Neuraxial Anesthesia and the Ubiquitous Platelet Count Question: How Low Is Too Low?

2021 ◽  
Vol 41 (4) ◽  
pp. 163-163
Author(s):  
B.M. Scavone ◽  
C.A. Wong
Keyword(s):  
Platelet Count ◽  
Neuraxial Anesthesia

Neuraxial Anesthesia and the Ubiquitous Platelet Count Question—How Low Is Too Low?

2021 ◽  
Vol 132 (6) ◽  
pp. 1527-1530
Author(s):  
Barbara M. Scavone ◽  
Cynthia A. Wong
Keyword(s):  
Platelet Count ◽  
Neuraxial Anesthesia

Thrombocytopenia in Surgery and Neuraxial Anesthesia

2020 ◽  
Vol 46 (03) ◽  
pp. 245-255
Author(s):  
Lise J. Estcourt
Keyword(s):  
Platelet Count ◽  
Observational Studies ◽  
Randomized Trials ◽  
Venous Catheter ◽  
Central Venous Catheters ◽  
Neuraxial Anesthesia ◽  
Major Surgery ◽  
Invasive Procedures ◽  
Central Venous ◽  
Epidural Catheters

AbstractThis is a review of the evidence for the use of different platelet count thresholds prior to invasive procedures and surgery. This review will focus on three procedures that are common in patients with thrombocytopenia—central venous catheter insertion, liver biopsy, and lumbar punctures and epidural catheters—as well as highlighting the lack of evidence for more major surgery. Tunneled or untunneled central venous catheters are low-risk procedures and can be safely performed without any intervention when the platelet count is 20 × 109/L or above. Evidence for their safety is more limited below this threshold, but as bleeding is easily treated, interventions should focus on treating any bleeding that occurs rather than preventative strategies. The available evidence for neuraxial anesthesia is based on very low-quality evidence from observational studies. Based on this evidence, the risk of an epidural hematoma is less than 0.19% (upper limit of 95% confidence interval) for pregnant women undergoing an epidural anesthetic when the platelet count is between 70 and 99 × 109/L. No randomized trials have been performed in children, nor have any randomized trials been performed in major or emergency surgeries.

Thrombocytopenia and neuraxial anesthesia: Are there platelet count thresholds?

2020 ◽  
Vol 63 ◽  
pp. 109751
Author(s):  
Jared A. Herman ◽  
Ivan Urits ◽  
Alan D. Kaye ◽  
Richard D. Urman ◽  
Omar Viswanath
Keyword(s):  
Platelet Count ◽  
Neuraxial Anesthesia

Do Extra-Platelet Sources Contribute to the Plasma Level of Thrombospondin?

1988 ◽  
Vol 59 (02) ◽  
pp. 273-276 ◽  
Author(s):  
J Dawes ◽  
D A Pratt ◽  
M S Dewar ◽  
F E Preston
Keyword(s):  
Platelet Count ◽  
Background Concentration ◽  
Serum Concentrations ◽  
Bone Marrow Depression ◽  
Serial Sampling ◽  
Control Serum ◽  
Platelet Release ◽  
Highly Correlated ◽  
The Relationship

SummaryThrombospondin, a trimeric glycoprotein contained in the platelet α-granules, has been proposed as a marker of in vivo platelet activation. However, it is also synthesised by a range of other cells. The extraplatelet contribution to plasma levels of thrombospondin was therefore estimated by investigating the relationship between plasma thrombospondin levels and platelet count in samples from profoundly thrombocytopenic patients with marrow hypoplasia, using the platelet-specific α-granule protein β-thromboglobulin as control. Serum concentrations of both proteins were highly correlated with platelet count, but while plasma β-thromboglobulin levels and platelet count also correlated, there was no relationship between the number of platelets and thrombospondin concentrations in plasma. Serial sampling of patients recovering from bone marrow depression indicated that the plasma thrombospondin contributed by platelets is superimposed on a background concentration of at least 50 ng/ml probably derived from a non-platelet source, and plasma thrombospondin levels do not simply reflect platelet release.

1-Desamino-8-D-Arginine Vasopressin (DDAVP) Infusion in Type IIB von Willebrand’s Disease: Shortening of Bleeding Time and Induction of a Variable Pseudothrombocytopenia

1990 ◽  
Vol 64 (01) ◽  
pp. 117-120 ◽  
Author(s):  
Alessandra Casonato ◽  
M Teresa Sartori ◽  
Luigi de Marco ◽  
Antonio Girolami
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Count ◽  
Arginine Vasopressin ◽  
Calcium Concentration ◽  
Sodium Citrate ◽  
Bleeding Time ◽  
Blood Collection ◽  
Von Willebrand's Disease ◽  
Blood Samples ◽  
Von Willebrand’S Disease

SummaryWe have investigated the effects of 1-desamino-8-D-arginine vasopressin (DDAVP) infusion on platelet count and bleeding time in 4 patients with type IIB von Willebrand’s disease (vWd). Three of four patients showed a normalization of the bleeding time within 1 h after the infusion, while bleeding time was not modified in the fourth. In accordance with the literature, thrombocytopenia was observed after DDAVP infusion, but this thrombocytopenia was due to the anticoagulants used for blood collection. In two patients (F. I., G. F.) no thrombocytopenia was observed when platelets were counted by fingerstick method but there was a 20% platelet decrease in blood samples collected in sodium citrate and a 50% decrease in samples collected in EDTA. Dramatic falls in platelet counts (70–95%) were observed in the additional two patients (C. A., D.Z.) after DDAVP infusion, when both sodium citrate or EDTA were used as anticoagulants. In the latter two patients there was also a 50% decrease in platelet count when the fingerstick method was used. The decrease in the patient’s platelet count in EDTA samples after DDAVP infusion could be prevented, in part, by the previous additions of an anti GPIb monoclonal antibody and an anti GPIIb-IIIa monoclonal antibody.Thus, the thrombocytopenia observed in the four IIB vWd patients studied after DDAVP infusion seems to be, at least partially, a pseudothrombocytopenia depending on the calcium concentration in the blood samples and the availability of GPIb and GPIIb-IIIa receptors. These findings and the normalization of the bleeding time observed in three of the four patients has led us to reconsider the possible use of DDAVP in the treatment of our IIB vWd patients.

Enhancement of ADP-induced Platelet Aggregation by Adrenaline in Vivo and Its Prevention

1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Endothelial Surface ◽  
Important Interaction ◽  
Blood Coagulability ◽  
The Difference

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.

Platelet Aggregation in Rats in Relation to Hyperuricaemia Induced by Dietary Single-Cell Protein and to Protein Deficiency

1978 ◽  
Vol 39 (02) ◽  
pp. 346-359 ◽  
Author(s):  
P D Winocour ◽  
M R Turner ◽  
T G Taylor ◽  
K A Munday
Keyword(s):  
Uric Acid ◽  
Platelet Count ◽  
Platelet Aggregation ◽  
Time Lag ◽  
Blood Platelet ◽  
Single Cell Protein ◽  
Cell Protein ◽  
Low Protein ◽  
Blood Platelet Count ◽  
Rat Platelets

SummaryA major limitation to single-cell protein (SCP) as a human food is its high nucleic acid content, the purine moiety of which is metabolised to uric acid. Rats given a Fusarium mould as a source of SCP in diets containing oxonate, a uricase inhibitor, showed elevated plasma and kidney uric acid concentrations after 21 d, which were related to the level of dietary mould. ADP-induced and thrombin-induced platelet aggregation was greater in the hyperuricaemic rats than in controls and a progressive increase in aggregation with increasing levels of dietary mould was observed. Furthermore a time-lag, exceeding the life-span of rat platelets, was observed between the development of hyperuricaemia and the increase in aggregation. A similar time-lag was observed between the lowering of the hyperuricaemia and the reduction of platelet aggregation when oxonate was removed from the diet.If human platelets react to uric acid in the same manner as rat platelets this might explain the link that has been suggested between hyperuricaemia and ischaemic heart disease. In that event diets high in nucleic acids might be contra-indicated in people at risk from ischaemic heart disease.In rats given a low protein diet (50 g casein/kg) for 21 d ADP-induced and thrombin-induced platelet aggregation and whole blood platelet count were reduced compared with control animals receiving 200 g casein/kg diet but not in rats given 90 or 130 g casein/kg diet. A study of the time course on this effect indicated that the reduction both in aggregation tendency and in whole blood platelet count occurred after 4 d of feeding the low protein diet. These values were further reduced with time.

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