Population-based interventions for preventing falls and fall-related injuries in older people

BACKGROUND

Around one-third of older adults aged 65 years or older who live in the community fall each year. Interventions to prevent falls can be designed to target the whole community, rather than selected individuals. These population-level interventions may be facilitated by different healthcare, social care, and community-level agencies. They aim to tackle the determinants that lead to risk of falling in older people, and include components such as community-wide polices for vitamin D supplementation for older adults, reducing fall hazards in the community or people's homes, or providing public health information or implementation of public health programmes that reduce fall risk (e.g. low-cost or free gym membership for older adults to encourage increased physical activity).

OBJECTIVES

To review and synthesise the current evidence on the effects of population-based interventions for preventing falls and fall-related injuries in older people. We defined population-based interventions as community-wide initiatives to change the underlying societal, cultural, or environmental conditions increasing the risk of falling.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases, and two trials registers in December 2020, and conducted a top-up search of CENTRAL, MEDLINE, and Embase in January 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), cluster RCTs, trials with stepped-wedge designs, and controlled non-randomised studies evaluating population-level interventions for preventing falls and fall-related injuries in adults ≥ 60 years of age. Population-based interventions target entire communities. We excluded studies only targeting people at high risk of falling or with specific comorbidities, or residents living in institutionalised settings.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane, and used GRADE to assess the certainty of the evidence. We prioritised seven outcomes: rate of falls, number of fallers, number of people experiencing one or more fall-related injuries, number of people experiencing one or more fall-related fracture, number of people requiring hospital admission for one or more falls, adverse events, and economic analysis of interventions. Other outcomes of interest were: number of people experiencing one or more falls requiring medical attention, health-related quality of life, fall-related mortality, and concerns about falling.

MAIN RESULTS

We included nine studies: two cluster RCTs and seven non-randomised trials (of which five were controlled before-and-after studies (CBAs), and two were controlled interrupted time series (CITS)). The numbers of older adults in intervention and control regions ranged from 1200 to 137,000 older residents in seven studies. The other two studies reported only total population size rather than numbers of older adults (67,300 and 172,500 residents). Most studies used hospital record systems to collect outcome data, but three only used questionnaire data in a random sample of residents; one study used both methods of data collection. The studies lasted between 14 months and eight years. We used Prevention of Falls Network Europe (ProFaNE) taxonomy to classify the types of interventions. All studies evaluated multicomponent falls prevention interventions. One study (n = 4542) also included a medication and nutrition intervention. We did not pool data owing to lack of consistency in study designs. Medication or nutrition Older people in the intervention area were offered free-of-charge daily supplements of calcium carbonate and vitamin D3. Although female residents exposed to this falls prevention programme had fewer fall-related hospital admissions (with no evidence of a difference for male residents) compared to a control area, we were unsure of this finding because the certainty of evidence was very low. This cluster RCT included high and unclear risks of bias in several domains, and we could not determine levels of imprecision in the effect estimate reported by study authors. Because this evidence is of very low certainty, we have not included quantitative results here. This study reported none of our other review outcomes. Multicomponent interventions Types of interventions included components of exercise, environment modification (home; community; public spaces), staff training, and knowledge and education. Studies included some or all of these components in their programme design. The effectiveness of multicomponent falls prevention interventions for all reported outcomes is uncertain. The two cluster RCTs included high or unclear risk of bias, and we had no reasons to upgrade the certainty of evidence from the non-randomised trial designs (which started as low-certainty evidence). We also noted possible imprecision in some effect estimates and inconsistent findings between studies. Given the very low-certainty evidence for all outcomes, we have not reported quantitative findings here. One cluster RCT reported lower rates of falls in the intervention area than the control area, with fewer people in the intervention area having one or more falls and fall-related injuries, but with little or no difference in the number of people having one or more fall-related fractures. In another cluster RCT (a multi-arm study), study authors reported no evidence of a difference in the number of female or male residents with falls leading to hospital admission after either a multicomponent intervention ("environmental and health programme") or a combination of this programme and the calcium and vitamin D3 programme (above). One CBA reported no difference in rate of falls between intervention and control group areas, and another CBA reported no difference in rate of falls inside or outside the home. Two CBAs found no evidence of a difference in the number of fallers, and another CBA found no evidence of a difference in fall-related injuries. One CITS found no evidence of a difference in the number of people having one or more fall-related fractures. No studies reported adverse events.

AUTHORS' CONCLUSIONS

Given the very low-certainty evidence, we are unsure whether population-based multicomponent or nutrition and medication interventions are effective at reducing falls and fall-related injuries in older adults. Methodologically robust cluster RCTs with sufficiently large communities and numbers of clusters are needed. Establishing a rate of sampling for population-based studies would help in determining the size of communities to include. Interventions should be described in detail to allow investigation of effectiveness of individual components of multicomponent interventions; using the ProFaNE taxonomy for this would improve consistency between studies.

Surgical versus non-surgical interventions for displaced intra-articular calcaneal fractures

BACKGROUND

Fractures of the calcaneus (heel bone) comprise up to 2% of all fractures. These fractures are mostly caused by a fall from a height, and are common in younger adults. Treatment can be surgical or non-surgical; however, there is clinical uncertainty over optimal management. This is an update of a Cochrane Review first published in 2013.

OBJECTIVES

To assess the effects (benefits and harms) of surgical versus conservative treatment of displaced intra-articular calcaneal fractures.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, CENTRAL, MEDLINE, Embase, and clinical trials registers in November 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing surgical versus non-surgical management of displaced intra-articular calcaneal fractures in skeletally mature adults (older than 14 years of age). For surgical treatment, we included closed manipulation with percutaneous wire fixation, open reduction with internal fixation (ORIF) with or without bone graft, or primary arthrodesis. For non-surgical treatment, we included ice, elevation and rest, or plaster cast or splint immobilisation.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We collected data for the following outcomes: function in the short term (within three months of injury) or long term (more than three months after injury), chronic pain, health-related quality of life (HRQoL) and ability to return to normal activities, as well as complications which may or may not have led to an unplanned return to theatre.

MAIN RESULTS

We included 10 RCTs and two quasi-RCTs with 1097 participants. Sample sizes in studies ranged from 29 to 424 participants. Most participants were male (86%), and the mean age in studies ranged from 28 to 52 years. In the surgical groups, participants were mostly managed with ORIF with plates, screws, or wires; one study used only minimally invasive techniques. Participants in the non-surgical groups were managed with a plaster cast, removable splint or a bandage, or with rest, elevation, and sometimes ice. Risk of performance bias was unavoidably high in all studies as it was not possible to blind participants and personnel to treatment; in addition, some studies were at high or unclear risk of other types of bias (including high risk of selection bias for quasi-RCTs, high risk of attrition bias, and unclear risk of selective reporting bias). We downgraded the certainty of all the evidence for serious risk of bias. We also downgraded the certainty of the evidence for imprecision for all outcomes (except for complications requiring return to theatre for subtalar arthrodesis) because the evidence was derived from few participants. We downgraded the evidence for subtalar arthrodesis for inconsistency because the pooled data included high levels of statistical heterogeneity. We found that surgical management may improve function at six to 24 months after injury when measured using the American Orthopaedic Foot and Ankle Society (AOFAS) score (mean difference (MD) 6.58, 95% confidence interval (CI) 1.04 to 12.12; 5 studies, 319 participants; low-certainty evidence). We are not aware of a published minimal clinically important difference (MCID) for the AOFAS score for this type of fracture. Previously published MCIDs for other foot conditions range from 2.0 to 7.9. No studies reported short-term function within three months of injury. Surgical management may reduce the number of people with chronic pain up to 24 months after injury (risk ratio (RR) 0.56, 95% CI 0.37 to 0.84; 4 studies, 175 participants; low-certainty evidence); this equates to 295 per 1000 fewer people with pain after surgical management (95% CI 107 to 422 per 1000). Surgical management may also lead to improved physical HRQoL (MD 6.49, 95% CI 2.49 to 10.48; 2 studies, 192 participants; low-certainty evidence). This outcome was measured using the physical component score of the 36-Item Short Form Health Survey. We used a change in effect of 5% to indicate a clinically important difference for this scoring system and thus judged that the difference in HRQoL between people treated surgically or non-surgically includes both clinically relevant and not relevant changes for those treated surgically. There may be little or no difference in the number of people who returned to work within 24 months (RR 1.26, 95% CI 0.94 to 1.68; 5 studies, 250 participants; low-certainty evidence) or who require secondary surgery for subtalar arthrodesis (RR 0.38, 95% CI 0.09 to 1.53; 3 studies, 657 participants; low-certainty evidence). For other complications requiring return to theatre in people treated surgically, we found low-certainty evidence for amputation (2.4%; 1 study, 42 participants), implant removal (3.4%; 3 studies, 321 participants), deep infection (5.3%; 1 study, 206 participants), and wound debridement (2.7%; 1 study, 73 participants). We found low-certainty evidence that 14% of participants who were treated surgically (7 studies, 847 participants) had superficial site infection.

AUTHORS' CONCLUSIONS

Our confidence in the evidence is limited. Although pooled evidence indicated that surgical treatment may lead to improved functional outcome but with an increased risk of unplanned second operations, we judged the evidence to be of low certainty as it was often derived from few participants in studies that were not sufficiently robust in design. We found no evidence of a difference between treatment options in the number of people who needed late reconstruction surgery for subtalar arthritis, although the estimate included the possibility of important harms and benefits. Large, well-conducted studies that attempt to minimise detection bias and that measure functional outcomes using calcaneal-specific measurement tools would increase the confidence in these findings. Given that minimally invasive surgical procedures are already becoming more prevalent in practice, research is urgently needed to determine whether these newer surgical techniques offer better outcomes with regard to function, pain, quality of life, and postoperative complications for intra-articular displaced calcaneal fractures.

Interventions for reducing red blood cell transfusion in adults undergoing hip fracture surgery: an overview of systematic reviews

BACKGROUND

Following hip fracture, people sustain an acute blood loss caused by the injury and subsequent surgery. Because the majority of hip fractures occur in older adults, blood loss may be compounded by pre-existing anaemia. Allogenic blood transfusions (ABT) may be given before, during, and after surgery to correct chronic anaemia or acute blood loss. However, there is uncertainty about the benefit-risk ratio for ABT. This is a potentially scarce resource, with availability of blood products sometimes uncertain. Other strategies from Patient Blood Management may prevent or minimise blood loss and avoid administration of ABT.

OBJECTIVES

To summarise the evidence from Cochrane Reviews and other systematic reviews of randomised or quasi-randomised trials evaluating the effects of pharmacological and non-pharmacological interventions, administered perioperatively, on reducing blood loss, anaemia, and the need for ABT in adults undergoing hip fracture surgery.

METHODS

In January 2022, we searched the Cochrane Library, MEDLINE, Embase, and five other databases for systematic reviews of randomised controlled trials (RCTs) of interventions given to prevent or minimise blood loss, treat the effects of anaemia, and reduce the need for ABT, in adults undergoing hip fracture surgery. We searched for pharmacological interventions (fibrinogen, factor VIIa and factor XIII, desmopressin, antifibrinolytics, fibrin and non-fibrin sealants and glue, agents to reverse the effects of anticoagulants, erythropoiesis agents, iron, vitamin B12, and folate replacement therapy) and non-pharmacological interventions (surgical approaches to reduce or manage blood loss, intraoperative cell salvage and autologous blood transfusion, temperature management, and oxygen therapy). We used Cochrane methodology, and assessed the methodological quality of included reviews using AMSTAR 2. We assessed the degree of overlap of RCTs between reviews. Because overlap was very high, we used a hierarchical approach to select reviews from which to report data; we compared the findings of selected reviews with findings from the other reviews. Outcomes were: number of people requiring ABT, volume of transfused blood (measured as units of packed red blood cells (PRC)), postoperative delirium, adverse events, activities of daily living (ADL), health-related quality of life (HRQoL), and mortality.

MAIN RESULTS

We found 26 systematic reviews including 36 RCTs (3923 participants), which only evaluated tranexamic acid and iron. We found no reviews of other pharmacological interventions or any non-pharmacological interventions. Tranexamic acid (17 reviews, 29 eligible RCTs) We selected reviews with the most recent search date, and which included data for the most outcomes. The methodological quality of these reviews was low. However, the findings were largely consistent across reviews. One review included 24 RCTs, with participants who had internal fixation or arthroplasty for different types of hip fracture. Tranexamic acid was given intravenously or topically during the perioperative period. In this review, based on a control group risk of 451 people per 1000, 194 fewer people per 1000 probably require ABT after receiving tranexamic acid (risk ratio (RR) 0.56, 95% confidence interval (CI) 0.46 to 0.68; 21 studies, 2148 participants; moderate-certainty evidence). We downgraded the certainty for possible publication bias. Review authors found that there was probably little or no difference in the risks of adverse events, reported as deep vein thrombosis (RR 1.16, 95% CI 0.74 to 1.81; 22 studies), pulmonary embolism (RR 1.01, 95% CI 0.36 to 2.86; 9 studies), myocardial infarction (RR 1.00, 95% CI 0.23 to 4.33; 8 studies), cerebrovascular accident (RR 1.45, 95% CI 0.56 to 3.70; 8 studies), or death (RR 1.01, 95% CI 0.70 to 1.46; 10 studies). We judged evidence from these outcomes to be moderate certainty, downgraded for imprecision. Another review, with a similarly broad inclusion criteria, included 10 studies, and found that tranexamic acid probably reduces the volume of transfused PRC (0.53 fewer units, 95% CI 0.27 to 0.80; 7 studies, 813 participants; moderate-certainty evidence). We downgraded the certainty because of unexplained high levels of statistical heterogeneity. No reviews reported outcomes of postoperative delirium, ADL, or HRQoL. Iron (9 reviews, 7 eligible RCTs) Whilst all reviews included studies in hip fracture populations, most also included other surgical populations. The most current, direct evidence was reported in two RCTs, with 403 participants with hip fracture; iron was given intravenously, starting preoperatively. This review did not include evidence for iron with erythropoietin. The methodological quality of this review was low. In this review, there was low-certainty evidence from two studies (403 participants) that there may be little or no difference according to whether intravenous iron was given in: the number of people who required ABT (RR 0.90, 95% CI 0.73 to 1.11), the volume of transfused blood (MD -0.07 units of PRC, 95% CI -0.31 to 0.17), infection (RR 0.99, 95% CI 0.55 to 1.80), or mortality within 30 days (RR 1.06, 95% CI 0.53 to 2.13). There may be little or no difference in delirium (25 events in the iron group compared to 26 events in control group; 1 study, 303 participants; low-certainty evidence). We are very unsure whether there was any difference in HRQoL, since it was reported without an effect estimate. The findings were largely consistent across reviews. We downgraded the evidence for imprecision, because studies included few participants, and the wide CIs indicated possible benefit and harm. No reviews reported outcomes of cognitive dysfunction, ADL, or HRQoL.

AUTHORS' CONCLUSIONS

Tranexamic acid probably reduces the need for ABT in adults undergoing hip fracture surgery, and there is probably little or no difference in adverse events. For iron, there may be little or no difference in overall clinical effects, but this finding is limited by evidence from only a few small studies. Reviews of these treatments did not adequately include patient-reported outcome measures (PROMS), and evidence for their effectiveness remains incomplete. We were unable to effectively explore the impact of timing and route of administration between reviews. A lack of systematic reviews for other types of pharmacological or any non-pharmacological interventions to reduce the need for ABT indicates a need for further evidence syntheses to explore this. Methodologically sound evidence syntheses should include PROMS within four months of surgery.

Effectiveness of the perioperative encounter in promoting regular exercise and physical activity: a systematic review and meta-analysis

BACKGROUND

Low levels of physical activity (PA) are associated with poorer health outcomes. The perioperative encounter (extending from initial contact in primary care to beyond discharge from hospital) is potentially a good time to intervene, but data regarding the effectiveness of interventions are scarce. To address this, we systematically reviewed existing literature to evaluate the effectiveness of interventions applied perioperatively to facilitate PA in the medium to long-term (at least six months after the intervention).

METHODS

In this systematic review and meta-analysis, we searched Central Register of Controlled Trials (CENTRAL, Cochrane Library), MEDLINE, CINAHL, Embase, PsycInfo, and SPORTDiscus from database inception to October 22nd 2020, with an updated search done on August 4th 2022. We searched clinical trials registers, and conducted forward- and backward-citation searches. We included randomised controlled trials and quasi-randomised trials comparing PA interventions with usual care, or another PA intervention, in adults who were scheduled for, or had recently undergone, surgery. We included trials which reported our primary outcomes: amount of PA or whether participants were engaged in PA at least six months after the intervention. A random effects meta-analysis was used to pool data across studies as risk ratios (RR), or standardised mean differences (SMDs), which we interpreted using Cohen. We used the Cochrane risk of bias tool and used GRADE to assess the certainty of the evidence. This study is registered with PROSPERO, CRD42019139008.

FINDINGS

We found 57 trials including 8548 adults and compared 71 interventions facilitating PA. Most interventions were started postoperatively and included multiple components. Compared with usual care, interventions may slightly increase the number of minutes of PA per day or week (SMD 0.17, 95% CI 0.09-0.26; 14 studies, 2172 participants; I² = 0%), and people's engagement in PA at the study's end (RR 1.19, 95% CI 0.96-1.47; 9 studies, 882 participants; I² = 25%); this was moderate-certainty evidence. Some studies compared two different types of interventions but it was often not feasible to combine data in analysis. The effect estimates generally indicated little difference between intervention designs and we judged all the evidence for these comparisons to be very low certainty. Thirty-six studies (63%) had low risk of selection bias for sequence generation, 27 studies (47%) had low risk of bias for allocation concealment, and 56 studies (98%) had a high risk of performance bias. For detection bias for PA outcomes, we judged 30 studies (53%) that used subjective measurement tools to have a high risk of detection bias.

INTERPRETATION

Interventions delivered in the perioperative setting, aimed at enhancing PA in the medium to long-term, may have overall benefit. However, because of imprecision in some of the findings, we could not rule out the possibility of no change in PA.

FUNDING

National Institute for Health Research Health Services and Delivery Research programme (NIHR127879).

Perioperative beta-blockers for preventing surgery-related mortality and morbidity in adults undergoing non-cardiac surgery

BACKGROUND

Randomized controlled trials (RCTs) have yielded conflicting results regarding the ability of beta-blockers to influence perioperative cardiovascular morbidity and mortality. Thus routine prescription of these drugs in an unselected population remains a controversial issue. A previous version of this review assessing the effectiveness of perioperative beta-blockers in cardiac and non-cardiac surgery was last published in 2018. The previous review has now been split into two reviews according to type of surgery. This is an update, and assesses the evidence in non-cardiac surgery only.

OBJECTIVES

To assess the effectiveness of perioperatively administered beta-blockers for the prevention of surgery-related mortality and morbidity in adults undergoing non-cardiac surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Biosis Previews and Conference Proceedings Citation Index-Science on 28 June 2019. We searched clinical trials registers and grey literature, and conducted backward- and forward-citation searching of relevant articles.

SELECTION CRITERIA

We included RCTs and quasi-randomized studies comparing beta-blockers with a control (placebo or standard care) administered during the perioperative period to adults undergoing non-cardiac surgery. If studies included surgery with different types of anaesthesia, we included them if 70% participants, or at least 100 participants, received general anaesthesia. We excluded studies in which all participants in the standard care control group were given a pharmacological agent that was not given to participants in the intervention group, studies in which all participants in the control group were given a beta-blocker, and studies in which beta-blockers were given with an additional agent (e.g. magnesium). We excluded studies that did not measure or report review outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 83 RCTs with 14,967 participants; we found no quasi-randomized studies. All participants were undergoing non-cardiac surgery, and types of surgery ranged from low to high risk. Types of beta-blockers were: propranolol, metoprolol, esmolol, landiolol, nadolol, atenolol, labetalol, oxprenolol, and pindolol. In nine studies, beta-blockers were titrated according to heart rate or blood pressure. Duration of administration varied between studies, as did the time at which drugs were administered; in most studies, it was intraoperatively, but in 18 studies it was before surgery, in six postoperatively, one multi-arm study included groups of different timings, and one study did not report timing of drug administration. Overall, we found that more than half of the studies did not sufficiently report methods used for randomization. All studies in which the control was standard care were at high risk of performance bias because of the open-label study design. Only two studies were prospectively registered with clinical trials registers, which limited the assessment of reporting bias. In six studies, participants in the control group were given beta-blockers as rescue therapy during the study period.The evidence for all-cause mortality at 30 days was uncertain; based on the risk of death in the control group of 25 per 1000, the effect with beta-blockers was between two fewer and 13 more per 1000 (risk ratio (RR) 1.17, 95% confidence interval (CI) 0.89 to 1.54; 16 studies, 11,446 participants; low-certainty evidence). Beta-blockers may reduce the incidence of myocardial infarction by 13 fewer incidences per 1000 (RR 0.72, 95% CI 0.60 to 0.87; 12 studies, 10,520 participants; low-certainty evidence). We found no evidence of a difference in cerebrovascular events (RR 1.65, 95% CI 0.97 to 2.81; 6 studies, 9460 participants; low-certainty evidence), or in ventricular arrhythmias (RR 0.72, 95% CI 0.35 to 1.47; 5 studies, 476 participants; very low-certainty evidence). Beta-blockers may reduce atrial fibrillation or flutter by 26 fewer incidences per 1000 (RR 0.41, 95% CI 0.21 to 0.79; 9 studies, 9080 participants; low-certainty evidence). However, beta-blockers may increase bradycardia by 55 more incidences per 1000 (RR 2.49, 95% CI 1.74 to 3.56; 49 studies, 12,239 participants; low-certainty evidence), and hypotension by 44 more per 1000 (RR 1.40, 95% CI 1.29 to 1.51; 49 studies, 12,304 participants; moderate-certainty evidence).We downgraded the certainty of the evidence owing to study limitations; some studies had high risks of bias, and the effects were sometimes altered when we excluded studies with a standard care control group (including only placebo-controlled trials showed an increase in early mortality and cerebrovascular events with beta-blockers). We also downgraded for inconsistency; one large, well-conducted, international study found a reduction in myocardial infarction, and an increase in cerebrovascular events and all-cause mortality, when beta-blockers were used, but other studies showed no evidence of a difference. We could not explain the reason for the inconsistency in the evidence for ventricular arrhythmias, and we also downgraded this outcome for imprecision because we found few studies with few participants.

AUTHORS' CONCLUSIONS

The evidence for early all-cause mortality with perioperative beta-blockers was uncertain. We found no evidence of a difference in cerebrovascular events or ventricular arrhythmias, and the certainty of the evidence for these outcomes was low and very low. We found low-certainty evidence that beta-blockers may reduce atrial fibrillation and myocardial infarctions. However, beta-blockers may increase bradycardia (low-certainty evidence) and probably increase hypotension (moderate-certainty evidence). Further evidence from large placebo-controlled trials is likely to increase the certainty of these findings, and we recommend the assessment of impact on quality of life. We found 18 studies awaiting classification; inclusion of these studies in future updates may also increase the certainty of the evidence.

Bispectral index for improving intraoperative awareness and early postoperative recovery in adults

BACKGROUND

The use of clinical signs, or end-tidal anaesthetic gas (ETAG), may not be reliable in measuring the hypnotic component of anaesthesia and may lead to either overdosage or underdosage resulting in adverse effects because of too deep or too light anaesthesia. Intraoperative awareness, whilst uncommon, may lead to serious psychological disturbance, and alternative methods to monitor the depth of anaesthesia may reduce the incidence of serious events. Bispectral index (BIS) is a numerical scale based on electrical activity in the brain. Using a BIS monitor to guide the dose of anaesthetic may have advantages over clinical signs or ETAG. This is an update of a review last published in 2014.

OBJECTIVES

To assess the effectiveness of BIS to reduce the risk of intraoperative awareness and early recovery times from general anaesthesia in adults undergoing surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and Web of Science on 26 March 2019. We searched clinical trial registers and grey literature, and handsearched reference lists of included studies and related reviews.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs in which BIS was used to guide anaesthesia compared with standard practice which was either clinical signs or end-tidal anaesthetic gas (ETAG) to guide the anaesthetic dose. We included adult participants undergoing any type of surgery under general anaesthesia regardless of whether included participants had a high risk of intraoperative awareness. We included only studies in which investigators aimed to evaluate the effectiveness of BIS for its role in monitoring intraoperative depth of anaesthesia or potential improvements in early recovery times from anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 52 studies with 41,331 participants; two studies were quasi-randomized and the remaining studies were RCTs. All studies included participants undergoing surgery under general anaesthesia. Three studies recruited only participants who were at high risk of intraoperative awareness, whilst two studies specifically recruited an unselected participant group. We analysed the data according to two comparison groups: BIS versus clinical signs; and BIS versus ETAG. Forty-eight studies used clinical signs as a comparison method, which included titration of anaesthesia according to criteria such as blood pressure or heart rate and, six studies used ETAG to guide anaesthesia. Whilst BIS target values differed between studies, all were within a range of values between 40 to 60.BIS versus clinical signsWe found low-certainty evidence that BIS-guided anaesthesia may reduce the risk of intraoperative awareness in a surgical population that were unselected or at high risk of awareness (Peto odds ratio (OR) 0.36, 95% CI 0.21 to 0.60; I2 = 61%; 27 studies; 9765 participants). However, events were rare with only five of 27 studies with reported incidences; we found that incidences of intraoperative awareness when BIS was used were three per 1000 (95% CI 2 to 6 per 1000) compared to nine per 1000 when anaesthesia was guided by clinical signs. Of the five studies with event data, one included participants at high risk of awareness and one included unselected participants, four used a structured questionnaire for assessment, and two used an adjudication process to identify confirmed or definite awareness.Early recovery times were also improved when BIS was used. We found low-certainty evidence that BIS may reduce the time to eye opening by mean difference (MD) 1.78 minutes (95% CI -2.53 to -1.03 minutes; 22 studies; 1494 participants), the time to orientation by MD 3.18 minutes (95% CI -4.03 to -2.33 minutes; 6 studies; 273 participants), and the time to discharge from the postanaesthesia care unit (PACU) by MD 6.86 minutes (95% CI -11.72 to -2 minutes; 13 studies; 930 participants).BIS versus ETAGAgain, events of intraoperative awareness were extremely rare, and we found no evidence of a difference in incidences of intraoperative awareness according to whether anaesthesia was guided by BIS or by ETAG in a surgical population at unselected or at high risk of awareness (Peto OR 1.13, 95% CI 0.56 to 2.26; I2 = 37%; 5 studies; 26,572 participants; low-certainty evidence). Incidences of intraoperative awareness were one per 1000 in both groups. Only three of five studies reported events, two included participants at high risk of awareness and one included unselected participants, all used a structured questionnaire for assessment and an adjudication process to identify confirmed or definite awareness.One large study (9376 participants) reported a reduced time to discharge from the PACU by a median of three minutes less, and we judged the certainty of this evidence to be low. No studies measured or reported the time to eye opening and the time to orientation.Certainty of the evidenceWe used GRADE to downgrade the evidence for all outcomes to low certainty. The incidence of intraoperative awareness is so infrequent such that, despite the inclusion of some large multi-centre studies in analyses, we believed that the effect estimates were imprecise. In addition, analyses included studies that we judged to have limitations owing to some assessments of high or unclear bias and in all studies, it was not possible to blind anaesthetists to the different methods of monitoring depth of anaesthesia.Studies often did not report a clear definition of intraoperative awareness. Time points of measurement differed, and methods used to identify intraoperative awareness also differed and we expected that some assessment tools were more comprehensive than others.

AUTHORS' CONCLUSIONS

Intraoperative awareness is infrequent and, despite identifying a large number of eligible studies, evidence for the effectiveness of using BIS to guide anaesthetic depth is imprecise. We found that BIS-guided anaesthesia compared to clinical signs may reduce the risk of intraoperative awareness and improve early recovery times in people undergoing surgery under general anaesthesia but we found no evidence of a difference between BIS-guided anaesthesia and ETAG-guided anaesthesia. We found six studies awaiting classification and two ongoing studies; inclusion of these studies in future updates may increase the certainty of the evidence.

Perioperative beta-blockers for preventing surgery-related mortality and morbidity in adults undergoing cardiac surgery

BACKGROUND

Randomized controlled trials (RCTs) have yielded conflicting results regarding the ability of beta-blockers to influence perioperative cardiovascular morbidity and mortality. Thus routine prescription of these drugs in unselected patients remains a controversial issue. A previous version of this review assessing the effectiveness of perioperative beta-blockers in cardiac and non-cardiac surgery was last published in 2018. The previous review has now been split into two reviews according to type of surgery. This is an update and assesses the evidence in cardiac surgery only.

OBJECTIVES

To assess the effectiveness of perioperatively administered beta-blockers for the prevention of surgery-related mortality and morbidity in adults undergoing cardiac surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Biosis Previews and Conference Proceedings Citation Index-Science on 28 June 2019. We searched clinical trials registers and grey literature, and conducted backward- and forward-citation searching of relevant articles.

SELECTION CRITERIA

We included RCTs and quasi-randomized studies comparing beta-blockers with a control (placebo or standard care) administered during the perioperative period to adults undergoing cardiac surgery. We excluded studies in which all participants in the standard care control group were given a pharmacological agent that was not given to participants in the intervention group, studies in which all participants in the control group were given a beta-blocker, and studies in which beta-blockers were given with an additional agent (e.g. magnesium). We excluded studies that did not measure or report review outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 63 studies with 7768 participants; six studies were quasi-randomized and the remaining were RCTs. All participants were undergoing cardiac surgery, and in most studies, at least some of the participants were previously taking beta-blockers. Types of beta-blockers were: propranolol, metoprolol, sotalol, esmolol, landiolol, acebutolol, timolol, carvedilol, nadolol, and atenolol. In twelve studies, beta-blockers were titrated according to heart rate or blood pressure. Duration of administration varied between studies, as did the time at which drugs were administered; in nine studies this was before surgery, in 20 studies during surgery, and in the remaining studies beta-blockers were started postoperatively. Overall, we found that most studies did not report sufficient details for us to adequately assess risk of bias. In particular, few studies reported methods used to randomize participants to groups. In some studies, participants in the control group were given beta-blockers as rescue therapy during the study period, and all studies in which the control was standard care were at high risk of performance bias because of the open-label study design. No studies were prospectively registered with clinical trials registers, which limited the assessment of reporting bias. We judged 68% studies to be at high risk of bias in at least one domain.Study authors reported few deaths (7 per 1000 in both the intervention and control groups), and we found low-certainty evidence that beta-blockers may make little or no difference to all-cause mortality at 30 days (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.47 to 1.90; 29 studies, 4099 participants). For myocardial infarctions, we found no evidence of a difference in events (RR 1.05, 95% CI 0.72 to 1.52; 25 studies, 3946 participants; low-certainty evidence). Few study authors reported cerebrovascular events, and the evidence was uncertain (RR 1.37, 95% CI 0.51 to 3.67; 5 studies, 1471 participants; very low-certainty evidence). Based on a control risk of 54 per 1000, we found low-certainty evidence that beta-blockers may reduce episodes of ventricular arrhythmias by 32 episodes per 1000 (RR 0.40, 95% CI 0.25 to 0.63; 12 studies, 2296 participants). For atrial fibrillation or flutter, there may be 163 fewer incidences with beta-blockers, based on a control risk of 327 incidences per 1000 (RR 0.50, 95% CI 0.42 to 0.59; 40 studies, 5650 participants; low-certainty evidence). However, the evidence for bradycardia and hypotension was less certain. We found that beta-blockers may make little or no difference to bradycardia (RR 1.63, 95% CI 0.92 to 2.91; 12 studies, 1640 participants; low-certainty evidence), or hypotension (RR 1.84, 95% CI 0.89 to 3.80; 10 studies, 1538 participants; low-certainty evidence).We used GRADE to downgrade the certainty of evidence. Owing to studies at high risk of bias in at least one domain, we downgraded each outcome for study limitations. Based on effect size calculations in the previous review, we found an insufficient number of participants in all outcomes (except atrial fibrillation) and, for some outcomes, we noted a wide confidence interval; therefore, we also downgraded outcomes owing to imprecision. The evidence for atrial fibrillation and length of hospital stay had a moderate level of statistical heterogeneity which we could not explain, and we, therefore, downgraded these outcomes for inconsistency.

AUTHORS' CONCLUSIONS

We found no evidence of a difference in early all-cause mortality, myocardial infarction, cerebrovascular events, hypotension and bradycardia. However, there may be a reduction in atrial fibrillation and ventricular arrhythmias when beta-blockers are used. A larger sample size is likely to increase the certainty of this evidence. Four studies awaiting classification may alter the conclusions of this review.

Pharmacological agents for adults with acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a life-threatening condition caused by direct or indirect injury to the lungs. Despite improvements in clinical management (for example, lung protection strategies), mortality in this patient group is at approximately 40%. This is an update of a previous version of this review, last published in 2004.

OBJECTIVES

To evaluate the effectiveness of pharmacological agents in adults with ARDS on mortality, mechanical ventilation, and fitness to return to work at 12 months.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and CINAHL on 10 December 2018. We searched clinical trials registers and grey literature, and handsearched reference lists of included studies and related reviews.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing pharmacological agents with control (placebo or standard therapy) to treat adults with established ARDS. We excluded trials of nitric oxide, inhaled prostacyclins, partial liquid ventilation, neuromuscular blocking agents, fluid and nutritional interventions and medical oxygen. We excluded studies published earlier than 2000, because of changes to lung protection strategies for people with ARDS since this date.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risks of bias. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 48 RCTs with 6299 participants who had ARDS; two included only participants with mild ARDS (also called acute lung injury). Most studies included causes of ARDS that were both direct and indirect injuries. We noted differences between studies, for example the time of administration or the size of dose, and because of unclear reporting we were uncertain whether all studies had used equivalent lung protection strategies.We included five types of agents as the primary comparisons in the review: corticosteroids, surfactants, N-acetylcysteine, statins, and beta-agonists. We included 15 additional agents (sivelestat, mesenchymal stem cells, ulinastatin, anisodimine, angiotensin-converting enzyme (ACE) inhibitor, recombinant human ACE2 (palifermin), AP301, granulocyte-macrophage colony stimulating factor (GM-CSF), levosimendan, prostacyclins, lisofylline, ketaconazole, nitroglycerins, L-2-oxothiazolidine-4-carboxylic acid (OTZ), and penehyclidine hydrochloride).We used GRADE to downgrade outcomes for imprecision (because of few studies and few participants), for study limitations (e.g. high risks of bias) and for inconsistency (e.g. differences between study data).Corticosteroids versus placebo or standard therapyCorticosteroids may reduce all-cause mortality within three months by 86 per 1000 patients (with as many as 161 fewer to 19 more deaths); however, the 95% confidence interval (CI) includes the possibility of both increased and reduced deaths (risk ratio (RR) 0.77, 95% CI 0.57 to 1.05; 6 studies, 574 participants; low-certainty evidence). Due to the very low-certainty evidence, we are uncertain whether corticosteroids make little or no difference to late all-cause mortality (later than three months) (RR 0.99, 95% CI 0.64 to 1.52; 1 study, 180 participants), or to the duration of mechanical ventilation (mean difference (MD) -4.30, 95% CI -9.72 to 1.12; 3 studies, 277 participants). We found that ventilator-free days up to day 28 (VFD) may be improved with corticosteroids (MD 4.09, 95% CI 1.74 to 6.44; 4 studies, 494 participants; low-certainty evidence). No studies reported adverse events leading to discontinuation of study medication, or fitness to return to work at 12 months (FTR).Surfactants versus placebo or standard therapyWe are uncertain whether surfactants make little or no difference to early mortality (RR 1.08, 95% CI 0.91 to 1.29; 9 studies, 1338 participants), or whether they reduce late all-cause mortality (RR 1.28, 95% CI 1.01 to 1.61; 1 study, 418 participants). Similarly, we are uncertain whether surfactants reduce the duration of mechanical ventilation (MD -2.50, 95% CI -4.95 to -0.05; 1 study, 16 participants), make little or no difference to VFD (MD -0.39, 95% CI -2.49 to 1.72; 2 studies, 344 participants), or to adverse events leading to discontinuation of study medication (RR 0.50, 95% CI 0.17 to 1.44; 2 studies, 88 participants). We are uncertain of these effects because we assessed them as very low-certainty. No studies reported FTR.N-aceytylcysteine versus placeboWe are uncertain whether N-acetylcysteine makes little or no difference to early mortality, because we assessed this as very low-certainty evidence (RR 0.64, 95% CI 0.32 to 1.30; 1 study, 36 participants). No studies reported late all-cause mortality, duration of mechanical ventilation, VFD, adverse events leading to study drug discontinuation, or FTR.Statins versus placeboStatins probably make little or no difference to early mortality (RR 0.99, 95% CI 0.78 to 1.26; 3 studies, 1344 participants; moderate-certainty evidence) or to VFD (MD 0.40, 95% CI -0.71 to 1.52; 3 studies, 1342 participants; moderate-certainty evidence). Statins may make little or no difference to duration of mechanical ventilation (MD 2.70, 95% CI -3.55 to 8.95; 1 study, 60 participants; low-certainty evidence). We could not include data for adverse events leading to study drug discontinuation in one study because it was unclearly reported. No studies reported late all-cause mortality or FTR.Beta-agonists versus placebo controlBeta-blockers probably slightly increase early mortality by 40 per 1000 patients (with as many as 119 more or 25 fewer deaths); however, the 95% CI includes the possibility of an increase as well as a reduction in mortality (RR 1.14, 95% CI 0.91 to 1.42; 3 studies, 646 participants; moderate-certainty evidence). Due to the very low-certainty evidence, we are uncertain whether beta-agonists increase VFD (MD -2.20, 95% CI -3.68 to -0.71; 3 studies, 646 participants), or make little or no difference to adverse events leading to study drug discontinuation (one study reported little or no difference between groups, and one study reported more events in the beta-agonist group). No studies reported late all-cause mortality, duration of mechanical ventilation, or FTR.

AUTHORS' CONCLUSIONS

We found insufficient evidence to determine with certainty whether corticosteroids, surfactants, N-acetylcysteine, statins, or beta-agonists were effective at reducing mortality in people with ARDS, or duration of mechanical ventilation, or increasing ventilator-free days. Three studies awaiting classification may alter the conclusions of this review. As the potential long-term consequences of ARDS are important to survivors, future research should incorporate a longer follow-up to measure the impacts on quality of life.

Information or education interventions for adult intensive care unit (ICU) patients and their carers

BACKGROUND

During intensive care unit (ICU) admission, patients and their carers experience physical and psychological stressors that may result in psychological conditions including anxiety, depression, and post-traumatic stress disorder (PTSD). Improving communication between healthcare professionals, patients, and their carers may alleviate these disorders. Communication may include information or educational interventions, in different formats, aiming to improve knowledge of the prognosis, treatment, or anticipated challenges after ICU discharge.

OBJECTIVES

To assess the effects of information or education interventions for improving outcomes in adult ICU patients and their carers.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, and PsycINFO from database inception to 10 April 2017. We searched clinical trials registries and grey literature, and handsearched reference lists of included studies and related reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), and planned to include quasi-RCTs, comparing information or education interventions presented to participants versus no information or education interventions, or comparing information or education interventions as part of a complex intervention versus a complex intervention without information or education. We included participants who were adult ICU patients, or their carers; these included relatives and non-relatives, including significant representatives of patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias, and applied GRADE criteria to assess certainty of the evidence.

MAIN RESULTS

We included eight RCTs with 1157 patient participants and 943 carer participants. We found no quasi-RCTs. We identified seven studies that await classification, and three ongoing studies.Three studies designed an intervention targeted at patients, four at carers, and one at both patients and carers. Studies included varied information: standardised or tailored, presented once or several times, and that included verbal or written information, audio recordings, multimedia information, and interactive information packs. Five studies reported robust methods of randomisation and allocation concealment. We noted high attrition rates in five studies. It was not feasible to blind participants, and we rated all studies as at high risk of performance bias, and at unclear risk of detection bias because most outcomes required self reporting.We attempted to pool data statistically, however this was not always possible due to high levels of heterogeneity. We calculated mean differences (MDs) using data reported from individual study authors where possible, and narratively synthesised the results. We reported the following two comparisons.Information or education intervention versus no information or education intervention (4 studies)For patient anxiety, we did not pool data from three studies (332 participants) owing to unexplained substantial statistical heterogeneity and possible clinical or methodological differences between studies. One study reported less anxiety when an intervention was used (MD -3.20, 95% confidence interval (CI) -3.38 to -3.02), and two studies reported little or no difference between groups (MD -0.40, 95% CI -4.75 to 3.95; MD -1.00, 95% CI -2.94 to 0.94). Similarly, for patient depression, we did not pool data from two studies (160 patient participants). These studies reported less depression when an information or education intervention was used (MD -2.90, 95% CI -4.00 to -1.80; MD -1.27, 95% CI -1.47 to -1.07). However, it is uncertain whether information or education interventions reduce patient anxiety or depression due to very low-certainty evidence.It is uncertain whether information or education interventions improve health-related quality of life due to very low-certainty evidence from one study reporting little or no difference between intervention groups (MD -1.30, 95% CI -4.99 to 2.39; 143 patient participants). No study reported adverse effects, knowledge acquisition, PTSD severity, or patient or carer satisfaction.We used the GRADE approach and downgraded certainty of the evidence owing to study limitations, inconsistencies between results, and limited data from few small studies.Information or education intervention as part of a complex intervention versus a complex intervention without information or education (4 studies)One study (three comparison groups; 38 participants) reported little or no difference between groups in patient anxiety (tailored information pack versus control: MD 0.09, 95% CI -3.29 to 3.47; standardised general ICU information versus control: MD -0.25, 95% CI -4.34 to 3.84), and little or no difference in patient depression (tailored information pack versus control: MD -1.26, 95% CI -4.48 to 1.96; standardised general ICU information versus control: MD -1.47, 95% CI -6.37 to 3.43). It is uncertain whether information or education interventions as part of a complex intervention reduce patient anxiety and depression due to very low-certainty evidence.One study (175 carer participants) reported fewer carer participants with poor comprehension among those given information (risk ratio 0.28, 95% CI 0.15 to 0.53), but again this finding is uncertain due to very low-certainty evidence.Two studies (487 carer participants) reported little or no difference in carer satisfaction; it is uncertain whether information or education interventions as part of a complex intervention increase carer satisfaction due to very low-certainty evidence. Adverse effects were reported in only one study: one participant withdrew because of deterioration in mental health on completion of anxiety and depression questionnaires, but the study authors did not report whether this participant was from the intervention or comparison group.We downgraded certainty of the evidence owing to study limitations, and limited data from few small studies.No studies reported severity of PTSD, or health-related quality of life.

AUTHORS' CONCLUSIONS

We are uncertain of the effects of information or education interventions given to adult ICU patients and their carers, as the evidence in all cases was of very low certainty, and our confidence in the evidence was limited. Ongoing studies may contribute more data and introduce more certainty when incorporated into future updates of the review.

Intravenous versus inhalational maintenance of anaesthesia for postoperative cognitive outcomes in elderly people undergoing non-cardiac surgery

BACKGROUND

The use of anaesthetics in the elderly surgical population (more than 60 years of age) is increasing. Postoperative delirium, an acute condition characterized by reduced awareness of the environment and a disturbance in attention, typically occurs between 24 and 72 hours after surgery and can affect up to 60% of elderly surgical patients. Postoperative cognitive dysfunction (POCD) is a new-onset of cognitive impairment which may persist for weeks or months after surgery.Traditionally, surgical anaesthesia has been maintained with inhalational agents. End-tidal concentrations require adjustment to balance the risks of accidental awareness and excessive dosing in elderly people. As an alternative, propofol-based total intravenous anaesthesia (TIVA) offers a more rapid recovery and reduces postoperative nausea and vomiting. Using TIVA with a target controlled infusion (TCI) allows plasma and effect-site concentrations to be calculated using an algorithm based on age, gender, weight and height of the patient.TIVA is a viable alternative to inhalational maintenance agents for surgical anaesthesia in elderly people. However, in terms of postoperative cognitive outcomes, the optimal technique is unknown.

OBJECTIVES

To compare maintenance of general anaesthesia for elderly people undergoing non-cardiac surgery using propofol-based TIVA or inhalational anaesthesia on postoperative cognitive function, mortality, risk of hypotension, length of stay in the postanaesthesia care unit (PACU), and hospital stay.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 11), MEDLINE (1946 to November 2017), Embase (1974 to November 2017), PsycINFO (1887 to November 2017). We searched clinical trials registers for ongoing studies, and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) with participants over 60 years of age scheduled for non-cardiac surgery under general anaesthesia. We planned to also include quasi-randomized trials. We compared maintenance of anaesthesia with propofol-based TIVA versus inhalational maintenance of anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias, and synthesized findings.

MAIN RESULTS

We included 28 RCTs with 4507 randomized participants undergoing different types of surgery (predominantly cardiovascular, laparoscopic, abdominal, orthopaedic and ophthalmic procedures). We found no quasi-randomized trials. Four studies are awaiting classification because we had insufficient information to assess eligibility.All studies compared maintenance with propofol-based TIVA versus inhalational maintenance of anaesthesia. Six studies were multi-arm and included additional TIVA groups, additional inhalational maintenance or both. Inhalational maintenance agents included sevoflurane (19 studies), isoflurane (eight studies), and desflurane (three studies), and was not specified in one study (reported as an abstract). Some studies also reported use of epidural analgesia/anaesthesia, fentanyl and remifentanil.We found insufficient reporting of randomization methods in many studies and all studies were at high risk of performance bias because it was not feasible to blind anaesthetists to study groups. Thirteen studies described blinding of outcome assessors. Three studies had a high of risk of attrition bias, and we noted differences in the use of analgesics between groups in six studies, and differences in baseline characteristics in five studies. Few studies reported clinical trials registration, which prevented assessment of risk of selective reporting bias.We found no evidence of a difference in incidences of postoperative delirium according to type of anaesthetic maintenance agents (odds ratio (OR) 0.59, 95% confidence interval (CI) 0.15 to 2.26; 321 participants; five studies; very low-certainty evidence); we noted during sensitivity analysis that using different time points in one study may influence direction of this result. Thirteen studies (3215 participants) reported POCD, and of these, six studies reported data that could not be pooled; we noted no difference in scores of POCD in four of these and in one study, data were at a time point incomparable to other studies. We excluded one large study from meta-analysis because study investigators had used non-standard anaesthetic management and this study was not methodologically comparable to other studies. We combined data for seven studies and found low-certainty evidence that TIVA may reduce POCD (OR 0.52, 95% CI 0.31 to 0.87; 869 participants).We found no evidence of a difference in mortality at 30 days (OR 1.21, 95% CI 0.33 to 4.45; 271 participants; three studies; very low-certainty evidence). Twelve studies reported intraoperative hypotension. We did not perform meta-analysis for 11 studies for this outcome. We noted visual inconsistencies in these data, which may be explained by possible variation in clinical management and medication used to manage hypotension in each study (downgraded to low-certainty evidence); one study reported data in a format that could not be combined and we noted little or no difference between groups in intraoperative hypotension for this study. Eight studies reported length of stay in the PACU, and we did not perform meta-analysis for seven studies. We noted visual inconsistencies in these data, which may be explained by possible differences in definition of time points for this outcome (downgraded to very low-certainty evidence); data were unclearly reported in one study. We found no evidence of a difference in length of hospital stay according to type of anaesthetic maintenance agent (mean difference (MD) 0 days, 95% CI -1.32 to 1.32; 175 participants; four studies; very low-certainty evidence).We used the GRADE approach to downgrade the certainty of the evidence for each outcome. Reasons for downgrading included: study limitations, because some included studies insufficiently reported randomization methods, had high attrition bias, or high risk of selective reporting bias; imprecision, because we found few studies; inconsistency, because we noted heterogeneity across studies.

AUTHORS' CONCLUSIONS

We are uncertain whether maintenance with propofol-based TIVA or with inhalational agents affect incidences of postoperative delirium, mortality, or length of hospital stay because certainty of the evidence was very low. We found low-certainty evidence that maintenance with propofol-based TIVA may reduce POCD. We were unable to perform meta-analysis for intraoperative hypotension or length of stay in the PACU because of heterogeneity between studies. We identified 11 ongoing studies from clinical trials register searches; inclusion of these studies in future review updates may provide more certainty for the review outcomes.

Colloids versus crystalloids for fluid resuscitation in critically ill people

BACKGROUND

Critically ill people may lose fluid because of serious conditions, infections (e.g. sepsis), trauma, or burns, and need additional fluids urgently to prevent dehydration or kidney failure. Colloid or crystalloid solutions may be used for this purpose. Crystalloids have small molecules, are cheap, easy to use, and provide immediate fluid resuscitation, but may increase oedema. Colloids have larger molecules, cost more, and may provide swifter volume expansion in the intravascular space, but may induce allergic reactions, blood clotting disorders, and kidney failure. This is an update of a Cochrane Review last published in 2013.

OBJECTIVES

To assess the effect of using colloids versus crystalloids in critically ill people requiring fluid volume replacement on mortality, need for blood transfusion or renal replacement therapy (RRT), and adverse events (specifically: allergic reactions, itching, rashes).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and two other databases on 23 February 2018. We also searched clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of critically ill people who required fluid volume replacement in hospital or emergency out-of-hospital settings. Participants had trauma, burns, or medical conditions such as sepsis. We excluded neonates, elective surgery and caesarean section. We compared a colloid (suspended in any crystalloid solution) versus a crystalloid (isotonic or hypertonic).

DATA COLLECTION AND ANALYSIS

Independently, two review authors assessed studies for inclusion, extracted data, assessed risk of bias, and synthesised findings. We assessed the certainty of evidence with GRADE.

MAIN RESULTS

We included 69 studies (65 RCTs, 4 quasi-RCTs) with 30,020 participants. Twenty-eight studied starch solutions, 20 dextrans, seven gelatins, and 22 albumin or fresh frozen plasma (FFP); each type of colloid was compared to crystalloids.Participants had a range of conditions typical of critical illness. Ten studies were in out-of-hospital settings. We noted risk of selection bias in some studies, and, as most studies were not prospectively registered, risk of selective outcome reporting. Fourteen studies included participants in the crystalloid group who received or may have received colloids, which might have influenced results.We compared four types of colloid (i.e. starches; dextrans; gelatins; and albumin or FFP) versus crystalloids.Starches versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using starches or crystalloids in mortality at: end of follow-up (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.86 to 1.09; 11,177 participants; 24 studies); within 90 days (RR 1.01, 95% CI 0.90 to 1.14; 10,415 participants; 15 studies); or within 30 days (RR 0.99, 95% CI 0.90 to 1.09; 10,135 participants; 11 studies).We found moderate-certainty evidence that starches probably slightly increase the need for blood transfusion (RR 1.19, 95% CI 1.02 to 1.39; 1917 participants; 8 studies), and RRT (RR 1.30, 95% CI 1.14 to 1.48; 8527 participants; 9 studies). Very low-certainty evidence means we are uncertain whether either fluid affected adverse events: we found little or no difference in allergic reactions (RR 2.59, 95% CI 0.27 to 24.91; 7757 participants; 3 studies), fewer incidences of itching with crystalloids (RR 1.38, 95% CI 1.05 to 1.82; 6946 participants; 2 studies), and fewer incidences of rashes with crystalloids (RR 1.61, 95% CI 0.90 to 2.89; 7007 participants; 2 studies).Dextrans versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using dextrans or crystalloids in mortality at: end of follow-up (RR 0.99, 95% CI 0.88 to 1.11; 4736 participants; 19 studies); or within 90 days or 30 days (RR 0.99, 95% CI 0.87 to 1.12; 3353 participants; 10 studies). We are uncertain whether dextrans or crystalloids reduce the need for blood transfusion, as we found little or no difference in blood transfusions (RR 0.92, 95% CI 0.77 to 1.10; 1272 participants, 3 studies; very low-certainty evidence). We found little or no difference in allergic reactions (RR 6.00, 95% CI 0.25 to 144.93; 739 participants; 4 studies; very low-certainty evidence). No studies measured RRT.Gelatins versus crystalloidsWe found low-certainty evidence that there may be little or no difference between gelatins or crystalloids in mortality: at end of follow-up (RR 0.89, 95% CI 0.74 to 1.08; 1698 participants; 6 studies); within 90 days (RR 0.89, 95% CI 0.73 to 1.09; 1388 participants; 1 study); or within 30 days (RR 0.92, 95% CI 0.74 to 1.16; 1388 participants; 1 study). Evidence for blood transfusion was very low certainty (3 studies), with a low event rate or data not reported by intervention. Data for RRT were not reported separately for gelatins (1 study). We found little or no difference between groups in allergic reactions (very low-certainty evidence).Albumin or FFP versus crystalloidsWe found moderate-certainty evidence that there is probably little or no difference between using albumin or FFP or using crystalloids in mortality at: end of follow-up (RR 0.98, 95% CI 0.92 to 1.06; 13,047 participants; 20 studies); within 90 days (RR 0.98, 95% CI 0.92 to 1.04; 12,492 participants; 10 studies); or within 30 days (RR 0.99, 95% CI 0.93 to 1.06; 12,506 participants; 10 studies). We are uncertain whether either fluid type reduces need for blood transfusion (RR 1.31, 95% CI 0.95 to 1.80; 290 participants; 3 studies; very low-certainty evidence). Using albumin or FFP versus crystalloids may make little or no difference to the need for RRT (RR 1.11, 95% CI 0.96 to 1.27; 3028 participants; 2 studies; very low-certainty evidence), or in allergic reactions (RR 0.75, 95% CI 0.17 to 3.33; 2097 participants, 1 study; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Using starches, dextrans, albumin or FFP (moderate-certainty evidence), or gelatins (low-certainty evidence), versus crystalloids probably makes little or no difference to mortality. Starches probably slightly increase the need for blood transfusion and RRT (moderate-certainty evidence), and albumin or FFP may make little or no difference to the need for renal replacement therapy (low-certainty evidence). Evidence for blood transfusions for dextrans, and albumin or FFP, is uncertain. Similarly, evidence for adverse events is uncertain. Certainty of evidence may improve with inclusion of three ongoing studies and seven studies awaiting classification, in future updates.

Continuation versus discontinuation of antiplatelet therapy for bleeding and ischaemic events in adults undergoing non-cardiac surgery

BACKGROUND

Antiplatelet agents are recommended for people with myocardial infarction and acute coronary syndromes, transient ischaemic attack or stroke, and for those in whom coronary stents have been inserted. People who take antiplatelet agents are at increased risk of adverse events when undergoing non-cardiac surgery because of these indications. However, taking antiplatelet therapy also introduces risk to the person undergoing surgery because the likelihood of bleeding is increased. Discontinuing antiplatelet therapy before surgery might reduce this risk but subsequently it might make thrombotic problems, such as myocardial infarction, more likely.

OBJECTIVES

To compare the effects of continuation versus discontinuation for at least five days of antiplatelet therapy on the occurrence of bleeding and ischaemic events in adults undergoing non-cardiac surgery under general, spinal or regional anaesthesia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 1), MEDLINE (1946 to January 2018), and Embase (1974 to January 2018). We searched clinical trials registers for ongoing studies, and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized controlled trials of adults who were taking single or dual antiplatelet therapy, for at least two weeks, and were scheduled for elective non-cardiac surgery. Included participants had at least one cardiac risk factor. We planned to include quasi-randomized studies.We excluded people scheduled for minor surgeries under local anaesthetic or sedation in which bleeding that required transfusion or additional surgery was unlikely. We included studies which compared perioperative continuation of antiplatelet therapy versus discontinuation of antiplatelet therapy or versus substitution of antiplatelet therapy with a placebo for at least five days before surgery.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias and synthesized findings. Our primary outcomes were: all-cause mortality at longest follow-up (up to six months); all-cause mortality (up to 30 days). Secondary outcomes included: blood loss requiring transfusion of blood products; blood loss requiring further surgical intervention; risk of ischaemic events. We used GRADE to assess the quality of evidence for each outcome MAIN RESULTS: We included five RCTs with 666 randomized adults. We identified three ongoing studies.All study participants were scheduled for elective general surgery (including abdominal, urological, orthopaedic and gynaecological surgery) under general, spinal or regional anaesthesia. Studies compared continuation of single or dual antiplatelet therapy (aspirin or clopidogrel) with discontinuation of therapy for at least five days before surgery.Three studies reported adequate methods of randomization, and two reported methods to conceal allocation. Three studies were placebo-controlled trials and were at low risk of performance bias, and three studies reported adequate methods to blind outcome assessors to group allocation. Attrition was limited in four studies and two studies had reported prospective registration with clinical trial registers and were at low risk of selective outcome reporting bias.We reported mortality at two time points: the longest follow-up reported by study authors up to six months, and time point reported by study authors up to 30 days. Five studies reported mortality up to six months (of which four studies had a longest follow-up at 30 days, and one study at 90 days) and we found that either continuation or discontinuation of antiplatelet therapy may make little or no difference to mortality up to six months (risk ratio (RR) 1.21, 95% confidence interval (CI) 0.34 to 4.27; 659 participants; low-certainty evidence); the absolute effect is three more deaths per 1000 with continuation of antiplatelets (ranging from eight fewer to 40 more). Combining the four studies with a longest follow-up at 30 days alone showed the same effect estimate, and we found that either continuation or discontinuation of antiplatelet therapy may make little or no difference to mortality at 30 days after surgery (RR 1.21, 95% CI 0.34 to 4.27; 616 participants; low-certainty evidence); the absolute effect is three more deaths per 1000 with continuation of antiplatelets (ranging from nine fewer to 42 more).We found that either continuation or discontinuation of antiplatelet therapy probably makes little or no difference in incidences of blood loss requiring transfusion (RR 1.37, 95% CI 0.83 to 2.26; 368 participants; absolute effect of 42 more participants per 1000 requiring transfusion in the continuation group, ranging from 19 fewer to 119 more; four studies; moderate-certainty evidence); and may make little or no difference in incidences of blood loss requiring additional surgery (RR 1.54, 95% CI 0.31 to 7.58; 368 participants; absolute effect of six more participants per 1000 requiring additional surgery in the continuation group, ranging from seven fewer to 71 more; four studies; low-certainty evidence). We found that either continuation or discontinuation of antiplatelet therapy may make little or no difference to incidences of ischaemic events (to include peripheral ischaemia, cerebral infarction, and myocardial infarction) within 30 days of surgery (RR 0.67, 95% CI 0.25 to 1.77; 616 participants; absolute effect of 17 fewer participants per 1000 with an ischaemic event in the continuation group, ranging from 39 fewer to 40 more; four studies; low-certainty evidence).We used the GRADE approach to downgrade evidence for all outcomes owing to limited evidence from few studies. We noted a wide confidence in effect estimates for mortality at the end of follow-up and at 30 days, and for blood loss requiring transfusion which suggested imprecision. We noted visual differences in study results for ischaemic events which suggested inconsistency.

AUTHORS' CONCLUSIONS

We found low-certainty evidence that either continuation or discontinuation of antiplatelet therapy before non-cardiac surgery may make little or no difference to mortality, bleeding requiring surgical intervention, or ischaemic events. We found moderate-certainty evidence that either continuation or discontinuation of antiplatelet therapy before non-cardiac surgery probably makes little or no difference to bleeding requiring transfusion. Evidence was limited to few studies with few participants, and with few events. The three ongoing studies may alter the conclusions of the review once published and assessed.

Melatonin for the promotion of sleep in adults in the intensive care unit

BACKGROUND

Patients in the intensive care unit (ICU) experience sleep deprivation caused by environmental disruption, such as high noise levels and 24-hour lighting, as well as increased patient care activities and invasive monitoring as part of their care. Sleep deprivation affects physical and psychological health, and patients perceive the quality of their sleep to be poor whilst in the ICU. Artificial lighting during night-time hours in the ICU may contribute to reduced production of melatonin in critically ill patients. Melatonin is known to have a direct effect on the circadian rhythm, and it appears to reset a natural rhythm, thus promoting sleep.

OBJECTIVES

To assess whether the quantity and quality of sleep may be improved by administration of melatonin to adults in the intensive care unit. To assess whether melatonin given for sleep promotion improves both physical and psychological patient outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 8), MEDLINE (1946 to September 2017), Embase (1974 to September 2017), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1937 to September 2017), and PsycINFO (1806 to September 2017). We searched clinical trials registers for ongoing studies, and conducted backward and forward citation searching of relevant articles.

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials with adult participants (over the age of 16) admitted to the ICU with any diagnoses given melatonin versus a comparator to promote overnight sleep. We included participants who were mechanically ventilated and those who were not mechanically ventilated. We planned to include studies that compared the use of melatonin, given at an appropriate clinical dose with the intention of promoting night-time sleep, against no agent; or against another agent administered specifically to promote sleep.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, assessed risk of bias, and synthesized findings. We assessed the quality of evidence with GRADE.

MAIN RESULTS

We included four studies with 151 randomized participants. Two studies included participants who were mechanically ventilated, one study included a mix of ventilated and non-ventilated participants and in one study participants were being weaned from mechanical ventilation. Three studies reported admission diagnoses, which varied: these included sepsis, pneumonia and cardiac or cardiorespiratory arrest. All studies compared melatonin against no agent; three were placebo-controlled trials; and one compared melatonin with usual care. All studies administered melatonin in the evening.All studies reported adequate methods for randomization and placebo-controlled trials were blinded at the participant and personnel level. We noted high risk of attrition bias in one study and were unclear about potential bias introduced in two studies with differences between participants at baseline.It was not appropriate to combine data owing to differences in measurement tools, or methods used to report data.The effects of melatonin on subjectively rated quantity and quality of sleep are uncertain (very low certainty evidence). Three studies (139 participants) reported quantity and quality of sleep as measured through reports of participants or family members or by personnel assessments. Study authors in one study reported no difference in sleep efficiency index scores between groups for participant assessment (using Richards-Campbell Sleep Questionnaire) and nurse assessment. Two studies reported no difference in duration of sleep observed by nurses.The effects of melatonin on objectively measured quantity and quality of sleep are uncertain (very low certainty evidence). Two studies (37 participants) reported quantity and quality of sleep as measured by polysomnography (PSG), actigraphy, bispectral index (BIS) or electroencephalogram (EEG). Study authors in one study reported no difference in sleep efficiency index scores between groups using BIS and actigraphy. These authors also reported longer sleep in participants given melatonin which was not statistically significant, and improved sleep (described as "better sleep") in participants given melatonin from analysis of area under the curve (AUC) of BIS data. One study used PSG but authors were unable to report data because of a large loss of participant data.One study (82 participants) reported no evidence of a difference in anxiety scores (very low certainty evidence). Two studies (94 participants) reported data for mortality: one study reported that overall one-third of participants died; and one study reported no evidence of difference between groups in hospital mortality (very low certainty). One study (82 participants) reported no evidence of a difference in length of ICU stay (very low certainty evidence). Effects of melatonin on adverse events were reported in two studies (107 participants), and are uncertain (very low certainty evidence): one study reported headache in one participant given melatonin, and one study reported excessive sleepiness in one participant given melatonin and two events in the control group (skin reaction in one participant, and excessive sleepiness in another participant).The certainty of the evidence for each outcome was limited by sparse data with few participants. We noted study limitations in some studies due to high attrition and differences between groups in baseline data; and doses of melatonin varied between studies. Methods used to measure data were not consistent for outcomes, and use of some measurement tools may not be effective for use on the ICU patient. All studies included participants in the ICU but we noted differences in ICU protocols, and one included study used a non-standard sedation protocol with participants which introduced indirectness to the evidence.

AUTHORS' CONCLUSIONS

We found insufficient evidence to determine whether administration of melatonin would improve the quality and quantity of sleep in ICU patients. We identified sparse data, and noted differences in study methodology, in ICU sedation protocols, and in methods used to measure and report sleep. We identified five ongoing studies from database and clinical trial register searches. Inclusion of data from these studies in future review updates would provide more certainty for the review outcomes.