Effect of Intravenous Infusion Solutions on Bioelectrical Impedance Spectroscopy

Background: Bioelectrical impedance (BIA) is often used to measure body fluid spaces and thereby body composition. However, in acute animal studies, we found that impedance was driven by the saline content of intravenous (IV) fluids and not by the volume. The aim of the study was to investigate the effect of 3 different fluids acutely administered on the change in impedance, specifically resistance (R). Materials and Methods: Nine healthy adults participated in 3 treatment (0.9% saline, 5% dextrose, and a mixture of 0.3% saline + 3.3% dextrose) experiments on nonconsecutive days. They all received 1 L of one of the treatments intravenously over a 1‐hour period. Repeated BIA measurements were performed prior to IV infusion and then every 5 minutes for the 1‐hour infusion period, plus 3 more measurements up to 15 minutes after the completion of the infusion. Results: The change in R in the 0.9% saline infusion experiment was significantly lower than that of the glucose and mixture treatment (P < .001). Conclusion: Bioelectrical impedance spectroscopy and BIA measure salt rather than the volume changes over the infusion period. Hence, in patients receiving IV fluids, BIA of any kind (single frequency or multifrequency) cannot be used to measure body fluid spaces or body composition.     

Surgical Decision Making in the BRCA‐Positive Population: Institutional Experience and Comparison with Recent Literature

A retrospective study was performed to document the uptake and extent of surgical intervention in patients with a known mutation in the BRCA1/2 genes and associated outcomes. Data were collected retrospectively on BRCA‐positive patients with and without cancer at the time of genetic testing. Our findings were compared to those published in the current literature. Of patients with cancer at testing, 61% chose bilateral mastectomies. Of patients without cancer, 54% chose risk‐reducing surgery (RRS) including risk‐reducing mastectomy (RRM), risk‐reducing salpingo‐oophorectomy (RRSO), or both. Time to surgery was significantly shorter to RRSO than to RRM. The literature suggests and our data support that acceptance of RRM in the BRCA‐positive population has gradually increased over time. Consistently high rates of RRSO uptake and short intervals from time‐of‐testing to RRSO demonstrate that RRSO is still more acceptable to this population than RRM.     

Prevalence and Contents of Advance Directives in Patients Receiving Home Parenteral Nutrition

Background: Ethical issues may arise with patients who receive home parenteral nutrition (HPN) and have a change in their overall health status. We sought to determine the extent of advance care planning and the use of advance directives (ADs) by patients receiving HPN. Materials and Methods: Retrospective review of the medical records of adult patients newly started on HPN at the Mayo Clinic, Rochester, Minnesota, between January 1, 2003, and December 31, 2012, to determine the prevalence and contents of their ADs. Results: A total of 537 patients met the inclusion criteria. Mean (SD) age at commencement of HPN was 52.8 (15.2) years, and 39% (n = 210) were men. Overall, 159 patients (30%) had ADs. Many mentioned specific life‐prolonging treatments: cardiopulmonary resuscitation (44 [28%]), mechanical ventilation (43 [27%]), and hemodialysis (19 [12%]). Almost half mentioned pain control (78 [49%]), comfort measures (65 [41%]), and end‐of‐life management of HPN (76 [48%]). Many also contained general statements about end‐of‐life care (no “heroic measures”). The proportion specifically addressing end‐of‐life management of HPN (48%) was much higher than that previously reported in other populations with other life‐supporting care such as cardiac devices. The primary diagnosis or the indication for HPN was not correlated with whether or not the patient had an AD (P = .07 and .46, respectively). Conclusion: Although almost one‐third of the patients had an AD, less than half specifically mentioned HPN in it, which suggests that such patients should be encouraged to execute an AD that specifically addresses end‐of‐life management of HPN.