flames of clinical curiosity.  In Chiefs’ Inquiry Corner (CIC) we attempt to succinctly answer actual clinical questions that have been raised on the wards and in the clinics of NYU’s teaching hospitals.  Our answers are not meant to be all encompassing or practice changing but rather to serve as springboards for further exploration. For those of us with short attention spans, we hope CIC satisfies that craving for a morsel of knowledge in a digestible format.

Click to toggle the answers!

The association between perioperative bacteriuria and development of a prosthetic joint infection (PJI) is not well-established, but some studies do demonstrate an increased risk compared to patients without bacteriuria. However, in a large prospective multicenter study of nearly 2500 patients, treatment of the bacteriuria was not shown to decrease the risk of subsequent PJI; additionally, the vast majority of patients who develop PJIs do not demonstrate concordance between the bacteria growing in the urine and the bacteria growing in the wound culture.

The presence of inflammation can make concurrent iron deficiency anemia difficult to diagnose, with international clinical guidelines providing various ferritin and transferrin saturation cutoffs for the diagnosis of iron deficiency in patients with chronic inflammatory conditions. In one small study of iron status in hemodialysis patients iron deficiency was classified based on laboratory response to IV iron treatment. A ferritin cutoff of 300 provided a sensitivity and specificity of 90% and 18% respectively, and a cutoff of 500 provided a sensitivity and specificity of 100% and 0% respectively.

Outside of experimental settings, we do not have conclusive evidence that ethanol increases serum lactate in the absence of other comorbid conditions. One small study checked lactate levels in 60 patients presenting to the emergency room with a blood alcohol concentration greater than 100mg/dL. Lactate was elevated between 2.5-5mmol/L in only 11% of patients, all of whom had an alternative explanation for the elevation. An elevated lactate in an intoxicated patient should prompt further evaluation.