28 Mar 06
Posted in Critical Care, Sepsis at 18:52 by Laci
By D Cheyron, B Bouchet, C Bruel, C Daubin, M Ramakers and P Charbonneau
Critical Care 2006, 10:R45 http://ccforum.com/content/10/2/R45
Introduction
Acquired antithrombin III (AT) deficiency may induce heparin resistance and premature membrane clotting during continuous renal replacement therapy (CRRT). The purpose of this study was to evaluate the effect of AT supplementation on filter lifespan in critically ill patients with septic shock requiring CRRT.
Methods
We conducted a retrospective case-control analysis based on a 4-year observational study with prospectively collected data in two medical intensive care units in a university hospital. In all, 106 patients with septic shock underwent CRRT during the study period (55 during 2001 to 2002 and 51 during 2003 to 2004). Of these, 78 had acquired AT deficiency (plasma level below 70%) at onset of renal supportive therapy, 40 in the first 2-year period and 38 in the last 2-year period. In the latter intervention period, patients received AT supplementation (50 IU/kg) during CRRT each time that plasma AT activity, measured once daily, fell below 70%.
Results
In a case-control analysis of the 78 patients with acquired AT deficiency, groups were similar for baseline characteristics, except in severity of illness as assessed by a higher Simplified Acute Physiology Score (SAPS) II after 2002. In comparison with controls, cases had a significantly greater AT level after AT supplementation, but not at baseline, and a smaller number of episodes of clots, without excess bleeding risk. The median hemofilter survival time was longer in the AT group than in the heparin group (44.5 versus 33.4 hours; p = 0.0045). The hemofiltration dose, assessed by the ratio of delivered to prescribed ultrafiltration, increased during intervention. AT supplementation was independently associated with a decrease in clotting rate, whereas femoral angioaccess and higher SAPS II were independent predictors of filter failure. However, mortality did not differ between periods, in the control period the observed mortality was significantly higher than predicted by the SAPS II score, unlike in the treatment period.
Conclusion
In sepsis patients requiring CRRT and with acquired AT deficiency, anticoagulation with unfractionated heparin plus AT supplementation prevent premature filter clotting and may contribute to improving outcome, but the cost-effectiveness of AT remains to be determined.
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27 Mar 06
Posted in Anesthesia, Bleeding, General, Venous thromboembolism at 20:36 by Laci
By P Roderick, G Ferris, K Wilson, H Halls, D Jackson, R Collins and C Baigent
Health Technol Assess 2005;9(49).
Objectives
The objectives of this study were to assess the benefits in terms of reductions in the risks of deep vein thrombosis (DVT) and of pulmonary embolism (PE), and hazards in terms of major bleeding, of: (i) mechanical compression (graduated compression stockings, intermittent pneumatic compression, footpumps); (ii) oral anticoagulants; (iii) dextran; and (iv) regional anaesthesia (as an alternative to general anaesthesia) in surgical and medical patients.
Search strategy
The strategy involved a systematic search of electronic databases (MEDLINE, EMBASE, BIOSIS, Derwent), search of the Antithrombotic Trialists’ Collaboration database, contact with trialists and manufacturers, and scrutiny of bibliographies of identified papers and reviews of thromboprophylaxis.
Selection criteria
Properly randomised trials were selected, including those reported in a non-English language, with at least one unconfounded comparison of the effect of one of the methods under review versus control, or a direct comparison between different versions of a method, or a direct comparison between a pharmacological agent (dextran or an oral anticoagulant) and low molecular weight or unfractionated heparin. Trials were included only if systematic assessment of DVT by radiological methods was planned.
Data collection and analysis
All trials identified as fitting the selection criteria were independently assessed by at least two review authors for methodological quality and the numbers of patients with primary and secondary outcomes were recorded. The primary outcomes were DVT, PE and major bleeding events, and proximal venous thrombosis (PVT) and fatal PE were secondary outcomes. Trials were subdivided into those that had assessed a method as the only means of thromboprophylaxis (‘monotherapy’) and those that had assessed the effects of adding a method to another form of thromboprophylaxis (‘adjunctive therapy’).
Main results
Mechanical compression methods reduced the risk of DVT by about two-thirds when used as monotherapy and by about half when added to a pharmacological method. These benefits were similar irrespective of the particular method used (graduated compression stockings, intermittent pneumatic compression or footpumps) and similar in each of the surgical groups studied. Mechanical methods reduced the risk of PVT by about half and the risk of PE by two-fifths.
Oral anticoagulants, when used as monotherapy, reduced the risk of DVT and of PVT by about half, and this protective effect appeared similar in each of the surgical groups studied. There was an apparently large four-fifths reduction in the role of PE, but not only was the magnitude of this reduction statistically uncertain, but also pulmonary embolism was reported by a minority of trials, so it may be subject to selection bias. Oral anticoagulant regimens approximately doubled the risk of major bleeding. Oral anticoagulant regimens appeared less effective at preventing DVT than heparin regimens [64% (standard error [SE] 8 ) greater risk of DVT], although were associated with less major bleeding [35% (10) risk reduction for major bleeds].
Dextran reduced the risk of DVT and of PVT by about half, again irrespective of the type of surgery, but too few studies had reported PE to provide reliable estimates of effect on this outcome. Dextran appeared to be less effective at preventing DVT than the heparin regimens studied. Dextran was associated with an increased risk of bleeding, but too few bleeds had occurred for the size of this excess risk to be estimated reliably.
Compared with general anaesthesia, regional anaesthesia reduced the risk of DVT by about half, and this benefit appeared similar in each of the surgical settings studied. Regional anaesthesia was associated with less major bleeding than general anaesthesia.
Conclusion
In the absence of a clear contraindication (such as severe peripheral arterial disease), patients undergoing a surgical procedure would be expected to derive net benefit from a mechanical compression method of thromboprophylaxis (such as graduated compression stockings), irrespective of their absolute risk of venous thromboembolism. Patients who are considered to be at particularly high risk of venous thromboembolism may also benefit from a pharmacological thromboprophylactic agent, but since oral anticoagulant and dextran regimens appear less effective at preventing DVT than standard low-dose unfractionated heparin or low molecular weight heparin regimens, they may be less suitable for patients at high risk of venous thromboembolism, even though they are associated with less bleeding. Whenever feasible, the use of regional anaesthesia as an alternative to general anaesthesia may also provide additional protection against venous thromboembolism. There is little information on the prevention of venous thromboembolism among high-risk medical patients (such as those with stroke), so further randomised trials in this area would be helpful.
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24 Mar 06
Posted in Critical Care, Mechanical ventilation at 15:52 by Laci
By EB Milbrandt, A Kersten, LA. Weissfeld, G Clermont, MP. Fink, DC. Angus
Crit Care Med 2005; 33:226 –229
Objective
To determine whether haloperidol use is associated with lower mortality in mechanically ventilated patients.
Design
Retrospective cohort analysis.
Setting
A large tertiary care academic medical center.
Patients
A total of 989 patients mechanically ventilated for >48 hrs.
Measurements and Main Results
We compared differences in hospital mortality between patients who received haloperidol within 2 days of initiation of mechanical ventilation and those who never received haloperidol. Despite similar baseline characteristics, patients treated with haloperidol had significantly lower hospital mortality compared with those who never received haloperidol (20.5% vs. 36.1%; p=.004). The lower associated mortality persisted after adjusting for age, comorbidity, severity of illness, degree of organ
dysfunction, admitting diagnosis, and other potential confounders.
Conclusions
Haloperidol was associated with significantly lower hospital mortality. These findings could have enormous implications for critically ill patients. Because of their observational nature and the potential risks associated with haloperidol use, they require confirmation in a randomized, controlled trial before being applied to routine patient care.
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15 Mar 06
Posted in Critical Care, Inotropic support, Sepsis at 15:48 by Laci
By Y Sakr, K Reinhart, J-L Vincent, C L Sprung, R Moreno, V Ranieri,et all
Critical Care Medicine 2006; 34:589-597
Objective
The optimal adrenergic support in shock is controversial. We investigated whether dopamine administration influences the outcome from shock.
Design
Cohort, multiple-center, observational study.
Setting
One hundred and ninety-eight European intensive care units.
Patients
All adult patients admitted to a participating intensive care unit between May 1 and May 15, 2002.
Measurements and Main Results
Patients were followed up until death, until hospital discharge, or for 60 days. Shock was defined as hemodynamic compromise necessitating the administration of vasopressor catecholamines. Of 3,147 patients, 1,058 (33.6%) had shock at any time; 462 (14.7%) had septic shock. The intensive care unit mortality rate for shock was 38.3% and 47.4% for septic shock. Of patients in shock, 375 (35.4%) received dopamine (dopamine group) and 683 (64.6%) never received dopamine. Age, gender, Simplified Acute Physiology Score II, and Sequential Organ Failure Assessment score were comparable between the two groups. The dopamine group had higher intensive care unit (42.9% vs. 35.7%, p = .02) and hospital (49.9% vs. 41.7%, p = .01) mortality rates. A Kaplan-Meier survival curve showed diminished 30 day-survival in the dopamine group (log rank = 4.6, p = .032). In a multivariate analysis with intensive care unit outcome as the dependent factor, age, cancer, medical admissions, higher mean Sequential Organ Failure Assessment score, higher mean fluid balance, and dopamine administration were independent risk factors for intensive care unit mortality in patients with shock.
Conclusions
This observational study suggests that dopamine administration may be associated with increased mortality rates in shock. There is a need for a prospective study comparing dopamine with other catecholamines in the management of circulatory shock.
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