Studies on Thrombocytosis. I. Hyperkalemia Due to Release of Potassium From Platelets During Coagulation1

Abstract

Remarkable elevation of the serum potassium concentration without associated manifestations of hyperkalemia was observed in a patient with an unexplained increase in the blood platelets (1). Studies of the phenomenon in this patient indicated that the excess of potassium was derived from the platelets during the coagulation of the blood. Hyperkalemia was encountered in certain other patients with thrombocytosis. In contrast, no striking elevation of the serum potassium concentration was observed when normal platelets were concentrated in vitro. METHODS AND MATERIALSPreparation of native blood and plasma specimens. Native (without anticoagulant) blood and plasma specimens were processed by previously described methods with reliance on the use of low temperatures and siliconetreated 2 equipment (2, 3). Platelet-free plasma was prepared from the blood specimen only after prior separation of platelet-rich plasma.Preparation of acid-citrate-dextrose plasma. Acidcitrate-dextrose3 (ACD) solution was added to whole blood prior to centrifugation in the proportion of one part of the anticoagulant to four parts of blood.Isolation of platelets. Blood (300 to 500 ml.) was collected from an antecubital vein into silicone-treated tubes packed in an icebath. Saftidonor4 sets were used for the collection of the blood in order to minimize trauma and exposure to surfaces such as occurs when blood is collected by multiple syringe technique. The blood was processed with and without the use of ACD anticoagulant. Native (without anticoagulant) and ACD plateletrich plasmas were prepared by slow speed centrifugation (1,500 to 2,000 rpm) in a refrigerated Servall angle centrifuge. A viscid plug of platelets was isolated from platelet-rich plasma by centrifuging at higher speeds (12,000 rpm). The supernatant plasma was thoroughly removed by draining and wiping the inside of the tube carefully. The platelet plug was placed in a deep-freeze. A small red button (red cells) was noted on the bottom of the platelet plug. In order to obtain a plug free of red and white cells, the red button with a small portion of the adjacent whitish material was removed while the plug was in a frozen state. The material removed was estimated to be less than 2 per cent of the volume of the plug.The platelet plug isolated from a measured volume of platelet-rich plasma was weighed and its volume determined by centrifugation in a graduated centrifuge tube. Platelet water was determined by allowing the wet plugs to reach constant weight by drying in an oven set at 800 C.Blood counts. Platelet counts were performed in duplicate by the phase microscopy method of Brecher and Cronkite (4). Counts on undiluted platelet-free plasma and serum were performed as previously described (3). Red and white blood cell counts on platelet-rich and platelet-free plasma and on serum were performed in the routine manner, using appropriate pipet dilutions.Potassium concentrations in serum, plasma and platelets. Native whole blood or plasma was placed in silicone-treated tubes for one h...

Pseudohyperkalaemia: a rare complication of splenectomy

“…Hartmann et al, who noted hyperkalaemia in the absence of common causes, first reported this in 1958. 1 The likelihood of pseudohyperkalaemia is highest in patients with primary thrombocytosis and polycythaemia rubra vera, followed by myelofibrosis and reactive thrombocytosis. 6 Two-thirds of splenectomy patients were shown to have pseudohyperkalaemia.…”

“…1 Elevated serum levels are the result of potassium release from platelets during aggregation and degranulation in vitro. A serum potassium level is collected in a clotted biochemistry bottle but a plasma potassium level is collected in a lithium/ sodium heparin bottle.…”

When is a high potassium not a high potassium?

“…1 As blood clots, potassium is released from platelets, white cells or red cells into the serum, giving a falsely high value. This process is avoided by use of plasma, which gives a more accurate estimation.…”

“…Factor X deficiency is usually inherited. 1 Of the acquired forms some are transient, possibly associated with infection, and, in these, spontaneous intracerebral haemorrhage does not seem to have been reported.…”

Pseudohyperkalemia in Serum: A New Insight into an Old Phenomenon

“…No toxic manifestation of hyperkalemia is present and no emergency therapy is required because the elevation of serum potassium concentration does not reflect the level of plasma potassium in vivo. Hartmann and his colleagues 1,2 concluded that the high potassium in serum is due to leakage from platelets in vitro during the clotting process, and was confirmed in many studies thereafter. [3][4][5][6][7] However, in 1960 Nilsson et al, 8 in order to explain some of the observed cases, suggested that potassium could be released from other cellular components and assumed that the red cells might be the source.…”