Post-operative acute kidney injury in non-suprainguinal vascular surgery patients with a pre-operative history of hypertension

Hypertension is an independent predictor of acute kidney injury (AKI) in non-cardiac surgery patients. There are a few published studies which report AKI following non-suprainguinal vascular procedures, but these studies have not investigated predictors of AKI, including anti-hypertensive medications and other comorbidities, in the hypertensive population alone. We sought to identify independent predictors of post-operative AKI in non-suprainguinal vascular surgery patients with a pre-operative history of hypertension. We performed univariate (chi-squared, or Fisher’s exact testing) and multivariate (binary logistic regression) statistical analysis of prospectively collected data from 243 adult hypertensive patients who underwent non-suprainguinal vascular surgery (lower limb amputation or peripheral artery bypass surgery) at a tertiary hospital between 2008 and 2011 in an attempt to identify possible associations between comorbidity, acute pre-operative antihypertensive medication administration, and post-operative AKI (a post-operative increase in serum creatinine of ≥ 25 % above the pre-operative measurement) in these patients. The incidence of post-operative AKI in this study was 5.3 % (95 % Confidence Interval: 3.2-8.9 %). Acute pre-operative β-blocker administration was independently associated with post-operative AKI in non-suprainguinal vascular surgery patients with a pre-operative history of hypertension (Odds Ratio: 3.24; 95 % Confidence Interval: 1.03-10.25). The acute pre-operative administration of β-blockers should be carefully considered in non-suprainguinal vascular surgery patients with a pre-operative history of hypertension, in lieu of an increased risk of potentially poor post-operative renal outcomes

The association between preoperative clinical risk factors and in-hospital strokes and death following carotid endarterectomy in South African patients

Background: Current surgical management of carotid artery disease includes carotid endarterectomy (CEA). In-hospital strokes and death following CEA might be associated with preinduction blood pressure (BP) measurements and other clinical risk factors.Method: The aim of our study was to determine whether or not there is an association between preinduction BP, other clinical risk factors, and in-hospital strokes or death following CEA in a cohort of South African patients. We collected data from medical records relating to clinical risk factors in patients, preinduction BP measurements, and in-hospital strokes and death, following CEA. The association between preinduction BP and clinical risk factors, and postoperative neurological morbidity and mortality, was analysed using univariate statistical methods.Results: Our cohort consisted of 76 patients who underwent CEA. Eight of these patients had in-hospital strokes or death following their surgery. An association between a history of hypertension or other clinical risk factors and an in-hospital stroke and death was not identified in these 76 CEA patients following univariate analysis. However, patients with preinduction BP within the lowest or highest quartile for preinduction BP were at a significantly increased risk of an in-hospital stroke and death following their surgery (p-value = 0.003). A subanalysis of patients who were hypertensive also showed this univariate association (p-value = 0.003).Conclusion: It is possible that extremes of preinduction BP might be associated with in-hospital strokes and death in CEA patients following their surgery, although further research is required to confirm this.Keywords: carotid endarterectomy, carotid stenosis, mortality, strokes, surger

The pharmacoeconomics of routine postoperative troponin surveillance to prevent and treat myocardial infarction after non-cardiac surgery

BACKGROUND: A postoperative troponin leak that was previously considered clinically insignificant has been independently associated with 30-day mortality in unselected surgical patients 45 years of age following non-cardiac surgery. OBJECTIVES: To determine whether routine troponin surveillance following non-cardiac surgery and initiation of aspirin and statin therapy in troponin-positive patients is cost-effective. METHODS: Pharmacoeconomic analysis to determine the cost-effectiveness of routine postoperative surveillance for patients aged 45 years undergoing non-cardiac surgery. We compared the total expected cost of hospital care of patients who received routine troponin surveillance and subsequent introduction of statin and aspirin therapy for 30 days in troponin-positive patients with the cost of hospital care of patients who did not receive troponin surveillance. We estimated a 25% relative risk reduction following statin and aspirin therapy for postoperative vascular mortality and non-fatal myocardial infarction. RESULTS: Routine troponin surveillance with initiation of aspirin and statin therapy was cost-effective, with an incremental cost of -R16 724 per event avoided. CONCLUSION: Routine postoperative troponin surveillance in non-cardiac surgical patients 45 years of age requiring a postoperative night in hospital is potentially cost-effective

Indications, Challenges, and Characteristics of Successful Implementation of Perioperative Registries in Low Resource Settings: : A Systematic Review

Acknowledgements The authors would like to thank Ms. Dilshaad Brey for her assistance during the database searches and in organising the search results. UCT Division of Global Surgery and Prof Maswime’s SA MRC Mid-career Scientist Award for partially funding this study. Funding Open access funding provided by University of Cape Town. This study was partially funded by the University of Cape Town Department of Global Surgery, and the Network for Perioperative and Critical Care (N4PCc).Peer reviewedPublisher PD

Natriuretic peptide-directed medical therapy: a systematic review

Abstract Natriuretic peptides (NP) are strongly associated with perioperative cardiovascular events. However, in patients with raised NP, it remains unknown whether treatment to reduce NP levels prior to surgery results in better perioperative outcomes. In this systematic review and meta-analysis, we investigate NP-directed medical therapy in non-surgical patients to provide guidance for NP-directed medical therapy in surgical patients. The protocol was registered with PROSPERO (CRD42017051468). The database search included MEDLINE (PubMed), CINAHL (EBSCO host), EMBASE (EBSCO host), ProQuest, Web of Science, and Cochrane database. The primary outcome was to determine whether NP-directed medical therapy is effective in reducing NP levels within 6 months, compared to standard of care. The secondary outcome was to determine whether reducing NP levels is associated with decreased mortality. Full texts of 18 trials were reviewed. NP-directed medical therapy showed no significant difference compared to standard care in decreasing NP levels (standardized mean difference − 0.04 (− 0.16, 0.07)), but was associated with a 6-month (relative risk (RR) 0.82 (95% confidence interval (CI) 0.68–0.99)) reduction in mortality

The pharmacoeconomics of routine postoperative troponin surveillance to prevent and treat myocardial infarction after non-cardiac surgery

Background. A postoperative troponin leak that was previously considered clinically insignificant has been independently associated with 30-day mortality in unselected surgical patients ≥45 years of age following non-cardiac surgery.Objectives. To determine whether routine troponin surveillance following non-cardiac surgery and initiation of aspirin and statin therapy in troponin-positive patients is cost-effective.Methods. Pharmacoeconomic analysis to determine the cost-effectiveness of routine postoperative surveillance for patients aged ≥45 years undergoing non-cardiac surgery. We compared the total expected cost of hospital care of patients who received routine troponin surveillance and subsequent introduction of statin and aspirin therapy for 30 days in troponin-positive patients with the cost of hospital care of patients who did not receive troponin surveillance. We estimated a 25% relative risk reduction following statin and aspirin therapy for postoperative vascular mortality and non-fatal myocardial infarction.Results. Routine troponin surveillance with initiation of aspirin and statin therapy was cost-effective, with an incremental cost of –R16 724 per event avoided. Conclusion. Routine postoperative troponin surveillance in non-cardiac surgical patients ≥45 years of age requiring a postoperative night in hospital is potentially cost-effective

The role of cardiac rehabilitation using exercise to decrease natriuretic peptide levels in non-surgical patients: a systematic review

Abstract Exercise is recommended in patients with cardiac failure. In the perioperative patient, exercise is also gaining popularity as a form of prehabilitation. In this meta-analysis, we examine if exercise is able to reduce natriuretic peptide levels. Natriuretic peptide (NP) has strong prognostic ability in identifying patients who will develop adverse postoperative cardiovascular outcomes. The protocol was registered with PROSPERO (CRD42017051468). The database search included MEDLINE (PubMed), CINAHL (EBSCO host), EMBASE (EBSCO host), ProQuest, Web of Science, and Cochrane database. The primary outcomes were to determine whether exercise therapy was effective in reducing NP levels as compared to control group, the shortest time period required to reduce NP levels after exercise therapy, and whether reducing NP levels decreased morbidity and mortality. Full texts of 16 trials were retrieved for this review. Exercise therapy showed a significant reduction in natriuretic peptide levels between the intervention and control groups (SMD − 0.45, 95% CI − 0.88 to − 0.03) with significant heterogeneity between the included trials. This was also shown in the within a 12-week period

The African surgical outcomes-2 (Asos-2) pilot trial, a mixed-methods implementation study

Funding Information: The ASOS-2 Pilot Trial was supported by a grant (OPP#1161108) from the Bill & Melinda Gates Foundation.Peer reviewe