The risk and prevention of venous thromboembolism in the pregnant traveller.

BACKGROUND: The average risk of venous thromboembolism (VTE) in long haul travellers is approximately 2.8 per 1000 travellers, which is increased in the presence of other VTE risk factors. In pregnant long-haul travellers, little is known in terms of the absolute risk of VTE in these women and, therefore, there is limited consensus on appropriate thromboprophylaxis in this setting. OBJECTIVE: This review will provide guidance to allow practitioners to safely minimize the risk of travel-related VTE in pregnant women. The suggestions provided are based on limited data, extrapolated risk estimates of VTE in pregnant travellers and recommendations from published guidelines. RESULTS: We found that the absolute VTE risk per flight appears to be <1% for the average pregnant or postpartum traveller. In pregnant travellers with a prior history of VTE, a potent thrombophilia or strong antepartum risk factors (e.g. combination of obesity and immobility), the risk of VTE with travel appears to be >1%. Postpartum, the risk of VTE with travel may be >1% for women with thrombophilias (particularly in those with a family history) and other transient risk factors and in women with a prior VTE. CONCLUSIONS: Based on our findings, we recommend simple measures be taken by all pregnant travellers, such as frequent ambulation, hydration and calf exercises. In those at an intermediate risk, we suggest a consideration of 20-30 mmHg compression stockings. In the highest risk group, we suggest careful consideration for low-molecular-weight heparin thromboprophylaxis. If there are specific concerns, we advise consultation with a thrombosis expert at the nearest local centre.

Disparity between Nephrologists' Opinions and Contemporary Practices for Community Follow-Up after AKI Hospitalization.

BACKGROUND AND OBJECTIVES: Recent guidelines suggest that patients should be evaluated after AKI for resolution versus progression of CKD. There is uncertainty as to the role of nephrologists in this process. The objective of this study was to compare the follow-up recommendations from nephrologists with contemporary processes of care for varying scenarios of patients hospitalized with AKI. DESIGN, SETTING PARTICIPANTS, & MEASUREMENTS: We surveyed Canadian nephrologists using a series of clinical vignettes of patients hospitalized with severe AKI and asked them to rank their likelihood of recommending follow-up for each patient after hospital discharge. We compared these responses with administrative health data on rates of community follow-up with nephrologists for patients hospitalized with AKI in Alberta, Canada between 2005 and 2014. RESULTS: One hundred forty-five nephrologists participated in the survey (46% of the physician membership of the Canadian Society of Nephrology). Nephrologists surveyed indicated that they would definitely or probably re-evaluate patients in 87% of the scenarios provided, with a higher likelihood of follow-up for patients with a history of preexisting CKD (89%), heart failure (92%), receipt of acute dialysis (91%), and less complete recovery of kidney function (98%). In contrast, only 24% of patients with similar characteristics were seen by a nephrologist in Alberta within 1 year after a hospitalization with AKI, with a trend toward lower rates of follow-up over more recent years of the study. Follow-up with a nephrologist was significantly less common among patients over the age of 80 years old (20%) and more common among patients with preexisting CKD (43%) or a nephrology consultation before or during AKI hospitalization (78% and 41%, respectively). CONCLUSIONS: There is a substantial disparity between the opinions of nephrologists and actual processes of care for nephrology evaluation of patients after hospitalization with severe AKI.

Pre-emptive correction for haemodialysis arteriovenous access stenosis.

BACKGROUND: Guidelines recommend routine arteriovenous (AV) graft and fistula surveillance (technology-based screening) in addition to clinical monitoring (physical examination) for early identification and pre-emptive correction of a stenosis before the access becomes dysfunctional. However, consequences on patient-relevant outcomes of pre-emptive correction of a stenosis in a functioning access as opposed to deferred correction, i.e. correction postponed to when the access becomes dysfunctional, are uncertain. OBJECTIVES: We aimed to evaluate 1) whether pre-emptive correction of an AV access stenosis improves clinically relevant outcomes; 2) whether the effects of pre-emptive correction of an AV access stenosis differ by access type (fistula versus graft), aim (primary and secondary prophylaxis), and surveillance method for primary prophylaxis (Doppler ultrasound for the screening of functional and anatomical changes versus measurement of the flow in the access); and 3) whether other factors (dialysis duration, access location, configuration or materials, algorithm for referral for intervention, intervention strategies (surgical versus radiological or other), or study design) explain the heterogeneity that might exist in the effect estimates. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Specialised Register to 30 November 2015 using search terms relevant to this review. SELECTION CRITERIA: We included all studies of any access surveillance method for early identification and pre-emptive treatment of an AV access stenosis. DATA COLLECTION AND ANALYSIS: We extracted data on potentially remediable and irremediable failure of the access (i.e. thrombosis and access loss respectively); infection and mortality; and resource use (hospitalisation, diagnostic and intervention procedures). Analysis was by a random effects model and results expressed as risk ratio (RR), hazard ratio (HR) or incidence rate ratio (IRR) with 95% confidence intervals (CI). MAIN RESULTS: We identified 14 studies (1390 participants), nine enrolled adults without a known access stenosis (primary prophylaxis; three studies including people using fistulas) and five enrolled adults with a documented stenosis in a non-dysfunctional access (secondary prophylaxis; three studies in people using fistulas). Study follow-up ranged from 6 to 38 months, and study size ranged from 58 to 189 participants. In low- to moderate-quality evidence (based on GRADE criteria) in adults treated with haemodialysis, relative to no surveillance and deferred correction, surveillance with pre-emptive correction of an AV stenosis reduced the risk of thrombosis (RR 0.79, 95% CI 0.65 to 0.97; I² = 30%; 18 study comparisons, 1212 participants), but had imprecise effect on the risk of access loss (RR 0.81, 95% CI 0.65 to 1.02; I² = 0%; 11 study comparisons, 972 participants). In analyses subgrouped by access type, pre-emptive stenosis correction did not reduce the risk of thrombosis (RR 0.95, 95% CI 0.8 to 1.12; I² = 0%; 11 study comparisons, 697 participants) or access loss in grafts (RR 0.9, 95% CI 0.71 to 1.15; I² = 0%; 7 study comparisons; 662 participants), but did reduce the risk of thrombosis (RR 0.5, 95% CI 0.35 to 0.71; I² = 0%; 7 study comparisons, 515 participants) and the risk of access loss in fistulas (RR 0.5, 95% CI 0.29 to 0.86; I² = 0%; 4 studies; 310 participants). Three of the four studies reporting access loss data in fistulas (199 participants) were conducted in the same centre. Insufficient data were available to assess whether benefits vary by prophylaxis aim in fistulas (i.e. primary and secondary prophylaxis). Although the magnitude of the effects of pre-emptive stenosis correction was considerable for patient-centred outcomes, results were either heterogeneous or imprecise. While pre-emptive stenosis correction may reduce the rates of hospitalisation (IRR 0.54, 95% CI 0.31 to 0.93; I² = 67%; 4 study comparisons, 219 participants) and use of catheters (IRR 0.58, 95% CI 0.35 to 0.98; I² = 53%; 6 study comparisons, 394 participants), it may also increase the rates of diagnostic procedures (IRR 1.78, 95% CI 1.18 to 2.67; I² = 62%; 7 study comparisons, 539 participants), infection (IRR 1.74, 95% CI 0.78 to 3.91; I² = 0%; 3 studies, 248 participants) and mortality (RR 1.38, 95% CI 0.91 to 2.11; I² = 0%; 5 studies, 386 participants).In general, risk of bias was high or unclear in most studies for many domains we assessed. Four studies were published after 2005 and only one had evidence of registration within a trial registry. No study reported information on authorship and/or involvement of the study sponsor in data collection, analysis, and interpretation. AUTHORS' CONCLUSIONS: Pre-emptive correction of a newly identified or known stenosis in a functional AV access does not improve access longevity. Although pre-emptive stenosis correction may be promising in fistulas existing evidence is insufficient to guide clinical practice and health policy. While pre-emptive stenosis correction may reduce the risk of hospitalisation, this benefit is uncertain whereas there may be a substantial increase (i.e. 80%) in the use of access-related procedures and procedure-related adverse events (e.g. infection, mortality). The net effects of pre-emptive correction on harms and resource use are thus unclear.

Preemptive Correction of Arteriovenous Access Stenosis: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Preemptive correction of a stenosis in an arteriovenous (AV) access (fistula or graft) that is adequately providing hemodialysis (functional AV access) may prolong access survival as compared to waiting for signs of access dysfunction to intervene (deferred salvage). However, the evidence in support of preemptive intervention is controversial. We evaluated benefits and harms of preemptive versus deferred correction of AV access stenosis. STUDY DESIGN: Systematic review and meta-analysis of randomized controlled trials. SETTING & POPULATION: Adults receiving hemodialysis by a functional AV access. SELECTION CRITERIA FOR STUDIES: We searched the Cochrane Kidney and Transplant Specialised Register and EMBASE to October 15, 2015. INTERVENTION: Active access surveillance (flow measurement and Doppler or venous pressure) and preemptive correction of a newly identified stenosis versus routine clinical monitoring and deferred salvage, or preemptive correction of a known stenosis versus deferred salvage. OUTCOMES: Access loss (primary outcome) and thrombosis (overall and by access type), infection, mortality, hospitalization, and access-related procedures. RESULTS: We included 14 trials (1,390 participants; follow-up, 6-38 months). Relative to deferred salvage, preemptive correction of AV access stenosis had a nonsignificant effect on risk for access loss (risk ratio [RR], 0.81; 95% CI, 0.65-1.02; I(2)=0%) and a significant effect on risk for thrombosis (RR, 0.79; 95% CI, 0.65-0.97; I(2)=30%). Treatment effects were larger in fistulas than in grafts for both risk for access loss (subgroup difference, P=0.05) and risk for thrombosis (subgroup difference, P=0.002). Results were heterogeneous or imprecise for mortality, rates of access-related infections or procedures, and hospitalization. LIMITATIONS: Small number and size of primary studies limited analysis power. CONCLUSIONS: Preemptive stenosis correction in a functional AV access does not improve access longevity. Although preemptive stenosis correction may be promising in fistulas, existing evidence is insufficient to guide clinical practice and health policy.