Mathias Opperer

Tranexamic acid use and postoperative outcomes in patients undergoing total hip or knee arthroplasty in the United States: retrospective analysis of effectiveness and safety

Objective To determine the effectiveness and safety of perioperative tranexamic acid use in patients undergoing total hip or knee arthroplasty in the United States. Design Retrospective cohort study; multilevel multivariable logistic regression models measured the association between tranexamic acid use in the perioperative period and outcomes. Setting 510 US hospitals from the claims based Premier Perspective database for 2006-12. Participants 872 416 patients who had total hip or knee arthroplasty. Intervention Perioperative intravenous tranexamic acid use by dose categories (none, ≤1000 mg, 2000 mg, and ≥3000 mg). Main outcome measures Allogeneic or autologous transfusion, thromboembolic complications (pulmonary embolism, deep venous thrombosis), acute renal failure, and combined complications (thromboembolic complications, acute renal failure, cerebrovascular events, myocardial infarction, in-hospital mortality). Results While comparable regarding average age and comorbidity index, patients receiving tranexamic acid (versus those who did not) showed lower rates of allogeneic or autologous transfusion (7.7% v 20.1%), thromboembolic complications (0.6% v 0.8%), acute renal failure (1.2% v 1.6%), and combined complications (1.9% v 2.6%); all P<0.01. In the multilevel models, tranexamic acid dose categories (versus no tranexamic acid use) were associated with significantly (P<0.001) decreased odds for allogeneic or autologous blood transfusions (odds ratio 0.31 to 0.38 by dose category) and no significantly increased risk for complications: thromboembolic complications (odds ratio 0.85 to 1.02), acute renal failure (0.70 to 1.11), and combined complications (0.75 to 0.98). Conclusions Tranexamic acid was effective in reducing the need for blood transfusions while not increasing the risk of complications, including thromboembolic events and renal failure. Thus our data provide incremental evidence of the potential effectiveness and safety of tranexamic acid in patients requiring orthopedic surgery.

Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients with Obstructive Sleep Apnea

The purpose of the Society of Anesthesia and Sleep Medicine guideline on preoperative screening and assessment of adult patients with obstructive sleep apnea (OSA) is to present recommendations based on the available clinical evidence on the topic where possible. As very few well-performed randomized studies in this field of perioperative care are available, most of the recommendations were developed by experts in the field through consensus processes involving utilization of evidence grading to indicate the level of evidence upon which recommendations were based. This guideline may not be appropriate for all clinical situations and all patients. The decision whether to follow these recommendations must be made by a responsible physician on an individual basis. Protocols should be developed by individual institutions taking into account the patients’ conditions, extent of interventions and available resources. This practice guideline is not intended to define standards of care or represent absolute requirements for patient care. The adherence to these guidelines cannot in any way guarantee successful outcomes and is rather meant to help individuals and institutions formulate plans to better deal with the challenges posed by perioperative patients with OSA. These recommendations reflect the current state of knowledge and its interpretation by a group of experts in the field at the time of publication. While these guidelines will be periodically updated, new information that becomes available between updates should be taken into account. Deviations in practice from guidelines may be justifiable and such deviations should not be interpreted as a basis for claims of negligence.

Does Obstructive Sleep Apnea Influence Perioperative Outcome? A Qualitative Systematic Review for the Society of Anesthesia and Sleep Medicine Task Force on Preoperative Preparation of Patients with Sleep-Disordered Breathing.

Obstructive sleep apnea (OSA) is a commonly encountered problem in the perioperative setting even though many patients remain undiagnosed at the time of surgery. The objective of this systematic review was to evaluate whether the diagnosis of OSA has an impact on postoperative outcomes. We performed a systematic review of studies published in PubMed-MEDLINE, MEDLINE In-Process, and other nonindexed citations, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Health Technology Assessment up to November 2014. Studies of adult patients with a diagnosis of OSA or high risk thereof, published in the English language, undergoing surgery or procedures under anesthesia care, and reporting ≥1 postoperative outcome were included. Overall, the included studies reported on 413,304 OSA and 8,556,279 control patients. The majority reported worse outcomes for a number of events, including pulmonary and combined complications, among patients with OSA versus the reference group. The association between OSA and in-hospital mortality varied among studies; 9 studies showed no impact of OSA on mortality, 3 studies suggested a decrease in mortality, and 1 study reported increased mortality. In summary, the majority of studies suggest that the presence of OSA is associated with an increased risk of postoperative complications.

Use of perioperative hydroxyethyl starch 6% and albumin 5% in elective joint arthroplasty and association with adverse outcomes: a retrospective population based analysis

Objective To determine whether the perioperative use of hydroxyethyl starch 6% and albumin 5% in elective joint arthroplasties are associated with an increased risk for perioperative complications. Design Retrospective cohort study of population based data between 2006 and 2013. Setting Data from 510 different hospitals across the United States participating in the Premier Perspective database. Participants 1 051 441 patients undergoing elective total hip and knee arthroplasties. Exposures Perioperative fluid resuscitation with hydroxyethyl starch 6% or albumin 5%, or neither. Main outcome measures Acute renal failure and thromboembolic, cardiac, and pulmonary complications. Results Compared with patients who received neither colloid, perioperative fluid resuscitation with hydroxyethyl starch 6% or albumin 5% was associated with an increased risk of acute renal failure (odds ratios 1.23 (95% confidence interval 1.13 to 1.34) and 1.56 (1.36 to 1.78), respectively) and most other complications. A recent decrease in hydroxyethyl starch 6% use was noted, whereas that of albumin 5% increased. Conclusions Similar to studies in critically ill patients, we showed that use of hydroxyethyl starch 6% was associated with an increased risk of acute renal failure and other complications in the elective perioperative orthopedic setting. This increased risk also applied to albumin 5%. These findings raise questions regarding the widespread use of these colloids in elective joint arthroplasty procedures.

Perioperative outcomes and type of anesthesia in hip surgical patients: An evidence based review.

Over the last decades the demand for hip surgery, be it elective or in a traumatic setting, has greatly increased and is projected to expand even further. Concurrent with demographic changes the affected population is burdened by an increase in average comorbidity and serious complications. It has been suggested that the choice of anesthesia not only affects the surgery setting but also the perioperative outcome as a whole. Therefore different approaches and anesthetic techniques have been developed to offer individual anesthetic and analgesic care to hip surgery patients. Recent studies on comparative effectiveness utilizing population based data have given us a novel insight on anesthetic practice and outcome, showing favorable results in the usage of regional vs general anesthesia. In this review we aim to give an overview of anesthetic techniques in use for hip surgery and their impact on perioperative outcome. While there still remains a scarcity of data investigating perioperative outcomes and anesthesia, most studies concur on a positive outcome in overall mortality, thromboembolic events, blood loss and transfusion requirements when comparing regional to general anesthesia. Much of the currently available evidence suggests that a comprehensive medical approach with emphasis on regional anesthesia can prove beneficial to patients and the health care system.

Perioperative pain control after total knee arthroplasty: An evidence based review of the role of peripheral nerve blocks

Over the last decades, the number of total knee arthroplasty procedures performed in the United States has been increasing dramatically. This very successful intervention, however, is associated with significant postoperative pain, and adequate postoperative analgesia is mandatory in order to allow for successful rehabilitation and recovery. The use of regional anesthesia and peripheral nerve blocks has facilitated and improved this goal. Many different approaches and techniques for peripheral nerve blockades, either landmark or, more recently, ultrasound guided have been described over the last decades. This includes but is not restricted to techniques discussed in this review. The introduction of ultrasound has improved many approaches to peripheral nerves either in success rate and/or time to block. Moreover, ultrasound has enhanced the safety of peripheral nerve blocks due to immediate needle visualization and as consequence needle guidance during the block. In contrast to patient controlled analgesia using opioids, patients with a regional anesthetic technique suffer from fewer adverse events and show higher patient satisfaction; this is important as hospital rankings and advertisement have become more common worldwide and many patients use these factors in order to choose a certain institution for a specific procedure. This review provides a short overview of currently used regional anesthetic and analgesic techniques focusing on related implications, considerations and outcomes.

Anesthetic Care for Orthopedic Patients: Is There a Potential for Differences in Care?

Background:Differences in health care represent a major health policy issue. Despite increasing evidence on the mediating role of anesthesia type used for surgery on perioperative outcome, there is a lack of data on potential care differences in this field. The authors aimed to determine whether anesthesia practice (use of neuraxial anesthesia [NA] or peripheral nerve block [PNB]) differs by patient and hospital factors. Methods:The authors extracted data on n = 1,062,152 hip and knee arthroplasty procedures from the Premier Perspective database (2006 to 2013). Multilevel multivariable logistic regression models measured associations (odds ratios [ORs] and 95% CIs) between patient/hospital factors and NA or PNB use. Results:Of all patients, 22.2% (n = 236,083) received NA and 17.9% (n = 189,732) received PNB. Lower adjusted odds for receiving NA were seen for black patients (OR, 0.88; 95% CI, 0.86 to 0.91) and those on Medicaid (OR, 0.78; 95% CI, 0.74 to 0.82) or without insurance (OR, 0.89; 95% CI, 0.81 to 0.98). Furthermore, teaching hospitals (compared with nonteaching hospitals) had lower adjusted odds for NA utilization (OR, 0.35; 95% CI, 0.14 to 0.89). Although generally similar patterns were seen for PNB utilization, the main difference was that particularly Hispanic patients were less likely to receive PNB compared with white patients (OR, 0.60; 95% CI, 0.56 to 0.65). Sensitivity analyses generally validated our results. Conclusions:Significant differences exist in the provision of regional anesthetic care with factors such as race and insurance type being important determinants of anesthetic practice. Further and in-depth research is needed to fully assess the background of these differences.

Anesthesia type and perioperative outcome: open colectomies in the United States

BACKGROUND Adding neuraxial to general anesthesia (GA) has been associated with improved perioperative outcome after orthopedic surgery. Presuming a similar effect in major abdominal surgery we studied its effect on perioperative outcome in open colectomy patients. MATERIALS AND METHODS Retrospective study using the Premier Perspective database (n = 98,290 elective open colectomies, 2006-2012). Multilevel multivariable logistic regression models measured the association between anesthesia type (GA or general and neuraxial anesthesia combined [GNA]) and perioperative outcome with odds ratios (OR) and 95% confidence intervals (CI). Outcomes were thromboembolism, acute myocardial infarction, postoperative infection, postoperative ileus, cerebrovascular events, blood transfusion, admission to an intensive care unit, and mechanical ventilation. RESULTS GA was used in 93.9%, GNA in 6.1%, with a similar Charlson comorbidity index between the groups (2.66 versus 2.72, respectively; P = 0.121). The multivariable analyses showed GNA (versus GA) to be associated with a significantly decreased risk for thromboembolism (OR 0.74; CI 0.58-0.93) and cerebrovascular events (OR 0.67; CI 0.51-0.88), whereas the association was nonsignificant for wound infections, pneumonia, and mechanical ventilation. However, GNA use was significantly associated with increased risk for acute myocardial infarction (OR 2.74; CI 2.19-3.43), urinary tract infection (OR 1.35; CI 1.21-1.50), postoperative ileus (OR 1.17; CI 1.09-1.26), blood transfusion (OR 1.12; CI 1.01-1.24), and admission to intensive care unit (OR 1.32; CI 1.22-1.43). CONCLUSIONS We found no clear pattern of consistent favorable results for patients undergoing their open colectomy under GNA. Further prospective research is needed to help identify those who are more likely to benefit from GNA use and its mechanism of actions.

Change in Off-Label Use of Bone Morphogenetic Protein in Spine Surgery and Associations with Adverse Outcome

Study Design Retrospective cohort study. Objective The U.S. Food and Drug Administration issued a warning in 2008 against off-label bone morphogenetic protein (BMP-2) use. We aimed to determine (off-label) BMP-2 use in two periods and associations with complications. Methods We included 340,393 patients undergoing spinal fusions from the Premier Perspective database (2006 to 2012). BMP-2 use was determined from billing in 2006 to 2008 versus 2009 to 2012. Outcomes included revisions, length of hospital stay (LOHS), and cost of hospital stay (COH). Multilevel regressions measured associations between BMP-2 and outcomes; odds ratios (ORs) and 95% confidence intervals (CIs) are reported. Results BMP-2 use decreased from 18.7% in 2006 to 11.5% in 2012. Off-label use remains but is decreasing, particularly for cervical anterior (5.1 versus 2.0%) and cervical posterior procedures (15.3 versus 8.5%; both p < 0.01 comparing 2006 to 2008 with 2009 to 2012). BMP-2 remains associated with increased LOHS (median 2 versus 3 days; both periods) and COH (median

Additives to local anesthetics for peripheral nerve blocks or local anesthesia: a review of the literature

15,455 versus