Pinch-off syndrome in patients with sickle cell disease receiving erythrocytapheresis.

A 6-year-old female with homozygous sickle cell disease had a central venous access device (CVAD) placed to facilitate chronic erythrocytapheresis. Erythrocytapheresis was ineffective due to the rare pinch-off syndrome causing communication between the dual lumen tubing. Awareness of and monitoring for the pinch-off syndrome is indicated in people with sickle cell disease and a CVAD for chronic erythrocytapheresis.

Midpoint CD34 measurement as a predictor of PBPC product yield in pediatric patients undergoing high-dose chemotherapy.

High-dose chemo/radiotherapy of sensitive tumors requires PBPC rescue doses of >3 x 10(6) CD34/kg (range: 3-20 x 10(6) CD34/kg). Because of the diversity of stem cell treatment protocols and clinical presentation of patients at the time of peripheral blood progenitor cell (PBPC) harvest, the use of the mid-point CD34 positive cell measurement was initiated to predict the final CD34-positive cell product yield/stem cell harvest. The measurement of CD34-positive cells at the mid-point of the initial setting of 5 total blood volumes (TBV) allows for the extension, shortening, or no change in the TBV processing to achieve a maximum goal of CD34-positive cells/kg body weight required for stem cell transplantation. The estimation of mid-point CD34-positive cells guided our center to extend 22 procedures, shorten 26 procedures, and leave 20 procedures unchanged. This investigation addresses three aspects of PBPC collection in pediatric patients: (1) the processing of large blood volumes (more than the defined 3 TBV and maximum up to 13 TBV in one session) to achieve good efficiency of the procedure; (2) the use of the mid-point CD34 measurement at 2.5 of 5 TBV initially set to predict the maximum goal of CD34 cells /kg needed on the same day of PBPC collection; and (3) PBPC collection in pediatric patients <10 kg body weight (as low as 5.8 kg body weight).

Clinical performance of an in-line, ex vivo point-of-care monitor: a multicenter study.

BACKGROUND: The management of critically ill infants and neonates includes frequent determination of arterial blood gas, electrolyte, and hematocrit values. An objective of attached point-of-care patient monitoring is to provide clinically relevant data without the adverse consequences associated with serial phlebotomy. METHODS: We prospectively determined the mean difference (and SD of the difference) from laboratory methods of an in-line, ex vivo monitor, the VIA LVM Blood Gas and Chemistry Monitoring System (VIA LVM Monitor; Metracor Technologies, Inc.), in 100 critically ill neonates and infants at seven children's hospitals. In doing so, we examined monitor stability with continuous use. In vivo patient test results from laboratory benchtop analyzers were compared with those from the VIA LVM Monitor on paired samples. In a separate in vitro comparison, benchtop analyzer and monitor test results were compared on whole-blood split samples. RESULTS: A total of 1414 concurrent, paired-sample measurements were obtained. The mean differences (SD of differences) from laboratory methods and r values for the combined data for the VIA LVM Monitor from the seven sites were 0.001 (0.026) and 0.97 for pH, 0.7 (3.6) mmHg and 0.94 for PCO(2), 4.2 (9.6) mmHg and 0.98 for PO(2), 0.0 (2.9) mmol/L and 0.87 for sodium, 0.1 (0.2) mmol/L and 0.96 for potassium, and 0.3% (2.9%) and 0.90 for hematocrit. Performance results were similar among the study sites with increasing time of monitor use and between in vivo paired-sample and in vitro split-sample test results. CONCLUSION: The VIA LVM Monitor can be used to assess critically ill neonates and infants.