Taking an idea to a research protocol

We present a nine-step process to assist with developing an idea into a research protocol. This process ensures that evidence-based medicine practice is followed to prevent redundant research questions. The first step is to identify broad research ideas with a potentially “weak” evidence base, rather than starting with a specific research question. The second step is to identify the knowledge gap within the intended field of research by examining the background literature. Thirdly, the focus will be on the “foreground knowledge” needed to frame a potential research question. The fourth step uses this potential research question to conduct a comprehensive literature research, and aims to determine whether or not the question has been asked before. The fifth step entails writing a study one-page summary which provides a succinct summary of what is intended. The sixth step involves writing the protocol. The rigid process of protocol writing will ensure that a number of important practical study issues are dealt with timeously. The seventh step is to discuss the protocol with experts. Their input will make the protocol more robust. The eighth step necessitates making a “social contract” that requires public commitment to the project. The final step is to write a grant application for the study. This serves to allow the researcher to identify the funding priorities of potential grant-funding agencies, thereby allowing the researcher to frame his or her research in such a manner that the financial support necessary for the success of the project will hopefully be ensured.Keywords: research; anaesthesia; protoco

Postoperative atrial fibrillation in patients on statins undergoing isolated cardiac valve surgery: a meta-analysis

Introduction: The efficacy of perioperative statin therapy in decreasing postoperative morbidity in patients undergoing valve replacements and repairs is unknown. The aim of our study was to determine whether or not the literature supports the hypothesis that statins decrease postoperative atrial fibrillation (AF), and hence improve short-term postoperative outcomes in patients undergoing isolated cardiac valve surgery.Method: We conducted a meta-analysis of studies on postoperative outcomes associated with statin therapy following isolated valve replacement or repair. The data was taken from published studies on valvular heart surgery patients. Participants were patients who underwent either isolated cardiac valve replacement or repair. Patients in the intervention group received statins prior to their surgery. Three databases were searched: Ovid Healthstar, 1966 to April 2012; Ovid Medline, 1946 to 31 May 2012; and Embase, 1974 to 30 May 2012. The meta-analysis was conducted using Review Manager® version 5.1.Results: Statins did not decrease the incidence of postoperative AF in patients undergoing isolated cardiac valve surgery [odds ratio (OR) 1.19, 95% confidence interval (CI): 0.80– 1.77)], although there was significant heterogeneity for the outcome of postoperative AF (I2 55%, 95% CI: 27–72). Statins were associated with a decrease in 30-day mortality (OR 0.43, 95% CI: 0.24–0.75).Conclusion: Although this meta-analysis suggests that chronic statin therapy did not prevent postoperative AF in unselected valvular heart surgical patients, the heterogeneity indicates that this outcome should be viewed with caution and further research is recommended.Keywords: atrial fibrillation, cardiac surgery, statin

Obstetric spinal hypotension: Preoperative risk factors and the development of a preliminary risk score – the PRAM score

Background. Obstetric spinal hypotension is a common and important problem during caesarean delivery. Identifying patients at risk for hypotension may guide clinical decision-making and allow timeous referral.Objective. Using preoperative risk factors, to develop a simple scoring system to predict systolic hypotension.Methods. This prospective, single-centre, observational study of patients undergoing elective or urgent caesarean delivery assessed body mass index, baseline heart rate, baseline mean arterial pressure (MAP), maternal age, urgency of surgery (elective v. non-elective) and preoperative haemoglobin concentration as predictors of spinal hypotension (systolic blood pressure <90 mmHg). We used empirical cut-point estimations in a logistic regression model to develop a scoring system for prediction of hypotension.Results. From 504 eligible patients, preoperative heart rate (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.00 - 1.03; p=0.012), preoperative MAP (OR 0.97, 95% CI 0.95 - 0.98; p<0.001) and maternal age (OR 1.05, 95% CI 1.02 - 1.08; p=0.002) were found to be predictors of hypotension. We derived a preliminary scoring system (pulse rate >90 bpm, age >25 years, MAP <90 mmHg – the PRAM score) for the prediction of systolic hypotension following obstetric spinal anaesthesia. Patients with three factors had a 53% chance of developing hypotension, compared with the overall incidence of 30%. The PRAM score showed good discrimination, with a c-statistic of 0.626 (95% CI 0.576 - 0.676) and good calibration.Conclusions. Preoperative heart rate, preoperative MAP and maternal age were predictive of hypotension in elective and emergency caesarean delivery. The PRAM score shows promise as a simple, practical means to identify these patients preoperatively, but requires prospective validation.

A prospective observational study of preoperative natriuretic peptide testing in adult non-cardiac surgical patients in hospitals in Western Cape Province, South Africa

Background. International guidelines recommend risk stratification to identify high-risk non-cardiac surgical patients. It is also recommended that all patients aged ≥45 years with significant cardiovascular disease should have preoperative natriuretic peptide (NP) testing. Abnormal preoperative B-type NPs have a strong association with postoperative cardiac complications. In South African hospitals, it is not known how many patients with significant cardiovascular disease scheduled for intermediate- to high-risk surgery will have raised NPs.Objectives. To determine the prevalence of abnormal (raised) NPs in non-cardiac surgical patients with cardiac clinical risk factors. A secondary objective was to develop a model to identify surgical patients who may benefit from preoperative NP screening.Methods. The inclusion criteria were patients aged ≥45 years presenting for elective, non-obstetric, intermediate- to high-risk non-cardiac surgery with at least one of the following cardiovascular risk factors: a history of ischaemic heart disease or peripheral vascular disease (coronary equivalent); a history of stroke or transient ischaemic attack; a history of congestive cardiac failure; diabetes mellitus currently on an oral hypoglycaemic agent or insulin; and serum creatinine level >175 µmol/L (>2.0 mg/dL). Blood samples for N-terminal-prohormone B-type NP (NT-proBNP) were collected before induction of anaesthesia. The preoperative prognostic threshold for abnormal (raised) NT-proBNP was ≥300 pg/mL. A generalised linear mixed model was used to determine the association between the risk factors and an abnormal NT-proBNP level.Results. Of 172 patients, 63 (37%) had an elevated preoperative NT-proBNP level. The comorbidities independently associated with elevated preoperative NT-proBNP were coronary artery disease or peripheral vascular disease, congestive cardiac failure, diabetes mellitus, and a creatinine level >175 µmol/L.Conclusions. We strongly recommend that non-cardiac surgical patients aged ≥45 years undergoing intermediate- or high-risk non-cardiac surgery with a history of coronary artery disease/peripheral vascular disease, congestive cardiac failure, diabetes mellitus or elevated creatinine have preoperative NP testing as part of risk stratification

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

South African Paediatric Surgical Outcomes Study : a 14-day prospective, observational cohort study of paediatric surgical patients

BACKGROUND : Children comprise a large proportion of the population in sub-Saharan Africa. The burden of paediatric surgical disease exceeds available resources in Africa, potentially increasing morbidity and mortality. There are few prospective paediatric perioperative outcomes studies, especially in low- and middle-income countries (LMICs). METHODS : We conducted a 14-day multicentre, prospective, observational cohort study of paediatric patients (aged <16 yrs) undergoing surgery in 43 government-funded hospitals in South Africa. The primary outcome was the incidence of in-hospital postoperative complications. RESULTS : We recruited 2024 patients at 43 hospitals. The overall incidence of postoperative complications was 9.7% [95% confidence interval (CI): 8.4–11.0]. The most common postoperative complications were infective (7.3%; 95% CI: 6.2–8.4%). In-hospital mortality rate was 1.1% (95% CI: 0.6–1.5), of which nine of the deaths (41%) were in ASA physical status 1 and 2 patients. The preoperative risk factors independently associated with postoperative complications were ASA physcial status, urgency of surgery, severity of surgery, and an infective indication for surgery. CONCLUSIONS : The risk factors, frequency, and type of complications after paediatric surgery differ between LMICs and high-income countries. The in-hospital mortality is 10 times greater than in high-income countries. These findings should be used to develop strategies to improve paediatric surgical outcomes in LMICs, and support the need for larger prospective, observational paediatric surgical outcomes research in LMICs. CLINICAL TRIAL REGISTRATION : NCT03367832.Jan Pretorius Research Fund; Discipline of Anaesthesiology and Critical Care, Nelson R Mandela School of Medicine, University of KwaZulu-Natal; Department of Anaesthesia and Perioperative Medicine, Groote Schuur Hospital and University of Cape Town; Department of Anaesthesia, University of the Witwatersrand; and the Paediatric Anaesthesia Community of South Africa (PACSA).https://bjanaesthesia.org2020-02-01gl2019Anaesthesiolog

Correlation between different methods of intraabdominal pressure monitoring in varying intraabdominal hypertension models

Background. Advances in intra-abdominal pressure (IAP) measurement have enabled better monitoring and physiological manipulation of patients with intra-abdominal hypertension or abdominal compartment syndrome. This study aimed to determine the correlation between transvesical (TV), transgastric (TG) and direct transperitoneal (TP) IAP monitoring at different IAPs in porcine models.Objectives. To assess the statistical agreement between TV, TG and TP pressure monitoring in a pneumoperitoneum and an intestinal obstruction intra-abdominal hypertension model at different IAPs.Methods. Fifty-nine pigs were divided into six groups: a control group (Cr; n=5), three pneumoperitoneum groups at pressures of 20 mmHg, 30 mmHg, and 40 mmHg (Pn20, Pn30, Pn40; n=40), and two intestinal-occlusion groups at pressures of 20 mmHg and 30 mmHg (Oc20, Oc30; n=14). IAP was simultaneously measured in each pig using the three methods at different times. The control group did not have any intervention to increase the IAP. Intra-class correlation was used to assess agreement between the methods.Results. At pressures &gt;20 mmHg, all three methods showed good correlation with each other (Pn20=0.87; Pn30=0.96; Pn40=0.88; Oc20=0.69; Oc30=0.86). Correlation between TP and TG (Cr=0.0; Pn20=0.85; Pn30=0.94; Pn40=0.90; Oc20=0.78; Oc30=0.78); TP and TV (Cr=0.0; Pn20=0.83; Pn30=0.95; Pn40=0.86; Oc20=0.59; Oc30=0.88); and importantly between TV and TG (Cr=0.0; Pn20=0.95; Pn30=0.98; Pn40=0.88; Oc20=0.69; Oc30=0.91) was good.Conclusion. All three measurement methods showed good correlation at pressures &gt;20 mmHg and were unaffected by the type of IAP model. These results suggest that either transvesical or transgastric pressure measurements can be used for IAP measurement when TP pressures are &gt;20 mmHg

The influence of clinical risk factors on pre-operative B-type natriuretic peptide risk stratification of vascular surgical patients

The role of the revised cardiac risk index in risk stratification has recently been challenged by studies reporting on the superior predictive ability of pre-operative B-type natriuretic peptides. We found that in 850 vascular surgical patients initially risk stratified using B-type natriuretic peptides, reclassification with the number of revised cardiac risk index risk factors worsened risk stratification (p?>?0.05 for <?0, <?2, <?3 and <?4 risk factors, and p?=?0.23 for <?1 risk factor). When evaluated with pre-operative B-type natriuretic peptides, none of the revised cardiac risk index risk factors were independent predictors of major adverse cardiac events in vascular patients. The only independent predictor was B-type natriuretic peptide stratification (OR 5.1, 95% CI 1.8-15 for the intermediate class, and OR 25, 95% CI 8.7-70 for the high-risk class). The clinical risk factors in the revised cardiac risk index cannot improve a risk stratification model based on B-type natriuretic peptides