The stability of 'add-on' coagulation assays in refrigerated citrated plasma stored on a packed cellular fraction

INTRODUCTION

Haematology laboratories are increasingly faced with requests for add-on coagulation testing. This study explores extending the specimen storage proposals by examining coagulation parameters on refrigerated citrated plasma retained on a cellular fraction over a 24-hour period.

METHODS

Sodium citrate (Sarstedt^® S-Monovette 3.2%) specimens from 206 patients in University Hospital Limerick, Ireland were refrigerated immediately post-analysis and re-analysed in the centrifuged primary container at 4, 8 and 24-hour intervals using the Diagnostica Stago coagulometer and reagent combination. Coagulation assays examined for statistically and clinically significant differences included PT, APTT, D-Dimer, fibrinogen and Protein C.

RESULTS

PT, APTT and Protein C values displayed statistical significance from 4 hours. Fibrinogen differences were statistically significant from 8 hours. D-Dimer differences were not statistically significant at any interval over the 24-hour period. The refrigerated storage limit for PT and APTT results was determined to be 4 hours. D-Dimer was the only test parameter to report a mean percentage variance >10%. However, result changes at the threshold region of 0.5 µg/mL FEU were found to be within assay precision limits and desirable bias up to 8 hours. Maximum mean differences for Protein C (-1.3%) and fibrinogen (2.3%) were within assay precision limits and desirable biases up to 24 hours.

CONCLUSION

PT and APTT results are stable in refrigerated citrated plasma maintained on a cellular fraction up to 4 hours post-phlebotomy. D-Dimers results are reliable up to 8 hours, while fibrinogen and Protein C results are stable for at least 24 hours.

Do Differences in Work Disability Duration Between Men and Women Vary by Province in Canada?

Purpose Research has shown that there are important sex and gender-based differences in the work disability duration of men and women. This research is often limited to single jurisdictions, using different outcome measures, and therefore has limited generalisability of findings. This study examined if differences between work disability of men and women differed by province and by duration of work disability. Methods Cohorts of injured workers in the Canadian provinces of British Columbia (BC), Manitoba (MB) and Ontario (ON) were analysed using workers' compensation data for work-related injuries occurring between 2007 and 2011. Work disability duration was measured using cumulative days in receipt of disability benefits paid during one-year post-injury. Poisson models with restricted cubic splines tested whether differences between men and women in the likelihood of transitioning off disability benefits varied by duration of work disability in each province, adjusting for confounders. Results Men transitioned off disability benefits faster than women for claim durations of up to two to four months, after which women transitioned off disability benefits faster until ten months. Differences between men and women were consistent across all jurisdictions. For claims longer than ten months, men transitioned off work disability benefits faster than women in BC and ON, but there were no significant differences between men and women in MB. Conclusions Differences in the work disability duration between men and women vary by province and duration of work disability. Claims management processes need to be sensitive to differences that men and women face and the timing of interventions.

Randomized controlled trial of the intraligamental use of a local anaesthetic (lignocaine 2%) versus controls in paediatric tooth extraction

BACKGROUND

Children still experience pain upon waking following dental extraction under general anaesthesia. Local anaesthetic has been shown to reduce this pain, but needs to be administered via a method that causes minimum injury or distress to the child.

AIM

This study aims to evaluate the use of intraligamental injection of local anaesthetic, under general anaesthesia prior to the extraction of the tooth, for postoperative pain control in children aged 2-5 years.

DESIGN

A randomized, single-blind, controlled trial of intraligamental lignocaine (2% lignocaine solution with adrenaline (epinephrine) 1 : 80 000) for primary teeth extraction under general anaesthesia was performed. Pain was scored by the investigators at 5-, 15-, 30-, and 60-min time points in the first hour using the Toddler-Preschooler Postoperative Pain Scale.

RESULTS

Eighty-six children were recruited in the study: 42 randomized in the lignocaine treatment group and 44 in the control group. There was no significant difference (P = 0.42, Mann-Whitney U-test) in the cumulative four time point median pain score over the first hour. In the lignocaine treatment group, this was 3 (interquantile range (IQR) 0-7.5) and in the control group this was 3 (IQR: 0-10). At the 5-min time point after the child returned from recovery, the pain score in the lignocaine group (0 IQR 0-1) was statistically lower than that in the control group (0 IQR 0-5) (P = 0.023). There was no difference in the 15-, 30-, or 60-min time points.

CONCLUSIONS

Intraligamental lignocaine used for dental extraction under general anaesthesia in young children initially causes less pain after recovery, but this difference is not sustained over the first hour after dental extraction.