Desmopressin for treatment of platelet dysfunction and reversal of antiplatelet agents: a systematic review and meta-analysis of randomized controlled trials.

Essentials The optimal management of patients with platelet dysfunction undergoing surgery is unclear. This meta-analysis compared perioperative administration of desmopressin to placebo. Desmopressin reduced red cell transfusions, blood loss and risk of re-operation due to bleeding. There were too few events to determine if there was a change in the risk of thrombotic events. SUMMARY: Background Platelet dysfunction, including that caused by antiplatelet agents, increases the risk of perioperative bleeding. The optimal management of patients with platelet dysfunction undergoing surgery is unclear. Objectives To assess whether desmopressin reduces perioperative allogeneic red cell transfusion and bleeding in patients with platelet dysfunction. Patients/Methods We searched for randomized controlled trials in The Cochrane Central Register of Controlled Trials, MEDLINE, PubMed, Embase, the Transfusion Evidence Library and the ISI Web of Science to 7th July 2016. Data were pooled using mean difference (MD), relative risks or Peto odds ratios (pOR) using a random-effects model. Results Ten trials with 596 participants were identified, all in the setting of cardiac surgery. Platelet dysfunction was due to antiplatelet agents in six trials and cardiopulmonary bypass in four trials. Patients treated with desmopressin were transfused with fewer red cells (MD, -0.65 units; 95% Confidence Interval [CI], -1.16 to -0.13 units), lost less blood (MD, -253.93 mL; 95% CI, -408.01 to -99.85 mL) and had a lower risk of re-operation due to bleeding (pOR, 0.39; 95% CI, 0.18-0.84). The GRADE quality of evidence was very low to moderate, suggesting considerable uncertainty over the results Conclusions Desmopressin may be a useful agent to reduce bleeding and transfusion requirements for people with platelet dysfunction or with a history of recent antiplatelet drug administration undergoing cardiac surgery.

Interventions to reduce vasovagal reactions in blood donors: a systematic review and meta-analysis.

Vasovagal reactions (VVRs) in blood donors have significant implications for the welfare of donors, donor retention and the management of donor sessions. We present a systematic review of interventions designed to prevent or reduce VVRs in blood donors. Electronic databases were searched for eligible randomised trials to March 2015. Data on study design and outcomes were extracted and pooled using random effects meta-analyses. Sixteen trials met the inclusion criteria: five trials (12 042 participants) of pre-donation water, eight trials (3500 participants) of applied muscle tension (AMT) and one trial each of AMT combined with water, caffeine, audio-visual distraction and/or social support. In donors receiving pre-donation water, the relative risk (RR) compared with controls for VVRs was 0·79 [95% confidence interval (CI) 0·70-0·89, P < 0·0001] and the mean difference (MD) in severity of VVRs measured with the Blood Donation Reactions Inventory (BDRI) score was -0·32 (95% CI -0·51 to -0·12, P < 0·0001). Excluding trials with a high risk of selection bias, the RR for VVRs was 0·70 (95% CI 0·45-1·11, P = 0·13). In donors who received AMT, there was no difference in the risk of chair recline in response to donor distress from controls (RR 0·76, 95% CI 0·53-1·10, P = 0·15), although the MD in BDRI score was -0·07 (95% CI -0·11 to -0·03, P = 0·0005). There was insufficient data to perform meta-analysis for other interventions. Current evidence on interventions to prevent or reduce VVRs in blood donors is indeed limited and does not provide strong support for the administration of pre-donation water or AMT during donation. Further large trials are required to reliably evaluate the effect of these and other interventions in the prevention of VVRs.

Cell therapy for heart disease: Trial sequential analyses of two Cochrane reviews.

Meta-analyses of cell therapy trials for heart disease have yielded discrepant results. To resolve limitations associated with meta-analyses, such as imprecision and accumulation of random errors, we conducted trial sequential analysis (TSA). Randomized controlled trials that administered autologous bone marrow-derived cells to patients who suffered acute myocardial infarction (AMI) or heart failure (HF) were included. TSA has been applied to two clinical outcomes, all-cause mortality and hospitalization for HF, and to left ventricular ejection fraction (LVEF), as a surrogate of heart function. The results suggest that there is evidence of reduction of the risk of mortality and hospitalization in HF, but insufficient evidence to determine treatment effect in AMI. Moreover, the treatment does not improve LVEF by more than a mean difference of 4% when administered to either AMI or HF patients. The required number of participants to include in a meta-analysis to detect treatment effect was also estimated.

Safety of blood donation from individuals with treated hypertension or non-insulin dependent type 2 diabetes - a systematic review.

BACKGROUND AND OBJECTIVES: This systematic review was aimed at finding evidence for the safety of blood donation by individuals with treated hypertension or type 2 diabetes. It was undertaken as part of a wider project to re-evaluate exclusion criteria for UK blood donors with a view to increasing eligibility. MATERIALS AND METHODS: Searches were undertaken in the Cochrane Library to 2008, MEDLINE (1950 onwards), EMBASE (1974 onwards), CINAHL (1982 onwards), BNID (1994 onwards), the NHSBT SRI Handsearching Database and the Web of Science (all years) to February 2008. Planned analysis was largely descriptive. RESULTS: We identified only 16 relevant papers. None of the identified studies directly addressed the review questions and methodological appraisal highlighted a number of deficiencies. However all included papers provided contributory data and the findings were consistent. No study found any evidence of increased risk to homologous (allogeneic) or autologous blood donors with treated hypertension or with raised baseline systolic blood pressure up to 200 mmHg. We found very few data relating to blood donation by diabetic subjects. CONCLUSIONS: No identified study indicated that raised baseline blood pressure level, treated hypertension or diabetes was predictive of increased adverse reactions in blood donors but the level of overall evidence was limited. This is the first attempt to systematically review a donor area as part of an approach to change longstanding practice recommendations, and may have implications for other recommendations for changes in donor acceptance criteria.

Drugs and blood transfusions: dogma- or evidence-based practice?

There is a lack of consensus on the safety of the coadministration of drugs and red blood cells (RBCs). A systematic review was undertaken to establish the evidence base for this question and assess how the evidence may be translated into present clinical day practice. Comprehensive searches of MEDLINE, EMBASE, CINAHL, the Cochrane Library and hand searching of transfusion journals, guidelines and websites identified 12 relevant papers: 11 in-vitro experiments and 1 case report. Data on incidences of haemolysis and agglutination following coadministration were extracted and analysed. Overall findings suggest that iron chelators (two papers), antimicrobials (three papers) and lower doses of opioids (three papers) are safe to coadminister with RBCs. Haemolysis was observed with higher doses of opioids (three papers). Transposition of these findings to clinical practice is limited because of the lack of clinical applicability of in-vitro experiments and diversity in how, and what, clinical outcome measures were used. Further evidence from true clinical settings would be required to inform clinical practice on the efficacy and safety of the coadministration of drugs and RBCs.

Improving the evidence base for transfusion medicine: the work of the UK systematic review initiative.

Clarifying the existing evidence base is crucial to improve the effectiveness of transfusion practice. The UK Systematic Review Initiative has been pursuing this objective primarily through writing systematic reviews on important topics in transfusion medicine. Here, we describe our progress for the past 5 years. We are the only research group that identifies transfusion medicine randomized controlled trials (RCTs) for the Cochrane Central Register of Controlled Trials, and to date, we have contributed 3002 RCT citations. The article considers future challenges including the need for wider involvement from the transfusion medicine community in the process of maintaining and updating systematic reviews and the identification and prioritization of topics for further clinical research including clinical trials. Collaboration between international and local research groups is important if these challenges are to be met.

Coblation versus other surgical techniques for tonsillectomy.

BACKGROUND: Tonsillectomy is one of the most commonly performed surgical procedures. There are several operative methods currently in use, but the superiority of one over another has not been clearly demonstrated. OBJECTIVES: To assess the effectiveness of coblation tonsillectomy compared with other surgical techniques in reducing morbidity. SEARCH STRATEGY: We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2006), MEDLINE (1966 to 2006) and EMBASE (1974 to 2006). The date of the last search was December 2006. SELECTION CRITERIA: Randomised controlled trials of children and adults undergoing tonsillectomy by means of coblation compared with any other surgical technique for removal of the tonsils. Trials were assessed for methodological quality according to the method outlined in the Cochrane Handbook for Systematic Reviews of Interventions 4.2.6. DATA COLLECTION AND ANALYSIS: Data were extracted using standardised data extraction forms. Authors were contacted where additional data were required. MAIN RESULTS: Nineteen studies were identified with sufficient data for further assessment. Four of these were excluded because intra-capsular tonsillectomy (i.e. tonsillotomy) rather than sub-capsular tonsillectomy was performed, and a further five studies because tonsils rather than participants were randomised. One further study was excluded because, although describing itself as a randomised trial, its participants turned out not to have been randomised to their intervention groups. Nine trials met the inclusion criteria, comparing coblation to other tonsillectomy techniques. All but two studies were of low quality and therefore a meta-analytical approach was not appropriate. In most studies, when considering most outcomes, there was no significant difference between coblation and other tonsillectomy techniques. AUTHORS' CONCLUSIONS: In terms of postoperative pain and speed and safety of recovery, there is inadequate evidence to determine whether coblation tonsillectomy is better or worse than other methods of tonsillectomy. Evidence from a large prospective audit suggests that it has been associated with a higher level of morbidity, in terms of postoperative bleeding. Large, well-designed randomised controlled trials supplemented by data from large prospective audits are needed to produce information on effectiveness and morbidity respectively.

Oral deferiprone for iron chelation in people with thalassaemia.

BACKGROUND: Thalassaemia major is a genetic disease characterised by a reduced ability to produce haemoglobin. Management of the resulting anaemia is through transfusions of red blood cells. Repeated transfusions result in excessive accumulation of iron in the body (iron overload), removal of which is achieved through iron chelation therapy. A commonly used iron chelator, deferiprone, has been found to be pharmacologically efficacious. However, important questions exist about the efficacy and safety of deferiprone compared to another iron chelator, desferrioxamine. OBJECTIVES: To summarise data from trials on the clinical efficacy and safety of deferiprone and to compare the clinical efficacy and safety of deferiprone for thalassaemia with desferrioxamine. SEARCH STRATEGY: We searched the Group's Haemoglobinopathies Trials Register, MEDLINE, EMBASE, Biological Abstracts, ZETOC, Current Controlled Trials and bibliographies of relevant publications. We contacted the manufacturers of deferiprone and desferrioxamine. Most recent searches: June 2006. SELECTION CRITERIA: Randomised controlled trials comparing deferiprone with another iron chelator; or comparing two schedules of deferiprone, in people with transfusion-dependent thalassaemia. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. Missing data were requested from the original investigators. MAIN RESULTS: Ten trials involving 398 people (range 10 to 144 people) were included. Nine trials compared deferiprone with desferrioxamine or a combination of deferiprone and desferrioxamine and one compared different schedules of deferiprone. There was little consistency between outcomes and little information to fully assess the methodological quality of most of the included trials. No trial reported long-term outcomes (mortality and end organ damage). There was no consistent effect on reduction of iron overload between all treatment comparisons, with the exception of urinary iron excretion in comparisons of deferiprone with desferrioxamine. An increase in iron excretion levels favoured deferiprone in one trial and desferrioxamine in three trials, even though measurement of urinary iron excretion underestimates total iron excretion by desferrioxamine.Adverse events were recorded in trials comparing deferiprone with desferrioxamine. There was evidence of adverse events in all treatment groups. Adverse events in one trial were significantly more likely with deferiprone than desferrioxamine, relative risk 2.24 (95% confidence interval 1.19 to 4.23). AUTHORS' CONCLUSIONS: We found no reason to change current treatment recommendations, namely deferiprone is indicated for treating iron overload in people with thalassaemia major when desferrioxamine is contraindicated or inadequate. However, there is an urgent need for adequately-powered, high quality trials comparing the overall clinical efficacy and long-term outcome of deferiprone with desferrioxamine.

Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia.

BACKGROUND: Recombinant factor VIIa (rFVIIa) is licensed for use in patients with haemophilia and inhibitory allo-antibodies. It is also increasingly being used for off-license indications to prevent bleeding in operations where blood loss is likely to be high, and/or to stop bleeding that is proving difficult to control by other means. OBJECTIVES: To assess the effectiveness of rFVIIa when used therapeutically to control active bleeding, or prophylactically to prevent (excessive) bleeding in patients without haemophilia. SEARCH STRATEGY: We searched the Cochrane Injuries Group's Specialised Register, CENTRAL, MEDLINE, EMBASE and other specialised databases up to March 2006. We also searched reference lists of articles and contacted experts in the field. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing rFVIIa with placebo, or one dose of rFVIIa with another, in any patient population with the exception of those with haemophilia. There was no restriction by outcomes examined, but this review focuses on mortality, blood loss or control of bleeding, red cell transfusion requirements, number of patients transfused and thromboembolic adverse events. DATA COLLECTION AND ANALYSIS: Two authors independently assessed potentially relevant studies for inclusion. Data were extracted and methodological quality was examined. Studies using rFVIIa prophylactically and those using rFVIIa therapeutically have been considered separately. Data were pooled using fixed and random effects models, but random effects models were preferred because of the variability in clinical features of the included studies. MAIN RESULTS: Thirteen trials met the inclusion criteria; all were placebo-controlled double-blind RCTs. Six trials involving 724 participants examined the prophylactic use of rFVIIa; 379 received rFVIIa. There were no outcomes by which any observed advantage, or disadvantage, of rFVIIa over placebo could not have been observed by chance alone. There were trends in favour of rFVIIa for a number of outcomes, particularly the number of participants transfused, pooled RR 0.85 (95% CI 0.72 to 1.01) but this was balanced by a trend against rFVIIa with respect to thromboembolic adverse events, pooled RR 1.25 (95% CI 0.76 to 2.07). Seven trials involving 1214 participants examined the therapeutic use of rFVIIa; 687 received rFVIIa. There were no outcomes where any observed advantage, or disadvantage, of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality, RR 0.82 (95% CI 0.64 to 1.04), although no other clear trends in favour of rFVIIa were noted for other desired outcomes. Interpretation of these results must take into account one study which could not be included in the quantitative summary but which showed results strongly in favour of rFVIIa for the treatment of intra-cerebral haemorrhage. There was a trend against rFVIIa with respect to thromboembolic adverse events; the RR 1.50 (95% CI 0.86 to 2.62). AUTHORS' CONCLUSIONS: Although rFVIIa has a role in the management of patients with haemophilia, its effectiveness as a more general haemostatic drug, either prophylactically or therapeutically, remains uncertain. Its effectiveness as a therapeutic agent, particularly for intra-cerebral haemorrhage, looks more encouraging than prophylactic use. The use of rFVIIa outside its current licensed indications should be very limited and its wider use await the results of ongoing and possibly newly commissioned RCTs. In the interim, rFVIIa use should be restricted to clinical trials.

Antidepressants for patients with tinnitus.

BACKGROUND: Tinnitus is described as the perception of sound or noise in the absence of real acoustic stimulation. It has been compared with chronic pain, and may be associated with depression or depressive symptoms which can affect quality of life and the ability to work. Antidepressant drugs have been used to treat tinnitus in patients with and without depressive symptoms. OBJECTIVES: To assess the effectiveness of antidepressants in the treatment of tinnitus and to ascertain whether any benefit was due to a direct tinnitus effect or a secondary effect due to treatment of concomitant depressive states. SEARCH STRATEGY: We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) The Cochrane Library Issue 1, 2006); MEDLINE (January 1951 to 2006); EMBASE (1974 to 2006), CINAHL (to 2006), PSYCINFO (to 2006), LILACS (to 2006), and Cambridge Scientific Abstracts. The date of the most recent search was March 2006. SELECTION CRITERIA: Randomised controlled clinical studies of antidepressant drugs versus placebo in patients with tinnitus. DATA COLLECTION AND ANALYSIS: The studies retrieved were critically appraised and data extracted independently by two authors. Where necessary study authors were contacted for further information. MAIN RESULTS: Five trials involving 525 patients were included. Four of these trials looked at the effect of tricyclic antidepressants on tinnitus, investigating 405 patients. One trial investigated the effect of a selective serotonin reuptake inhibitor (SSRI) in a group of 120 patients. No trials involving other antidepressant agents met the inclusion criteria. Only the trial using the SSRI drug met the highest quality standard. None of the other included trials met the highest quality standard, due to use of inadequate outcome measures, large drop out rates or failure to separate the effects on tinnitus from the effects on symptoms of anxiety and depression. All the trials assessing tricyclic antidepressants suggested that there was a slight improvement in tinnitus but these effects may have been attributable to methodological bias. The trial that investigated the SSRI drug found no overall improvement in any of the validated outcome measures that were used in the study although there was possible benefit for a subgroup that received higher doses of the drug. This observation merits further investigation. Reports of side effects including sedation, sexual dysfunction and dry mouth were common. AUTHORS' CONCLUSIONS: There is insufficient evidence to say that antidepressant drug therapy improves tinnitus.

Interventions for recurrent idiopathic epistaxis (nosebleeds) in children.

BACKGROUND: Recurrent idiopathic epistaxis (nosebleeds) in children is repeated nasal bleeding in patients up to the age of 16 for which no specific cause has been identified. Although nosebleeds are very common in children, and most cases are self-limiting or settle with simple measures (such as pinching the nose), more severe recurrent cases can require treatment from a healthcare professional. However, there is no consensus on the effectiveness of the different clinical interventions currently used in managing this condition. OBJECTIVES: To assess the effects of different interventions for the management of recurrent idiopathic epistaxis in children. SEARCH STRATEGY: We searched the Cochrane ENT Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue 3, 2003), MEDLINE (January 1966 to August 2003), EMBASE (January 1980 to August 2003), CINAHL (January 1982 to August 2003), and reference lists of relevant articles. SELECTION CRITERIA: We identified all randomised controlled trials (with or without blinding) in which any surgical or medical intervention for the treatment of recurrent idiopathic epistaxis in children was evaluated in comparison with either no treatment, a placebo, or another intervention, and in which the frequency and severity of episodes of nasal bleeding following treatment was stated or calculable. The full text articles of all the retrieved trials of possible relevance were reviewed by the two reviewers and the inclusion criteria applied independently. DATA COLLECTION AND ANALYSIS: Trials were graded for methodological quality using the Cochrane approach. Data extraction was performed in a standardised manner by one reviewer and rechecked by the other, and where necessary investigators were contacted to obtain missing information. A meta-analysis was not undertaken because of the heterogeneity of the treatments, procedures and quality of the included trials. A narrative overview of the results is therefore presented. MAIN RESULTS: Three studies - two randomised controlled trials (RCTs) and one controlled clinical trial (CCT) - involving 256 participants satisfied the inclusion criteria. One RCT compared Naseptin antiseptic cream with no treatment, the second RCT compared Vaseline(R) petroleum jelly with no treatment, and the CCT compared Naseptin antiseptic cream with silver nitrate cautery. Overall, results were inconclusive, with no statistically significant difference found between the compared treatments. No serious adverse effects were reported from any of the interventions, although children receiving silver nitrate cautery reported that it was a painful experience (despite the use of local anaesthetic). REVIEWER'S CONCLUSIONS: The optimal management of children with recurrent idiopathic epistaxis is unknown. High quality randomised controlled trials comparing interventions either with placebo or no treatment, and with a follow-up period of at least a year, are needed to assess the relative merits of the various treatments currently in use.

Ear drops for the removal of ear wax.

BACKGROUND: Problems attributed to the accumulation of wax (cerumen) are one of the most common reasons for people to present to their general practitioners with ear trouble (Sharp 1990). Treatment for this condition often involves use of a wax softening agent (cerumenolytic) in order to disperse the cerumen and reduce the need for syringing, or to facilitate syringing should it prove necessary, but there is no consensus on the effectiveness of the wide variety of cerumenolytics in use. OBJECTIVES: To assess the effectiveness of ear drops (cerumenolytics) for the removal of symptomatic ear wax. SEARCH STRATEGY: We searched the Cochrane ENT Group Register, the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 1, 2003), and MEDLINE and EMBASE up to March 2003. Reference lists of all trials were also manually searched. SELECTION CRITERIA: We identified all randomised controlled trials (with or without blinding) in which a cerumenolytic was evaluated in comparison with either no treatment, a placebo, or other cerumenolytics in participants with hard or impacted ear wax, and in which the proportion of participants with sufficient clearance of the external canal to make further mechanical clearance unnecessary (primary outcome measure) was stated or calculable. The full text articles of all the retrieved trials of possible relevance were reviewed by the two reviewers and the inclusion criteria applied independently. Any differences in opinion about which studies to include in the review were resolved by discussion. DATA COLLECTION AND ANALYSIS: Trials were graded for methodological quality using the Cochrane approach. Data extraction was performed in a standardised manner by one reviewer and rechecked by the other reviewer, and where necessary investigators were contacted to obtain missing information. Meta-analysis was neither possible nor considered appropriate because of the heterogeneity of the treatments, treatment amounts and durations, trial procedures, and scoring systems. A narrative overview of the results is therefore presented. MAIN RESULTS: Eight trials satisfied the inclusion criteria, the majority of which were of poor quality. In all, 587 participants received one of nine different cerumenolytics. One trial compared active treatments with no treatment, two trials compared active treatments with water or a saline 'placebo', and all eight trials placed two or more active treatments in head-to-head comparisons. Seven trials included syringing as a secondary treatment where necessary.Overall, results were inconclusive. One trial found a significant difference between one of three active agents (Cerumol) in comparison to no treatment, but no statistically significant difference was found between these three agents (sodium bicarbonate ear drops; Cerumol; sterile water). In two trials no statistical difference was found between the effectiveness of either sodium bicarbonate ear drops, Cerumol, Cerumenex or Colace versus a sterile water or saline 'placebo'. Three trials (from the same source) found statistically significant differences in favour of the same active agent (Exterol) in comparison to glycerol and Cerumol. Three trials found no statistically significant difference between two or more cerumenolytics (Otocerol versus Cerumol; Audax versus Earex; sodium bicarbonate ear drops versus Cerumol). Two trials comparing the same two cerumenolytics (Cerumenex versus Colace) also failed to show any significant benefit of one over the other. No serious adverse effects were reported from any of the interventions. REVIEWER'S CONCLUSIONS: Trials to date have been heterogeneous and of poor quality, making it difficult to offer any definitive recommendations on the effectiveness of cerumenolytics for the removal of symptomatic ear wax. Future trials should be of high methodological quality, have large sample sizes, and compare both oil-based and water-based solvents with placebo and/or no treatment.