No abstract

Measurement of blood volume, both of its plasma and red cell portion, is a useful tool in clinical and experimental investigation. It provides basic data for the assay of the total quantity of individual blood components, as well as for the evaluation of observed hemodynamic changes in acute or chronic disturbances of the circulation. Blood volume determinations have proved of value in the study of congestive heart failure, the anemias, thyroid disorders, renal disease, and pregnancy; and they have been particularly useful-during the recent war years in the study of hemorrhage, burns and shock, and in the development of blood substitutes and blood cell preservatives.It seems reasonable to state that the dye method (1, 2) measures the circulating plasma volume with a high degree of accuracy both in normal and pathologic states, and in many clinical and experimentally induced abnormal circulatory conditions. This view appears to be shared by investigators who have had firsthand experience with the technique (3, 4).Perhaps the best experimental evidence that the method accurately measures changes in plasma volume was obtained in a series of experiments in which the increase in plasma volume following the intravenous injection of concentrated (25 per cent) human serum albumin was measured (5).The osmotic equivalent of 1 gram of this protein was found by Scatchard et al (6) to be 18 ml. of H20; the average increase in plasma volume in 11 male human subjects was 17.4 ml. of H20 (5) per gram of albumin.

Results of the propensity-matched retrospective analysis suggested that avoiding isoflurane significantly reduced the duration of hospitalization. In contrast, length-of-stay was comparable in our prospective trial. Volatile anesthetic choice should not be based on concerns about the duration of hospitalization. These studies illustrate the importance of following even the best retrospective analysis with a prospective trial.

The delayed-release tablet formulation of posaconazole (POS-tab) results in higher plasma POS trough concentrations (C min ) than the oral suspension (POS-susp), which raises the question of the utility of therapeutic drug monitoring (TDM). We aimed to compare the variability of the POS C min for the two formulations and identify determinants of the POS-tab C min and its variability. Demographic, biological, and clinical data from 77 allogeneic hematopoietic stem cell transplant patients (874 C min ) treated with POS-tab (n ϭ 41), POS-susp (n ϭ 29), or both (n ϭ 7) from January 2015 to December 2016 were collected retrospectively. Interpatient and within-subject coefficients of variation (CVs) of the C min adjusted to dose (D) were calculated for each formulation. Between-group comparisons were performed using a linear mixed effects model. The POS C min was higher for the tablet than for the suspension (median [25th-75th percentile]: 1.8 [1.2-2.4] mg/liter versus 1.2 [0.7-1.6] mg/liter, P Ͻ 0.0001). Interpatient CVs for the tablet and suspension were 60.8 versus 63.5% (P ϭ 0.7), whereas within-subject CVs were 39.7 and 44.9%, respectively (P ϭ 0.3). Univariate analysis showed that age and treatment by POS-tab were significantly and positively associated with the POS C min , whereas diarrhea was associated with a diminished POS C min . Multivariate analysis identified treatment with POS-tab and diarrhea as independent factors of the POS C min , with a trend toward a lower impact of diarrhea during treatment with POS-tab (P ϭ 0.07). Despite increased POS exposure with the tablet formulation, the variability of the POS C min was not significantly lower than that of the suspension. This suggests that TDM may still be useful to optimize tablet POS therapy.

Purpose: Choroidal nevus can cause overlying chronic retinal pigment epithelium (RPE) degenerative features, but frank retinal invasion is exquisitely rare. Procedures: This is a retrospective review of 8 cases of choroidal nevus with retinal invasion with evaluation of clinical and imaging features. Results: At the time of diagnosis of choroidal nevus with retinal invasion, mean patient age was 65 years. Mean tumor basal diameter was 7 mm, and mean thickness was 2.3 mm. Retinal invasion was ophthalmoscopically visible in all eyes. Related features included drusen (n = 4/8) and RPE fibrous metaplasia (n = 2/8). Overlying lipofuscin, subretinal fluid, RPE detachment, and retinal edema were absent. On B-scan ultrasonography, the lesion was dome-shaped (n = 7/7) and echo-dense (n = 6/7). Optical coherence tomography demonstrated outer retinal invasion (n = 8/8) with additional inner retinal invasion (n = 3/8). The tissue was hypoautofluorescent at the site of invasion (n = 6/7). Over a mean follow-up of 40 months, tumor enlargement was detected in 2 eyes and managed with observation (< 1 mm enlargement) or plaque radiotherapy (5 mm enlargement). Nevus hypoautofluorescence was correlated with nevus stability (p = 0.035). Conclusion: Retinal invasion of the choroidal nevus is rare. In this series of 8 cases, only 1 demonstrated transformation to melanoma over a mean interval of 40 months. Long-term monitoring of such lesions is warranted.