Automated haematology: construction of univariate reference ranges for blood cell count and size

The theory of reference ranges advocated by the International Committee for Standardization in Haematology (ICSH) was tested experimentally for an aperture impedance and a flow cytometric system. The reference sample was drawn from volunteer blood donors and the sampling procedure carefully standardised. Subjects were partitioned for gender and smoking habits, and their ages noted. Reference ranges were constructed from Gaussian statistics, after objective evaluation of the data, based on an assumed occurrence of one false positive measurement in every twenty samples. Different reference ranges were obtained on the two different systems for some haematological parameters, and partitioning also produced differences in calculated reference ranges. We conclude that strict adherence to the ICSH recommendations is almost impossible. Nevertheless, it is important that all laboratories should construct their own local reference ranges for their specific analytical systems before cost effective clinical decisions can be made.

Alternative treatment to tracheostomy in obstructive sleep apnea syndrome: nasal continuous positive airway pressure in young children

Two groups of prepubertal children with severe obstructive sleep apnea syndrome received continuous positive airway pressure (CPAP) treatment using a nasal mask. The five children in group A had nasal CPAP only in a hospital setting; the five children in group B received the treatment at home as well. Four of these five children, who have now been followed for as long as 10 months, have adapted well to the treatment at home. The problems encountered with nasal CPAP as a home treatment, such as poor cooperation from parents, allergic rashes, eye irritation resulting from air leaks, are discussed. Despite the problems, nasal CPAP is a valid alternative to tracheostomy in children as young as 3 years of age.

Training mental health workers in psychiatric rehabilitation

Staff members from nine mental health agencies were trained in psychiatric rehabilitation technology. The trainers then received intensive followup to assist them in implementing the technology in their own agencies. Evaluation of the impact of the "training of trainers" strategy suggested that mental health workers were able to acquire and apply the skills of psychiatric rehabilitation. The training strategy also appeared to be effective in helping the agencies adopt the philosophy, principles, and skills of psychiatric rehabilitation.

The routine measurement of platelet volume: a comparison of aperture-impedance and flow cytometric systems

The effect of dipotassium ethylenediaminetetraaceticacid (EDTA) on the platelet count and mean volume (MPV) was evaluated using two routine measurement systems, a Coulter S Plus Phase 1 (S+) and a Technicon H6000 (H6000). In normal subjects (n = 29) MPV increased by 17% during 39 h storage in EDTA when measured by the S+. In contrast MPV decreased by 22% when measured by the H6000. MPV differences of up to 40% were observed between the two systems. Concomitant platelet counts, in both systems, changed by less than 4%. Using the anticoagulant sodium citrate and prostaglandin E1 (Na-citrate/PGE1 there were no significant changes in MPV measured by the S+ during 7 h storage, although a linear decrease in platelet count was observed. A decrease in H6000 MPV was observed whether the blood was stored in EDTA or Na-citrate/PGE1. Methodology, anticoagulation and storage time all influence MPV. Until these determinants are standardized the clinical value of MPV cannot be assessed.

The routine measurement of platelet volume: a comparison of light-scattering and aperture-impedance technologies

The effect of dipotassium ethylenediaminetetra-acetic acid (EDTA) on platelet count and mean volume (MPV) was evaluated using two routine measurement systems, a Coulter S Plus (Phase 1) (S+) and a Technicon H6000 (H6000). In normal subjects (n = 29) MPV increased by 17% during 39 h storage in EDTA when measured by the S+. In contrast MPV decreased by 22% when measured by the H6000. MPV differences of up to 40% were observed between the two systems. Concomitant platelet counts, in both systems, changed by less than 4%. A mathematical model of the variation of MPV with storage time was constructed, enabling experimental results to be extrapolated, with accuracy, to time zero (MPV0). The H6000 average MPV0 was significantly larger than the S+ average MPV0. Using the anticoagulant sodium citrate and prostaglandin E1 (NaCitrate-PGE1) there were no significant changes in MPV measured by the S+ during 7 h storage, although a linear decrease in platelet count was observed. A decrease in H6000 MPV was observed whether the blood was stored in EDTA or NaCitrate-PGE1. Methodology, anti-coagulation and storage time all influence MPV. Until these determinants are standardised the clinical value of MPV cannot be assessed.

Sulphasalazine induced agranulocytosis

Two patients seen in a short period with sulphasalazine (Salazopyrin) induced agranulocytosis are reported. Both patients recovered from this episode.