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An accurate creatinine (Cr) estimate is pivotal for the assessment of renal function. Both patient- and practice-spawned factors palliate the test accuracy of serum creatinine (sCr) and can erratically represent actual kidney function. This study evaluated the caregivers’ awareness of enzymatic serum creatinine (E-sCr) assay interfering in dopamine/dobutamine (DD)-infused patient samples and the frequency of such interference in a critical care setting. We conducted an sCr awareness survey among UT Southwestern physicians, nurses, and pharmacists. We then performed a cross-sectional E-sCr comparison against the kinetic Jaffe method using the DD-infused patient samples collected from central venous catheters (CVC), peripherally inserted central catheter (PICC) lines, and the peripheral vein (PV). We retrospectively compared the longitudinal E-sCr results of the CVC/PICC draws with the corresponding blood urea nitrogen (BUN) levels. The survey results show a significant lack of awareness among caregivers about the negative interference of DD infusions on E-sCr. Cross-sectional E-sCr assessment relative to the Jaffe method displayed a negative interference in 12% of CVC/PICC line samples (7/57 DD-infused patients) compared to none in the PV draws. A longitudinal assessment of E-sCr, BUN, and potassium (K) levels from CVC/PICC line samples further confirmed a spurious decrease for E-sCr in about 12/50 (24%) patients who did not show a concurrent BUN or K decrease. The results suggest that a direct PV sampling accompanied by clinical laboratory-directed proactive discussion/activities can foster awareness among caregivers and eschew the false E-sCr estimates in DD-infused patients.

Eight of 101 children (8%) seen serially in consultation in an outpatient failure-to-thrive (FTT) clinic had isolated serum bicarbonate (TCO2) levels between 16 and 20 MEQ/dL (normal 22 to 30 MEQ/dL). None of these eight patients had signs or symptoms of renal disease, and all had nonorganic etiologic factors associated with their malnutrition. At the time of this review, follow-up TCO2 measurements were available for seven of the eight children who had attained normal weight (wt/age greater than fifth percentile on National Center for Health Statistics (NCHS) growth chart). All these children had normal TCO2 levels and no evidence of renal disease on follow-up more than 12 months later. Clinicians treating undernourished children who have low TCO2 measurements and have no signs or symptoms of renal disease and identified nonorganic factors, should consider a trial of therapies directed at nonorganic factors. Clinicians should be aware that a high percentage of undernourished children without other medical disease may have abnormal TCO2 measurements that correct after the institution of adequate caloric intake.

Sera from 13 of 14 children with acute haemolytic uraemic syndrome (HUS) contained complement-fixing IgG and IgM antibodies that lysed cultured human umbilical vein endothelial cells. In 3 of 3 sera tested, no lysis of dermal fibroblasts was observed. The endothelial cell antigen was lost after treatment of the cells with gamma interferon. In contrast, only 3 of 5 adult patients with acute, non-relapsing, thrombotic thrombocytopenic purpura (TTP) had lytic anti-endothelial antibodies and only 1 of these recognised an antigen lost upon gamma interferon treatment. None of 32 control sera contained lytic anti-endothelial cell antibodies. These data suggest that HUS involves a disorder of immunoregulation and that a unique class of anti-endothelial cell antibodies is produced that may take part in the pathogenesis of vascular injury in HUS.