Background: Extreme leukocytosis is known to induce remarkable variations of some clinical chemistry tests, thus leading to possible clinical misinterpretation. This study aimed to define whether also moderate leukocytosis may influence the stability of glucose and blood gases.
Methods: Blood samples are sent to the local laboratory through a pneumatic tube system. Clinical chemistry testing is routinely performed using Lithium-heparin tubes (for glucose) and heparin blood gases syringes (for blood gas analysis). Stability of glucose (in uncentrifuged blood tubes) and blood gases (in syringes) was hence evaluated in samples maintained at room temperature. Results were also analyzed in 2 subgroups of samples with different leukocyte counts, i.e., those with leukocytes <15 × 109/L and those with leukocytes >15 × 109/L.
Results: An accelerated decrease of pH was observed in blood gases syringes with leukocytosis (i.e., >15 × 109/L), while no difference was noted for other blood gases parameters (PCO2, PO2). Spurious and time-dependent hypoglycemia was noted in uncentrifuged blood tubes of patients with leukocytosis.
Conclusions: The results of our study suggest that even modest leukocytosis (i.e., around 15 × 109/L), which is frequently encountered in clinical and laboratory practice, may be associated with significant variations of both glucose and pH. This would lead us to conclude that results of these parameters shall be accompanied by those of hematologic testing to prevent clinical misinterpretation, namely with leukocyte counts.
Uvod: Poznato je da ekstremna leukocitoza izaziva značajne varijacije nekih kliničkih hemijskih testova, što dovodi do moguće pogrešne kliničke interpretacije. Cilj ovog rada bio je da se utvrdi da li i umerena leukocitoza može uticati na stabilnost glukoze i gasova u krvi.
Metode: Uzorci krvi su poslati u lokalnu laboratoriju preko pneumatskog sistema cevi. Klinička hemijska ispitivanja se rutinski izvode koristeći litijum-heparinske epruvete (za glukozu) i heparinske gasove (za analizu gasa u krvi). Stabil nost glukoze (u necentrifugiranim epruvetama krvi) i gasova u krvi (u špricevima) je zbog toga procenjena na uzorcima koji su održavani na sobnoj temperaturi. Rezultati su tako|e analizirani u 2 podgrupe uzoraka sa različitim brojem leukocita, to jest, sa leukocitima < 15 × 109/L i sa leukocitima > 15 × 109/L.
Rezultati: U špricu sa gasovima u krvi sa leukocitozom (tj. > 15 × 109/L) primećeno je ubrzano smanjenje pH vrednosti, pri čemu nije zabeležena razlika za druge parametre gasova krvi (PCO2, PO2). Lažna i vremenski zavisna hipoglikemija zabeležena je u necentrifugiranim epruvetama pacijenata sa leukocitozom.
Zaključak: Rezultati našeg istraživanja ukazuju da čak i skromna leukocitoza (tj. oko 15 × 109/L), koja se često sreće u kliničkoj i laboratorijskoj praksi, može biti povezana sa značajnim varijacijama i glukoze i pH. To nas je navelo na zaključak da rezultati ovih parametara moraju biti propraćeni rezultatima hematološkog testiranja kako bi se sprečila pogrešna klinička interpretacija, a sve zbog broja leukocita.
Keywords: blood gases; glucose; preanalytical variability.
2020 Guillaume Grzych, Estelle Roland, David Beauvais, Patrice Maboudou, Giuseppe Lippi, published by CEON/CEES.