The Effects of a Practice Change in The Umbilical Arterial Catheter Regimen for Less Than 800-Gram Infants.

Abstract

Background: We have previously demonstrated through a randomized study that in comparison to a hyptonic regimen, an isotonic amino acid (IAA) umbilical arterial catheter (UAC) solution/flush regimen is associated with less hemolysis, improved nutrition and alterations in fluid/electrolyte balance. We hypothesized that the difference in fluid/electrolyte balance was contributed to by differences in renal function in the 2 groups in relation to the generation of plasma free hemoglobin secondary to hemolysis. Since implementation of findings from a controlled study may be met with unpredictable obstacles and results, we have continued to monitor data as the isotonic regimen was introduced into practice.Objective: To assess the introduction of an IAA UAC infusion/flush regimen into general practice and to evaluate fluid/electrolyte status in infants before (group 1) and after (group 2) implementation in an effort to delineate underlying factors related to fluid/electrolyte balance in infants <800 g BW.Design/Methods: This was a retrospective review of information collected for QI purposes. Patients, < 800 g with UAC in place, were identified from 2 available databases. IRB approval was obtained The data was analyzed to determine differences in serum sodium (Na), potassium (K), blood urea nitrogen, (BUN), creatinine (Cr); fluid balance, BUN:Cr ratio; and line complications. Based on data from our previous study, 24 infants in each group would provide powers of 99%, 94%, and 94% (á= 0.05) for sodium levels, intakes, and urine outputs, respectively.Results: The data of 33 and 24 infants were evaluated from the time period before and after the change in practice respectively. The new practice was implemented in 86% of cases. There were no group differences in demographics. Mean GA (range) 25 wks (22–28), BW 651 g (435–782), days with UAC 5.7 (1–13). Na level was higher and K level lower in group 2 in the 1st 2 days of life. There was no difference in UAC complications, Cr, BUN levels, urinary output or volume intake. BUN:Cr ratio was higher in group 2 in comparison to group 1 (25±7 vs 21±9, respectively; P<.05). There was also a significant difference in the number of critical high and low Na values between the two groups.Conclusion: The difference in BUN:Cr ratio supports the theory of improved renal function resulting in relative volume depletion in the IAA UAC group. Other group differences were not as pronounces as in the controlled trial, possibly relating to the imprecise implementation of the new practice. These findings support need for monitoring introduction of practices from controlled trials.