Pharmacologic myocardial protection in patients undergoing noncardiac surgery: a quantitative systematic review

A number of drugs have been tested in clinical trials to decrease cardiac complications in patients undergoing noncardiac surgery. To compare the results of these studies, we conducted a quantitative systematic review. Medline, Embase, and Cochrane databases were searched for randomized trials that assessed myocardial ischemia, myocardial infarction, 30-day cardiac mortality, and adverse effects. Data were combined using a fixed-effect model and expressed as Peto odds ratios (OR) with 95% confidence interval (CI) and as numbers-needed-to-treat/harm (NNT/H). Twenty-one trials involving 3646 patients were included: 11 trials using beta-blockers (6 drugs; 866 patients), 6 clonidine or mivazerol (614 patients), 3 diltiazem or verapamil (121 patients), and 1 nitroglycerin (45 patients). All trials had an inactive control; there were no direct comparisons. beta-blockers decreased ischemic episodes during surgery (7.6% versus 20.2% with placebo; OR 0.32 [95% CI, 0.17-0.58]; NNT 8) and after surgery (15.2% versus 27.9% with control; OR 0.46 [95% CI, 0.26-0.81]; NNT 8). alpha(2)-agonists decreased ischemia during surgery only (19.4% versus 32.8%; OR 0.47 [95% CI, 0.33-0.68]; NNT 7). beta-blockers reduced the risk of myocardial infarction (0.9% versus 5.2%; OR 0.19 [95% CI, 0.08-0.48]; NNT 23) but only when 2 trials with high-risk patients were included. The effect of alpha(2)-agonists on myocardial infarction was not significant (6.1% versus 7.3%; OR 0.85 [95% CI, 0.62-1.14]). beta-blockers significantly decreased the risk of cardiac death from 3.9% to 0.8% (OR 0.25 [95% CI, 0.09-0.73], NNT 32). alpha(2)-agonists significantly decreased the risk of cardiac death from 2.3% to 1.1% (OR 0.50 [95% CI, 0.28-0.91], NNT 83). For calcium channel blockers and nitroglycerin, evidence of any benefit was lacking. The most common adverse effect was bradycardia, which occurred in 24.5% of patients receiving a beta adrenergic blocker versus 9.1% of controls (OR 3.76 [95% CI, 2.45-5.77], NNH 6).     

Prevention of contrast-induced nephropathy in vascular patients undergoing angiography: a randomized controlled trial of intravenous N-acetylcysteine

OBJECTIVE(S): Apart from proper hydration, only oral N-acetylcysteine (NAC) has shown efficacy in reducing radiographic contrast media (RCM)-induced acute renal failure, though its benefit has been challenged. We investigated the effect of intravenous (i.v.) NAC on renal function in patients with vascular disease receiving RCM for angiography. METHODS: Single-center, randomized, double-blind, placebo-controlled trial. Based on a previous study, a trial with 44 patients each in placebo and treatment arms would give at least 80% power to show a statistically significant difference at the 5% level. Vascular patients undergoing angiography were consented and segregated into those whose serum creatinine (SC) level was normal or raised (men >1.32 mg/dl; women >1.07 mg/dL). All patients received 500 mL i.v. normal saline 6 to 12 hours prior to and then after angiography. Groups with normal SC and raised SC were randomly assigned to either 1 g of NAC with normal saline before and after angiography or nothing (placebo). Main outcome measures were change in SC and creatinine clearance (CrCl) as measured 1, 2, and 7 days postangiography (with comparison between active and placebo groups using unpaired t test) and incidence of acute renal decline (>25% or 0.5 mg/dL rise in SC) at 48 hours (with comparison between active and placebo using the Fisher exact test). RESULTS: Forty-six patients received NAC (29 normal SC, 17 raised SC), and 48 received placebo (27 normal SC, 21 raised SC). There was no significant difference in postangiography SC or CrCl at any of the time points measured between NAC and placebo in patients with either normal or raised SC. In the raised SC group, 3 patients from both the NAC and placebo groups suffered acute renal declines. Importantly, at 48 hours, the impaired SC group had a significant reduction in CrCl (-14% +/- 41% vs +18% +/- 58%: P = .0142) and a significant rise in SC (+7.0 +/- 25% vs -1.6% +/- 10%; P = .0246) when compared with the normal SC group. CONCLUSIONS: NAC (i.v. at 1 g) precontrast and postcontrast does not confer any benefit in preventing RCM-induced nephropathy in vascular patients. Patients with pre-existing raised SC have an increased risk of renal impairment as defined by a fall in CrCl and a rise in SC post-RCM when compared with patients with normal SC who appear to benefit from hydration.     

Preoperative coronary revascularization in high-risk patients undergoing vascular surgery: a core review

Patients undergoing vascular surgery are at increased risk for cardiac complications related to the presence of underlying coronary artery disease. Preoperative cardiac evaluation may help to identify high-risk patients in whom coronary angiography may be planned with subsequent coronary revascularization for the purpose of improving perioperative and long-term cardiac outcomes. However, the indications and efficacy for type of revascularization for the reduction of cardiac complications compared to medical therapy has been controversial. My aim in this review is to summarize the role of preoperative revascularization compared to conservative medical therapy before elective vascular surgery using current evidence from published studies.     

Frailty adversely affects outcomes of patients undergoing spine surgery: a systematic review

BackgroundWith an aging population, there are an increasing number of elderly patients undergoing spine surgery. Recent literature in other surgical specialties suggest frailty to be an important predictor of outcomes.PurposeThe aim of this review was to examine the association between frailty and outcomes after spine surgery.Study DesignA systematic review was performed.Patient SampleElectronic databases from 1946 to 2020 were searched to identify articles on frailty and spine surgery.Outcome MeasuresThe primary outcome was adverse events. Secondary outcomes included other measures of morbidity, mortality, and patient outcomes.MethodsSample size, mean age, age limitation, data source, study design, primary pathology, surgical procedure performed, follow-up period, assessment of frailty used, surgical outcomes, and impact of frailty on outcomes were extracted from eligible studies. Quality and bias were assessed using the PRISMA 27-point item checklist and the QUADAS-2 tool.ResultsThirty-two studies were selected for review, with a total of 127,813 patients. There were eight different frailty indices/measures. Regardless of how frailty was measured, frailty was associated with an increased risk of adverse events, mortality, extended length of stay, readmission, and nonhome discharge.ConclusionThere is strong evidence that frailty is associated with an increased risk of morbidity and mortality in patients who received spine surgery. However, it remains inconclusive whether frailty impacts patient outcomes and quality of life after surgery.     

Preoperative intra-aortic balloon pump in patients undergoing coronary bypass surgery: a systematic review and meta-analysis

OBJECTIVES: To assess the effectiveness of preoperative intra-aortic balloon pump (IABP) placement in high-risk patients undergoing coronary bypass surgery (CABG). The primary outcome was hospital mortality and secondary outcomes were IABP-related complications (bleeding, leg ischemia, aortic dissection). METHODS: MEDLINE, EMBASE, Cochrane registry of Controlled Trials, and reference lists of relevant articles were searched. We included randomized controlled trials (RCTs), and cohort studies that fulfilled our a priori inclusion criteria. Eligibility decisions, relevance, study validity, and data extraction were performed in duplicate using pre-specified criteria. Meta-analysis was conducted using a random effects model. RESULTS: Ten publications fulfilled our eligibility criteria, of which four were RCTs and six were cohort studies with controls. There were statistical as well as clinical heterogeneity among included studies. A total of 1034 patients received preoperative IABP and 1329 did not receive preoperative IABP. The pooled odds ratio (OR) for hospital mortality in patients treated with preoperative IABP was 0.41 (95% CI, 0.21-0.82, p = 0.01). The number needed to treat was 17. The pooled OR for hospital mortality from randomized trials was 0.18 (95% CI, 0.06-0.57, p = 0.003) and from cohort studies was 0.54 (95% CI, 0.24-1.2, p = 0.13). Overall, 3.7% (13 of 349) of patients who received preoperative IABP developed either limb ischemia or haematoma at the IABP insertion site, and most of these complications improved after discontinuation of IABP. CONCLUSION: Evidence from this meta-analysis support the use of preoperative IABP in high-risk patients to reduce hospital mortality.     

Liberal or restrictive fluid management during elective surgery: a systematic review and meta-analysis

This article reviews if a restrictive fluid management policy reduces the complication rate if compared to liberal fluid management policy during elective surgery. The PubMed database was explored by 2 independent researchers. We used the following search terms: “Blood transfusion (MESH); transfusion need; fluid therapy (MESH); permissive hypotension; fluid management; resuscitation; restrictive fluid management; liberal fluid management; elective surgery; damage control resuscitation; surgical procedures, operative (MESH); wounds (MESH); injuries (MESH); surgery; trauma patients.” A secondary search in the Medline, EMBASE, Web of Science, and Cochrane library revealed no additional results. We selected randomized controlled trials performed during elective surgeries. Patients were randomly assigned to a restrictive fluid management policy or to a liberal fluid management policy during elective surgery. The patient characteristics and the type of surgery varied. All but 3 studies reported American Society of Anaesthesiologists groups 1 to 3 as the inclusion criterion. The primary outcome of interest is total number of patients with a complication and the complication rate. Secondary outcome measures are infection rate, transfusion need, postoperative rebleeding, hospital stay, and renal function. In total, 1397 patients were analyzed (693 restrictive protocol, 704 liberal protocol). Meta-analysis showed that in the restrictive group as compared with the liberal group, fewer patients experienced a complication (relative risk [RR], 0.65; 95% confidence interval [CI], 0.55-0.78). The total complication rate (RR, 0.57; 95% CI, 0.52-0.64), risk of infection (RR, 0.62; 95% CI, 0.48-0.79), and transfusion rate (RR, 0.81; 95% CI, 0.66-0.99) were also lower. The postoperative rebleeding did not differ in both groups: RR, 0.76 (95% CI, 0.28-2.06). We conclude that compared with a liberal fluid policy, a restrictive fluid policy in elective surgery results in a 35% reduction in patients with a complication and should be advised as the preferred fluid management policy.     

Hydroxychloroquine in IgA nephropathy: a systematic review

BackgroundHydroxychloroquine (HCQ) has recently been reported to be a promising and safe anti-proteinuric agent for IgA nephropathy (IgAN) patients. In the present systematic review, we aimed to summarize the evidence concerning the benefits and risks of HCQ therapy in IgAN.MethodsElectronic databases were searched for randomized, cohort, or case-control studies with IgAN biopsy-proven patients comparing the effects of HCQ with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers or immunosuppression on proteinuria reduction.ResultsFive studies, one randomized and three observational, involving a total of 504 patients, were eligible for inclusion. Overall, there was a tendency of HCQ treatment to reduce proteinuria. In the studies where the control arm was supportive therapy, HCQ significantly reduced proteinuria at 6 months. However, in the studies that compared HCQ to immunosuppressive therapy, we found no difference in proteinuria reduction. HCQ had no impact on eGFR.ConclusionHCQ seems to be an efficient alternative therapy for patients with IgAN who insufficiently respond to conventional therapy. However, ethnically diverse randomized controlled studies with long-term follow-up are needed.     

Prognostic factors for morbidity and mortality in elderly patients undergoing acute gastrointestinal surgery: a systematic review

Background

Elderly patients undergoing acute gastrointestinal (GI) surgery experience increased morbidity and mortality compared with younger and elective patients. Prognostic factors can be used to counsel patients of these risks and, if modifiable, to minimize them. We reviewed the literature on prognostic factors for adverse outcomes in elderly patients undergoing acute GI surgery.

Methods

We searched PubMed and Embase using a strategy developed in collaboration with an expert librarian. Studies examining independent associations between prognostic factors and morbidity or mortality in patients aged 65 and older undergoing acute GI surgery were selected. We extracted data using a standardized form and assessed study quality using the QUIPS tool.

Results

Nine cohort studies representing 2958 patients satisfied our selection criteria. All studies focused on postoperative mortality. Thirty-four prognostic factors were examined, with significant variability across studies. There was limited or conflicting evidence for most prognostic factors. Meta-analysis was only possible for the American Society of Anesthesiologists (ASA) score, which was found to be associated with mortality in 4 studies (pooled odds ratio 2.77, 95% confidence interval 0.92–8.41). Conclusion: While acute GI surgery in elderly patients is becoming increasingly common, the literature on prognostic factors for morbidity and mortality in this patient population lags behind. Further research is needed to help guide patient care and potentially improve outcomes.     

Efficacy of probiotics in patients with morbid obesity undergoing bariatric surgery: a systematic review and meta-analysis

Bariatric surgery is considered effective for morbid obesity, and probiotic supplementation might provide some benefits. We aimed to revise the evidence regarding probiotic supplementation in patients with morbid obesity undergoing bariatric surgery. MEDLINE, Embase, Web of Science, CENTRAL, and trial registers were searched up to April 1, 2020. We included randomized controlled trials and controlled clinical trials, and outcomes of interest were weight change, quality of life, gastrointestinal symptoms, and adverse events. All stages of the review were done by 2 authors independently and we followed Cochrane Handbook guidance. We screened 2541 references and included 5 studies. Probiotics may have minor to no effect regarding percentage excess weight loss (%EWL) at 6 weeks (mean difference [MD], .28; 95% CI, −9.53 to 10.09; 44 participants, 2 studies), 3 months (MD, 5.47; 95% CI, −3.22 to 14.17; 165 participants, 3 studies), 6 months (MD, .46; 95% CI, −8.14 to 9.07; 115 participants, 2 studies), and 12 months post surgery (MD, .35; 95% CI, −8.66 to 9.37; 123 participants, 2 studies). We observed short-term improvement in gastrointestinal symptoms. There was no important effect on quality of life and no meaningful adverse events. Because probiotic supplementation might provide some benefit with respect to weight loss, might alleviate some gastrointestinal symptoms, and is associated with minor or no adverse events, continuous supplementation might be worth considering in certain individuals. Our findings are based on the body of evidence of very low certainty, and further well-designed randomized controlled trials are required to elucidate the effect and strengthen the certainty in the estimates.     

Prioritizing patients for elective surgery: a systematic review

Background: Priority scoring tools are mooted as means for dealing with burgeoning elective surgical waiting lists. There is ongoing development work in New Zealand, Canada and the UK. This emerging international perspective is invaluable in determining the application of these tools and addressing any pitfalls. Methods: A systematic electronic literature review was performed. Information was also retrieved using a search of reference lists of all papers included in the review and contact with those who were involved in the development of such criteria. Results: The ethical basis of prioritization differed among priority scoring tools and in a number was not stated. The majority of tools covered criteria for specific procedures. Delphi consensus methods and regression were the predominant methods for ­deter­mining ­specific criteria. Authors’ opinions were the main source of generic criteria. Linear and non‐linear models or matrices sum­mated criteria. Conclusion: There is debate over the ethical basis for prioritization. It is a concern that it is not addressed in many studies. The development of generic criteria showed a dearth of consensus approaches that represents a significant gap in our knowledge. On the aspects of summation and weighting, the impact of assumptions on the prioritization of patients may not have been fully explored.     

Preoperative assessment and prehabilitation in patients with obesity undergoing non-bariatric surgery: A systematic review

Study objectiveThe optimal methods of preoperative assessment and prehabilitation specific to patients with obesity undergoing non-bariatric surgery have not been described. We investigated two questions: 1) which methods of preoperative assessment in patients with obesity are associated with improved patient management, and 2) which methods of prehabilitation in patients with obesity are associated with improved patient outcomes?DesignSystematic review.SettingPreoperative assessment and optimisation, and postoperative outcomes.PatientsPatients with obesity scheduled for surgery of any type.InterventionsWe searched six electronic databases for clinical studies addressing either preoperative assessment or preoperative optimisation.MeasurementsThe primary outcome measure for the assessment review was any impact on preoperative disease diagnosis or progression, or postoperative complications. The primary outcome measure for the prehabilitation review was any postoperative change in disease or health status, or any medical or surgical complications.Main resultsTwenty one papers were included in the assessment review (total of 5090 participants) and twenty five for prehabilitation (30,170 participants). Approximately two thirds of papers reported on bariatric surgery populations. In the assessment review, studies reported on either the preoperative detection of comorbidities or the prediction of postoperative complications. The only assessment tool with any suggestion of benefit was polysomnography. A range of methods of prehabilitation were found for question 2. Forty eight percent of papers reported improvement in some or all study outcomes. The most successful intervention was exercise, with 4 of 5 exercise-based trials showing improvement in either some or all postoperative outcomes.ConclusionsThere is a limited body of work addressing preoperative assessment and prehabilitation specific to surgical patients with obesity, especially when undergoing non-bariatric surgery. Preoperative polysomnography was shown to improve both the diagnosis of obstructive sleep apnoea and the prediction of postoperative complications. Half of the prehabilitation studies showed evidence of benefit. From this review, we were unable to make strong recommendations as to best practice in patients with obesity presenting for non-bariatric surgery.     

Metal hypersensitivity testing in patients undergoing joint replacement: a systematic review

We report a systematic review and meta-analysis of the peer-reviewed literature focusing on metal sensitivity testing in patients undergoing total joint replacement (TJR). Our purpose was to assess the risk of developing metal hypersensitivity post-operatively and its relationship with outcome and to investigate the advantages of performing hypersensitivity testing. We undertook a comprehensive search of the citations quoted in PubMed and EMBASE: 22 articles (comprising 3634 patients) met the inclusion criteria. The frequency of positive tests increased after TJR, especially in patients with implant failure or a metal-on-metal coupling. The probability of developing a metal allergy was higher post-operatively (odds ratio (OR) 1.52 (95% confidence interval (CI) 1.06 to 2.31)), and the risk was further increased when failed implants were compared with stable TJRs (OR 2.76 (95% CI 1.14 to 6.70)). Hypersensitivity testing was not able to discriminate between stable and failed TJRs, as its predictive value was not statistically proven. However, it is generally thought that hypersensitivity testing should be performed in patients with a history of metal allergy and in failed TJRs, especially with metal-on-metal implants and when the cause of the loosening is doubtful.