Scaling of Hemolysis in Needles and Catheters

Abstract

Hemolysis in clinical blood samples leads to inaccurate assay results and often to the need for repeated blood draws. In vitro experiments were conducted to determine the influence on hemolysis in phlebotomy needles and catheters of pressure difference, cannula diameter, and cannula material. Fresh blood from five human volunteers was forced from a syringe inside a pressurized chamber through 14, 18, and 22 gauge 304 stainless steel needles and polyurethane and Teflon catheters, all 40 mm long. Hemolysis was measured in the samples by a spectrophotometer. It was found that hemolysis increased with increases in pressure difference and cannula diameter and no consistent trend could be identified with regard to cannula material. The pressure differences required for significant hemolysis were above those typical of clinical venipuncture blood draws. While there was substantial variability among individuals, the hemolysis values scaled with exponent S = (t/t0)[(tau/tau0)-1]2, where t is the characteristic duration of shear, t0 is a time constant, tau is the wall shear stress, and tau0 is the wall shear stress threshold below which no hemolysis occurs. A hemolysis threshold including both time and shear stress was also defined for S = constant. The threshold implies that a threshold shear stress exists below which erythrocytes are not damaged for any length of exposure time, but that red cells may be damaged by an arbitrarily short period of exposure to sufficiently large shear stress.

Asialoglycoprotein receptor facilitates hemolysis in patients with alcoholic liver cirrhosis

“…39 -41 Based on previous descriptions of the application of mechanical stress to erythrocytes in vitro, 24,39,42 we developed an assay in which agglutinated erythrocytes were exposed to shear stress. In this assay, erythrocytes lysed dependent on their degree of agglutination.…”

“…24 The suspension containing the agglutinated red blood cells was diluted to 5 mL and passed three times through an 18-gauge needle with a defined speed of 50 mL/minute applied by a syringe pump. This was a setting under which hemolysis of nonagglutinated red blood cells from healthy donors was minimal.…”

Hemolysis in needles.

“…There are some steady flow losses in the syringe and also by the fluid and syringe plunger inertia that account for the pressure difference in the chamber pres ure and the pressure across the needle [ 14].…”

“…synnge Figure 13. Schematic of the experimental setup with needle in the reverse orientation [14] in the syringe through the needle. A syringe adapter facilitated an air-tight seal between the syringe and the chamber, and hold-down clamps allowed quick attachment of the assembly to the chamber.…”

Modelagem matemática da fluidodinâmica não-newtoniana e bifásica simplificada da hemólise induzida mecanicamente em sistemas de bombeamento centrífugo de sangue

“…Diversos estudos experimentais têm sido dedicados à avaliação de danos às células vermelhas sanguíneas (Sharp e Mohammad, 1998), (De Wachter et al, 1997), ; eles são realizados tipicamente fazendo fluir o sangue em um simulador analógico 5 através do dispositivo artificial e medindo-se a quantidade de hemoglobina livre de plasma no final de cada ciclo da experiência. No entanto, tais investigações experimentais demandam tempo e recursos financeiros, tendo em vista que cada modificação de projeto requer adaptações, ajustes e por vezes, a construção de novos dispositivos, peças ou componentes.…”