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M P W Grocott

Publications and source records attributed to M P W Grocott.

7 recordsLinked to original sources
PubMed2006

Just scratching the surface: varied coagulation effects of polymer containers on TEG variables.

BACKGROUND AND OBJECTIVE: Different types of polymer surfaces affect the activation of platelets and coagulation pathway containers depending on their surface qualities. Importantly, this could produce variability of coagulation results obtained with thrombelastographical analysis. We assessed the effects of blood storage on thrombelastograph, TEG, variables using polypropylene and polycarbonate containers. METHODS: An in vitro experiment was performed, with eight volunteers in each limb. Fresh whole blood was stored in polypropylene or polycarbonate tubes prior to TEGanalysis, to assess the role of these plastics in the TEG results obtained. RESULTS: The polycarbonate tubes displayed slower onset of coagulation and greater variability of data for all four basic TEG variables (r-time, k-time, alpha-angle and maximum amplitude, P < 0.05). Polycarbonate results fell outside manufacturer reference ranges. CONCLUSIONS: It is likely that this is due to the altered surface properties and charge effects of the containers affecting proteins and platelets differently. Caution should be used in choosing which containers are used for storage of fresh blood prior to coagulation assessment, as variable results will follow where different types of plastic containers are employed.

Blood Coagulation↗
PubMed2004

A descriptive study of the variation in baseline levels of antiendotoxin core antibodies between US and UK populations.

Low levels of naturally occurring antibodies to the core section of endotoxin (EndoCAb) have been shown to be predictors of poor outcome following major surgery. We performed a retrospective study comparing pre-operative levels in US surgical patients, UK surgical patients and healthy volunteers. Both IgM and IgG EndoCAb levels were higher in the US surgical patients when compared with the other groups (approximately twice as high in the case of IgG EndoCAb). This may reflect genetic or environmental variability between the patient groups, differences in the disease processes, the disparity in the delivery of health care between the two countries or degradation of the samples in transfer.

Antibodies, Bacterial↗
PubMed2002

Coagulation effects of in vitro serial haemodilution with a balanced electrolyte hetastarch solution compared with a saline-based hetastarch solution and lactated Ringer's solution.

The hydroxyethyl starches are a group of compounds that has been associated with impairment of coagulation when large volumes are administered. The thrombelastograph is commonly used to assess point-of-care whole blood coagulation. Little is known about the dose-response relationships of haemodilution, and it is reasonable to assume that a linear association exists. This may not be the case with altered electrolyte compositions of the fluids used for haemodilution. We have therefore conducted an in vitro study of haemodilution of human whole blood using lactated Ringer's solution and two high molecular weight hetastarches, one in a balanced salt solution, the other in a 0.9% saline solution. The thrombelastograph, commonly used for the assessment of the coagulation effects of synthetic colloids, was used as the coagulation assessment device. Serial haemodilution with hetastarch in a balanced salt solution demonstrated a biphasic response (of r-times and k-times, as well as alpha angles), with haemodilution in the 20-40% range causing enhanced coagulation, and higher degrees of dilution causing a decrease in overall coagulation performance. A similar picture was observed with lactated Ringer's solution, but only significantly so in alpha angles. Hetastarch in saline did not display this initial increased coagulability at mild to moderate dilutions. This biphasic response of lactated Ringer's solution and hetastarch in a balanced salt solution reflects the complex interaction of fluids and the coagulation system, and that these effects cannot be attributed to simple haemodilution. On the other hand, there was a linear decrease in maximum amplitude with haemodilution. Maximum amplitude was particularly affected by both starches, which is an expected finding in view of the known interaction between the hydroxyethyl starches and von Willebrand's factor.

Blood Coagulation↗
PubMed2002

Resuscitation fluids.

BACKGROUND AND OBJECTIVES: The aim of this review was to summarize the properties of the commonly available resuscitation fluids and highlight where knowledge of the characteristics of individual fluids might guide their use in clinical practice. Some of the current controversies surrounding resuscitation fluids are also discussed. Blood or blood products, or strategies of fluid administration, are not focused upon. CONCLUSIONS: The clinical trial data does not support the concept of a therapeutic advantage for either crystalloids or colloids, despite claimed theoretical advantages for both classes of fluid. The available colloid solutions have quite distinct profiles of activity, both in terms of their plasma volume expansion profile and other physiological and pharmacological properties. Recent data suggests that physiologically balanced crystalloid and colloid solutions may improve clinical outcomes when compared with saline-based fluids.

Colloids↗