Felix van Lier

Epidural Analgesia Is Associated with Improved Health Outcomes of Surgical Patients with Chronic Obstructive Pulmonary Disease

Background:Patients with chronic obstructive pulmonary disease (COPD) have increased postoperative morbidity and mortality. Epidural analgesia (EDA) improves postoperative outcome but may worsen postoperative lung function. It is unknown whether patients with COPD benefit from EDA. The objective of this study was to determine whether patients with COPD undergoing major abdominal surgery benefit from EDA in addition to general anesthesia. Methods:This cohort study included 541 consecutive patients with COPD who underwent major abdominal surgery between 1995 and 2007 at a university medical center. Propensity scores estimating the probability of receiving EDA were used in multivariate correction. The primary outcome was postoperative pneumonia and 30-day mortality. Results:There were 324 patients (60%) who received EDA in addition to general anesthesia. The incidence of postoperative pneumonia (16% vs. 11%; P = 0.08) and 30-day mortality (9% vs. 5%; P = 0.03) was lower in patients who received EDA. After correction EDA was associated with improved outcome for postoperative pneumonia (OR 0.5; 95% CI: 0.3–0.9; P = 0.03). The strongest preventive effect was seen in patients with the most severe type of COPD. Conclusion:This study provides evidence that in patients with COPD who are scheduled for major abdominal surgery, epidural analgesia decreases postoperative pulmonary complications.

Perioperative strokes and β-blockade

-blocker therapy was associated with an improved car- diac outcome, overall mortality was increased in the metoprolol-treated group. This was partially related to the increased incidence of postoperative stroke occur- ring early after surgery. These findings might have im- portant implications on perioperative -blocker use, not only for initiation of therapy before surgery in -blocker naive patients but also whether or not to continue ther- apy throughout surgery. This commentary reviews the incidence and pathophysiology of perioperative stroke and the relation of -blockers and perioperative stroke, focusing on noncardiac surgery. The risk of clinically apparent perioperative brain in- jury such as stroke varies widely among different types of surgery. Whereas patients undergoing general surgery appear to be at low risk (0.08 - 0.7%), those undergoing heart valve surgery and aortic arch repair have a high incidence of perioperative stroke (8 -10%). 2 In Europe, 40 million general surgical procedures are performed annually. Therefore, it is estimated that 32,000 -280,000 patients suffer from postoperative stroke. However, the true incidence of cerebral complications is probably underestimated because subtle forms of brain injury are commonly classified as delirium that may only be de- tected by rigorous neuropsychological testing. The knowledge of the pathophysiology of postopera- tive cerebral complications is predominantly based on cardiothoracic surgery patients. It is estimated that 62% of strokes in this population have an embolic origin, 10% are related to hypoperfusion, and 10% have multiple causes. 2 Importantly, only 1% of strokes are caused by intracerebral hemorrhage. However, it should be ac- knowledged that the true pathophysiological basis of perioperative stroke is not as straightforward as it might seem. Embolic and hypoperfusion cerebral infarction most likely do not occur in isolation. 3 Impaired clear- ance of emboli (washout) seems to be the link between hypoperfusion, embolism, and ischemic stroke. 4 Intra- operative microemboli and low middle cerebral artery blood flow velocity are additive in predicting develop- ment of cerebral ischemic events after carotid endarter- ectomy. 5 Second, newer data wherein sensitive diffusion weighted magnetic resonance imaging (MRI) was per- formed suggest that as many as two-thirds of postcardiac surgery strokes have watershed or hypoperfusion pat- tern. 6 Finally, what appears to be occurring in cardiac surgery patients is that there is a rising prevalence of mostly unrecognized cerebral vascular disease concur- rent with the rising age of our population. In fact, one study (that interestingly excluded patients with known cerebral vascular disease) found that as many as 75% of patients had evidence of impaired cerebral perfusion based on single photon emission computed tomography (SPECT) imaging before coronary artery bypass grafting (CABG) surgery. 7 Approximately 45% of perioperative strokes are iden- tified within the first day after surgery. The remaining 55% occur after uneventful recovery from anesthesia, from the second postoperative day onward. Early embo- lism results especially from manipulations of the heart and aorta or release of particulate matter from the car- diopulmonary-bypass pump. Delayed embolism is often attributed to postoperative atrial fibrillation, myocardial infarction resulting from an imbalance between myocar- dial oxygen supply and demand, and coagulopathy. Compared to stroke after cardiac surgery, the pathophys- iology of stroke after noncardiac surgery is ill defined. Perioperative hemodynamic instability and cardiac events, such as myocardial infarction and arrhythmias, likely play a major role. Recently, the POISE study identified a new risk factor for perioperative ischemic strokes: high-dose meto- prolol succinate initiated for cardiac protection in patients undergoing noncardiac surgery.

Effect of Chronic Beta-Blocker Use on Stroke After Noncardiac Surgery

The incidence of postoperative stroke ranges from 0.08% to 0.7% in noncardiac surgery. Recently, the PeriOperative ISchemic Evaluation (POISE) study reported an incidence of postoperative stroke of 1% in patients scheduled for noncardiac surgery when beta blockers were initiated immediately before surgery. To assess the association between chronic beta-blocker use and postoperative stroke in noncardiac surgery, we undertook a case-control study among 186,779 patients who underwent noncardiac surgery from 2000 to 2008 at the Erasmus Medical Centre. Patients who were undergoing intracerebral surgery or carotid surgery or who had head and/or carotid trauma were excluded. The case subjects were 34 patients (0.02%) who had experienced a stroke within 30 days after surgery. Of the remaining patients, 2 controls were selected for each case and were stratified according to calendar year, type of surgery, and age. For cases and controls, information was obtained regarding beta-blocker use before surgery, the presence of cardiac risk factors, and the use of other cardiovascular medication. The use of beta blockers was as common in the cases as in the controls (29% vs 29%; p = 1.0). The adjusted odds ratio for postoperative stroke among beta-blocker users compared with nonusers was 0.4 (95% confidence interval 0.1 to 1.5). Similar results were obtained in the subgroups of patients stratified according to the use of cardiovascular therapy and the presence of cardiac risk factors. In conclusion, the present case-control study has shown no increased risk of postoperative stroke in patients taking chronic beta-blocker therapy.

Impact of Prophylactic β-Blocker Therapy to Prevent Stroke After Noncardiac Surgery

beta Blockers are widely used to improve the postoperative cardiac outcome in patients with coronary artery disease scheduled for noncardiac surgery. However, recently serious concerns regarding the safety of perioperative beta blockers have emerged. To assess the incidence, risk factors, and beta-blocker use associated with postoperative stroke in the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE) trials, we evaluated all 3,884 patients of the DECREASE trials for postoperative stroke. All cardiac risk factors and medication use were assessed. The incidence of stroke within 30 days after surgery was recorded. The incidence of postoperative stroke in the DECREASE trials was 0.46% (18 of 3,884). For the beta-blocker users, the incidence was 0.5%. All the strokes had an ischemic origin. A history of stroke was associated with a greater incidence of postoperative stroke (odds ratio [OR] 3.79, 95% confidence interval [CI] 1.2 to 11.6). Statins and anticoagulants were not associated with postoperative stroke (OR 0.85, 95% CI 0.3 to 2.4; and OR 1.27, 95% CI 0.4 to 4.6, respectively). No association with bisoprolol therapy was found (OR 1.16, 95% CI 0.4 to 3.4). In conclusion, with a low-dose bisoprolol regimen started > or =30 days before surgery, no association was observed between beta-blocker use and postoperative stroke.

Impact of haemoglobin concentration on cardiovascular outcome after vascular surgery: a retrospective observational cohort study.

BACKGROUND Although low preoperative haemoglobin (Hb) concentration is a well known risk factor for adverse outcome, little is known about decreases in Hb and postoperative Hb concentrations. OBJECTIVES The aim of this study was to evaluate the prognostic impact of both pre- and postoperative Hb concentrations (divided into low, intermediate and high tertiles) as well as Hb decrease, defined as preoperative minus postoperative Hb (g dl−1), on postoperative cardiovascular events in vascular surgery patients. DESIGN A retrospective observational cohort study. SETTING Erasmus University Medical Centre, Rotterdam, the Netherlands, from 1 January 2002 to 31 December 2011. PATIENTS One thousand four hundred and eighty-four patients underwent elective open or endovascular abdominal aortic repair (aneurysm or stenosis), lower extremity arterial repair or carotid surgery. Patients for whom pre or postoperative Hb concentrations were not available were excluded. MAIN OUTCOME MEASURES The study endpoint was 30-day postoperative cardiovascular events, including myocardial infarction, heart failure, arrhythmias, stroke, asymptomatic troponin-T release and cardiovascular death. RESULTS In 1041 patients, both pre and postoperative Hb concentrations were available. Thirty-day cardiovascular events occurred in 221 (21%) patients. Multivariable logistic regression analyses, adjusting for age, sex, Revised Cardiac Risk Index (high-risk surgery, coronary heart disease, heart failure, cerebrovascular disease, diabetes mellitus, renal insufficiency), hypertension and hypercholesterolaemia, demonstrated that low preoperative Hb (8.7 to 12.9 g dl−1) was associated with 30-day events [odds ratio (OR) 1.7; 95% confidence interval (CI) 1.1 to 2.5]. Intermediate (10.6 to 12.1 g dl−1) and low (7.4 to 10.5 g dl−1) postoperative Hb and Hb decrease were also associated with an independently increased risk of 30-day events (intermediate Hb: OR 1.7; 95% CI 1.1 to 2.7; low Hb: OR 3.1; 95% CI 2.0 to 4.8; and Hb decrease: OR 1.2; 95% CI 1.1 to 1.3, respectively). Sensitivity analyses excluding patients with transfusions (n = 314) demonstrated that only postoperative Hb concentrations remained associated with a high risk of 30-day cardiovascular events (intermediate Hb: OR 1.8; 95% CI 1.0 to 3.3 and low Hb: OR 2.0; 95% CI 1.0 to 4.0). CONCLUSION Pre and postoperative Hb concentrations and Hb decrease are all related to 30-day cardiovascular events in elective vascular surgery patients. Postoperative Hb concentrations are the strongest predictor of 30-day cardiovascular events.

Effect of Major and Minor Surgery on Plasma Levels of Arginine, Citrulline, Nitric Oxide Metabolites, and Ornithine in Humans

Objective: To determine the effect of surgical invasiveness on plasma levels of arginine, citrulline, ornithine, and nitric oxide (NO) in humans. Background: Surgical trauma may have a profound effect on the metabolism of NO. However, human studies reported both increased and decreased NO levels after hemorrhagic shock. Arginine, citrulline, and ornithine are key amino acids involved in NO metabolism, but studies evaluating these amino acids together with NO and during 2 types of surgery are lacking. This study tests the hypothesis that major surgery has a more profound effect on plasma levels of arginine, citrulline, NO, and ornithine than minor surgery. Methods: Fifteen patients undergoing minor surgery (vulvectomy) and 13 patients undergoing major surgery (laparotomy) were prospectively followed up for 4 days. Plasma was collected for evaluation of levels of arginine, citrulline, NO, and ornithine. Results: Throughout the experiment, arginine levels did not significantly differ between experimental groups. Perioperative plasma citrulline levels were significantly lower in the laparotomy group than in the vulvectomy group, whereas both groups showed a decrease in citrulline levels at the end of the operation and 24 hours postoperatively. Roughly the same pattern was seen for plasma NO and ornithine levels. However, ornithine levels in the laparotomy group showed a more drastic decrease at the end of the operation and 24 hours postoperatively than citrulline and NO levels. Conclusions: The level of surgical invasiveness has the most profound effect on plasma levels of ornithine. In addition, heavier surgical trauma is paired with lower postoperative levels of citrulline and NO metabolites than lighter surgery. It is suggested that surgical trauma stimulates the laparotomy group to consume significantly more ornithine, possibly for use in wound healing.

One-Year Follow-Up After Hybrid Thoracoabdominal Aortic Repair: Potentially Important Issue for Preoperative Decision-Making

Background: Compared to open thoracoabdominal aortic aneurysm (TAAA) repair, hybrid repair is thought to be less invasive with better perioperative outcomes. Due to the extent of the operation and long recovery period, studying perioperative results may not be sufficient for evaluation of the true treatment effect. The aim of this study is to evaluate 1-year mortality and morbidity in patients with TAAA undergoing hybrid repair. Methods: In a retrospective cohort study, all medical records of patients undergoing hybrid repair for TAAA at the Erasmus University Medical Center between January 2007 and January 2015 were studied. Primary outcome measures were 30-day and 1-year mortality. Secondary outcome measures included major in-hospital postoperative complications. Results: A total of 15 patients were included. All-cause mortality was 33% (5 of the 15) at 30 days and 60% (9 of the 15) at 1 year. Aneurysm-related mortality was 33% (5 of the 15) and 53% (8 of the 15) at 30-day and 1-year follow-up, respectively, with colon ischemia being the most common cause of death. Major complication rate was high: myocardial infarction in 2 (13%) cases, acute kidney failure in 5 (33%) cases, bowel ischemia in 3 (20%) cases, and spinal cord ischemia in 1 (7%) case. Conclusion: The presumed less invasive nature of hybrid TAAA repair does not seem to result in lower complication rates. The high mortality rate at 30 days continues to rise dramatically thereafter, suggesting that 1-year mortality is a more useful clinical parameter to use in preoperative decision-making for this kind of repair.

Risk modification for postoperative pulmonary embolism: Timing of postoperative prophylaxis☆

INTRODUCTION Risk factors for postoperative pulmonary embolism can often not be modified and are patient related. The purpose of this case control study was to identify possible modifiable risk factors for postoperative pulmonary embolism. MATERIALS AND METHODS We undertook a case control study among 210,269 patients who underwent noncardiac surgery from 2000 to 2009 at the Erasmus Medical Center. Case subjects were all 199 (0.09%) patients who experienced a pulmonary embolism within 30 days after surgery. From the remaining patients, 1 control was selected for each case and was stratified according to calendar year. For cases and controls, information was obtained regarding risk factors and the type and dose of thromboprophylaxis as well as the time of postoperative initiation. RESULTS Overweight, surgery for malignancy, a history of cerebrovascular disease and a history of thromboemblic diseases, intraoperative blood transfusions and delayed use of thromboprophylaxis were more common in cases than in controls. After correction delayed use of thromboprophylaxis was associated with a 4 fold increased risk (OR 4.1; 95% CI: 2.1 - 7.7) for postoperative pulmonary embolism. CONCLUSION Delayed timing of postoperative thromboprophylaxis is an important modifiable risk factor for postoperative pulmonary embolism after noncardiac surgery. This study emphasises the importance of on time administration of thromboprophylaxis.