The Influence of COVID-19 Disease on Pre-Analytical Blood Sample Haemolysis Rates in Three Acute Medical Units: An Interrupted Time Series Analysis.

The COVID-19 pandemic impacted delivery of health services. The aim of our study was to determine the impact of COVID-19 disease on pre-analytical blood sample haemolysis by modelling the daily haemolysis rates variations pre and post COVID-19 infections. Ethics approval was obtained prior to study commencing. Interrupted Time Series data analysis was conducted on UK National Health Service Acute Admissions Unit 25-month (1 February 2019 to 28 February 2021) biochemistry (total and haemolysed) blood sample dataset. Interruption was set on 23 March 2021, the start of the first UK lockdown. Daily haemolysis rate (% samples haemolysed) data were fitted with a spline curve to determine influence of haemolysis rates on short or medium-term temporal trends. Linear regression was performed so as to determine long-term temporal trends pre- and post-intervention. There were 32,316 biochemistry blood sample results: 19,058 pre and 13,258 (342 days) from the post-intervention period. Overall median daily haemolysis rate was 7.3% (range: 0-30.6%), 7.7% pre-intervention versus 6.5% post-intervention (p<0.0001). The proportion of haemolysis cases negatively correlated with the number of samples processed (rho=0.09; p=0.01). The pre-intervention slope was -1.70 %.y-1, y intercept 9.04%; post-intervention slope was -1.88%.y-1, y intercept was 10.2%; with no difference in either the slope (p=0.87) or intercept (p=0.16). There was no association between short-term variation in haemolysis rates with changes in practice due to COVID-19 disease and the disease itself. The negative correlation between haemolysis rate and the number of samples processed highlights the importance of continued venepuncture practice to facilitate haemolysis rate reduction.

The impact of venepuncture training on the reduction of pre-analytical blood sample haemolysis rates: A systematic review.

BACKGROUND: Venepuncture involves the introduction of a needle into a vein to collect a representative blood sample for laboratory testing. In the pre-analytical phase, haemolysis (the rupturing of erythrocytes and release of their contents into the extracellular compartment) has safety, quality and cost implications. Training in correct venepuncture practice has the potential to reduce in vitro haemolysis rates, but the evidence for this notion has yet to be synthesised. DESIGN: Systematic review (PRISMA Checklist). METHODS: Published studies on the effectiveness of venepuncture training on haemolysis rates were searched in relevant databases. The McMaster critical appraisal tool was used to assess methodological quality. The GRADE tool was used to evaluate the body of evidence in relation to the research questions. Implementation fidelity was also scrutinised in each study. RESULTS: Eight out of 437 retrieved studies met the inclusion criteria. None were randomised controlled trials (RCT). Between-study heterogeneity in design, intervention characteristics and the biochemical threshold for haemolysis precluded a meta-analysis. Post-training reductions in haemolysis rates of between 0.4%-19.8% were reported in four of the studies, which developed their intervention according to a clear evidence base and included mentoring in the intervention. Rises in haemolysis rates of between 1.3%-1.9% were reported in two studies, while the intervention effect was inconsistent within two other studies. CONCLUSION: There are no RCTS on the effectiveness of venepuncture training for reducing haemolysis rates, and findings from the existing uncontrolled studies are unclear. For a more robust evidence base, we recommend more RCTs with standardisation of haemolysis thresholds and training-related factors. RELEVANCE TO CLINICAL PRACTICE: While venepuncture training is an important factor influencing quality of blood sample in clinical practice, more robust evidence is needed to make specific recommendations about training content for reduction of haemolysis rates. Standardisation of haemolysis thresholds would also enable future meta-analyses.

Level of confidence in venepuncture and knowledge in determining causes of blood sample haemolysis among clinical staff and phlebotomists.

AIMS AND OBJECTIVES: To investigate the association between confidence level in venepuncture and knowledge in determining causes of blood sample haemolysis among clinical staff and phlebotomists. BACKGROUND: Various collection methods are used to perform venepuncture, also called phlebotomy, the act of drawing blood from a patient using a needle. The collection method used has an impact on preanalytical blood sample haemolysis. Haemolysis is the breakdown of red blood cells, which makes the sample unsuitable. Despite available evidence on the common causes, extensive literature search showed a lack of published evidence on the association of haemolysis with staff confidence and knowledge. DESIGN: A quantitative primary research design using survey method. METHODS: A purposive sample of 290 clinical staff and phlebotomists conducting venepuncture in one North England hospital participated in this quantitative survey. A three-section web-based questionnaire comprising demographic profile, confidence and competence levels, and knowledge sections was used to collect data in 2012. The chi-squared test for independence was used to compare the distribution of responses for categorical data. anova was used to determine mean difference in the knowledge scores of staff with different confidence levels. RESULTS: Almost 25% clinical staff and phlebotomists participated in the survey. There was an increase in confidence at the last venepuncture among staff of all categories. While doctors' scores were higher compared with healthcare assistants', p ≤ 0·001, nurses' were of wide range and lowest. There was no statistically significant difference (at the 5% level) in the total knowledge scores and confidence level at the last venepuncture F(2,4·690) = 1·67, p = 0·31 among staff of all categories. CONCLUSION: Evidence-based measures are required to boost staff knowledge base of preanalytical blood sample haemolysis for standardised and quality service. Monitoring and evaluation of the training, conducting and monitoring haemolysis rate are equally crucial. RELEVANCE TO CLINICAL PRACTICE: Although the hospital is succeeding in providing regular training in venepuncture, this is only one aspect of quality. The process and outcome also need interventions.