Blood Donation Abstracts 2

©

Current applications of therapeutic phlebotomy.
(Assi and Baz, 2014) Download
Phlebotomy, known also as bloodletting or venesection, is a major therapeutic procedure that has been performed by physicians in various civilisations since antiquity up to the present1,2. In the past it was practised using cupping, lancets or by the application of leeches2 . This procedure often weakened the patient and resulted in his or her death. A famous example is that of President George Washington who died in 1799 following the removal of approximately 1.7 litres of blood during a bloodletting procedure for acute epiglottitis3.

Blood donation and testosterone replacement therapy.
            (Chin-Yee et al., 2017) Download
BACKGROUND:  Polycythemia is the most common adverse effect of testosterone replacement therapy (TRT) and may predispose patients to adverse vascular events. Current Canadian guidelines recommend regular laboratory monitoring and discontinuing TRT or reducing the dose if the hematocrit exceeds 54% (hemoglobin ≥180 g/L). This threshold has been interpreted by some physicians and patients to indicate the need for phlebotomy or blood donation while on TRT. STUDY DESIGN AND METHODS:  We reviewed all male blood donors in Southwestern Ontario at Canadian Blood Services from December 2013 to March 2016 who self-identified or were found on donor screening to be on TRT. Hemoglobin concentration was measured at the time of donation or clinic visit and with each subsequent appointment in repeat donors. RESULTS:  We identified 39 patients on TRT who presented for blood donation over a 2-year period. The mean hemoglobin level at all clinic visits was 173 g/L (range, 134-205 g/L; n = 108). Hemoglobin concentrations of 180 g/L or more (calculated hematocrit, ≥54%) were measured at 25% of appointments. Of the 27 repeat donors, 12 (44%) had persistently elevated hemoglobin levels (≥180 g/L) at subsequent donations. CONCLUSION:  Hemoglobin concentrations were elevated in donors on TRT, and significant numbers had hemoglobin levels above those recommended by current guidelines. These data also suggest that repeat blood donation was insufficient to maintain a hematocrit below 54%. Our findings raise concerns about the persistent risk of vascular events in these donors, particularly when coupled with the misperception by patients and health care providers that donation has reduced or eliminated the risks of TRT-induced polycythemia.


Therapeutic phlebotomy: a review of diagnoses and treatment considerations.
            (Cook, 2010) Download
In the United States, phlebotomies are most often performed for reinfusion of blood to a designated or nondesignated recipient at a later time. These are known, respectively, as autologous or allogenic donations. For a few rare blood disorders, however, phlebotomy is performed as a medical intervention for disease management. These are referred to as therapeutic phlebotomies. Four classifications of blood disorders are discussed here for which symptoms and complications can be managed by the use of therapeutic phlebotomy. The article also offers considerations for setting up a therapeutic phlebotomy program.

Phlebotomy treatment for elimination of perfluoroalkyl acids in a highly exposed family: a retrospective case-series.
            (Genuis et al., 2014) Download
BACKGROUND:  Perfluoroalkyl acids (PFAAs) are a family of commonly used synthetic chemicals that have become widespread environmental contaminants. In human serum, perfluorohexane sulfonate (PFHxS), perflurooctane sulfonate (PFOS), and perfluorooctanoate (PFOA) are most frequently detected, in part owing to their long elimination half-lives of between 3.8 yrs (PFOA) and 8.5 yrs (PFHxS). These PFAAs also cross the placenta and have been associated with developmental toxicity, and some are considered likely human carcinogens. Interventions to eliminate PFAAs in highly contaminated individuals would reduce future health risks, but minimal research has been conducted on methods to facilitate accelerated human clearance of these persistent substances. METHODS:  Six patients with elevated serum concentrations from a single family were treated by intermittent phlebotomy over a 4-5 year period at intervals similar to, or less frequent than what is done for routine blood donation at Canadian Blood Services. The apparent elimination half-life (HLapp) for PFHxS, PFOS, and PFOA in this treated population was calculated in each patient and compared to the intrinsic elimination half-lives (HLin) from a literature reference population of untreated fluorochemical manufacturing plant retirees (n = 26, age >55 yrs). RESULTS:  For all three PFAAs monitored during phlebotomy, HLapp in each of the family members (except the mother, who had a low rate of venesection) was significantly shorter than the geometric mean HL measured in the reference population, and in some cases were even shorter compared to the fastest eliminator in the reference population. CONCLUSION:  This study suggests significantly accelerated PFAA clearance with regular phlebotomy treatment, but the small sample size and the lack of controls in this clinical intervention precludes drawing firm conclusions. Given the minimal risks of intermittent phlebotomy, this may be an effective and safe clinical intervention to diminish the body burden of PFAAs in highly exposed people.


 

Blood donation and blood donor mortality after adjustment for a healthy donor effect.
            (Ullum et al., 2015) Download
BACKGROUND:  Studies have repeatedly demonstrated that blood donors experience lower mortality than the general population. While this may suggest a beneficial effect of blood donation, it may also reflect the selection of healthy persons into the donor population. To overcome this bias, we investigated the relation between blood donation frequency and mortality within a large cohort of blood donors. In addition, our analyses also took into consideration the effects of presumed health differences linked to donation behavior. STUDY DESIGN AND METHODS:  Using the Scandinavian Donation and Transfusion database (SCANDAT), we assessed the association between annual number of donations in 5-year windows and donor mortality by means of Poisson regression analysis. The analyses included adjustment for demographic characteristics and for an internal healthy donor effect, estimated among elderly donors exempted from continued donation because of age criteria. RESULTS:  Statistical analyses included 1,182,495 donors of whom 15,401 died during 9,526,627 person-years of follow-up. Analyses adjusted only for demographic characteristics showed a 18.6% reduction in mortality per additional annual donation (95% confidence interval [CI], 16.8%-20.4%). After additional adjustment for the internal healthy donor effect, each additional annual donation was associated with a 7.5% decreased mortality risk 7.5% (95% CI, 5.7%-9.4%). CONCLUSION:  We observed an inverse relationship between donation frequency and mortality. The magnitude of the association was reduced after adjustment for an estimate of self-selection in the donor population. Our observations indicate that repeated blood donation is not associated with premature death, but cannot be interpreted as conclusive evidence of a beneficial health effect.

Beyond leeches. Therapeutic phlebotomy today.
            (Wright and Finical, 2000) Download
George Washington prevailed as commander in chief of the ContinentalArmy during the American Revolution and went on to become the first of president of the nation. But even he couldn’t survive the drainage of nine pints of blood in 24 hours - a treatment he underwent for a throat infection in 1799.

 


References

Assi, TB and E Baz (2014), ‘Current applications of therapeutic phlebotomy.’, Blood Transfus, 12 Suppl 1 s75-83. PubMed: 24120605
Chin-Yee, B, et al. (2017), ‘Blood donation and testosterone replacement therapy.’, Transfusion, 57 (3), 578-81. PubMed: 28150363
Cook, LS (2010), ‘Therapeutic phlebotomy: a review of diagnoses and treatment considerations.’, J Infus Nurs, 33 (2), 81-88. PubMed: 20228645
Genuis, SJ, et al. (2014), ‘Phlebotomy treatment for elimination of perfluoroalkyl acids in a highly exposed family: a retrospective case-series.’, PLoS One, 9 (12), e114295. PubMed: 25504057
Ullum, H, et al. (2015), ‘Blood donation and blood donor mortality after adjustment for a healthy donor effect.’, Transfusion, 55 (10), 2479-85. PubMed: 26098293
Wright, SM and J Finical (2000), ‘Beyond leeches. Therapeutic phlebotomy today.’, Am J Nurs, 100 (7), 55-9, 61, 63. PubMed: 10914071