ObjectivesNon-adherence to therapy is an important cause of suboptimal blood pressure control but few practical tools exist to accurately and routinely detect it. We used a simple urine-based assay to evaluate the prevalence of antihypertensive treatment non-adherence and its impact on blood pressure in a specialist hypertension centre.Methods208 hypertensive patients (125 new referrals, 66 follow-up patients with inadequate blood pressure control and 17 renal denervation referrals) underwent assessment of antihypertensive drug intake using high-performance liquid chromatography-tandem mass spectrometry (HP LC-MS/MS) urine analysis at the time of clinical appointment. A total of 40 most commonly prescribed antihypertensive medications (or their metabolites) were screened for in spot urine samples.ResultsOverall, 25% of patients were totally or partially non-adherent to antihypertensive treatment (total non-adherence 10.1%, partial non-adherence 14.9%). The highest prevalence of partial and total non-adherence was among follow-up patients with inadequate blood pressure control (28.8%) and those referred for consideration of renal denervation (23.5%), respectively. There was a linear relationship between blood pressure and the numerical difference in detected/prescribed antihypertensive medications—every unit increase in this difference was associated with 3.0 (1.1) mm Hg, 3.1 (0.7) mm Hg and 1.9 (0.7) mm Hg increase in adjusted clinic systolic blood pressure, clinic diastolic blood pressure (DBP) and 24 h mean daytime DBP (p=0.0051, p=8.62×10−6, p=0.0057), respectively.ConclusionsNon-adherence to blood pressure lowering therapy is common, particularly in patients with suboptimal blood pressure control and those referred for renal denervation. HP LC-MS/MS urine analysis could be used to exclude non-adherence and better stratify further investigations and intervention.

Objective Deficiency of thiamin (vitamin B1) causes a range of neuropsychiatric symptoms that resemble those reported in patients with anorexia nervosa (AN) but the prevalence of thiamin deficiency in AN has not been reliably established. This study was designed to investigate the prevalence of thiamin deficiency in AN. Method Thirty‐seven patients attending a specialist eating disorders unit and meeting all or some of the DSM‐IV criteria for AN were compared with 50 blood donor controls. All subjects underwent measurement of erythrocyte transketolase activation following the addition of thiamin pyrophosphate, the standard biochemical test for thiamin deficiency. Deficiency was defined as a result more than 2 SD above the mean of the control population. Results Fourteen patients (38%) had results in the deficient range; 7 (19%) met the most stringent published criterion for deficiency. Deficiency was not related to duration of eating restraint, frequency of vomiting, or alcohol consumption. Discussion Thiamin deficiency may account for some of the neuropsychiatric symptoms of AN and routine screening or supplementation may be indicated. © 2000 by John Wiley & Sons, Inc. Int J Eat Disord 28: 451–454, 2000.

Fluid resuscitation aims to maintain intravenous volume without significant effects on haemostasis. Several different types of i.v. fluid are available for use in a patient who has suffered trauma, but there is evidence that some resuscitation fluids may affect primary haemostasis. We have compared the effects of two resuscitation fluids, Haemaccel and Gelofusin, on platelet aggregation in vitro. These resuscitation fluids are both based on gelatin but Haemaccel contains a high concentration of Ca2+ whereas Gelofusin does not. Their effects on platelet aggregation in whole blood, induced by a range of different agents, were determined using a platelet-counting technique. Both Haemaccel and Gelofusin prevented platelet aggregation induced by ristocetin (P < 0.05, Mann-Whitney). In addition, Haemaccel proved to be a potent inhibitor of the platelet aggregation that occurred in response to all of the other agonists investigated: adenosine diphosphate, platelet-activating factor, collagen, a thromboxane A2 mimetic (U46619) and epinephrine. The additional inhibitory effects of Haemaccel were largely, but not completely, attributable to its high Ca2+ content. Inhibition of platelet aggregation by ristocetin may indicate a mechanism by which Haemaccel or Gelofusin may contribute to impaired haemostasis. The presence in Haemaccel of high concentrations of Ca2+, which is largely responsible for inhibition of the aggregation induced by other agents, may provide an additional means by which haemostasis could be impaired.

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Summary.A prospective randomized double-blind study was performed to determine the effects of three colloids, Haemaccel, Gelofusine and albumin, and also saline on platelet activation, platelet aggregation (induced by adenosine diphosphate (ADP), epinephrine, collagen) platelet agglutination by ristocetin and other hemostatic variables in 55 patients undergoing primary unilateral total hip replacement. The¯uids were administered according to normal clinical practice and assessments were made immediately before, at the end, and 2 h after the end of surgery. Surgery was accompanied by thrombin generation (increases in thrombin/antithrombin III complex, prothrombin F1 2 fragment) platelet activation (bTG) and compromised coagulation. Generally, the platelet activation appeared to result in platelet desensitization and brought about a persistent reduction in platelet aggregation to ADP and epinephrine, irrespective of the¯uid used. Additionally, Haemaccel and Gelofusine inhibited ristocetin-induced platelet agglutination and albumin inhibited collagen-induced platelet aggregation. Gross inhibitory effects of Haemaccel that had been predicted from an earlier in vitro study did not occur. Particular¯uids had selective additional effects on the hemostatic system. Albumin infusion served to maintain plasma albumin at normal concentrations postsurgery. The two gelatin preparations, Haemaccel and Gelofusine, maintained plasma viscosity. All three colloids led to a transient increase in activated partial thromboplastin time postsurgery and also a transient fall in the concentration of factor VIII, which were accompanied by a transient increase in bleeding time, but there was no measurable increase in blood loss. Inhibition of platelet aggregation by certain colloids may provide additional protection against the increased thrombotic risk in patients following major surgery.